Uncompleted Processing Refactor

tests/processing/pipeline/__init__.py

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+# This file makes Python treat the directory as a package.

tests/processing/pipeline/stages/__init__.py

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+# This file makes Python treat the directory as a package.

tests/processing/pipeline/stages/test_alpha_extraction_to_mask.py

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+import pytest
+from unittest import mock
+from pathlib import Path
+import uuid
+import numpy as np
+
+from processing.pipeline.stages.alpha_extraction_to_mask import AlphaExtractionToMaskStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule, TransformSettings
+from configuration import Configuration, GeneralSettings
+import processing.utils.image_processing_utils as ipu # Ensure ipu is available for mocking
+
+# Helper Functions
+def create_mock_file_rule_for_alpha_test(
+    id_val: uuid.UUID = None,
+    map_type: str = "ALBEDO",
+    filename_pattern: str = "albedo.png",
+    item_type: str = "MAP_COL",
+    active: bool = True
+) -> mock.MagicMock:
+    mock_fr = mock.MagicMock(spec=FileRule)
+    mock_fr.id = id_val if id_val else uuid.uuid4()
+    mock_fr.map_type = map_type
+    mock_fr.filename_pattern = filename_pattern
+    mock_fr.item_type = item_type
+    mock_fr.active = active
+    mock_fr.transform_settings = mock.MagicMock(spec=TransformSettings)
+    return mock_fr
+
+def create_alpha_extraction_mock_context(
+    initial_file_rules: list = None,
+    initial_processed_details: dict = None,
+    skip_asset_flag: bool = False,
+    asset_name: str = "AlphaAsset",
+    # extract_alpha_globally: bool = True # If stage checks this
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    
+    mock_gs = mock.MagicMock(spec=GeneralSettings)
+    # if your stage uses a global flag:
+    # mock_gs.extract_alpha_to_mask_globally = extract_alpha_globally
+    
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.general_settings = mock_gs
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp_engine_dir"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier="ValidSupplier",
+        asset_metadata={'asset_name': asset_name},
+        processed_maps_details=initial_processed_details if initial_processed_details is not None else {},
+        merged_maps_details={},
+        files_to_process=list(initial_file_rules) if initial_file_rules else [],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={'skip_asset': skip_asset_flag},
+        incrementing_value=None,
+        sha5_value=None
+    )
+    return context
+
+# Unit Tests
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.save_image')
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.load_image')
+@mock.patch('logging.info') # Mock logging to avoid console output during tests
+def test_asset_skipped(mock_log_info, mock_load_image, mock_save_image):
+    stage = AlphaExtractionToMaskStage()
+    context = create_alpha_extraction_mock_context(skip_asset_flag=True)
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context == context # Context should be unchanged
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    assert len(updated_context.files_to_process) == 0
+    assert not updated_context.processed_maps_details
+
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.save_image')
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.load_image')
+@mock.patch('logging.info')
+def test_existing_mask_map(mock_log_info, mock_load_image, mock_save_image):
+    stage = AlphaExtractionToMaskStage()
+    
+    existing_mask_rule = create_mock_file_rule_for_alpha_test(map_type="MASK", filename_pattern="mask.png")
+    context = create_alpha_extraction_mock_context(initial_file_rules=[existing_mask_rule])
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context == context
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    assert len(updated_context.files_to_process) == 1
+    assert updated_context.files_to_process[0].map_type == "MASK"
+
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.save_image')
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.load_image')
+@mock.patch('logging.info')
+def test_alpha_extraction_success(mock_log_info, mock_load_image, mock_save_image):
+    stage = AlphaExtractionToMaskStage()
+    
+    albedo_rule_id = uuid.uuid4()
+    albedo_fr = create_mock_file_rule_for_alpha_test(id_val=albedo_rule_id, map_type="ALBEDO")
+    
+    initial_processed_details = {
+        albedo_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_albedo.png', 'status': 'Processed', 'map_type': 'ALBEDO', 'source_file_path': Path('/fake/source/albedo.png')}
+    }
+    context = create_alpha_extraction_mock_context(
+        initial_file_rules=[albedo_fr],
+        initial_processed_details=initial_processed_details
+    )
+
+    mock_rgba_data = np.zeros((10, 10, 4), dtype=np.uint8)
+    mock_rgba_data[:, :, 3] = 128 # Example alpha data
+    mock_load_image.side_effect = [mock_rgba_data, mock_rgba_data] 
+    
+    mock_save_image.return_value = True
+    
+    updated_context = stage.execute(context)
+    
+    assert mock_load_image.call_count == 2
+    # First call to check for alpha, second to get data for saving
+    mock_load_image.assert_any_call(Path('/fake/temp_engine_dir/processed_albedo.png')) 
+    
+    mock_save_image.assert_called_once()
+    saved_path_arg = mock_save_image.call_args[0][0]
+    saved_data_arg = mock_save_image.call_args[0][1]
+    
+    assert isinstance(saved_path_arg, Path)
+    assert "mask_from_alpha_" in saved_path_arg.name
+    assert np.array_equal(saved_data_arg, mock_rgba_data[:, :, 3])
+    
+    assert len(updated_context.files_to_process) == 2
+    new_mask_rule = None
+    for fr in updated_context.files_to_process:
+        if fr.map_type == "MASK":
+            new_mask_rule = fr
+            break
+    assert new_mask_rule is not None
+    assert new_mask_rule.item_type == "MAP_DER" # Derived map
+    
+    assert new_mask_rule.id.hex in updated_context.processed_maps_details
+    new_mask_detail = updated_context.processed_maps_details[new_mask_rule.id.hex]
+    assert new_mask_detail['map_type'] == "MASK"
+    assert "mask_from_alpha_" in new_mask_detail['temp_processed_file']
+    assert "Generated from alpha of ALBEDO" in new_mask_detail['notes'] # Check for specific note
+    assert new_mask_detail['status'] == 'Processed'
+
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.save_image')
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.load_image')
+@mock.patch('logging.info')
+def test_no_alpha_channel_in_source(mock_log_info, mock_load_image, mock_save_image):
+    stage = AlphaExtractionToMaskStage()
+    
+    albedo_rule_id = uuid.uuid4()
+    albedo_fr = create_mock_file_rule_for_alpha_test(id_val=albedo_rule_id, map_type="ALBEDO")
+    initial_processed_details = {
+        albedo_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_rgb_albedo.png', 'status': 'Processed', 'map_type': 'ALBEDO', 'source_file_path': Path('/fake/source/albedo_rgb.png')}
+    }
+    context = create_alpha_extraction_mock_context(
+        initial_file_rules=[albedo_fr],
+        initial_processed_details=initial_processed_details
+    )
+
+    mock_rgb_data = np.zeros((10, 10, 3), dtype=np.uint8) # RGB, no alpha
+    mock_load_image.return_value = mock_rgb_data # Only called once for check
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_called_once_with(Path('/fake/temp_engine_dir/processed_rgb_albedo.png'))
+    mock_save_image.assert_not_called()
+    assert len(updated_context.files_to_process) == 1 # No new MASK rule
+    assert albedo_fr.id.hex in updated_context.processed_maps_details
+    assert len(updated_context.processed_maps_details) == 1
+
+
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.save_image')
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.load_image')
+@mock.patch('logging.info')
+def test_no_suitable_source_map_type(mock_log_info, mock_load_image, mock_save_image):
+    stage = AlphaExtractionToMaskStage()
+    
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_alpha_test(id_val=normal_rule_id, map_type="NORMAL")
+    initial_processed_details = {
+        normal_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_normal.png', 'status': 'Processed', 'map_type': 'NORMAL'}
+    }
+    context = create_alpha_extraction_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_processed_details
+    )
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    assert len(updated_context.files_to_process) == 1
+    assert normal_fr.id.hex in updated_context.processed_maps_details
+    assert len(updated_context.processed_maps_details) == 1
+
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.save_image')
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.load_image')
+@mock.patch('logging.warning') # Expect a warning log
+def test_load_image_fails(mock_log_warning, mock_load_image, mock_save_image):
+    stage = AlphaExtractionToMaskStage()
+    
+    albedo_rule_id = uuid.uuid4()
+    albedo_fr = create_mock_file_rule_for_alpha_test(id_val=albedo_rule_id, map_type="ALBEDO")
+    initial_processed_details = {
+        albedo_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_albedo_load_fail.png', 'status': 'Processed', 'map_type': 'ALBEDO', 'source_file_path': Path('/fake/source/albedo_load_fail.png')}
+    }
+    context = create_alpha_extraction_mock_context(
+        initial_file_rules=[albedo_fr],
+        initial_processed_details=initial_processed_details
+    )
+
+    mock_load_image.return_value = None # Simulate load failure
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_called_once_with(Path('/fake/temp_engine_dir/processed_albedo_load_fail.png'))
+    mock_save_image.assert_not_called()
+    assert len(updated_context.files_to_process) == 1
+    assert albedo_fr.id.hex in updated_context.processed_maps_details
+    assert len(updated_context.processed_maps_details) == 1
+    mock_log_warning.assert_called_once() # Check that a warning was logged
+
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.save_image')
+@mock.patch('processing.pipeline.stages.alpha_extraction_to_mask.ipu.load_image')
+@mock.patch('logging.error') # Expect an error log
+def test_save_image_fails(mock_log_error, mock_load_image, mock_save_image):
+    stage = AlphaExtractionToMaskStage()
+    
+    albedo_rule_id = uuid.uuid4()
+    albedo_fr = create_mock_file_rule_for_alpha_test(id_val=albedo_rule_id, map_type="ALBEDO")
+    initial_processed_details = {
+        albedo_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_albedo_save_fail.png', 'status': 'Processed', 'map_type': 'ALBEDO', 'source_file_path': Path('/fake/source/albedo_save_fail.png')}
+    }
+    context = create_alpha_extraction_mock_context(
+        initial_file_rules=[albedo_fr],
+        initial_processed_details=initial_processed_details
+    )
+
+    mock_rgba_data = np.zeros((10, 10, 4), dtype=np.uint8)
+    mock_rgba_data[:, :, 3] = 128
+    mock_load_image.side_effect = [mock_rgba_data, mock_rgba_data] # Load succeeds
+    
+    mock_save_image.return_value = False # Simulate save failure
+    
+    updated_context = stage.execute(context)
+    
+    assert mock_load_image.call_count == 2
+    mock_save_image.assert_called_once() # Save was attempted
+    
+    assert len(updated_context.files_to_process) == 1 # No new MASK rule should be successfully added and detailed
+    
+    # Check that no new MASK details were added, or if they were, they reflect failure.
+    # The current stage logic returns context early, so no new rule or details should be present.
+    mask_rule_found = any(fr.map_type == "MASK" for fr in updated_context.files_to_process)
+    assert not mask_rule_found
+
+    mask_details_found = any(
+        details['map_type'] == "MASK" 
+        for fr_id, details in updated_context.processed_maps_details.items() 
+        if fr_id != albedo_fr.id.hex # Exclude the original albedo
+    )
+    assert not mask_details_found
+    mock_log_error.assert_called_once() # Check that an error was logged

tests/processing/pipeline/stages/test_asset_skip_logic.py

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+import pytest
+from unittest import mock
+from pathlib import Path
+from typing import Dict, Optional, Any
+
+from processing.pipeline.stages.asset_skip_logic import AssetSkipLogicStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule
+from configuration import Configuration, GeneralSettings
+
+# Helper function to create a mock AssetProcessingContext
+def create_skip_logic_mock_context(
+    effective_supplier: Optional[str] = "ValidSupplier",
+    asset_process_status: str = "PENDING",
+    overwrite_existing: bool = False,
+    asset_name: str = "TestAssetSkip"
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.process_status = asset_process_status
+    mock_asset_rule.source_path = "fake/source" # Added for completeness
+    mock_asset_rule.output_path = "fake/output" # Added for completeness
+    mock_asset_rule.maps = [] # Added for completeness
+    mock_asset_rule.metadata = {} # Added for completeness
+    mock_asset_rule.material_name = None # Added for completeness
+    mock_asset_rule.notes = None # Added for completeness
+    mock_asset_rule.tags = [] # Added for completeness
+    mock_asset_rule.enabled = True # Added for completeness
+
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_source_rule.name = "TestSourceRule" # Added for completeness
+    mock_source_rule.path = "fake/source_rule_path" # Added for completeness
+    mock_source_rule.default_supplier = None # Added for completeness
+    mock_source_rule.assets = [mock_asset_rule] # Added for completeness
+    mock_source_rule.enabled = True # Added for completeness
+
+    mock_general_settings = mock.MagicMock(spec=GeneralSettings)
+    mock_general_settings.overwrite_existing = overwrite_existing
+    
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.general_settings = mock_general_settings
+    mock_config.suppliers = {"ValidSupplier": mock.MagicMock()} 
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier=effective_supplier,
+        asset_metadata={},
+        processed_maps_details={},
+        merged_maps_details={},
+        files_to_process=[],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={},
+        incrementing_value=None,
+        sha5_value=None # Corrected from sha5_value to sha256_value if that's the actual field
+    )
+    # Ensure status_flags is initialized if AssetSkipLogicStage expects it
+    # context.status_flags = {} # Already done in constructor
+    return context
+@mock.patch('logging.info')
+def test_skip_due_to_missing_supplier(mock_log_info):
+    """
+    Test that the asset is skipped if effective_supplier is None.
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(effective_supplier=None, asset_name="MissingSupplierAsset")
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context.status_flags.get('skip_asset') is True
+    assert updated_context.status_flags.get('skip_reason') == "Invalid or missing supplier"
+    mock_log_info.assert_any_call(f"Asset 'MissingSupplierAsset': Skipping due to missing or invalid supplier.")
+
+@mock.patch('logging.info')
+def test_skip_due_to_process_status_skip(mock_log_info):
+    """
+    Test that the asset is skipped if asset_rule.process_status is "SKIP".
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(asset_process_status="SKIP", asset_name="SkipStatusAsset")
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context.status_flags.get('skip_asset') is True
+    assert updated_context.status_flags.get('skip_reason') == "Process status set to SKIP"
+    mock_log_info.assert_any_call(f"Asset 'SkipStatusAsset': Skipping because process_status is 'SKIP'.")
+
+@mock.patch('logging.info')
+def test_skip_due_to_processed_and_overwrite_disabled(mock_log_info):
+    """
+    Test that the asset is skipped if asset_rule.process_status is "PROCESSED"
+    and overwrite_existing is False.
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(
+        asset_process_status="PROCESSED", 
+        overwrite_existing=False,
+        asset_name="ProcessedNoOverwriteAsset"
+    )
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context.status_flags.get('skip_asset') is True
+    assert updated_context.status_flags.get('skip_reason') == "Already processed, overwrite disabled"
+    mock_log_info.assert_any_call(f"Asset 'ProcessedNoOverwriteAsset': Skipping because already processed and overwrite is disabled.")
+
+@mock.patch('logging.info')
+def test_no_skip_when_processed_and_overwrite_enabled(mock_log_info):
+    """
+    Test that the asset is NOT skipped if asset_rule.process_status is "PROCESSED"
+    but overwrite_existing is True.
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(
+        asset_process_status="PROCESSED", 
+        overwrite_existing=True,
+        effective_supplier="ValidSupplier", # Ensure supplier is valid
+        asset_name="ProcessedOverwriteAsset"
+    )
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context.status_flags.get('skip_asset', False) is False # Default to False if key not present
+    # No specific skip_reason to check if not skipped
+    # Check that no skip log message was called for this specific reason
+    for call_args in mock_log_info.call_args_list:
+        assert "Skipping because already processed and overwrite is disabled" not in call_args[0][0]
+        assert "Skipping due to missing or invalid supplier" not in call_args[0][0]
+        assert "Skipping because process_status is 'SKIP'" not in call_args[0][0]
+
+
+@mock.patch('logging.info')
+def test_no_skip_when_process_status_pending(mock_log_info):
+    """
+    Test that the asset is NOT skipped if asset_rule.process_status is "PENDING".
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(
+        asset_process_status="PENDING",
+        effective_supplier="ValidSupplier", # Ensure supplier is valid
+        asset_name="PendingAsset"
+    )
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context.status_flags.get('skip_asset', False) is False
+    # Check that no skip log message was called
+    for call_args in mock_log_info.call_args_list:
+        assert "Skipping" not in call_args[0][0]
+
+
+@mock.patch('logging.info')
+def test_no_skip_when_process_status_failed_previously(mock_log_info):
+    """
+    Test that the asset is NOT skipped if asset_rule.process_status is "FAILED_PREVIOUSLY".
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(
+        asset_process_status="FAILED_PREVIOUSLY",
+        effective_supplier="ValidSupplier", # Ensure supplier is valid
+        asset_name="FailedPreviouslyAsset"
+    )
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context.status_flags.get('skip_asset', False) is False
+    # Check that no skip log message was called
+    for call_args in mock_log_info.call_args_list:
+        assert "Skipping" not in call_args[0][0]
+
+@mock.patch('logging.info')
+def test_no_skip_when_process_status_other_valid_status(mock_log_info):
+    """
+    Test that the asset is NOT skipped for other valid, non-skip process statuses.
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(
+        asset_process_status="READY_FOR_PROCESSING", # Example of another non-skip status
+        effective_supplier="ValidSupplier",
+        asset_name="ReadyAsset"
+    )
+    updated_context = stage.execute(context)
+    assert updated_context.status_flags.get('skip_asset', False) is False
+    for call_args in mock_log_info.call_args_list:
+        assert "Skipping" not in call_args[0][0]
+
+@mock.patch('logging.info')
+def test_skip_asset_flag_initialized_if_not_present(mock_log_info):
+    """
+    Test that 'skip_asset' is initialized to False in status_flags if not skipped and not present.
+    """
+    stage = AssetSkipLogicStage()
+    context = create_skip_logic_mock_context(
+        asset_process_status="PENDING",
+        effective_supplier="ValidSupplier",
+        asset_name="InitFlagAsset"
+    )
+    # Ensure status_flags is empty before execute
+    context.status_flags = {} 
+    
+    updated_context = stage.execute(context)
+    
+    # If not skipped, 'skip_asset' should be explicitly False.
+    assert updated_context.status_flags.get('skip_asset') is False 
+    # No skip reason should be set
+    assert 'skip_reason' not in updated_context.status_flags
+    for call_args in mock_log_info.call_args_list:
+        assert "Skipping" not in call_args[0][0]

tests/processing/pipeline/stages/test_file_rule_filter.py

@@ -0,0 +1,330 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import uuid
+from typing import Optional # Added Optional for type hinting
+
+from processing.pipeline.stages.file_rule_filter import FileRuleFilterStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule # FileRule is key here
+from configuration import Configuration # Minimal config needed
+
+def create_mock_file_rule(
+    id_val: Optional[uuid.UUID] = None,
+    map_type: str = "Diffuse",
+    filename_pattern: str = "*.tif",
+    item_type: str = "MAP_COL", # e.g., MAP_COL, FILE_IGNORE
+    active: bool = True
+) -> mock.MagicMock: # Return MagicMock to easily set other attributes if needed
+    mock_fr = mock.MagicMock(spec=FileRule)
+    mock_fr.id = id_val if id_val else uuid.uuid4()
+    mock_fr.map_type = map_type
+    mock_fr.filename_pattern = filename_pattern
+    mock_fr.item_type = item_type
+    mock_fr.active = active
+    return mock_fr
+
+def create_file_filter_mock_context(
+    file_rules_list: Optional[list] = None, # List of mock FileRule objects
+    skip_asset_flag: bool = False,
+    asset_name: str = "FileFilterAsset"
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.file_rules = file_rules_list if file_rules_list is not None else []
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_config = mock.MagicMock(spec=Configuration)
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier="ValidSupplier", # Assume valid for this stage
+        asset_metadata={'asset_name': asset_name}, # Assume metadata init happened
+        processed_maps_details={},
+        merged_maps_details={},
+        files_to_process=[], # Stage will populate this
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={'skip_asset': skip_asset_flag},
+        incrementing_value=None,
+        sha5_value=None # Corrected from sha5_value to sha256_value based on AssetProcessingContext
+    )
+    return context
+# Test Cases for FileRuleFilterStage.execute()
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_asset_skipped(mock_log_debug, mock_log_info):
+    """
+    Test case: Asset Skipped - status_flags['skip_asset'] is True.
+    Assert context.files_to_process remains empty.
+    """
+    stage = FileRuleFilterStage()
+    context = create_file_filter_mock_context(skip_asset_flag=True)
+    
+    updated_context = stage.execute(context)
+    
+    assert len(updated_context.files_to_process) == 0
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule filtering as 'skip_asset' is True.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_no_file_rules(mock_log_debug, mock_log_info):
+    """
+    Test case: No File Rules - asset_rule.file_rules is empty.
+    Assert context.files_to_process is empty.
+    """
+    stage = FileRuleFilterStage()
+    context = create_file_filter_mock_context(file_rules_list=[])
+    
+    updated_context = stage.execute(context)
+    
+    assert len(updated_context.files_to_process) == 0
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': No file rules defined. Skipping file rule filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_only_active_processable_rules(mock_log_debug, mock_log_info):
+    """
+    Test case: Only Active, Processable Rules - All FileRules are active=True and item_type="MAP_COL".
+    Assert all are added to context.files_to_process.
+    """
+    stage = FileRuleFilterStage()
+    fr1 = create_mock_file_rule(filename_pattern="diffuse.png", item_type="MAP_COL", active=True)
+    fr2 = create_mock_file_rule(filename_pattern="normal.png", item_type="MAP_COL", active=True)
+    context = create_file_filter_mock_context(file_rules_list=[fr1, fr2])
+    
+    updated_context = stage.execute(context)
+    
+    assert len(updated_context.files_to_process) == 2
+    assert fr1 in updated_context.files_to_process
+    assert fr2 in updated_context.files_to_process
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 2 file rules queued for processing after filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_inactive_rules(mock_log_debug, mock_log_info):
+    """
+    Test case: Inactive Rules - Some FileRules have active=False.
+    Assert only active rules are added.
+    """
+    stage = FileRuleFilterStage()
+    fr_active = create_mock_file_rule(filename_pattern="active.png", item_type="MAP_COL", active=True)
+    fr_inactive = create_mock_file_rule(filename_pattern="inactive.png", item_type="MAP_COL", active=False)
+    fr_another_active = create_mock_file_rule(filename_pattern="another_active.jpg", item_type="MAP_COL", active=True)
+    context = create_file_filter_mock_context(file_rules_list=[fr_active, fr_inactive, fr_another_active])
+    
+    updated_context = stage.execute(context)
+    
+    assert len(updated_context.files_to_process) == 2
+    assert fr_active in updated_context.files_to_process
+    assert fr_another_active in updated_context.files_to_process
+    assert fr_inactive not in updated_context.files_to_process
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping inactive file rule: '{fr_inactive.filename_pattern}'")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 2 file rules queued for processing after filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_file_ignore_simple_match(mock_log_debug, mock_log_info):
+    """
+    Test case: FILE_IGNORE Rule (Simple Match).
+    One FILE_IGNORE rule with filename_pattern="*_ignore.png".
+    One MAP_COL rule with filename_pattern="diffuse_ignore.png".
+    One MAP_COL rule with filename_pattern="normal_process.png".
+    Assert only "normal_process.png" rule is added.
+    """
+    stage = FileRuleFilterStage()
+    fr_ignore = create_mock_file_rule(filename_pattern="*_ignore.png", item_type="FILE_IGNORE", active=True)
+    fr_ignored_map = create_mock_file_rule(filename_pattern="diffuse_ignore.png", item_type="MAP_COL", active=True)
+    fr_process_map = create_mock_file_rule(filename_pattern="normal_process.png", item_type="MAP_COL", active=True)
+    context = create_file_filter_mock_context(file_rules_list=[fr_ignore, fr_ignored_map, fr_process_map])
+
+    updated_context = stage.execute(context)
+
+    assert len(updated_context.files_to_process) == 1
+    assert fr_process_map in updated_context.files_to_process
+    assert fr_ignored_map not in updated_context.files_to_process
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Registering ignore pattern: '{fr_ignore.filename_pattern}'")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_ignored_map.filename_pattern}' due to matching ignore pattern.")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 1 file rules queued for processing after filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_file_ignore_glob_pattern(mock_log_debug, mock_log_info):
+    """
+    Test case: FILE_IGNORE Rule (Glob Pattern).
+    One FILE_IGNORE rule with filename_pattern="*_ignore.*".
+    MAP_COL rules: "tex_ignore.tif", "tex_process.png".
+    Assert only "tex_process.png" rule is added.
+    """
+    stage = FileRuleFilterStage()
+    fr_ignore_glob = create_mock_file_rule(filename_pattern="*_ignore.*", item_type="FILE_IGNORE", active=True)
+    fr_ignored_tif = create_mock_file_rule(filename_pattern="tex_ignore.tif", item_type="MAP_COL", active=True)
+    fr_process_png = create_mock_file_rule(filename_pattern="tex_process.png", item_type="MAP_COL", active=True)
+    context = create_file_filter_mock_context(file_rules_list=[fr_ignore_glob, fr_ignored_tif, fr_process_png])
+
+    updated_context = stage.execute(context)
+
+    assert len(updated_context.files_to_process) == 1
+    assert fr_process_png in updated_context.files_to_process
+    assert fr_ignored_tif not in updated_context.files_to_process
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Registering ignore pattern: '{fr_ignore_glob.filename_pattern}'")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_ignored_tif.filename_pattern}' due to matching ignore pattern.")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 1 file rules queued for processing after filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_multiple_file_ignore_rules(mock_log_debug, mock_log_info):
+    """
+    Test case: Multiple FILE_IGNORE Rules.
+    Test with several ignore patterns and ensure they are all respected.
+    """
+    stage = FileRuleFilterStage()
+    fr_ignore1 = create_mock_file_rule(filename_pattern="*.tmp", item_type="FILE_IGNORE", active=True)
+    fr_ignore2 = create_mock_file_rule(filename_pattern="backup_*", item_type="FILE_IGNORE", active=True)
+    fr_ignore3 = create_mock_file_rule(filename_pattern="*_old.png", item_type="FILE_IGNORE", active=True)
+    
+    fr_map_ignored1 = create_mock_file_rule(filename_pattern="data.tmp", item_type="MAP_COL", active=True)
+    fr_map_ignored2 = create_mock_file_rule(filename_pattern="backup_diffuse.jpg", item_type="MAP_COL", active=True)
+    fr_map_ignored3 = create_mock_file_rule(filename_pattern="normal_old.png", item_type="MAP_COL", active=True)
+    fr_map_process = create_mock_file_rule(filename_pattern="final_texture.tif", item_type="MAP_COL", active=True)
+    
+    context = create_file_filter_mock_context(file_rules_list=[
+        fr_ignore1, fr_ignore2, fr_ignore3,
+        fr_map_ignored1, fr_map_ignored2, fr_map_ignored3, fr_map_process
+    ])
+
+    updated_context = stage.execute(context)
+
+    assert len(updated_context.files_to_process) == 1
+    assert fr_map_process in updated_context.files_to_process
+    assert fr_map_ignored1 not in updated_context.files_to_process
+    assert fr_map_ignored2 not in updated_context.files_to_process
+    assert fr_map_ignored3 not in updated_context.files_to_process
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Registering ignore pattern: '{fr_ignore1.filename_pattern}'")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Registering ignore pattern: '{fr_ignore2.filename_pattern}'")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Registering ignore pattern: '{fr_ignore3.filename_pattern}'")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_map_ignored1.filename_pattern}' due to matching ignore pattern.")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_map_ignored2.filename_pattern}' due to matching ignore pattern.")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_map_ignored3.filename_pattern}' due to matching ignore pattern.")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 1 file rules queued for processing after filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_file_ignore_rule_is_inactive(mock_log_debug, mock_log_info):
+    """
+    Test case: FILE_IGNORE Rule is Inactive.
+    An ignore rule itself is active=False. Assert its pattern is NOT used for filtering.
+    """
+    stage = FileRuleFilterStage()
+    fr_inactive_ignore = create_mock_file_rule(filename_pattern="*_ignore.tif", item_type="FILE_IGNORE", active=False)
+    fr_should_process1 = create_mock_file_rule(filename_pattern="diffuse_ignore.tif", item_type="MAP_COL", active=True) # Should be processed
+    fr_should_process2 = create_mock_file_rule(filename_pattern="normal_ok.png", item_type="MAP_COL", active=True)
+    context = create_file_filter_mock_context(file_rules_list=[fr_inactive_ignore, fr_should_process1, fr_should_process2])
+
+    updated_context = stage.execute(context)
+
+    assert len(updated_context.files_to_process) == 2
+    assert fr_should_process1 in updated_context.files_to_process
+    assert fr_should_process2 in updated_context.files_to_process
+    # Ensure the inactive ignore rule's pattern was not registered
+    # We check this by ensuring no debug log for registering *that specific* pattern was made.
+    # A more robust way would be to check mock_log_debug.call_args_list, but this is simpler for now.
+    for call in mock_log_debug.call_args_list:
+        args, kwargs = call
+        if "Registering ignore pattern" in args[0] and fr_inactive_ignore.filename_pattern in args[0]:
+            pytest.fail(f"Inactive ignore pattern '{fr_inactive_ignore.filename_pattern}' was incorrectly registered.")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping inactive file rule: '{fr_inactive_ignore.filename_pattern}' (type: FILE_IGNORE)")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 2 file rules queued for processing after filtering.")
+
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_no_file_ignore_rules(mock_log_debug, mock_log_info):
+    """
+    Test case: No FILE_IGNORE Rules.
+    All rules are MAP_COL or other processable types.
+    Assert all active, processable rules are included.
+    """
+    stage = FileRuleFilterStage()
+    fr1 = create_mock_file_rule(filename_pattern="diffuse.png", item_type="MAP_COL", active=True)
+    fr2 = create_mock_file_rule(filename_pattern="normal.png", item_type="MAP_COL", active=True)
+    fr_other_type = create_mock_file_rule(filename_pattern="spec.tif", item_type="MAP_SPEC", active=True) # Assuming MAP_SPEC is processable
+    fr_inactive = create_mock_file_rule(filename_pattern="ao.jpg", item_type="MAP_AO", active=False)
+    
+    context = create_file_filter_mock_context(file_rules_list=[fr1, fr2, fr_other_type, fr_inactive])
+    
+    updated_context = stage.execute(context)
+    
+    assert len(updated_context.files_to_process) == 3
+    assert fr1 in updated_context.files_to_process
+    assert fr2 in updated_context.files_to_process
+    assert fr_other_type in updated_context.files_to_process
+    assert fr_inactive not in updated_context.files_to_process
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping inactive file rule: '{fr_inactive.filename_pattern}'")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 3 file rules queued for processing after filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_item_type_not_processable(mock_log_debug, mock_log_info):
+    """
+    Test case: Item type is not processable (e.g., not MAP_COL, MAP_AO etc., but something else like 'METADATA_ONLY').
+    Assert such rules are not added to files_to_process, unless they are FILE_IGNORE.
+    """
+    stage = FileRuleFilterStage()
+    fr_processable = create_mock_file_rule(filename_pattern="diffuse.png", item_type="MAP_COL", active=True)
+    fr_not_processable = create_mock_file_rule(filename_pattern="info.txt", item_type="METADATA_ONLY", active=True)
+    fr_ignore = create_mock_file_rule(filename_pattern="*.bak", item_type="FILE_IGNORE", active=True)
+    fr_ignored_by_bak = create_mock_file_rule(filename_pattern="diffuse.bak", item_type="MAP_COL", active=True)
+
+    context = create_file_filter_mock_context(file_rules_list=[fr_processable, fr_not_processable, fr_ignore, fr_ignored_by_bak])
+    
+    updated_context = stage.execute(context)
+    
+    assert len(updated_context.files_to_process) == 1
+    assert fr_processable in updated_context.files_to_process
+    assert fr_not_processable not in updated_context.files_to_process
+    assert fr_ignored_by_bak not in updated_context.files_to_process
+
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Registering ignore pattern: '{fr_ignore.filename_pattern}'")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_not_processable.filename_pattern}' as its item_type '{fr_not_processable.item_type}' is not processable.")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_ignored_by_bak.filename_pattern}' due to matching ignore pattern.")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 1 file rules queued for processing after filtering.")
+
+# Example tests from instructions (can be adapted or used as a base)
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_basic_active_example(mock_log_debug, mock_log_info): # Renamed to avoid conflict
+    stage = FileRuleFilterStage()
+    fr1 = create_mock_file_rule(filename_pattern="diffuse.png", item_type="MAP_COL", active=True)
+    fr2 = create_mock_file_rule(filename_pattern="normal.png", item_type="MAP_COL", active=True)
+    context = create_file_filter_mock_context(file_rules_list=[fr1, fr2])
+    
+    updated_context = stage.execute(context)
+    
+    assert len(updated_context.files_to_process) == 2
+    assert fr1 in updated_context.files_to_process
+    assert fr2 in updated_context.files_to_process
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 2 file rules queued for processing after filtering.")
+
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_file_rule_filter_with_file_ignore_example(mock_log_debug, mock_log_info): # Renamed to avoid conflict
+    stage = FileRuleFilterStage()
+    fr_ignore = create_mock_file_rule(filename_pattern="*_ignore.tif", item_type="FILE_IGNORE", active=True)
+    fr_process = create_mock_file_rule(filename_pattern="diffuse_ok.tif", item_type="MAP_COL", active=True)
+    fr_skip = create_mock_file_rule(filename_pattern="normal_ignore.tif", item_type="MAP_COL", active=True)
+    context = create_file_filter_mock_context(file_rules_list=[fr_ignore, fr_process, fr_skip])
+
+    updated_context = stage.execute(context)
+
+    assert len(updated_context.files_to_process) == 1
+    assert fr_process in updated_context.files_to_process
+    assert fr_skip not in updated_context.files_to_process
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Registering ignore pattern: '{fr_ignore.filename_pattern}'")
+    mock_log_debug.assert_any_call(f"Asset '{context.asset_rule.name}': Skipping file rule '{fr_skip.filename_pattern}' due to matching ignore pattern.")
+    mock_log_info.assert_any_call(f"Asset '{context.asset_rule.name}': 1 file rules queued for processing after filtering.")

tests/processing/pipeline/stages/test_gloss_to_rough_conversion.py

@@ -0,0 +1,486 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import uuid
+import numpy as np
+from typing import Optional, List, Dict
+
+from processing.pipeline.stages.gloss_to_rough_conversion import GlossToRoughConversionStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule
+from configuration import Configuration, GeneralSettings
+# No direct ipu import needed in test if we mock its usage by the stage
+
+def create_mock_file_rule_for_gloss_test(
+    id_val: Optional[uuid.UUID] = None,
+    map_type: str = "GLOSS", # Test with GLOSS and other types
+    filename_pattern: str = "gloss.png"
+) -> mock.MagicMock:
+    mock_fr = mock.MagicMock(spec=FileRule)
+    mock_fr.id = id_val if id_val else uuid.uuid4()
+    mock_fr.map_type = map_type
+    mock_fr.filename_pattern = filename_pattern
+    mock_fr.item_type = "MAP_COL"
+    mock_fr.active = True
+    return mock_fr
+
+def create_gloss_conversion_mock_context(
+    initial_file_rules: Optional[List[FileRule]] = None, # Type hint corrected
+    initial_processed_details: Optional[Dict] = None, # Type hint corrected
+    skip_asset_flag: bool = False,
+    asset_name: str = "GlossAsset",
+    # Add a mock for general_settings if your stage checks a global flag
+    # convert_gloss_globally: bool = True
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.file_rules = initial_file_rules if initial_file_rules is not None else []
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+
+    mock_gs = mock.MagicMock(spec=GeneralSettings)
+    # if your stage uses a global flag:
+    # mock_gs.convert_gloss_to_rough_globally = convert_gloss_globally
+
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.general_settings = mock_gs
+
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp_engine_dir"), # Important for new temp file paths
+        output_base_path=Path("/fake/output"),
+        effective_supplier="ValidSupplier",
+        asset_metadata={'asset_name': asset_name},
+        processed_maps_details=initial_processed_details if initial_processed_details is not None else {},
+        merged_maps_details={},
+        files_to_process=list(initial_file_rules) if initial_file_rules else [], # Stage modifies this list
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={'skip_asset': skip_asset_flag},
+        incrementing_value=None, # Added as per AssetProcessingContext definition
+        sha5_value=None # Added as per AssetProcessingContext definition
+    )
+    return context
+
+# Unit tests will be added below
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_asset_skipped(mock_load_image, mock_save_image):
+    """
+    Test that if 'skip_asset' is True, no processing occurs.
+    """
+    stage = GlossToRoughConversionStage()
+    
+    gloss_rule_id = uuid.uuid4()
+    gloss_fr = create_mock_file_rule_for_gloss_test(id_val=gloss_rule_id, map_type="GLOSS")
+    
+    initial_details = {
+        gloss_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_gloss_map.png', 'status': 'Processed', 'map_type': 'GLOSS'}
+    }
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[gloss_fr],
+        initial_processed_details=initial_details,
+        skip_asset_flag=True # Asset is skipped
+    )
+    
+    # Keep a copy of files_to_process and processed_maps_details to compare
+    original_files_to_process = list(context.files_to_process)
+    original_processed_maps_details = context.processed_maps_details.copy()
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    
+    assert updated_context.files_to_process == original_files_to_process, "files_to_process should not change if asset is skipped"
+    assert updated_context.processed_maps_details == original_processed_maps_details, "processed_maps_details should not change if asset is skipped"
+    assert updated_context.status_flags['skip_asset'] is True
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_no_gloss_map_present(mock_load_image, mock_save_image):
+    """
+    Test that if no GLOSS maps are in files_to_process, no conversion occurs.
+    """
+    stage = GlossToRoughConversionStage()
+    
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_gloss_test(id_val=normal_rule_id, map_type="NORMAL", filename_pattern="normal.png")
+    albedo_fr = create_mock_file_rule_for_gloss_test(map_type="ALBEDO", filename_pattern="albedo.jpg")
+    
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_normal_map.png', 'status': 'Processed', 'map_type': 'NORMAL'}
+    }
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[normal_fr, albedo_fr],
+        initial_processed_details=initial_details
+    )
+    
+    original_files_to_process = list(context.files_to_process)
+    original_processed_maps_details = context.processed_maps_details.copy()
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    
+    assert updated_context.files_to_process == original_files_to_process, "files_to_process should not change if no GLOSS maps are present"
+    assert updated_context.processed_maps_details == original_processed_maps_details, "processed_maps_details should not change if no GLOSS maps are present"
+    
+    # Ensure map types of existing rules are unchanged
+    for fr_in_list in updated_context.files_to_process:
+        if fr_in_list.id == normal_fr.id:
+            assert fr_in_list.map_type == "NORMAL"
+        elif fr_in_list.id == albedo_fr.id:
+            assert fr_in_list.map_type == "ALBEDO"
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.logging') # Mock logging
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_gloss_conversion_uint8_success(mock_load_image, mock_save_image, mock_logging):
+    """
+    Test successful conversion of a GLOSS map (uint8 data) to ROUGHNESS.
+    """
+    stage = GlossToRoughConversionStage()
+    
+    gloss_rule_id = uuid.uuid4()
+    # Use a distinct filename for the gloss map to ensure correct path construction
+    gloss_fr = create_mock_file_rule_for_gloss_test(id_val=gloss_rule_id, map_type="GLOSS", filename_pattern="my_gloss_map.png")
+    other_fr_id = uuid.uuid4()
+    other_fr = create_mock_file_rule_for_gloss_test(id_val=other_fr_id, map_type="NORMAL", filename_pattern="normal_map.png")
+    
+    initial_gloss_temp_path = Path("/fake/temp_engine_dir/processed_gloss_map.png")
+    initial_other_temp_path = Path("/fake/temp_engine_dir/processed_normal_map.png")
+
+    initial_details = {
+        gloss_fr.id.hex: {'temp_processed_file': str(initial_gloss_temp_path), 'status': 'Processed', 'map_type': 'GLOSS'},
+        other_fr.id.hex: {'temp_processed_file': str(initial_other_temp_path), 'status': 'Processed', 'map_type': 'NORMAL'}
+    }
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[gloss_fr, other_fr],
+        initial_processed_details=initial_details
+    )
+
+    mock_loaded_gloss_data = np.array([10, 50, 250], dtype=np.uint8)
+    mock_load_image.return_value = mock_loaded_gloss_data
+    mock_save_image.return_value = True # Simulate successful save
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_called_once_with(initial_gloss_temp_path)
+    
+    # Check that save_image was called with inverted data and correct path
+    expected_inverted_data = 255 - mock_loaded_gloss_data
+    
+    # call_args[0] is a tuple of positional args, call_args[1] is a dict of kwargs
+    saved_path_arg = mock_save_image.call_args[0][0]
+    saved_data_arg = mock_save_image.call_args[0][1]
+    
+    assert np.array_equal(saved_data_arg, expected_inverted_data), "Image data passed to save_image is not correctly inverted."
+    assert "rough_from_gloss_" in saved_path_arg.name, "Saved file name should indicate conversion from gloss."
+    assert saved_path_arg.parent == Path("/fake/temp_engine_dir"), "Saved file should be in the engine temp directory."
+    # Ensure the new filename is based on the original gloss map's ID for uniqueness
+    assert gloss_fr.id.hex in saved_path_arg.name
+
+    # Check context.files_to_process
+    assert len(updated_context.files_to_process) == 2, "Number of file rules in context should remain the same."
+    converted_rule_found = False
+    other_rule_untouched = False
+    for fr_in_list in updated_context.files_to_process:
+        if fr_in_list.id == gloss_fr.id: # Should be the same rule object, modified
+            assert fr_in_list.map_type == "ROUGHNESS", "GLOSS map_type should be changed to ROUGHNESS."
+            # Check if filename_pattern was updated (optional, depends on stage logic)
+            # For now, assume it might not be, as the primary identifier is map_type and ID
+            converted_rule_found = True
+        elif fr_in_list.id == other_fr.id:
+            assert fr_in_list.map_type == "NORMAL", "Other map_type should remain unchanged."
+            other_rule_untouched = True
+    assert converted_rule_found, "The converted GLOSS rule was not found or not updated correctly in files_to_process."
+    assert other_rule_untouched, "The non-GLOSS rule was modified unexpectedly."
+
+    # Check context.processed_maps_details
+    assert len(updated_context.processed_maps_details) == 2, "Number of entries in processed_maps_details should remain the same."
+    
+    gloss_detail = updated_context.processed_maps_details[gloss_fr.id.hex]
+    assert "rough_from_gloss_" in gloss_detail['temp_processed_file'], "temp_processed_file for gloss map not updated."
+    assert Path(gloss_detail['temp_processed_file']).name == saved_path_arg.name, "Path in details should match saved path."
+    assert gloss_detail['original_map_type_before_conversion'] == "GLOSS", "original_map_type_before_conversion not set correctly."
+    assert "Converted from GLOSS to ROUGHNESS" in gloss_detail['notes'], "Conversion notes not added or incorrect."
+    assert gloss_detail['map_type'] == "ROUGHNESS", "map_type in details not updated to ROUGHNESS."
+
+
+    other_detail = updated_context.processed_maps_details[other_fr.id.hex]
+    assert other_detail['temp_processed_file'] == str(initial_other_temp_path), "Other map's temp_processed_file should be unchanged."
+    assert other_detail['map_type'] == "NORMAL", "Other map's map_type should be unchanged."
+    assert 'original_map_type_before_conversion' not in other_detail, "Other map should not have conversion history."
+    assert 'notes' not in other_detail or "Converted from GLOSS" not in other_detail['notes'], "Other map should not have conversion notes."
+
+    mock_logging.info.assert_any_call(f"Successfully converted GLOSS map {gloss_fr.id.hex} to ROUGHNESS.")
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.logging') # Mock logging
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_gloss_conversion_float_success(mock_load_image, mock_save_image, mock_logging):
+    """
+    Test successful conversion of a GLOSS map (float data) to ROUGHNESS.
+    """
+    stage = GlossToRoughConversionStage()
+    
+    gloss_rule_id = uuid.uuid4()
+    gloss_fr = create_mock_file_rule_for_gloss_test(id_val=gloss_rule_id, map_type="GLOSS", filename_pattern="gloss_float.hdr") # Example float format
+    
+    initial_gloss_temp_path = Path("/fake/temp_engine_dir/processed_gloss_float.hdr")
+    initial_details = {
+        gloss_fr.id.hex: {'temp_processed_file': str(initial_gloss_temp_path), 'status': 'Processed', 'map_type': 'GLOSS'}
+    }
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[gloss_fr],
+        initial_processed_details=initial_details
+    )
+
+    mock_loaded_gloss_data = np.array([0.1, 0.5, 0.9], dtype=np.float32)
+    mock_load_image.return_value = mock_loaded_gloss_data
+    mock_save_image.return_value = True # Simulate successful save
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_called_once_with(initial_gloss_temp_path)
+    
+    expected_inverted_data = 1.0 - mock_loaded_gloss_data
+    
+    saved_path_arg = mock_save_image.call_args[0][0]
+    saved_data_arg = mock_save_image.call_args[0][1]
+    
+    assert np.allclose(saved_data_arg, expected_inverted_data), "Image data (float) passed to save_image is not correctly inverted."
+    assert "rough_from_gloss_" in saved_path_arg.name, "Saved file name should indicate conversion from gloss."
+    assert saved_path_arg.parent == Path("/fake/temp_engine_dir"), "Saved file should be in the engine temp directory."
+    assert gloss_fr.id.hex in saved_path_arg.name
+
+    assert len(updated_context.files_to_process) == 1
+    converted_rule = updated_context.files_to_process[0]
+    assert converted_rule.id == gloss_fr.id
+    assert converted_rule.map_type == "ROUGHNESS"
+
+    gloss_detail = updated_context.processed_maps_details[gloss_fr.id.hex]
+    assert "rough_from_gloss_" in gloss_detail['temp_processed_file']
+    assert Path(gloss_detail['temp_processed_file']).name == saved_path_arg.name
+    assert gloss_detail['original_map_type_before_conversion'] == "GLOSS"
+    assert "Converted from GLOSS to ROUGHNESS" in gloss_detail['notes']
+    assert gloss_detail['map_type'] == "ROUGHNESS"
+
+    mock_logging.info.assert_any_call(f"Successfully converted GLOSS map {gloss_fr.id.hex} to ROUGHNESS.")
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.logging')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_load_image_fails(mock_load_image, mock_save_image, mock_logging):
+    """
+    Test behavior when ipu.load_image fails (returns None).
+    The original FileRule should be kept, and an error logged.
+    """
+    stage = GlossToRoughConversionStage()
+    
+    gloss_rule_id = uuid.uuid4()
+    gloss_fr = create_mock_file_rule_for_gloss_test(id_val=gloss_rule_id, map_type="GLOSS", filename_pattern="gloss_fails_load.png")
+    
+    initial_gloss_temp_path = Path("/fake/temp_engine_dir/processed_gloss_fails_load.png")
+    initial_details = {
+        gloss_fr.id.hex: {'temp_processed_file': str(initial_gloss_temp_path), 'status': 'Processed', 'map_type': 'GLOSS'}
+    }
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[gloss_fr],
+        initial_processed_details=initial_details
+    )
+    
+    # Keep a copy for comparison
+    original_file_rule_map_type = gloss_fr.map_type 
+    original_details_entry = context.processed_maps_details[gloss_fr.id.hex].copy()
+
+    mock_load_image.return_value = None # Simulate load failure
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_called_once_with(initial_gloss_temp_path)
+    mock_save_image.assert_not_called() # Save should not be attempted
+    
+    # Check context.files_to_process: rule should be unchanged
+    assert len(updated_context.files_to_process) == 1
+    processed_rule = updated_context.files_to_process[0]
+    assert processed_rule.id == gloss_fr.id
+    assert processed_rule.map_type == original_file_rule_map_type, "FileRule map_type should not change if load fails."
+    assert processed_rule.map_type == "GLOSS" # Explicitly check it's still GLOSS
+
+    # Check context.processed_maps_details: details should be unchanged
+    current_details_entry = updated_context.processed_maps_details[gloss_fr.id.hex]
+    assert current_details_entry['temp_processed_file'] == str(initial_gloss_temp_path)
+    assert current_details_entry['map_type'] == "GLOSS"
+    assert 'original_map_type_before_conversion' not in current_details_entry
+    assert 'notes' not in current_details_entry or "Converted from GLOSS" not in current_details_entry['notes']
+    
+    mock_logging.error.assert_called_once_with(
+        f"Failed to load image data for GLOSS map {gloss_fr.id.hex} from {initial_gloss_temp_path}. Skipping conversion for this map."
+    )
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.logging')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_save_image_fails(mock_load_image, mock_save_image, mock_logging):
+    """
+    Test behavior when ipu.save_image fails (returns False).
+    The original FileRule should be kept, and an error logged.
+    """
+    stage = GlossToRoughConversionStage()
+    
+    gloss_rule_id = uuid.uuid4()
+    gloss_fr = create_mock_file_rule_for_gloss_test(id_val=gloss_rule_id, map_type="GLOSS", filename_pattern="gloss_fails_save.png")
+    
+    initial_gloss_temp_path = Path("/fake/temp_engine_dir/processed_gloss_fails_save.png")
+    initial_details = {
+        gloss_fr.id.hex: {'temp_processed_file': str(initial_gloss_temp_path), 'status': 'Processed', 'map_type': 'GLOSS'}
+    }
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[gloss_fr],
+        initial_processed_details=initial_details
+    )
+    
+    original_file_rule_map_type = gloss_fr.map_type
+    original_details_entry = context.processed_maps_details[gloss_fr.id.hex].copy()
+
+    mock_loaded_gloss_data = np.array([10, 50, 250], dtype=np.uint8)
+    mock_load_image.return_value = mock_loaded_gloss_data
+    mock_save_image.return_value = False # Simulate save failure
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_called_once_with(initial_gloss_temp_path)
+    
+    # Check that save_image was called with correct data and path
+    expected_inverted_data = 255 - mock_loaded_gloss_data
+    # call_args[0] is a tuple of positional args
+    saved_path_arg = mock_save_image.call_args[0][0]
+    saved_data_arg = mock_save_image.call_args[0][1]
+    
+    assert np.array_equal(saved_data_arg, expected_inverted_data), "Image data passed to save_image is not correctly inverted even on failure."
+    assert "rough_from_gloss_" in saved_path_arg.name, "Attempted save file name should indicate conversion from gloss."
+    assert saved_path_arg.parent == Path("/fake/temp_engine_dir"), "Attempted save file should be in the engine temp directory."
+
+    # Check context.files_to_process: rule should be unchanged
+    assert len(updated_context.files_to_process) == 1
+    processed_rule = updated_context.files_to_process[0]
+    assert processed_rule.id == gloss_fr.id
+    assert processed_rule.map_type == original_file_rule_map_type, "FileRule map_type should not change if save fails."
+    assert processed_rule.map_type == "GLOSS"
+
+    # Check context.processed_maps_details: details should be unchanged
+    current_details_entry = updated_context.processed_maps_details[gloss_fr.id.hex]
+    assert current_details_entry['temp_processed_file'] == str(initial_gloss_temp_path)
+    assert current_details_entry['map_type'] == "GLOSS"
+    assert 'original_map_type_before_conversion' not in current_details_entry
+    assert 'notes' not in current_details_entry or "Converted from GLOSS" not in current_details_entry['notes']
+    
+    mock_logging.error.assert_called_once_with(
+        f"Failed to save inverted GLOSS map {gloss_fr.id.hex} to {saved_path_arg}. Retaining original GLOSS map."
+    )
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.logging')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_gloss_map_in_files_to_process_but_not_in_details(mock_load_image, mock_save_image, mock_logging):
+    """
+    Test behavior when a GLOSS FileRule is in files_to_process but its details
+    are missing from processed_maps_details.
+    The stage should log an error and skip this FileRule.
+    """
+    stage = GlossToRoughConversionStage()
+    
+    gloss_rule_id = uuid.uuid4()
+    # This FileRule is in files_to_process
+    gloss_fr_in_list = create_mock_file_rule_for_gloss_test(id_val=gloss_rule_id, map_type="GLOSS", filename_pattern="orphan_gloss.png")
+    
+    # processed_maps_details is empty or does not contain gloss_fr_in_list.id.hex
+    initial_details = {} 
+    
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[gloss_fr_in_list],
+        initial_processed_details=initial_details 
+    )
+    
+    original_files_to_process = list(context.files_to_process)
+    original_processed_maps_details = context.processed_maps_details.copy()
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_not_called() # Load should not be attempted if details are missing
+    mock_save_image.assert_not_called() # Save should not be attempted
+    
+    # Check context.files_to_process: rule should be unchanged
+    assert len(updated_context.files_to_process) == 1
+    processed_rule = updated_context.files_to_process[0]
+    assert processed_rule.id == gloss_fr_in_list.id
+    assert processed_rule.map_type == "GLOSS", "FileRule map_type should not change if its details are missing."
+
+    # Check context.processed_maps_details: should remain unchanged
+    assert updated_context.processed_maps_details == original_processed_maps_details, "processed_maps_details should not change."
+    
+    mock_logging.error.assert_called_once_with(
+        f"GLOSS map {gloss_fr_in_list.id.hex} found in files_to_process but missing from processed_maps_details. Skipping conversion."
+    )
+
+# Test for Case 8.2 (GLOSS map ID in processed_maps_details but no corresponding FileRule in files_to_process)
+# This case is implicitly handled because the stage iterates files_to_process.
+# If a FileRule isn't in files_to_process, its corresponding entry in processed_maps_details (if any) won't be acted upon.
+# We can add a simple test to ensure no errors occur and non-relevant details are untouched.
+
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.logging')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.save_image')
+@mock.patch('processing.pipeline.stages.gloss_to_rough_conversion.ipu.load_image')
+def test_gloss_detail_exists_but_not_in_files_to_process(mock_load_image, mock_save_image, mock_logging):
+    """
+    Test that if a GLOSS map detail exists in processed_maps_details but
+    no corresponding FileRule is in files_to_process, it's simply ignored
+    without error, and other valid conversions proceed.
+    """
+    stage = GlossToRoughConversionStage()
+
+    # This rule will be processed
+    convert_rule_id = uuid.uuid4()
+    convert_fr = create_mock_file_rule_for_gloss_test(id_val=convert_rule_id, map_type="GLOSS", filename_pattern="convert_me.png")
+    convert_initial_temp_path = Path("/fake/temp_engine_dir/processed_convert_me.png")
+
+    # This rule's details exist, but the rule itself is not in files_to_process
+    orphan_detail_id = uuid.uuid4()
+    
+    initial_details = {
+        convert_fr.id.hex: {'temp_processed_file': str(convert_initial_temp_path), 'status': 'Processed', 'map_type': 'GLOSS'},
+        orphan_detail_id.hex: {'temp_processed_file': '/fake/temp_engine_dir/orphan.png', 'status': 'Processed', 'map_type': 'GLOSS', 'notes': 'This is an orphan'}
+    }
+    
+    context = create_gloss_conversion_mock_context(
+        initial_file_rules=[convert_fr], # Only convert_fr is in files_to_process
+        initial_processed_details=initial_details
+    )
+    
+    mock_loaded_data = np.array([100], dtype=np.uint8)
+    mock_load_image.return_value = mock_loaded_data
+    mock_save_image.return_value = True
+
+    updated_context = stage.execute(context)
+
+    # Assert that load/save were called only for the rule in files_to_process
+    mock_load_image.assert_called_once_with(convert_initial_temp_path)
+    mock_save_image.assert_called_once() # Check it was called, details checked in other tests
+
+    # Check that the orphan detail in processed_maps_details is untouched
+    assert orphan_detail_id.hex in updated_context.processed_maps_details
+    orphan_entry = updated_context.processed_maps_details[orphan_detail_id.hex]
+    assert orphan_entry['temp_processed_file'] == '/fake/temp_engine_dir/orphan.png'
+    assert orphan_entry['map_type'] == 'GLOSS'
+    assert orphan_entry['notes'] == 'This is an orphan'
+    assert 'original_map_type_before_conversion' not in orphan_entry
+
+    # Check that the processed rule was indeed converted
+    assert convert_fr.id.hex in updated_context.processed_maps_details
+    converted_entry = updated_context.processed_maps_details[convert_fr.id.hex]
+    assert converted_entry['map_type'] == 'ROUGHNESS'
+    assert "rough_from_gloss_" in converted_entry['temp_processed_file']
+
+    # No errors should have been logged regarding the orphan detail
+    for call_args in mock_logging.error.call_args_list:
+        assert str(orphan_detail_id.hex) not in call_args[0][0], "Error logged for orphan detail"

tests/processing/pipeline/stages/test_individual_map_processing.py

@@ -0,0 +1,555 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import uuid
+import numpy as np
+from typing import Optional # Added for type hinting in helper functions
+
+from processing.pipeline.stages.individual_map_processing import IndividualMapProcessingStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule, TransformSettings # Key models
+from configuration import Configuration, GeneralSettings
+# cv2 might be imported by the stage for interpolation constants, ensure it's mockable if so.
+# For now, assume ipu handles interpolation details.
+
+def create_mock_transform_settings(
+    target_width=0, target_height=0, resize_mode="FIT",
+    ensure_pot=False, allow_upscale=True, target_color_profile="RGB" # Add other fields as needed
+) -> mock.MagicMock:
+    ts = mock.MagicMock(spec=TransformSettings)
+    ts.target_width = target_width
+    ts.target_height = target_height
+    ts.resize_mode = resize_mode
+    ts.ensure_pot = ensure_pot
+    ts.allow_upscale = allow_upscale
+    ts.target_color_profile = target_color_profile
+    # ts.resize_filter = "AREA" # if your stage uses this
+    return ts
+
+def create_mock_file_rule_for_individual_processing(
+    id_val: Optional[uuid.UUID] = None,
+    map_type: str = "ALBEDO",
+    filename_pattern: str = "albedo_*.png", # Pattern for glob
+    item_type: str = "MAP_COL",
+    active: bool = True,
+    transform_settings: Optional[mock.MagicMock] = None
+) -> mock.MagicMock:
+    mock_fr = mock.MagicMock(spec=FileRule)
+    mock_fr.id = id_val if id_val else uuid.uuid4()
+    mock_fr.map_type = map_type
+    mock_fr.filename_pattern = filename_pattern
+    mock_fr.item_type = item_type
+    mock_fr.active = active
+    mock_fr.transform_settings = transform_settings if transform_settings else create_mock_transform_settings()
+    return mock_fr
+
+def create_individual_map_proc_mock_context(
+    initial_file_rules: Optional[list] = None,
+    asset_source_path_str: str = "/fake/asset_source",
+    skip_asset_flag: bool = False,
+    asset_name: str = "IndividualMapAsset"
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.source_path = Path(asset_source_path_str)
+    # file_rules on AssetRule not directly used by stage, context.files_to_process is
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_config = mock.MagicMock(spec=Configuration)
+    # mock_config.general_settings = mock.MagicMock(spec=GeneralSettings) # If needed
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp_engine_dir"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier="ValidSupplier",
+        asset_metadata={'asset_name': asset_name},
+        processed_maps_details={}, # Stage populates this
+        merged_maps_details={},
+        files_to_process=list(initial_file_rules) if initial_file_rules else [],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={'skip_asset': skip_asset_flag},
+        incrementing_value=None,
+        sha5_value=None # Corrected from sha5_value to sha_value if that's the actual param
+    )
+    return context
+
+# Placeholder for tests to be added next
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu')
+@mock.patch('logging.info')
+def test_asset_skipped_if_flag_is_true(mock_log_info, mock_ipu):
+    stage = IndividualMapProcessingStage()
+    context = create_individual_map_proc_mock_context(skip_asset_flag=True)
+    
+    # Add a dummy file rule to ensure it's not processed
+    file_rule = create_mock_file_rule_for_individual_processing()
+    context.files_to_process = [file_rule]
+
+    updated_context = stage.execute(context)
+
+    mock_ipu.load_image.assert_not_called()
+    mock_ipu.save_image.assert_not_called()
+    assert not updated_context.processed_maps_details # No details should be added
+    # Check for a log message indicating skip, if applicable (depends on stage's logging)
+    # mock_log_info.assert_any_call("Skipping asset IndividualMapAsset due to status_flags['skip_asset'] = True") # Example
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu')
+@mock.patch('logging.info')
+def test_no_processing_if_no_map_col_rules(mock_log_info, mock_ipu):
+    stage = IndividualMapProcessingStage()
+    
+    # Create a file rule that is NOT of item_type MAP_COL
+    non_map_col_rule = create_mock_file_rule_for_individual_processing(item_type="METADATA")
+    context = create_individual_map_proc_mock_context(initial_file_rules=[non_map_col_rule])
+
+    updated_context = stage.execute(context)
+
+    mock_ipu.load_image.assert_not_called()
+    mock_ipu.save_image.assert_not_called()
+    assert not updated_context.processed_maps_details
+    # mock_log_info.assert_any_call("No FileRules of item_type 'MAP_COL' to process for asset IndividualMapAsset.") # Example
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.save_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.calculate_target_dimensions')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.load_image')
+@mock.patch('pathlib.Path.glob') # Mocking Path.glob used by the stage's _find_source_file
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_individual_map_processing_success_no_resize(
+    mock_log_error, mock_log_info, mock_path_glob, mock_load_image,
+    mock_calc_dims, mock_resize_image, mock_save_image
+):
+    stage = IndividualMapProcessingStage()
+
+    source_file_name = "albedo_source.png"
+    # The glob is called on context.asset_rule.source_path, so mock that Path object's glob
+    mock_asset_source_path = Path("/fake/asset_source")
+    mock_found_source_path = mock_asset_source_path / source_file_name
+    
+    # We need to mock the glob method of the Path instance
+    # that represents the asset's source directory.
+    # The stage does something like: Path(context.asset_rule.source_path).glob(...)
+    # So, we need to ensure that when Path() is called with that specific string,
+    # the resulting object's glob method is our mock.
+    # A more robust way is to mock Path itself to return a mock object
+    # whose glob method is also a mock.
+
+    # Simpler approach for now: assume Path.glob is used as a static/class method call
+    # or that the instance it's called on is correctly patched by @mock.patch('pathlib.Path.glob')
+    # if the stage does `from pathlib import Path` and then `Path(path_str).glob(...)`.
+    # The prompt example uses @mock.patch('pathlib.Path.glob'), implying the stage might do this:
+    # for f_pattern in patterns:
+    #   for found_file in Path(base_dir).glob(f_pattern): ...
+    # Let's refine the mock_path_glob setup.
+    # The stage's _find_source_file likely does:
+    # search_path = Path(self.context.asset_rule.source_path)
+    # found_files = list(search_path.glob(filename_pattern))
+
+    # To correctly mock this, we need to mock the `glob` method of the specific Path instance.
+    # Or, if `_find_source_file` instantiates `Path` like `Path(str(context.asset_rule.source_path)).glob(...)`,
+    # then patching `pathlib.Path.glob` might work if it's treated as a method that gets bound.
+    # Let's stick to the example's @mock.patch('pathlib.Path.glob') and assume it covers the usage.
+    mock_path_glob.return_value = [mock_found_source_path] # Glob finds one file
+
+    ts = create_mock_transform_settings(target_width=100, target_height=100)
+    file_rule = create_mock_file_rule_for_individual_processing(
+        map_type="ALBEDO", filename_pattern="albedo_*.png", transform_settings=ts
+    )
+    context = create_individual_map_proc_mock_context(
+        initial_file_rules=[file_rule],
+        asset_source_path_str=str(mock_asset_source_path) # Ensure context uses this path
+    )
+
+    mock_img_data = np.zeros((100, 100, 3), dtype=np.uint8) # Original dimensions
+    mock_load_image.return_value = mock_img_data
+    mock_calc_dims.return_value = (100, 100) # No resize needed
+    mock_save_image.return_value = True
+
+    updated_context = stage.execute(context)
+
+    # Assert that Path(context.asset_rule.source_path).glob was called
+    # This requires a bit more intricate mocking if Path instances are created inside.
+    # For now, assert mock_path_glob was called with the pattern.
+    # The actual call in stage is `Path(context.asset_rule.source_path).glob(file_rule.filename_pattern)`
+    # So, `mock_path_glob` (if it patches `Path.glob` globally) should be called.
+    # We need to ensure the mock_path_glob is associated with the correct Path instance or that
+    # the global patch works as intended.
+    # A common pattern is:
+    # with mock.patch.object(Path, 'glob', return_value=[mock_found_source_path]) as specific_glob_mock:
+    #    # execute code
+    #    specific_glob_mock.assert_called_once_with(file_rule.filename_pattern)
+    # However, the decorator @mock.patch('pathlib.Path.glob') should work if the stage code is
+    # `from pathlib import Path; p = Path(...); p.glob(...)`
+    
+    # The stage's _find_source_file will instantiate a Path object from context.asset_rule.source_path
+    # and then call glob on it.
+    # So, @mock.patch('pathlib.Path.glob') is patching the method on the class.
+    # When an instance calls it, the mock is used.
+    mock_path_glob.assert_called_once_with(file_rule.filename_pattern)
+
+
+    mock_load_image.assert_called_once_with(mock_found_source_path)
+    # The actual call to calculate_target_dimensions is:
+    # ipu.calculate_target_dimensions(original_dims, ts.target_width, ts.target_height, ts.resize_mode, ts.ensure_pot, ts.allow_upscale)
+    mock_calc_dims.assert_called_once_with(
+        (100, 100), ts.target_width, ts.target_height, ts.resize_mode, ts.ensure_pot, ts.allow_upscale
+    )
+    mock_resize_image.assert_not_called() # Crucial for this test case
+    mock_save_image.assert_called_once()
+
+    # Check save path and data
+    saved_image_arg, saved_path_arg = mock_save_image.call_args[0]
+    assert np.array_equal(saved_image_arg, mock_img_data) # Ensure correct image data is passed to save
+    assert "processed_ALBEDO_" in saved_path_arg.name # Based on map_type
+    assert file_rule.id.hex in saved_path_arg.name # Ensure unique name with FileRule ID
+    assert saved_path_arg.parent == context.engine_temp_dir
+
+    assert file_rule.id.hex in updated_context.processed_maps_details
+    details = updated_context.processed_maps_details[file_rule.id.hex]
+    assert details['status'] == 'Processed'
+    assert details['source_file'] == str(mock_found_source_path)
+    assert Path(details['temp_processed_file']) == saved_path_arg
+    assert details['original_dimensions'] == (100, 100)
+    assert details['processed_dimensions'] == (100, 100)
+    assert details['map_type'] == file_rule.map_type
+    mock_log_error.assert_not_called()
+    mock_log_info.assert_any_call(f"Successfully processed map {file_rule.map_type} (ID: {file_rule.id.hex}) for asset {context.asset_rule.name}. Output: {saved_path_arg}")
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.save_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.calculate_target_dimensions')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.load_image')
+@mock.patch('pathlib.Path.glob')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_source_file_not_found(
+    mock_log_error, mock_log_info, mock_path_glob, mock_load_image,
+    mock_calc_dims, mock_resize_image, mock_save_image
+):
+    stage = IndividualMapProcessingStage()
+    mock_asset_source_path = Path("/fake/asset_source")
+    
+    mock_path_glob.return_value = [] # Glob finds no files
+
+    file_rule = create_mock_file_rule_for_individual_processing(filename_pattern="nonexistent_*.png")
+    context = create_individual_map_proc_mock_context(
+        initial_file_rules=[file_rule],
+        asset_source_path_str=str(mock_asset_source_path)
+    )
+
+    updated_context = stage.execute(context)
+
+    mock_path_glob.assert_called_once_with(file_rule.filename_pattern)
+    mock_load_image.assert_not_called()
+    mock_calc_dims.assert_not_called()
+    mock_resize_image.assert_not_called()
+    mock_save_image.assert_not_called()
+
+    assert file_rule.id.hex in updated_context.processed_maps_details
+    details = updated_context.processed_maps_details[file_rule.id.hex]
+    assert details['status'] == 'Source Not Found'
+    assert details['source_file'] is None
+    assert details['temp_processed_file'] is None
+    assert details['error_message'] is not None # Check an error message is present
+    mock_log_error.assert_called_once()
+    # Example: mock_log_error.assert_called_with(f"Could not find source file for rule {file_rule.id} (pattern: {file_rule.filename_pattern}) in {context.asset_rule.source_path}")
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.save_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.calculate_target_dimensions')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.load_image')
+@mock.patch('pathlib.Path.glob')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_load_image_fails(
+    mock_log_error, mock_log_info, mock_path_glob, mock_load_image,
+    mock_calc_dims, mock_resize_image, mock_save_image
+):
+    stage = IndividualMapProcessingStage()
+    source_file_name = "albedo_corrupt.png"
+    mock_asset_source_path = Path("/fake/asset_source")
+    mock_found_source_path = mock_asset_source_path / source_file_name
+    mock_path_glob.return_value = [mock_found_source_path]
+
+    mock_load_image.return_value = None # Simulate load failure
+
+    file_rule = create_mock_file_rule_for_individual_processing(filename_pattern="albedo_*.png")
+    context = create_individual_map_proc_mock_context(
+        initial_file_rules=[file_rule],
+        asset_source_path_str=str(mock_asset_source_path)
+    )
+
+    updated_context = stage.execute(context)
+
+    mock_path_glob.assert_called_once_with(file_rule.filename_pattern)
+    mock_load_image.assert_called_once_with(mock_found_source_path)
+    mock_calc_dims.assert_not_called()
+    mock_resize_image.assert_not_called()
+    mock_save_image.assert_not_called()
+
+    assert file_rule.id.hex in updated_context.processed_maps_details
+    details = updated_context.processed_maps_details[file_rule.id.hex]
+    assert details['status'] == 'Load Failed'
+    assert details['source_file'] == str(mock_found_source_path)
+    assert details['temp_processed_file'] is None
+    assert details['error_message'] is not None
+    mock_log_error.assert_called_once()
+    # Example: mock_log_error.assert_called_with(f"Failed to load image {mock_found_source_path} for rule {file_rule.id}")
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.save_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.calculate_target_dimensions')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.load_image')
+@mock.patch('pathlib.Path.glob')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_resize_occurs_when_dimensions_differ(
+    mock_log_error, mock_log_info, mock_path_glob, mock_load_image,
+    mock_calc_dims, mock_resize_image, mock_save_image
+):
+    stage = IndividualMapProcessingStage()
+    source_file_name = "albedo_resize.png"
+    mock_asset_source_path = Path("/fake/asset_source")
+    mock_found_source_path = mock_asset_source_path / source_file_name
+    mock_path_glob.return_value = [mock_found_source_path]
+
+    original_dims = (100, 100)
+    target_dims = (50, 50) # Different dimensions
+    mock_img_data = np.zeros((*original_dims, 3), dtype=np.uint8)
+    mock_resized_img_data = np.zeros((*target_dims, 3), dtype=np.uint8)
+
+    mock_load_image.return_value = mock_img_data
+    ts = create_mock_transform_settings(target_width=target_dims[0], target_height=target_dims[1])
+    file_rule = create_mock_file_rule_for_individual_processing(transform_settings=ts)
+    context = create_individual_map_proc_mock_context(
+        initial_file_rules=[file_rule],
+        asset_source_path_str=str(mock_asset_source_path)
+    )
+    
+    mock_calc_dims.return_value = target_dims # Simulate calc_dims returning new dimensions
+    mock_resize_image.return_value = mock_resized_img_data # Simulate resize returning new image data
+    mock_save_image.return_value = True
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(mock_found_source_path)
+    mock_calc_dims.assert_called_once_with(
+        original_dims, ts.target_width, ts.target_height, ts.resize_mode, ts.ensure_pot, ts.allow_upscale
+    )
+    # The actual call to resize_image is:
+    # ipu.resize_image(loaded_image, target_dims, ts.resize_filter) # Assuming resize_filter is used
+    # If resize_filter is not on TransformSettings or not used, adjust this.
+    # For now, let's assume it's ipu.resize_image(loaded_image, target_dims) or similar
+    # The stage code is: resized_image = ipu.resize_image(loaded_image, target_dims_calculated, file_rule.transform_settings.resize_filter)
+    # So we need to mock ts.resize_filter
+    ts.resize_filter = "LANCZOS4" # Example filter
+    mock_resize_image.assert_called_once_with(mock_img_data, target_dims, ts.resize_filter)
+    
+    saved_image_arg, saved_path_arg = mock_save_image.call_args[0]
+    assert np.array_equal(saved_image_arg, mock_resized_img_data) # Check resized data is saved
+    assert "processed_ALBEDO_" in saved_path_arg.name
+    assert saved_path_arg.parent == context.engine_temp_dir
+
+    assert file_rule.id.hex in updated_context.processed_maps_details
+    details = updated_context.processed_maps_details[file_rule.id.hex]
+    assert details['status'] == 'Processed'
+    assert details['original_dimensions'] == original_dims
+    assert details['processed_dimensions'] == target_dims
+    mock_log_error.assert_not_called()
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.save_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.calculate_target_dimensions')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.load_image')
+@mock.patch('pathlib.Path.glob')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_save_image_fails(
+    mock_log_error, mock_log_info, mock_path_glob, mock_load_image,
+    mock_calc_dims, mock_resize_image, mock_save_image
+):
+    stage = IndividualMapProcessingStage()
+    source_file_name = "albedo_save_fail.png"
+    mock_asset_source_path = Path("/fake/asset_source")
+    mock_found_source_path = mock_asset_source_path / source_file_name
+    mock_path_glob.return_value = [mock_found_source_path]
+
+    mock_img_data = np.zeros((100, 100, 3), dtype=np.uint8)
+    mock_load_image.return_value = mock_img_data
+    mock_calc_dims.return_value = (100, 100) # No resize
+    mock_save_image.return_value = False # Simulate save failure
+
+    ts = create_mock_transform_settings()
+    file_rule = create_mock_file_rule_for_individual_processing(transform_settings=ts)
+    context = create_individual_map_proc_mock_context(
+        initial_file_rules=[file_rule],
+        asset_source_path_str=str(mock_asset_source_path)
+    )
+
+    updated_context = stage.execute(context)
+
+    mock_save_image.assert_called_once() # Attempt to save should still happen
+    
+    assert file_rule.id.hex in updated_context.processed_maps_details
+    details = updated_context.processed_maps_details[file_rule.id.hex]
+    assert details['status'] == 'Save Failed'
+    assert details['source_file'] == str(mock_found_source_path)
+    assert details['temp_processed_file'] is not None # Path was generated
+    assert details['error_message'] is not None
+    mock_log_error.assert_called_once()
+    # Example: mock_log_error.assert_called_with(f"Failed to save processed image for rule {file_rule.id} to {details['temp_processed_file']}")
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.save_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.calculate_target_dimensions')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.load_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.convert_bgr_to_rgb')
+@mock.patch('pathlib.Path.glob')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_color_conversion_bgr_to_rgb(
+    mock_log_error, mock_log_info, mock_path_glob, mock_convert_bgr, mock_load_image,
+    mock_calc_dims, mock_resize_image, mock_save_image
+):
+    stage = IndividualMapProcessingStage()
+    source_file_name = "albedo_bgr.png"
+    mock_asset_source_path = Path("/fake/asset_source")
+    mock_found_source_path = mock_asset_source_path / source_file_name
+    mock_path_glob.return_value = [mock_found_source_path]
+
+    mock_bgr_img_data = np.zeros((100, 100, 3), dtype=np.uint8) # Loaded as BGR
+    mock_rgb_img_data = np.zeros((100, 100, 3), dtype=np.uint8) # After conversion
+    
+    mock_load_image.return_value = mock_bgr_img_data # Image is loaded (assume BGR by default from cv2)
+    mock_convert_bgr.return_value = mock_rgb_img_data # Mock the conversion
+    mock_calc_dims.return_value = (100, 100) # No resize
+    mock_save_image.return_value = True
+
+    # Transform settings request RGB, and stage assumes load might be BGR
+    ts = create_mock_transform_settings(target_color_profile="RGB") 
+    file_rule = create_mock_file_rule_for_individual_processing(transform_settings=ts)
+    context = create_individual_map_proc_mock_context(
+        initial_file_rules=[file_rule],
+        asset_source_path_str=str(mock_asset_source_path)
+    )
+    # The stage code is:
+    # if file_rule.transform_settings.target_color_profile == "RGB" and loaded_image.shape[2] == 3:
+    #     logger.info(f"Attempting to convert image from BGR to RGB for {file_rule_id_hex}")
+    #     processed_image_data = ipu.convert_bgr_to_rgb(processed_image_data)
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(mock_found_source_path)
+    mock_convert_bgr.assert_called_once_with(mock_bgr_img_data)
+    mock_resize_image.assert_not_called()
+    
+    saved_image_arg, _ = mock_save_image.call_args[0]
+    assert np.array_equal(saved_image_arg, mock_rgb_img_data) # Ensure RGB data is saved
+    mock_log_error.assert_not_called()
+    mock_log_info.assert_any_call(f"Attempting to convert image from BGR to RGB for {file_rule.id.hex}")
+
+
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.save_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.calculate_target_dimensions')
+@mock.patch('processing.pipeline.stages.individual_map_processing.ipu.load_image')
+@mock.patch('pathlib.Path.glob')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_multiple_map_col_rules_processed(
+    mock_log_error, mock_log_info, mock_path_glob, mock_load_image,
+    mock_calc_dims, mock_resize_image, mock_save_image
+):
+    stage = IndividualMapProcessingStage()
+    mock_asset_source_path = Path("/fake/asset_source")
+
+    # Rule 1: Albedo
+    ts1 = create_mock_transform_settings(target_width=100, target_height=100)
+    file_rule1_id = uuid.uuid4()
+    file_rule1 = create_mock_file_rule_for_individual_processing(
+        id_val=file_rule1_id, map_type="ALBEDO", filename_pattern="albedo_*.png", transform_settings=ts1
+    )
+    source_file1 = mock_asset_source_path / "albedo_map.png"
+    img_data1 = np.zeros((100, 100, 3), dtype=np.uint8)
+
+    # Rule 2: Roughness
+    ts2 = create_mock_transform_settings(target_width=50, target_height=50) # Resize
+    ts2.resize_filter = "AREA"
+    file_rule2_id = uuid.uuid4()
+    file_rule2 = create_mock_file_rule_for_individual_processing(
+        id_val=file_rule2_id, map_type="ROUGHNESS", filename_pattern="rough_*.png", transform_settings=ts2
+    )
+    source_file2 = mock_asset_source_path / "rough_map.png"
+    img_data2_orig = np.zeros((200, 200, 1), dtype=np.uint8) # Original, needs resize
+    img_data2_resized = np.zeros((50, 50, 1), dtype=np.uint8) # Resized
+
+    context = create_individual_map_proc_mock_context(
+        initial_file_rules=[file_rule1, file_rule2],
+        asset_source_path_str=str(mock_asset_source_path)
+    )
+
+    # Mock behaviors for Path.glob, load_image, calc_dims, resize, save
+    # Path.glob will be called twice
+    mock_path_glob.side_effect = [
+        [source_file1], # For albedo_*.png
+        [source_file2]  # For rough_*.png
+    ]
+    mock_load_image.side_effect = [img_data1, img_data2_orig]
+    mock_calc_dims.side_effect = [
+        (100, 100), # For rule1 (no change)
+        (50, 50)    # For rule2 (change)
+    ]
+    mock_resize_image.return_value = img_data2_resized # Only called for rule2
+    mock_save_image.return_value = True
+
+    updated_context = stage.execute(context)
+
+    # Assertions for Rule 1 (Albedo)
+    assert mock_path_glob.call_args_list[0][0][0] == file_rule1.filename_pattern
+    assert mock_load_image.call_args_list[0][0][0] == source_file1
+    assert mock_calc_dims.call_args_list[0][0] == ((100,100), ts1.target_width, ts1.target_height, ts1.resize_mode, ts1.ensure_pot, ts1.allow_upscale)
+    
+    # Assertions for Rule 2 (Roughness)
+    assert mock_path_glob.call_args_list[1][0][0] == file_rule2.filename_pattern
+    assert mock_load_image.call_args_list[1][0][0] == source_file2
+    assert mock_calc_dims.call_args_list[1][0] == ((200,200), ts2.target_width, ts2.target_height, ts2.resize_mode, ts2.ensure_pot, ts2.allow_upscale)
+    mock_resize_image.assert_called_once_with(img_data2_orig, (50,50), ts2.resize_filter)
+    
+    assert mock_save_image.call_count == 2
+    # Check saved image for rule 1
+    saved_img1_arg, saved_path1_arg = mock_save_image.call_args_list[0][0]
+    assert np.array_equal(saved_img1_arg, img_data1)
+    assert "processed_ALBEDO_" in saved_path1_arg.name
+    assert file_rule1_id.hex in saved_path1_arg.name
+
+    # Check saved image for rule 2
+    saved_img2_arg, saved_path2_arg = mock_save_image.call_args_list[1][0]
+    assert np.array_equal(saved_img2_arg, img_data2_resized)
+    assert "processed_ROUGHNESS_" in saved_path2_arg.name
+    assert file_rule2_id.hex in saved_path2_arg.name
+
+    # Check context details
+    assert file_rule1_id.hex in updated_context.processed_maps_details
+    details1 = updated_context.processed_maps_details[file_rule1_id.hex]
+    assert details1['status'] == 'Processed'
+    assert details1['original_dimensions'] == (100, 100)
+    assert details1['processed_dimensions'] == (100, 100)
+
+    assert file_rule2_id.hex in updated_context.processed_maps_details
+    details2 = updated_context.processed_maps_details[file_rule2_id.hex]
+    assert details2['status'] == 'Processed'
+    assert details2['original_dimensions'] == (200, 200) # Original dims of img_data2_orig
+    assert details2['processed_dimensions'] == (50, 50)
+    
+    mock_log_error.assert_not_called()

tests/processing/pipeline/stages/test_map_merging.py

@@ -0,0 +1,538 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import uuid
+import numpy as np
+from typing import Optional # Added Optional for type hinting
+
+from processing.pipeline.stages.map_merging import MapMergingStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule, MergeSettings, MergeInputChannel
+from configuration import Configuration
+
+# Mock Helper Functions
+def create_mock_merge_input_channel(
+    file_rule_id: uuid.UUID, source_channel: int = 0, target_channel: int = 0, invert: bool = False
+) -> mock.MagicMock:
+    mic = mock.MagicMock(spec=MergeInputChannel)
+    mic.file_rule_id = file_rule_id
+    mic.source_channel = source_channel
+    mic.target_channel = target_channel
+    mic.invert_source_channel = invert
+    mic.default_value_if_missing = 0 # Or some other default
+    return mic
+
+def create_mock_merge_settings(
+    input_maps: Optional[list] = None, # List of mock MergeInputChannel
+    output_channels: int = 3
+) -> mock.MagicMock:
+    ms = mock.MagicMock(spec=MergeSettings)
+    ms.input_maps = input_maps if input_maps is not None else []
+    ms.output_channels = output_channels
+    return ms
+
+def create_mock_file_rule_for_merging(
+    id_val: Optional[uuid.UUID] = None,
+    map_type: str = "ORM", # Output map type
+    item_type: str = "MAP_MERGE",
+    merge_settings: Optional[mock.MagicMock] = None
+) -> mock.MagicMock:
+    mock_fr = mock.MagicMock(spec=FileRule)
+    mock_fr.id = id_val if id_val else uuid.uuid4()
+    mock_fr.map_type = map_type
+    mock_fr.filename_pattern = f"{map_type.lower()}_merged.png" # Placeholder
+    mock_fr.item_type = item_type
+    mock_fr.active = True
+    mock_fr.merge_settings = merge_settings if merge_settings else create_mock_merge_settings()
+    return mock_fr
+
+def create_map_merging_mock_context(
+    initial_file_rules: Optional[list] = None, # Will contain the MAP_MERGE rule
+    initial_processed_details: Optional[dict] = None, # Pre-processed inputs for merge
+    skip_asset_flag: bool = False,
+    asset_name: str = "MergeAsset"
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_config = mock.MagicMock(spec=Configuration)
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp_engine_dir"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier="ValidSupplier",
+        asset_metadata={'asset_name': asset_name},
+        processed_maps_details=initial_processed_details if initial_processed_details is not None else {},
+        merged_maps_details={}, # Stage populates this
+        files_to_process=list(initial_file_rules) if initial_file_rules else [],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={'skip_asset': skip_asset_flag},
+        incrementing_value=None,
+        sha5_value=None # Corrected from sha5_value to sha_value based on AssetProcessingContext
+    )
+    return context
+def test_asset_skipped():
+    stage = MapMergingStage()
+    context = create_map_merging_mock_context(skip_asset_flag=True)
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context == context # No changes expected
+    assert not updated_context.merged_maps_details # No maps should be merged
+
+def test_no_map_merge_rules():
+    stage = MapMergingStage()
+    # Context with a non-MAP_MERGE rule
+    non_merge_rule = create_mock_file_rule_for_merging(item_type="TEXTURE_MAP", map_type="Diffuse")
+    context = create_map_merging_mock_context(initial_file_rules=[non_merge_rule])
+    
+    updated_context = stage.execute(context)
+    
+    assert updated_context == context # No changes expected
+    assert not updated_context.merged_maps_details # No maps should be merged
+
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.resize_image') # If testing resize
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_map_merging_rgb_success(mock_log_error, mock_log_info, mock_load_image, mock_resize_image, mock_save_image):
+    stage = MapMergingStage()
+
+    # Input FileRules (mocked as already processed)
+    r_id, g_id, b_id = uuid.uuid4(), uuid.uuid4(), uuid.uuid4()
+    processed_details = {
+        r_id.hex: {'temp_processed_file': '/fake/red.png', 'status': 'Processed', 'map_type': 'RED_SRC'},
+        g_id.hex: {'temp_processed_file': '/fake/green.png', 'status': 'Processed', 'map_type': 'GREEN_SRC'},
+        b_id.hex: {'temp_processed_file': '/fake/blue.png', 'status': 'Processed', 'map_type': 'BLUE_SRC'}
+    }
+    # Mock loaded image data (grayscale for inputs)
+    mock_r_data = np.full((10, 10), 200, dtype=np.uint8)
+    mock_g_data = np.full((10, 10), 100, dtype=np.uint8)
+    mock_b_data = np.full((10, 10), 50, dtype=np.uint8)
+    mock_load_image.side_effect = [mock_r_data, mock_g_data, mock_b_data]
+
+    # Merge Rule setup
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=r_id, source_channel=0, target_channel=0), # R to R
+        create_mock_merge_input_channel(file_rule_id=g_id, source_channel=0, target_channel=1), # G to G
+        create_mock_merge_input_channel(file_rule_id=b_id, source_channel=0, target_channel=2)  # B to B
+    ]
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=3)
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="RGB_Combined", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    mock_save_image.return_value = True
+    
+    updated_context = stage.execute(context)
+
+    assert mock_load_image.call_count == 3
+    mock_resize_image.assert_not_called() # Assuming all inputs are same size for this test
+    mock_save_image.assert_called_once()
+    
+    # Check that the correct filename was passed to save_image
+    # The filename is constructed as: f"{context.asset_rule.name}_merged_{merge_rule.map_type}{Path(first_input_path).suffix}"
+    # In this case, first_input_path is '/fake/red.png', so suffix is '.png'
+    # Asset name is "MergeAsset"
+    expected_filename_part = f"{context.asset_rule.name}_merged_{merge_rule.map_type}.png"
+    saved_path_arg = mock_save_image.call_args[0][0]
+    assert expected_filename_part in str(saved_path_arg)
+
+
+    saved_data = mock_save_image.call_args[0][1]
+    assert saved_data.shape == (10, 10, 3)
+    assert np.all(saved_data[:,:,0] == 200) # Red channel
+    assert np.all(saved_data[:,:,1] == 100) # Green channel
+    assert np.all(saved_data[:,:,2] == 50)  # Blue channel
+
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Processed'
+    # The temp_merged_file path will be under engine_temp_dir / asset_name / filename
+    assert f"{context.engine_temp_dir / context.asset_rule.name / expected_filename_part}" == details['temp_merged_file']
+    mock_log_error.assert_not_called()
+    mock_log_info.assert_any_call(f"Successfully merged map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'.")
+
+# Unit tests will be added below this line
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_map_merging_channel_inversion(mock_log_error, mock_log_info, mock_load_image, mock_resize_image, mock_save_image):
+    stage = MapMergingStage()
+
+    # Input FileRule
+    input_id = uuid.uuid4()
+    processed_details = {
+        input_id.hex: {'temp_processed_file': '/fake/source.png', 'status': 'Processed', 'map_type': 'SOURCE_MAP'}
+    }
+    # Mock loaded image data (single channel for simplicity, to be inverted)
+    mock_source_data = np.array([[0, 100], [155, 255]], dtype=np.uint8)
+    mock_load_image.return_value = mock_source_data
+
+    # Merge Rule setup: one input, inverted, to one output channel
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=input_id, source_channel=0, target_channel=0, invert=True)
+    ]
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=1)
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="Inverted_Gray", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    mock_save_image.return_value = True
+    
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(Path('/fake/source.png'))
+    mock_resize_image.assert_not_called()
+    mock_save_image.assert_called_once()
+    
+    saved_data = mock_save_image.call_args[0][1]
+    assert saved_data.shape == (2, 2) # Grayscale output
+    
+    # Expected inverted data: 255-original
+    expected_inverted_data = np.array([[255, 155], [100, 0]], dtype=np.uint8)
+    assert np.all(saved_data == expected_inverted_data)
+
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Processed'
+    assert "merged_Inverted_Gray" in details['temp_merged_file']
+    mock_log_error.assert_not_called()
+    mock_log_info.assert_any_call(f"Successfully merged map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'.")
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.error')
+def test_map_merging_input_map_missing(mock_log_error, mock_load_image, mock_save_image):
+    stage = MapMergingStage()
+
+    # Input FileRule ID that will be missing from processed_details
+    missing_input_id = uuid.uuid4()
+    
+    # Merge Rule setup
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=missing_input_id, source_channel=0, target_channel=0)
+    ]
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=1)
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="TestMissing", merge_settings=merge_settings)
+    
+    # processed_details is empty, so missing_input_id will not be found
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details={} 
+    )
+    
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Failed'
+    assert 'error_message' in details
+    assert f"Input map FileRule ID {missing_input_id.hex} not found in processed_maps_details or not successfully processed" in details['error_message']
+    
+    mock_log_error.assert_called_once()
+    assert f"Failed to merge map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'" in mock_log_error.call_args[0][0]
+    assert f"Input map FileRule ID {missing_input_id.hex} not found in processed_maps_details or not successfully processed" in mock_log_error.call_args[0][0]
+
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.error')
+def test_map_merging_input_map_status_not_processed(mock_log_error, mock_load_image, mock_save_image):
+    stage = MapMergingStage()
+
+    input_id = uuid.uuid4()
+    processed_details = {
+        # Status is 'Failed', not 'Processed'
+        input_id.hex: {'temp_processed_file': '/fake/source.png', 'status': 'Failed', 'map_type': 'SOURCE_MAP'}
+    }
+    
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=input_id, source_channel=0, target_channel=0)
+    ]
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=1)
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="TestNotProcessed", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Failed'
+    assert 'error_message' in details
+    assert f"Input map FileRule ID {input_id.hex} not found in processed_maps_details or not successfully processed" in details['error_message']
+    
+    mock_log_error.assert_called_once()
+    assert f"Failed to merge map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'" in mock_log_error.call_args[0][0]
+    assert f"Input map FileRule ID {input_id.hex} not found in processed_maps_details or not successfully processed" in mock_log_error.call_args[0][0]
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.error')
+def test_map_merging_load_image_fails(mock_log_error, mock_load_image, mock_save_image):
+    stage = MapMergingStage()
+
+    input_id = uuid.uuid4()
+    processed_details = {
+        input_id.hex: {'temp_processed_file': '/fake/source.png', 'status': 'Processed', 'map_type': 'SOURCE_MAP'}
+    }
+    
+    # Configure mock_load_image to raise an exception
+    mock_load_image.side_effect = Exception("Failed to load image")
+
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=input_id, source_channel=0, target_channel=0)
+    ]
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=1)
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="TestLoadFail", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(Path('/fake/source.png'))
+    mock_save_image.assert_not_called()
+    
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Failed'
+    assert 'error_message' in details
+    assert "Failed to load image for merge input" in details['error_message']
+    assert str(Path('/fake/source.png')) in details['error_message']
+    
+    mock_log_error.assert_called_once()
+    assert f"Failed to merge map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'" in mock_log_error.call_args[0][0]
+    assert "Failed to load image for merge input" in mock_log_error.call_args[0][0]
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.error')
+def test_map_merging_save_image_fails(mock_log_error, mock_load_image, mock_save_image):
+    stage = MapMergingStage()
+
+    input_id = uuid.uuid4()
+    processed_details = {
+        input_id.hex: {'temp_processed_file': '/fake/source.png', 'status': 'Processed', 'map_type': 'SOURCE_MAP'}
+    }
+    mock_source_data = np.full((10, 10), 128, dtype=np.uint8)
+    mock_load_image.return_value = mock_source_data
+    
+    # Configure mock_save_image to return False (indicating failure)
+    mock_save_image.return_value = False
+
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=input_id, source_channel=0, target_channel=0)
+    ]
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=1)
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="TestSaveFail", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(Path('/fake/source.png'))
+    mock_save_image.assert_called_once() # save_image is called, but returns False
+    
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Failed'
+    assert 'error_message' in details
+    assert "Failed to save merged map" in details['error_message']
+    
+    mock_log_error.assert_called_once()
+    assert f"Failed to merge map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'" in mock_log_error.call_args[0][0]
+    assert "Failed to save merged map" in mock_log_error.call_args[0][0]
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_map_merging_dimension_mismatch_handling(mock_log_error, mock_log_info, mock_load_image, mock_resize_image, mock_save_image):
+    stage = MapMergingStage()
+
+    # Input FileRules
+    id1, id2 = uuid.uuid4(), uuid.uuid4()
+    processed_details = {
+        id1.hex: {'temp_processed_file': '/fake/img1.png', 'status': 'Processed', 'map_type': 'IMG1_SRC'},
+        id2.hex: {'temp_processed_file': '/fake/img2.png', 'status': 'Processed', 'map_type': 'IMG2_SRC'}
+    }
+    
+    # Mock loaded image data with different dimensions
+    mock_img1_data = np.full((10, 10), 100, dtype=np.uint8) # 10x10
+    mock_img2_data_original = np.full((5, 5), 200, dtype=np.uint8) # 5x5, will be resized
+    
+    mock_load_image.side_effect = [mock_img1_data, mock_img2_data_original]
+
+    # Mock resize_image to return an image of the target dimensions
+    # For simplicity, it just creates a new array of the target size filled with a value.
+    mock_img2_data_resized = np.full((10, 10), 210, dtype=np.uint8) # Resized to 10x10
+    mock_resize_image.return_value = mock_img2_data_resized
+
+    # Merge Rule setup: two inputs, one output channel (e.g., averaging them)
+    # Target channel 0 for both, the stage should handle combining them if they map to the same target.
+    # However, the current stage logic for multiple inputs to the same target channel is to take the last one.
+    # Let's make them target different channels for a clearer test of resize.
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=id1, source_channel=0, target_channel=0),
+        create_mock_merge_input_channel(file_rule_id=id2, source_channel=0, target_channel=1) 
+    ]
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=2) # Outputting 2 channels
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="ResizedMerge", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    mock_save_image.return_value = True
+    
+    updated_context = stage.execute(context)
+
+    assert mock_load_image.call_count == 2
+    mock_load_image.assert_any_call(Path('/fake/img1.png'))
+    mock_load_image.assert_any_call(Path('/fake/img2.png'))
+
+    # Assert resize_image was called for the second image to match the first's dimensions
+    mock_resize_image.assert_called_once()
+    # The first argument to resize_image is the image data, second is target_shape tuple (height, width)
+    # np.array_equal is needed for comparing numpy arrays in mock calls
+    assert np.array_equal(mock_resize_image.call_args[0][0], mock_img2_data_original)
+    assert mock_resize_image.call_args[0][1] == (10, 10) 
+
+    mock_save_image.assert_called_once()
+    
+    saved_data = mock_save_image.call_args[0][1]
+    assert saved_data.shape == (10, 10, 2) # 2 output channels
+    assert np.all(saved_data[:,:,0] == mock_img1_data)     # First channel from img1
+    assert np.all(saved_data[:,:,1] == mock_img2_data_resized) # Second channel from resized img2
+
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Processed'
+    assert "merged_ResizedMerge" in details['temp_merged_file']
+    mock_log_error.assert_not_called()
+    mock_log_info.assert_any_call(f"Resized input map from {Path('/fake/img2.png')} from {mock_img2_data_original.shape} to {(10,10)} to match first loaded map.")
+    mock_log_info.assert_any_call(f"Successfully merged map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'.")
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.resize_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_map_merging_to_grayscale_output(mock_log_error, mock_log_info, mock_load_image, mock_resize_image, mock_save_image):
+    stage = MapMergingStage()
+
+    # Input FileRule (e.g., an RGB image)
+    input_id = uuid.uuid4()
+    processed_details = {
+        input_id.hex: {'temp_processed_file': '/fake/rgb_source.png', 'status': 'Processed', 'map_type': 'RGB_SRC'}
+    }
+    # Mock loaded image data (3 channels)
+    mock_rgb_data = np.full((10, 10, 3), [50, 100, 150], dtype=np.uint8)
+    mock_load_image.return_value = mock_rgb_data
+
+    # Merge Rule setup: take the Green channel (source_channel=1) from input and map it to the single output channel (target_channel=0)
+    merge_inputs = [
+        create_mock_merge_input_channel(file_rule_id=input_id, source_channel=1, target_channel=0) # G to Grayscale
+    ]
+    # output_channels = 1 for grayscale
+    merge_settings = create_mock_merge_settings(input_maps=merge_inputs, output_channels=1) 
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="GrayscaleFromGreen", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    mock_save_image.return_value = True
+    
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(Path('/fake/rgb_source.png'))
+    mock_resize_image.assert_not_called() 
+    mock_save_image.assert_called_once()
+    
+    saved_data = mock_save_image.call_args[0][1]
+    assert saved_data.shape == (10, 10) # Grayscale output (2D)
+    assert np.all(saved_data == 100)    # Green channel's value
+
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Processed'
+    assert "merged_GrayscaleFromGreen" in details['temp_merged_file']
+    mock_log_error.assert_not_called()
+    mock_log_info.assert_any_call(f"Successfully merged map '{merge_rule.map_type}' for asset '{context.asset_rule.name}'.")
+
+@mock.patch('processing.pipeline.stages.map_merging.ipu.save_image')
+@mock.patch('processing.pipeline.stages.map_merging.ipu.load_image')
+@mock.patch('logging.error')
+def test_map_merging_default_value_if_missing_channel(mock_log_error, mock_load_image, mock_save_image):
+    stage = MapMergingStage()
+
+    input_id = uuid.uuid4()
+    processed_details = {
+        # Input is a grayscale image (1 channel)
+        input_id.hex: {'temp_processed_file': '/fake/gray_source.png', 'status': 'Processed', 'map_type': 'GRAY_SRC'}
+    }
+    mock_gray_data = np.full((10, 10), 50, dtype=np.uint8)
+    mock_load_image.return_value = mock_gray_data
+    
+    # Merge Rule: try to read source_channel 1 (which doesn't exist in grayscale)
+    # and use default_value_if_missing for target_channel 0.
+    # Also, read source_channel 0 (which exists) for target_channel 1.
+    mic1 = create_mock_merge_input_channel(file_rule_id=input_id, source_channel=1, target_channel=0)
+    mic1.default_value_if_missing = 128 # Set a specific default value
+    mic2 = create_mock_merge_input_channel(file_rule_id=input_id, source_channel=0, target_channel=1)
+
+    merge_settings = create_mock_merge_settings(input_maps=[mic1, mic2], output_channels=2)
+    merge_rule_id = uuid.uuid4()
+    merge_rule = create_mock_file_rule_for_merging(id_val=merge_rule_id, map_type="DefaultValueTest", merge_settings=merge_settings)
+    
+    context = create_map_merging_mock_context(
+        initial_file_rules=[merge_rule], 
+        initial_processed_details=processed_details
+    )
+    mock_save_image.return_value = True
+    
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(Path('/fake/gray_source.png'))
+    mock_save_image.assert_called_once()
+    
+    saved_data = mock_save_image.call_args[0][1]
+    assert saved_data.shape == (10, 10, 2)
+    assert np.all(saved_data[:,:,0] == 128) # Default value for missing source channel 1
+    assert np.all(saved_data[:,:,1] == 50)  # Value from existing source channel 0
+
+    assert merge_rule.id.hex in updated_context.merged_maps_details
+    details = updated_context.merged_maps_details[merge_rule.id.hex]
+    assert details['status'] == 'Processed'
+    mock_log_error.assert_not_called()

tests/processing/pipeline/stages/test_metadata_finalization_save.py

@@ -0,0 +1,359 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import datetime
+import json # For comparing dumped content
+import uuid
+from typing import Optional, Dict, Any
+
+from processing.pipeline.stages.metadata_finalization_save import MetadataFinalizationAndSaveStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule
+from configuration import Configuration, GeneralSettings # Added GeneralSettings as it's in the helper
+
+
+def create_metadata_save_mock_context(
+    status_flags: Optional[Dict[str, Any]] = None,
+    initial_asset_metadata: Optional[Dict[str, Any]] = None,
+    processed_details: Optional[Dict[str, Any]] = None,
+    merged_details: Optional[Dict[str, Any]] = None,
+    asset_name: str = "MetaSaveAsset",
+    output_path_pattern_val: str = "{asset_name}/metadata/{filename}",
+    # ... other common context fields ...
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.output_path_pattern = output_path_pattern_val
+    mock_asset_rule.id = uuid.uuid4() # Needed for generate_path_from_pattern if it uses it
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_source_rule.name = "MetaSaveSource"
+    
+    mock_config = mock.MagicMock(spec=Configuration)
+    # mock_config.general_settings = mock.MagicMock(spec=GeneralSettings) # If needed
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp_engine_dir"),
+        output_base_path=Path("/fake/output_base"), # For generate_path
+        effective_supplier="ValidSupplier",
+        asset_metadata=initial_asset_metadata if initial_asset_metadata is not None else {},
+        processed_maps_details=processed_details if processed_details is not None else {},
+        merged_maps_details=merged_details if merged_details is not None else {},
+        files_to_process=[],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags=status_flags if status_flags is not None else {},
+        incrementing_value="001", # Example for path generation
+        sha5_value="abc"      # Example for path generation
+    )
+    return context
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.json.dump')
+@mock.patch('builtins.open', new_callable=mock.mock_open)
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.generate_path_from_pattern')
+@mock.patch('datetime.datetime')
+def test_asset_skipped_before_metadata_init(
+    mock_dt, mock_gen_path, mock_mkdir, mock_file_open, mock_json_dump
+):
+    """
+    Tests that if an asset is marked for skipping and has no initial metadata,
+    the stage returns early without attempting to save metadata.
+    """
+    stage = MetadataFinalizationAndSaveStage()
+    context = create_metadata_save_mock_context(
+        status_flags={'skip_asset': True},
+        initial_asset_metadata={} # Explicitly empty
+    )
+
+    updated_context = stage.execute(context)
+
+    # Assert that no processing or saving attempts were made
+    mock_dt.now.assert_not_called() # Should not even try to set end time if no metadata
+    mock_gen_path.assert_not_called()
+    mock_mkdir.assert_not_called()
+    mock_file_open.assert_not_called()
+    mock_json_dump.assert_not_called()
+
+    assert updated_context.asset_metadata == {} # Metadata remains empty
+    assert 'metadata_file_path' not in updated_context.asset_metadata
+    assert updated_context.status_flags.get('metadata_save_error') is None
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.json.dump')
+@mock.patch('builtins.open', new_callable=mock.mock_open)
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.generate_path_from_pattern')
+@mock.patch('datetime.datetime')
+def test_asset_skipped_after_metadata_init(
+    mock_dt, mock_gen_path, mock_mkdir, mock_file_open, mock_json_dump
+):
+    """
+    Tests that if an asset is marked for skipping but has initial metadata,
+    the status is updated to 'Skipped' and metadata is saved.
+    """
+    stage = MetadataFinalizationAndSaveStage()
+    
+    fixed_now = datetime.datetime(2023, 1, 1, 12, 0, 0)
+    mock_dt.now.return_value = fixed_now
+    
+    fake_metadata_path_str = "/fake/output_base/SkippedAsset/metadata/SkippedAsset_metadata.json"
+    mock_gen_path.return_value = fake_metadata_path_str
+    
+    initial_meta = {'asset_name': "SkippedAsset", 'status': "Pending"}
+    
+    context = create_metadata_save_mock_context(
+        asset_name="SkippedAsset",
+        status_flags={'skip_asset': True},
+        initial_asset_metadata=initial_meta
+    )
+    
+    updated_context = stage.execute(context)
+    
+    mock_dt.now.assert_called_once()
+    mock_gen_path.assert_called_once_with(
+        context.asset_rule.output_path_pattern,
+        context.asset_rule,
+        context.source_rule,
+        context.output_base_path,
+        context.asset_metadata, # Original metadata passed for path gen
+        context.incrementing_value,
+        context.sha5_value,
+        filename_override=f"{context.asset_rule.name}_metadata.json"
+    )
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    mock_file_open.assert_called_once_with(Path(fake_metadata_path_str), 'w')
+    mock_json_dump.assert_called_once()
+    
+    dumped_data = mock_json_dump.call_args[0][0]
+    assert dumped_data['status'] == "Skipped"
+    assert dumped_data['processing_end_time'] == fixed_now.isoformat()
+    assert 'processed_map_details' not in dumped_data # Should not be present if skipped early
+    assert 'merged_map_details' not in dumped_data   # Should not be present if skipped early
+    
+    assert updated_context.asset_metadata['status'] == "Skipped"
+    assert updated_context.asset_metadata['processing_end_time'] == fixed_now.isoformat()
+    assert updated_context.asset_metadata['metadata_file_path'] == fake_metadata_path_str
+    assert updated_context.status_flags.get('metadata_save_error') is None
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.json.dump')
+@mock.patch('builtins.open', new_callable=mock.mock_open) # Mocks open()
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.generate_path_from_pattern')
+@mock.patch('datetime.datetime')
+def test_metadata_save_success(mock_dt, mock_gen_path, mock_mkdir, mock_file_open, mock_json_dump):
+    """
+    Tests successful metadata finalization and saving, including serialization of Path objects.
+    """
+    stage = MetadataFinalizationAndSaveStage()
+    
+    fixed_now = datetime.datetime(2023, 1, 1, 12, 30, 0)
+    mock_dt.now.return_value = fixed_now
+    
+    fake_metadata_path_str = "/fake/output_base/MetaSaveAsset/metadata/MetaSaveAsset_metadata.json"
+    mock_gen_path.return_value = fake_metadata_path_str
+    
+    initial_meta = {'asset_name': "MetaSaveAsset", 'status': "Pending", 'processing_start_time': "2023-01-01T12:00:00"}
+    # Example of a Path object that needs serialization
+    proc_details = {'map1': {'temp_processed_file': Path('/fake/temp_engine_dir/map1.png'), 'final_file_path': Path('/fake/output_base/MetaSaveAsset/map1.png')}} 
+    merged_details = {'merged_map_A': {'output_path': Path('/fake/output_base/MetaSaveAsset/merged_A.png')}}
+    
+    context = create_metadata_save_mock_context(
+        initial_asset_metadata=initial_meta,
+        processed_details=proc_details,
+        merged_details=merged_details,
+        status_flags={} # No errors, no skip
+    )
+    
+    updated_context = stage.execute(context)
+    
+    mock_dt.now.assert_called_once()
+    mock_gen_path.assert_called_once_with(
+        context.asset_rule.output_path_pattern,
+        context.asset_rule,
+        context.source_rule,
+        context.output_base_path,
+        context.asset_metadata, # The metadata *before* adding end_time, status etc.
+        context.incrementing_value,
+        context.sha5_value,
+        filename_override=f"{context.asset_rule.name}_metadata.json"
+    )
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True) # Checks parent dir of fake_metadata_path_str
+    mock_file_open.assert_called_once_with(Path(fake_metadata_path_str), 'w')
+    mock_json_dump.assert_called_once()
+    
+    # Check what was passed to json.dump
+    dumped_data = mock_json_dump.call_args[0][0]
+    assert dumped_data['status'] == "Processed"
+    assert dumped_data['processing_end_time'] == fixed_now.isoformat()
+    assert 'processing_start_time' in dumped_data # Ensure existing fields are preserved
+
+    # Verify processed_map_details and Path serialization
+    assert 'processed_map_details' in dumped_data
+    assert dumped_data['processed_map_details']['map1']['temp_processed_file'] == '/fake/temp_engine_dir/map1.png'
+    assert dumped_data['processed_map_details']['map1']['final_file_path'] == '/fake/output_base/MetaSaveAsset/map1.png'
+
+    # Verify merged_map_details and Path serialization
+    assert 'merged_map_details' in dumped_data
+    assert dumped_data['merged_map_details']['merged_map_A']['output_path'] == '/fake/output_base/MetaSaveAsset/merged_A.png'
+            
+    assert updated_context.asset_metadata['metadata_file_path'] == fake_metadata_path_str
+    assert updated_context.asset_metadata['status'] == "Processed"
+    assert updated_context.status_flags.get('metadata_save_error') is None
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.json.dump')
+@mock.patch('builtins.open', new_callable=mock.mock_open)
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.generate_path_from_pattern')
+@mock.patch('datetime.datetime')
+def test_processing_failed_due_to_previous_error(
+    mock_dt, mock_gen_path, mock_mkdir, mock_file_open, mock_json_dump
+):
+    """
+    Tests that if a previous stage set an error flag, the status is 'Failed'
+    and metadata (including any existing details) is saved.
+    """
+    stage = MetadataFinalizationAndSaveStage()
+    
+    fixed_now = datetime.datetime(2023, 1, 1, 12, 45, 0)
+    mock_dt.now.return_value = fixed_now
+    
+    fake_metadata_path_str = "/fake/output_base/FailedAsset/metadata/FailedAsset_metadata.json"
+    mock_gen_path.return_value = fake_metadata_path_str
+    
+    initial_meta = {'asset_name': "FailedAsset", 'status': "Processing"}
+    # Simulate some details might exist even if a later stage failed
+    proc_details = {'map1_partial': {'temp_processed_file': Path('/fake/temp_engine_dir/map1_partial.png')}}
+    
+    context = create_metadata_save_mock_context(
+        asset_name="FailedAsset",
+        initial_asset_metadata=initial_meta,
+        processed_details=proc_details,
+        merged_details={}, # No merged details if processing failed before that
+        status_flags={'file_processing_error': True, 'error_message': "Something went wrong"}
+    )
+    
+    updated_context = stage.execute(context)
+    
+    mock_dt.now.assert_called_once()
+    mock_gen_path.assert_called_once() # Path generation should still occur
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    mock_file_open.assert_called_once_with(Path(fake_metadata_path_str), 'w')
+    mock_json_dump.assert_called_once()
+    
+    dumped_data = mock_json_dump.call_args[0][0]
+    assert dumped_data['status'] == "Failed"
+    assert dumped_data['processing_end_time'] == fixed_now.isoformat()
+    assert 'error_message' in dumped_data # Assuming error messages from status_flags are copied
+    assert dumped_data['error_message'] == "Something went wrong"
+
+    # Check that existing details are included
+    assert 'processed_map_details' in dumped_data
+    assert dumped_data['processed_map_details']['map1_partial']['temp_processed_file'] == '/fake/temp_engine_dir/map1_partial.png'
+    assert 'merged_map_details' in dumped_data # Should be present, even if empty
+    assert dumped_data['merged_map_details'] == {}
+            
+    assert updated_context.asset_metadata['status'] == "Failed"
+    assert updated_context.asset_metadata['metadata_file_path'] == fake_metadata_path_str
+    assert updated_context.status_flags.get('metadata_save_error') is None
+    # Ensure the original error flag is preserved
+    assert updated_context.status_flags['file_processing_error'] is True
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.json.dump')
+@mock.patch('builtins.open', new_callable=mock.mock_open)
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.generate_path_from_pattern')
+@mock.patch('datetime.datetime')
+@mock.patch('logging.error') # To check if error is logged
+def test_generate_path_fails(
+    mock_log_error, mock_dt, mock_gen_path, mock_mkdir, mock_file_open, mock_json_dump
+):
+    """
+    Tests behavior when generate_path_from_pattern raises an exception.
+    Ensures status is updated, error flag is set, and no save is attempted.
+    """
+    stage = MetadataFinalizationAndSaveStage()
+    
+    fixed_now = datetime.datetime(2023, 1, 1, 12, 50, 0)
+    mock_dt.now.return_value = fixed_now
+    
+    mock_gen_path.side_effect = Exception("Simulated path generation error")
+    
+    initial_meta = {'asset_name': "PathFailAsset", 'status': "Processing"}
+    context = create_metadata_save_mock_context(
+        asset_name="PathFailAsset",
+        initial_asset_metadata=initial_meta,
+        status_flags={} 
+    )
+    
+    updated_context = stage.execute(context)
+    
+    mock_dt.now.assert_called_once() # Time is set before path generation
+    mock_gen_path.assert_called_once() # generate_path_from_pattern is called
+    
+    # File operations should NOT be called if path generation fails
+    mock_mkdir.assert_not_called()
+    mock_file_open.assert_not_called()
+    mock_json_dump.assert_not_called()
+    
+    mock_log_error.assert_called_once() # Check that an error was logged
+    # Example: check if the log message contains relevant info, if needed
+    # assert "Failed to generate metadata path" in mock_log_error.call_args[0][0]
+
+    assert updated_context.asset_metadata['status'] == "Failed" # Or a more specific error status
+    assert 'processing_end_time' in updated_context.asset_metadata # End time should still be set
+    assert updated_context.asset_metadata['processing_end_time'] == fixed_now.isoformat()
+    assert 'metadata_file_path' not in updated_context.asset_metadata # Path should not be set
+    
+    assert updated_context.status_flags.get('metadata_save_error') is True
+    assert 'error_message' in updated_context.asset_metadata # Check if error message is populated
+    assert "Simulated path generation error" in updated_context.asset_metadata['error_message']
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.json.dump')
+@mock.patch('builtins.open', new_callable=mock.mock_open)
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('processing.pipeline.stages.metadata_finalization_save.generate_path_from_pattern')
+@mock.patch('datetime.datetime')
+@mock.patch('logging.error') # To check if error is logged
+def test_json_dump_fails(
+    mock_log_error, mock_dt, mock_gen_path, mock_mkdir, mock_file_open, mock_json_dump
+):
+    """
+    Tests behavior when json.dump raises an exception during saving.
+    Ensures status is updated, error flag is set, and error is logged.
+    """
+    stage = MetadataFinalizationAndSaveStage()
+    
+    fixed_now = datetime.datetime(2023, 1, 1, 12, 55, 0)
+    mock_dt.now.return_value = fixed_now
+    
+    fake_metadata_path_str = "/fake/output_base/JsonDumpFailAsset/metadata/JsonDumpFailAsset_metadata.json"
+    mock_gen_path.return_value = fake_metadata_path_str
+    
+    mock_json_dump.side_effect = IOError("Simulated JSON dump error") # Or TypeError for non-serializable
+    
+    initial_meta = {'asset_name': "JsonDumpFailAsset", 'status': "Processing"}
+    context = create_metadata_save_mock_context(
+        asset_name="JsonDumpFailAsset",
+        initial_asset_metadata=initial_meta,
+        status_flags={}
+    )
+    
+    updated_context = stage.execute(context)
+    
+    mock_dt.now.assert_called_once()
+    mock_gen_path.assert_called_once()
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    mock_file_open.assert_called_once_with(Path(fake_metadata_path_str), 'w')
+    mock_json_dump.assert_called_once() # json.dump was attempted
+    
+    mock_log_error.assert_called_once()
+    # assert "Failed to save metadata JSON" in mock_log_error.call_args[0][0]
+
+    assert updated_context.asset_metadata['status'] == "Failed" # Or specific "Metadata Save Failed"
+    assert 'processing_end_time' in updated_context.asset_metadata
+    assert updated_context.asset_metadata['processing_end_time'] == fixed_now.isoformat()
+    # metadata_file_path might be set if path generation succeeded, even if dump failed.
+    # Depending on desired behavior, this could be asserted or not.
+    # For now, let's assume it's set if path generation was successful.
+    assert updated_context.asset_metadata['metadata_file_path'] == fake_metadata_path_str 
+                                                                    
+    assert updated_context.status_flags.get('metadata_save_error') is True
+    assert 'error_message' in updated_context.asset_metadata
+    assert "Simulated JSON dump error" in updated_context.asset_metadata['error_message']

tests/processing/pipeline/stages/test_metadata_initialization.py

@@ -0,0 +1,169 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import datetime
+import uuid
+from typing import Optional
+
+from processing.pipeline.stages.metadata_initialization import MetadataInitializationStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule
+from configuration import Configuration, GeneralSettings
+
+# Helper function to create a mock AssetProcessingContext
+def create_metadata_init_mock_context(
+    skip_asset_flag: bool = False,
+    asset_name: str = "MetaAsset",
+    asset_id: uuid.UUID = None, # Allow None to default to uuid.uuid4()
+    source_path_str: str = "source/meta_asset",
+    output_pattern: str = "{asset_name}/{map_type}",
+    tags: list = None,
+    custom_fields: dict = None,
+    source_rule_name: str = "MetaSource",
+    source_rule_id: uuid.UUID = None, # Allow None to default to uuid.uuid4()
+    eff_supplier: Optional[str] = "SupplierMeta",
+    app_version_str: str = "1.0.0-test",
+    inc_val: Optional[str] = None,
+    sha_val: Optional[str] = None
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.id = asset_id if asset_id is not None else uuid.uuid4()
+    mock_asset_rule.source_path = Path(source_path_str)
+    mock_asset_rule.output_path_pattern = output_pattern
+    mock_asset_rule.tags = tags if tags is not None else ["tag1", "test_tag"]
+    mock_asset_rule.custom_fields = custom_fields if custom_fields is not None else {"custom_key": "custom_value"}
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_source_rule.name = source_rule_name
+    mock_source_rule.id = source_rule_id if source_rule_id is not None else uuid.uuid4()
+    
+    mock_general_settings = mock.MagicMock(spec=GeneralSettings)
+    mock_general_settings.app_version = app_version_str
+    
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.general_settings = mock_general_settings
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier=eff_supplier,
+        asset_metadata={},
+        processed_maps_details={},
+        merged_maps_details={},
+        files_to_process=[],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={'skip_asset': skip_asset_flag},
+        incrementing_value=inc_val,
+        sha5_value=sha_val
+    )
+    return context
+
+@mock.patch('processing.pipeline.stages.metadata_initialization.datetime')
+def test_metadata_initialization_not_skipped(mock_datetime_module):
+    stage = MetadataInitializationStage()
+    
+    fixed_now = datetime.datetime(2023, 10, 26, 12, 0, 0, tzinfo=datetime.timezone.utc)
+    mock_datetime_module.datetime.now.return_value = fixed_now
+    
+    asset_id_val = uuid.uuid4()
+    source_id_val = uuid.uuid4()
+    
+    context = create_metadata_init_mock_context(
+        skip_asset_flag=False,
+        asset_id=asset_id_val,
+        source_rule_id=source_id_val,
+        inc_val="001",
+        sha_val="abcde"
+    )
+    
+    updated_context = stage.execute(context)
+    
+    assert isinstance(updated_context.asset_metadata, dict)
+    assert isinstance(updated_context.processed_maps_details, dict)
+    assert isinstance(updated_context.merged_maps_details, dict)
+    
+    md = updated_context.asset_metadata
+    assert md['asset_name'] == "MetaAsset"
+    assert md['asset_id'] == str(asset_id_val)
+    assert md['source_rule_name'] == "MetaSource"
+    assert md['source_rule_id'] == str(source_id_val)
+    assert md['source_path'] == "source/meta_asset"
+    assert md['effective_supplier'] == "SupplierMeta"
+    assert md['output_path_pattern'] == "{asset_name}/{map_type}"
+    assert md['processing_start_time'] == fixed_now.isoformat()
+    assert md['status'] == "Pending"
+    assert md['version'] == "1.0.0-test"
+    assert md['tags'] == ["tag1", "test_tag"]
+    assert md['custom_fields'] == {"custom_key": "custom_value"}
+    assert md['incrementing_value'] == "001"
+    assert md['sha5_value'] == "abcde"
+
+@mock.patch('processing.pipeline.stages.metadata_initialization.datetime')
+def test_metadata_initialization_not_skipped_none_inc_sha(mock_datetime_module):
+    stage = MetadataInitializationStage()
+    
+    fixed_now = datetime.datetime(2023, 10, 26, 12, 0, 0, tzinfo=datetime.timezone.utc)
+    mock_datetime_module.datetime.now.return_value = fixed_now
+    
+    context = create_metadata_init_mock_context(
+        skip_asset_flag=False,
+        inc_val=None,
+        sha_val=None
+    )
+    
+    updated_context = stage.execute(context)
+    
+    md = updated_context.asset_metadata
+    assert 'incrementing_value' not in md # Or assert md['incrementing_value'] is None, depending on desired behavior
+    assert 'sha5_value' not in md # Or assert md['sha5_value'] is None
+
+def test_metadata_initialization_skipped():
+    stage = MetadataInitializationStage()
+    context = create_metadata_init_mock_context(skip_asset_flag=True)
+    
+    # Make copies of initial state to ensure they are not modified
+    initial_asset_metadata = dict(context.asset_metadata)
+    initial_processed_maps = dict(context.processed_maps_details)
+    initial_merged_maps = dict(context.merged_maps_details)
+            
+    updated_context = stage.execute(context)
+    
+    assert updated_context.asset_metadata == initial_asset_metadata
+    assert updated_context.processed_maps_details == initial_processed_maps
+    assert updated_context.merged_maps_details == initial_merged_maps
+    assert not updated_context.asset_metadata # Explicitly check it's empty as per initial setup
+    assert not updated_context.processed_maps_details
+    assert not updated_context.merged_maps_details
+
+@mock.patch('processing.pipeline.stages.metadata_initialization.datetime')
+def test_tags_and_custom_fields_are_copies(mock_datetime_module):
+    stage = MetadataInitializationStage()
+    fixed_now = datetime.datetime(2023, 10, 26, 12, 0, 0, tzinfo=datetime.timezone.utc)
+    mock_datetime_module.datetime.now.return_value = fixed_now
+
+    original_tags = ["original_tag"]
+    original_custom_fields = {"original_key": "original_value"}
+
+    context = create_metadata_init_mock_context(
+        skip_asset_flag=False,
+        tags=original_tags,
+        custom_fields=original_custom_fields
+    )
+
+    # Modify originals after context creation but before stage execution
+    original_tags.append("modified_after_creation")
+    original_custom_fields["new_key_after_creation"] = "new_value"
+
+    updated_context = stage.execute(context)
+
+    md = updated_context.asset_metadata
+    assert md['tags'] == ["original_tag"] # Should not have "modified_after_creation"
+    assert md['tags'] is not original_tags # Ensure it's a different object
+
+    assert md['custom_fields'] == {"original_key": "original_value"} # Should not have "new_key_after_creation"
+    assert md['custom_fields'] is not original_custom_fields # Ensure it's a different object

tests/processing/pipeline/stages/test_normal_map_green_channel.py

@@ -0,0 +1,323 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import uuid
+import numpy as np
+import logging # Added for mocking logger
+
+from processing.pipeline.stages.normal_map_green_channel import NormalMapGreenChannelStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule
+from configuration import Configuration, GeneralSettings
+
+# Helper functions
+def create_mock_file_rule_for_normal_test(
+    id_val: uuid.UUID = None, # Corrected type hint from Optional[uuid.UUID]
+    map_type: str = "NORMAL", 
+    filename_pattern: str = "normal.png"
+) -> mock.MagicMock:
+    mock_fr = mock.MagicMock(spec=FileRule)
+    mock_fr.id = id_val if id_val else uuid.uuid4()
+    mock_fr.map_type = map_type
+    mock_fr.filename_pattern = filename_pattern
+    mock_fr.item_type = "MAP_COL" # As per example, though not directly used by stage
+    mock_fr.active = True # As per example
+    return mock_fr
+
+def create_normal_map_mock_context(
+    initial_file_rules: list = None, # Corrected type hint
+    initial_processed_details: dict = None, # Corrected type hint
+    invert_green_globally: bool = False,
+    skip_asset_flag: bool = False,
+    asset_name: str = "NormalMapAsset"
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    
+    mock_gs = mock.MagicMock(spec=GeneralSettings)
+    mock_gs.invert_normal_map_green_channel_globally = invert_green_globally 
+    
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.general_settings = mock_gs
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp_engine_dir"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier="ValidSupplier",
+        asset_metadata={'asset_name': asset_name},
+        processed_maps_details=initial_processed_details if initial_processed_details is not None else {},
+        merged_maps_details={},
+        files_to_process=list(initial_file_rules) if initial_file_rules else [],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={'skip_asset': skip_asset_flag},
+        incrementing_value=None, # Added as per AssetProcessingContext constructor
+        sha5_value=None # Added as per AssetProcessingContext constructor
+    )
+    return context
+
+# Unit tests will be added below
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+def test_asset_skipped(mock_load_image, mock_save_image):
+    stage = NormalMapGreenChannelStage()
+    normal_fr = create_mock_file_rule_for_normal_test(map_type="NORMAL")
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_normal.png', 'status': 'Processed', 'map_type': 'NORMAL', 'notes': ''}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=True,
+        skip_asset_flag=True # Asset is skipped
+    )
+    original_details = context.processed_maps_details.copy()
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    assert updated_context.processed_maps_details == original_details
+    assert normal_fr in updated_context.files_to_process # Ensure rule is still there
+
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+def test_no_normal_map_present(mock_load_image, mock_save_image):
+    stage = NormalMapGreenChannelStage()
+    # Create a non-normal map rule
+    diffuse_fr = create_mock_file_rule_for_normal_test(map_type="DIFFUSE", filename_pattern="diffuse.png")
+    initial_details = {
+        diffuse_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_diffuse.png', 'status': 'Processed', 'map_type': 'DIFFUSE', 'notes': ''}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[diffuse_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=True # Inversion enabled, but no normal map
+    )
+    original_details = context.processed_maps_details.copy()
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    assert updated_context.processed_maps_details == original_details
+    assert diffuse_fr in updated_context.files_to_process
+
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+def test_normal_map_present_inversion_disabled(mock_load_image, mock_save_image):
+    stage = NormalMapGreenChannelStage()
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_normal_test(id_val=normal_rule_id, map_type="NORMAL")
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': '/fake/temp_engine_dir/processed_normal.png', 'status': 'Processed', 'map_type': 'NORMAL', 'notes': 'Initial note'}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=False # Inversion disabled
+    )
+    original_details_entry = context.processed_maps_details[normal_fr.id.hex].copy()
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_not_called()
+    mock_save_image.assert_not_called()
+    assert updated_context.processed_maps_details[normal_fr.id.hex] == original_details_entry
+    assert normal_fr in updated_context.files_to_process
+
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_normal_map_inversion_uint8_success(mock_log_debug, mock_log_info, mock_load_image, mock_save_image):
+    stage = NormalMapGreenChannelStage()
+    
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_normal_test(id_val=normal_rule_id, map_type="NORMAL")
+    
+    initial_temp_path = Path('/fake/temp_engine_dir/processed_normal.png')
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': str(initial_temp_path), 'status': 'Processed', 'map_type': 'NORMAL', 'notes': 'Initial note'}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=True # Enable inversion
+    )
+
+    # R=10, G=50, B=100
+    mock_loaded_normal_data = np.array([[[10, 50, 100]]], dtype=np.uint8) 
+    mock_load_image.return_value = mock_loaded_normal_data
+    mock_save_image.return_value = True # Simulate successful save
+    
+    updated_context = stage.execute(context)
+    
+    mock_load_image.assert_called_once_with(initial_temp_path)
+    
+    # Check that save_image was called with green channel inverted
+    assert mock_save_image.call_count == 1
+    saved_path_arg, saved_data_arg = mock_save_image.call_args[0]
+    
+    assert saved_data_arg[0,0,0] == 10 # R unchanged
+    assert saved_data_arg[0,0,1] == 255 - 50 # G inverted
+    assert saved_data_arg[0,0,2] == 100 # B unchanged
+    
+    assert isinstance(saved_path_arg, Path)
+    assert "normal_g_inv_" in saved_path_arg.name
+    assert saved_path_arg.parent == initial_temp_path.parent # Should be in same temp dir
+
+    normal_detail = updated_context.processed_maps_details[normal_fr.id.hex]
+    assert "normal_g_inv_" in normal_detail['temp_processed_file']
+    assert Path(normal_detail['temp_processed_file']).name == saved_path_arg.name
+    assert "Green channel inverted" in normal_detail['notes']
+    assert "Initial note" in normal_detail['notes'] # Check existing notes preserved
+    
+    assert normal_fr in updated_context.files_to_process
+
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+@mock.patch('logging.info')
+@mock.patch('logging.debug')
+def test_normal_map_inversion_float_success(mock_log_debug, mock_log_info, mock_load_image, mock_save_image):
+    stage = NormalMapGreenChannelStage()
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_normal_test(id_val=normal_rule_id, map_type="NORMAL")
+    initial_temp_path = Path('/fake/temp_engine_dir/processed_normal_float.png')
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': str(initial_temp_path), 'status': 'Processed', 'map_type': 'NORMAL', 'notes': 'Float image'}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=True
+    )
+
+    # R=0.1, G=0.25, B=0.75
+    mock_loaded_normal_data = np.array([[[0.1, 0.25, 0.75]]], dtype=np.float32)
+    mock_load_image.return_value = mock_loaded_normal_data
+    mock_save_image.return_value = True
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(initial_temp_path)
+    
+    assert mock_save_image.call_count == 1
+    saved_path_arg, saved_data_arg = mock_save_image.call_args[0]
+
+    assert np.isclose(saved_data_arg[0,0,0], 0.1) # R unchanged
+    assert np.isclose(saved_data_arg[0,0,1], 1.0 - 0.25) # G inverted
+    assert np.isclose(saved_data_arg[0,0,2], 0.75) # B unchanged
+    
+    assert "normal_g_inv_" in saved_path_arg.name
+    normal_detail = updated_context.processed_maps_details[normal_fr.id.hex]
+    assert "normal_g_inv_" in normal_detail['temp_processed_file']
+    assert "Green channel inverted" in normal_detail['notes']
+    assert "Float image" in normal_detail['notes']
+    assert normal_fr in updated_context.files_to_process
+
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+@mock.patch('logging.error')
+def test_load_image_fails(mock_log_error, mock_load_image, mock_save_image):
+    stage = NormalMapGreenChannelStage()
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_normal_test(id_val=normal_rule_id, map_type="NORMAL")
+    initial_temp_path_str = '/fake/temp_engine_dir/processed_normal_load_fail.png'
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': initial_temp_path_str, 'status': 'Processed', 'map_type': 'NORMAL', 'notes': 'Load fail test'}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=True
+    )
+    original_details_entry = context.processed_maps_details[normal_fr.id.hex].copy()
+
+    mock_load_image.return_value = None # Simulate load failure
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(Path(initial_temp_path_str))
+    mock_save_image.assert_not_called()
+    mock_log_error.assert_called_once()
+    assert f"Failed to load image {Path(initial_temp_path_str)} for green channel inversion." in mock_log_error.call_args[0][0]
+    
+    # Details should be unchanged
+    assert updated_context.processed_maps_details[normal_fr.id.hex] == original_details_entry
+    assert normal_fr in updated_context.files_to_process
+
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+@mock.patch('logging.error')
+def test_save_image_fails(mock_log_error, mock_load_image, mock_save_image):
+    stage = NormalMapGreenChannelStage()
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_normal_test(id_val=normal_rule_id, map_type="NORMAL")
+    initial_temp_path = Path('/fake/temp_engine_dir/processed_normal_save_fail.png')
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': str(initial_temp_path), 'status': 'Processed', 'map_type': 'NORMAL', 'notes': 'Save fail test'}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=True
+    )
+    original_details_entry = context.processed_maps_details[normal_fr.id.hex].copy()
+
+    mock_loaded_normal_data = np.array([[[10, 50, 100]]], dtype=np.uint8)
+    mock_load_image.return_value = mock_loaded_normal_data
+    mock_save_image.return_value = False # Simulate save failure
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(initial_temp_path)
+    mock_save_image.assert_called_once() # Save is attempted
+    
+    saved_path_arg = mock_save_image.call_args[0][0] # Get the path it tried to save to
+    mock_log_error.assert_called_once()
+    assert f"Failed to save green channel inverted image to {saved_path_arg}." in mock_log_error.call_args[0][0]
+    
+    # Details should be unchanged
+    assert updated_context.processed_maps_details[normal_fr.id.hex] == original_details_entry
+    assert normal_fr in updated_context.files_to_process
+
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.save_image')
+@mock.patch('processing.pipeline.stages.normal_map_green_channel.ipu.load_image')
+@mock.patch('logging.error')
+@pytest.mark.parametrize("unsuitable_data, description", [
+    (np.array([[1, 2], [3, 4]], dtype=np.uint8), "2D array"), # 2D array
+    (np.array([[[1, 2]]], dtype=np.uint8), "2-channel image") # Image with less than 3 channels
+])
+def test_image_not_suitable_for_inversion(mock_log_error, mock_load_image, mock_save_image, unsuitable_data, description):
+    stage = NormalMapGreenChannelStage()
+    normal_rule_id = uuid.uuid4()
+    normal_fr = create_mock_file_rule_for_normal_test(id_val=normal_rule_id, map_type="NORMAL")
+    initial_temp_path_str = f'/fake/temp_engine_dir/unsuitable_{description.replace(" ", "_")}.png'
+    initial_details = {
+        normal_fr.id.hex: {'temp_processed_file': initial_temp_path_str, 'status': 'Processed', 'map_type': 'NORMAL', 'notes': f'Unsuitable: {description}'}
+    }
+    context = create_normal_map_mock_context(
+        initial_file_rules=[normal_fr],
+        initial_processed_details=initial_details,
+        invert_green_globally=True
+    )
+    original_details_entry = context.processed_maps_details[normal_fr.id.hex].copy()
+
+    mock_load_image.return_value = unsuitable_data
+
+    updated_context = stage.execute(context)
+
+    mock_load_image.assert_called_once_with(Path(initial_temp_path_str))
+    mock_save_image.assert_not_called() # Save should not be attempted
+    mock_log_error.assert_called_once()
+    assert f"Image at {Path(initial_temp_path_str)} is not suitable for green channel inversion (e.g., not RGB/RGBA)." in mock_log_error.call_args[0][0]
+    
+    # Details should be unchanged
+    assert updated_context.processed_maps_details[normal_fr.id.hex] == original_details_entry
+    assert normal_fr in updated_context.files_to_process

tests/processing/pipeline/stages/test_output_organization.py

@@ -0,0 +1,417 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import shutil # To check if shutil.copy2 is called
+import uuid
+from typing import Optional # Added for type hinting in helper
+
+from processing.pipeline.stages.output_organization import OutputOrganizationStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule # For context setup
+from configuration import Configuration, GeneralSettings
+
+def create_output_org_mock_context(
+    status_flags: Optional[dict] = None,
+    asset_metadata_status: str = "Processed", # Default to processed for testing copy
+    processed_map_details: Optional[dict] = None,
+    merged_map_details: Optional[dict] = None,
+    overwrite_setting: bool = False,
+    asset_name: str = "OutputOrgAsset",
+    output_path_pattern_val: str = "{asset_name}/{map_type}/{filename}"
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.output_path_pattern = output_path_pattern_val
+    # Need FileRules on AssetRule if stage tries to look up output_filename_pattern from them
+    # For simplicity, assume stage constructs output_filename for now if not found on FileRule
+    mock_asset_rule.file_rules = [] # Or mock FileRules if stage uses them for output_filename_pattern
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_source_rule.name = "OutputOrgSource"
+    
+    mock_gs = mock.MagicMock(spec=GeneralSettings)
+    mock_gs.overwrite_existing = overwrite_setting
+    
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.general_settings = mock_gs
+
+    # Ensure asset_metadata has a status
+    initial_asset_metadata = {'asset_name': asset_name, 'status': asset_metadata_status}
+
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp_engine_dir"),
+        output_base_path=Path("/fake/output_final"),
+        effective_supplier="ValidSupplier",
+        asset_metadata=initial_asset_metadata,
+        processed_maps_details=processed_map_details if processed_map_details is not None else {},
+        merged_maps_details=merged_map_details if merged_map_details is not None else {},
+        files_to_process=[], # Not directly used by this stage, but good to have
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags=status_flags if status_flags is not None else {},
+        incrementing_value="001",
+        sha5_value="xyz" # Corrected from sha5_value to sha256_value if that's the actual param, or ensure it's a valid param. Assuming sha5_value is a typo and should be something like 'unique_id' or similar if not sha256. For now, keeping as sha5_value as per instructions.
+    )
+    return context
+@mock.patch('shutil.copy2')
+@mock.patch('logging.info') # To check for log messages
+def test_output_organization_asset_skipped_by_status_flag(mock_log_info, mock_shutil_copy):
+    stage = OutputOrganizationStage()
+    context = create_output_org_mock_context(status_flags={'skip_asset': True})
+    
+    updated_context = stage.execute(context)
+    
+    mock_shutil_copy.assert_not_called()
+    # Check if a log message indicates skipping, if applicable
+    # e.g., mock_log_info.assert_any_call("Skipping output organization for asset OutputOrgAsset due to skip_asset flag.")
+    assert 'final_output_files' not in updated_context.asset_metadata # Or assert it's empty
+    assert updated_context.asset_metadata['status'] == "Processed" # Status should not change if skipped due to flag before stage logic
+    # Add specific log check if the stage logs this event
+    # For now, assume no copy is the primary check
+
+@mock.patch('shutil.copy2')
+@mock.patch('logging.warning') # Or info, depending on how failure is logged
+def test_output_organization_asset_failed_by_metadata_status(mock_log_warning, mock_shutil_copy):
+    stage = OutputOrganizationStage()
+    context = create_output_org_mock_context(asset_metadata_status="Failed")
+    
+    updated_context = stage.execute(context)
+    
+    mock_shutil_copy.assert_not_called()
+    # Check for a log message indicating skipping due to failure status
+    # e.g., mock_log_warning.assert_any_call("Skipping output organization for asset OutputOrgAsset as its status is Failed.")
+    assert 'final_output_files' not in updated_context.asset_metadata # Or assert it's empty
+    assert updated_context.asset_metadata['status'] == "Failed" # Status remains Failed
+
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_output_organization_success_no_overwrite(
+    mock_log_error, mock_log_info, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    
+    proc_id_1 = uuid.uuid4().hex
+    merged_id_1 = uuid.uuid4().hex
+    
+    processed_details = {
+        proc_id_1: {'status': 'Processed', 'temp_processed_file': '/fake/temp_engine_dir/proc1.png', 'map_type': 'Diffuse', 'output_filename': 'OutputOrgAsset_Diffuse.png'}
+    }
+    merged_details = {
+        merged_id_1: {'status': 'Processed', 'temp_merged_file': '/fake/temp_engine_dir/merged1.png', 'map_type': 'ORM', 'output_filename': 'OutputOrgAsset_ORM.png'}
+    }
+    
+    context = create_output_org_mock_context(
+        processed_map_details=processed_details,
+        merged_map_details=merged_details,
+        overwrite_setting=False
+    )
+    
+    # Mock generate_path_from_pattern to return different paths for each call
+    final_path_proc1 = Path("/fake/output_final/OutputOrgAsset/Diffuse/OutputOrgAsset_Diffuse.png")
+    final_path_merged1 = Path("/fake/output_final/OutputOrgAsset/ORM/OutputOrgAsset_ORM.png")
+    # Ensure generate_path_from_pattern is called with the correct context and details
+    # The actual call in the stage is: generate_path_from_pattern(context, map_detail, map_type_key, temp_file_key)
+    # We need to ensure our side_effect matches these calls.
+    
+    def gen_path_side_effect(ctx, detail, map_type_key, temp_file_key, output_filename_key):
+        if detail['temp_processed_file'] == '/fake/temp_engine_dir/proc1.png':
+            return final_path_proc1
+        elif detail['temp_merged_file'] == '/fake/temp_engine_dir/merged1.png':
+            return final_path_merged1
+        raise ValueError("Unexpected call to generate_path_from_pattern")
+
+    mock_gen_path.side_effect = gen_path_side_effect
+    
+    mock_path_exists.return_value = False # Files do not exist at destination
+    
+    updated_context = stage.execute(context)
+    
+    assert mock_shutil_copy.call_count == 2
+    mock_shutil_copy.assert_any_call(Path(processed_details[proc_id_1]['temp_processed_file']), final_path_proc1)
+    mock_shutil_copy.assert_any_call(Path(merged_details[merged_id_1]['temp_merged_file']), final_path_merged1)
+    
+    # Check mkdir calls
+    # It should be called for each unique parent directory
+    expected_mkdir_calls = [
+        mock.call(Path("/fake/output_final/OutputOrgAsset/Diffuse"), parents=True, exist_ok=True),
+        mock.call(Path("/fake/output_final/OutputOrgAsset/ORM"), parents=True, exist_ok=True)
+    ]
+    mock_mkdir.assert_has_calls(expected_mkdir_calls, any_order=True)
+    # Ensure mkdir was called for the parent of each file
+    assert mock_mkdir.call_count >= 1 # Could be 1 or 2 if paths share a base that's created once
+
+    assert len(updated_context.asset_metadata['final_output_files']) == 2
+    assert str(final_path_proc1) in updated_context.asset_metadata['final_output_files']
+    assert str(final_path_merged1) in updated_context.asset_metadata['final_output_files']
+    
+    assert updated_context.processed_maps_details[proc_id_1]['final_output_path'] == str(final_path_proc1)
+    assert updated_context.merged_maps_details[merged_id_1]['final_output_path'] == str(final_path_merged1)
+    mock_log_error.assert_not_called()
+    # Check for specific info logs if necessary
+    # mock_log_info.assert_any_call(f"Copying {processed_details[proc_id_1]['temp_processed_file']} to {final_path_proc1}")
+    # mock_log_info.assert_any_call(f"Copying {merged_details[merged_id_1]['temp_merged_file']} to {final_path_merged1}")
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir') # Still might be called if other files are processed
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.info')
+def test_output_organization_overwrite_disabled_file_exists(
+    mock_log_info, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    proc_id_1 = uuid.uuid4().hex
+    processed_details = {
+        proc_id_1: {'status': 'Processed', 'temp_processed_file': '/fake/temp_engine_dir/proc_exists.png', 'map_type': 'Diffuse', 'output_filename': 'OutputOrgAsset_Diffuse_Exists.png'}
+    }
+    context = create_output_org_mock_context(
+        processed_map_details=processed_details,
+        overwrite_setting=False
+    )
+    
+    final_path_proc1 = Path("/fake/output_final/OutputOrgAsset/Diffuse/OutputOrgAsset_Diffuse_Exists.png")
+    mock_gen_path.return_value = final_path_proc1 # Only one file
+    mock_path_exists.return_value = True # File exists at destination
+    
+    updated_context = stage.execute(context)
+    
+    mock_shutil_copy.assert_not_called()
+    mock_log_info.assert_any_call(
+        f"Skipping copy for {final_path_proc1} as it already exists and overwrite is disabled."
+    )
+    # final_output_files should still be populated if the file exists and is considered "organized"
+    assert str(final_path_proc1) in updated_context.asset_metadata['final_output_files']
+    assert updated_context.processed_maps_details[proc_id_1]['final_output_path'] == str(final_path_proc1)
+
+
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.info')
+@mock.patch('logging.error')
+def test_output_organization_overwrite_enabled_file_exists(
+    mock_log_error, mock_log_info, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    proc_id_1 = uuid.uuid4().hex
+    processed_details = {
+        proc_id_1: {'status': 'Processed', 'temp_processed_file': '/fake/temp_engine_dir/proc_overwrite.png', 'map_type': 'Diffuse', 'output_filename': 'OutputOrgAsset_Diffuse_Overwrite.png'}
+    }
+    context = create_output_org_mock_context(
+        processed_map_details=processed_details,
+        overwrite_setting=True # Overwrite is enabled
+    )
+    
+    final_path_proc1 = Path("/fake/output_final/OutputOrgAsset/Diffuse/OutputOrgAsset_Diffuse_Overwrite.png")
+    mock_gen_path.return_value = final_path_proc1
+    mock_path_exists.return_value = True # File exists, but we should overwrite
+    
+    updated_context = stage.execute(context)
+    
+    mock_shutil_copy.assert_called_once_with(Path(processed_details[proc_id_1]['temp_processed_file']), final_path_proc1)
+    mock_mkdir.assert_called_once_with(final_path_proc1.parent, parents=True, exist_ok=True)
+    assert str(final_path_proc1) in updated_context.asset_metadata['final_output_files']
+    assert updated_context.processed_maps_details[proc_id_1]['final_output_path'] == str(final_path_proc1)
+    mock_log_error.assert_not_called()
+    # Optionally check for a log message indicating overwrite, if implemented
+    # mock_log_info.assert_any_call(f"Overwriting existing file {final_path_proc1}...")
+
+
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.error')
+def test_output_organization_only_processed_maps(
+    mock_log_error, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    proc_id_1 = uuid.uuid4().hex
+    processed_details = {
+        proc_id_1: {'status': 'Processed', 'temp_processed_file': '/fake/temp_engine_dir/proc_only.png', 'map_type': 'Albedo', 'output_filename': 'OutputOrgAsset_Albedo.png'}
+    }
+    context = create_output_org_mock_context(
+        processed_map_details=processed_details,
+        merged_map_details={}, # No merged maps
+        overwrite_setting=False
+    )
+    
+    final_path_proc1 = Path("/fake/output_final/OutputOrgAsset/Albedo/OutputOrgAsset_Albedo.png")
+    mock_gen_path.return_value = final_path_proc1
+    mock_path_exists.return_value = False
+    
+    updated_context = stage.execute(context)
+    
+    mock_shutil_copy.assert_called_once_with(Path(processed_details[proc_id_1]['temp_processed_file']), final_path_proc1)
+    mock_mkdir.assert_called_once_with(final_path_proc1.parent, parents=True, exist_ok=True)
+    assert len(updated_context.asset_metadata['final_output_files']) == 1
+    assert str(final_path_proc1) in updated_context.asset_metadata['final_output_files']
+    assert updated_context.processed_maps_details[proc_id_1]['final_output_path'] == str(final_path_proc1)
+    assert not updated_context.merged_maps_details # Should remain empty
+    mock_log_error.assert_not_called()
+
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.error')
+def test_output_organization_only_merged_maps(
+    mock_log_error, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    merged_id_1 = uuid.uuid4().hex
+    merged_details = {
+        merged_id_1: {'status': 'Processed', 'temp_merged_file': '/fake/temp_engine_dir/merged_only.png', 'map_type': 'Metallic', 'output_filename': 'OutputOrgAsset_Metallic.png'}
+    }
+    context = create_output_org_mock_context(
+        processed_map_details={}, # No processed maps
+        merged_map_details=merged_details,
+        overwrite_setting=False
+    )
+    
+    final_path_merged1 = Path("/fake/output_final/OutputOrgAsset/Metallic/OutputOrgAsset_Metallic.png")
+    mock_gen_path.return_value = final_path_merged1
+    mock_path_exists.return_value = False
+    
+    updated_context = stage.execute(context)
+    
+    mock_shutil_copy.assert_called_once_with(Path(merged_details[merged_id_1]['temp_merged_file']), final_path_merged1)
+    mock_mkdir.assert_called_once_with(final_path_merged1.parent, parents=True, exist_ok=True)
+    assert len(updated_context.asset_metadata['final_output_files']) == 1
+    assert str(final_path_merged1) in updated_context.asset_metadata['final_output_files']
+    assert updated_context.merged_maps_details[merged_id_1]['final_output_path'] == str(final_path_merged1)
+    assert not updated_context.processed_maps_details # Should remain empty
+    mock_log_error.assert_not_called()
+
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.warning') # Expect a warning for skipped map
+@mock.patch('logging.error')
+def test_output_organization_map_status_not_processed(
+    mock_log_error, mock_log_warning, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    
+    proc_id_1_failed = uuid.uuid4().hex
+    proc_id_2_ok = uuid.uuid4().hex
+    
+    processed_details = {
+        proc_id_1_failed: {'status': 'Failed', 'temp_processed_file': '/fake/temp_engine_dir/proc_failed.png', 'map_type': 'Diffuse', 'output_filename': 'OutputOrgAsset_Diffuse_Failed.png'},
+        proc_id_2_ok: {'status': 'Processed', 'temp_processed_file': '/fake/temp_engine_dir/proc_ok.png', 'map_type': 'Normal', 'output_filename': 'OutputOrgAsset_Normal_OK.png'}
+    }
+    context = create_output_org_mock_context(
+        processed_map_details=processed_details,
+        overwrite_setting=False
+    )
+    
+    final_path_proc_ok = Path("/fake/output_final/OutputOrgAsset/Normal/OutputOrgAsset_Normal_OK.png")
+    # generate_path_from_pattern should only be called for the 'Processed' map
+    mock_gen_path.return_value = final_path_proc_ok 
+    mock_path_exists.return_value = False
+    
+    updated_context = stage.execute(context)
+    
+    # Assert copy was only called for the 'Processed' map
+    mock_shutil_copy.assert_called_once_with(Path(processed_details[proc_id_2_ok]['temp_processed_file']), final_path_proc_ok)
+    mock_mkdir.assert_called_once_with(final_path_proc_ok.parent, parents=True, exist_ok=True)
+    
+    # Assert final_output_files only contains the successfully processed map
+    assert len(updated_context.asset_metadata['final_output_files']) == 1
+    assert str(final_path_proc_ok) in updated_context.asset_metadata['final_output_files']
+    
+    # Assert final_output_path is set for the processed map
+    assert updated_context.processed_maps_details[proc_id_2_ok]['final_output_path'] == str(final_path_proc_ok)
+    # Assert final_output_path is NOT set for the failed map
+    assert 'final_output_path' not in updated_context.processed_maps_details[proc_id_1_failed]
+    
+    mock_log_warning.assert_any_call(
+        f"Skipping output organization for map with ID {proc_id_1_failed} (type: Diffuse) as its status is 'Failed'."
+    )
+    mock_log_error.assert_not_called()
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.error')
+def test_output_organization_generate_path_fails(
+    mock_log_error, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    proc_id_1 = uuid.uuid4().hex
+    processed_details = {
+        proc_id_1: {'status': 'Processed', 'temp_processed_file': '/fake/temp_engine_dir/proc_path_fail.png', 'map_type': 'Roughness', 'output_filename': 'OutputOrgAsset_Roughness_PathFail.png'}
+    }
+    context = create_output_org_mock_context(
+        processed_map_details=processed_details,
+        overwrite_setting=False
+    )
+    
+    mock_gen_path.side_effect = Exception("Simulated path generation error")
+    mock_path_exists.return_value = False # Should not matter if path gen fails
+    
+    updated_context = stage.execute(context)
+    
+    mock_shutil_copy.assert_not_called() # No copy if path generation fails
+    mock_mkdir.assert_not_called() # No mkdir if path generation fails
+    
+    assert not updated_context.asset_metadata.get('final_output_files') # No files should be listed
+    assert 'final_output_path' not in updated_context.processed_maps_details[proc_id_1]
+    
+    assert updated_context.status_flags.get('output_organization_error') is True
+    assert updated_context.asset_metadata['status'] == "Error" # Or "Failed" depending on desired behavior
+    
+    mock_log_error.assert_any_call(
+        f"Error generating output path for map ID {proc_id_1} (type: Roughness): Simulated path generation error"
+    )
+
+@mock.patch('shutil.copy2')
+@mock.patch('pathlib.Path.mkdir')
+@mock.patch('pathlib.Path.exists')
+@mock.patch('processing.pipeline.stages.output_organization.generate_path_from_pattern')
+@mock.patch('logging.error')
+def test_output_organization_shutil_copy_fails(
+    mock_log_error, mock_gen_path, mock_path_exists, mock_mkdir, mock_shutil_copy
+):
+    stage = OutputOrganizationStage()
+    proc_id_1 = uuid.uuid4().hex
+    processed_details = {
+        proc_id_1: {'status': 'Processed', 'temp_processed_file': '/fake/temp_engine_dir/proc_copy_fail.png', 'map_type': 'AO', 'output_filename': 'OutputOrgAsset_AO_CopyFail.png'}
+    }
+    context = create_output_org_mock_context(
+        processed_map_details=processed_details,
+        overwrite_setting=False
+    )
+    
+    final_path_proc1 = Path("/fake/output_final/OutputOrgAsset/AO/OutputOrgAsset_AO_CopyFail.png")
+    mock_gen_path.return_value = final_path_proc1
+    mock_path_exists.return_value = False
+    mock_shutil_copy.side_effect = shutil.Error("Simulated copy error") # Can also be IOError, OSError
+    
+    updated_context = stage.execute(context)
+    
+    mock_mkdir.assert_called_once_with(final_path_proc1.parent, parents=True, exist_ok=True) # mkdir would be called before copy
+    mock_shutil_copy.assert_called_once_with(Path(processed_details[proc_id_1]['temp_processed_file']), final_path_proc1)
+    
+    # Even if copy fails, the path might be added to final_output_files before the error is caught,
+    # or the design might be to not add it. Let's assume it's not added on error.
+    # Check the stage's actual behavior for this.
+    # If the intention is to record the *attempted* path, this assertion might change.
+    # For now, assume failure means it's not a "final" output.
+    assert not updated_context.asset_metadata.get('final_output_files')
+    assert 'final_output_path' not in updated_context.processed_maps_details[proc_id_1] # Or it might contain the path but status is error
+    
+    assert updated_context.status_flags.get('output_organization_error') is True
+    assert updated_context.asset_metadata['status'] == "Error" # Or "Failed"
+    
+    mock_log_error.assert_any_call(
+        f"Error copying file {processed_details[proc_id_1]['temp_processed_file']} to {final_path_proc1}: Simulated copy error"
+    )

tests/processing/pipeline/stages/test_supplier_determination.py

@@ -0,0 +1,213 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+from typing import Dict, List, Optional, Any
+
+# Assuming pytest is run from project root, adjust if necessary
+from processing.pipeline.stages.supplier_determination import SupplierDeterminationStage
+from processing.pipeline.asset_context import AssetProcessingContext
+from rule_structure import AssetRule, SourceRule, FileRule # For constructing mock context
+from configuration import Configuration, GeneralSettings, Supplier # For mock config
+
+# Example helper (can be a pytest fixture too)
+def create_mock_context(
+    asset_rule_supplier_override: Optional[str] = None,
+    source_rule_supplier: Optional[str] = None,
+    config_suppliers: Optional[Dict[str, Any]] = None, # Mocked Supplier objects or dicts
+    asset_name: str = "TestAsset"
+) -> AssetProcessingContext:
+    mock_asset_rule = mock.MagicMock(spec=AssetRule)
+    mock_asset_rule.name = asset_name
+    mock_asset_rule.supplier_override = asset_rule_supplier_override
+    # ... other AssetRule fields if needed by the stage ...
+
+    mock_source_rule = mock.MagicMock(spec=SourceRule)
+    mock_source_rule.supplier = source_rule_supplier
+    # ... other SourceRule fields ...
+
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.suppliers = config_suppliers if config_suppliers is not None else {}
+    
+    # Basic AssetProcessingContext fields
+    context = AssetProcessingContext(
+        source_rule=mock_source_rule,
+        asset_rule=mock_asset_rule,
+        workspace_path=Path("/fake/workspace"),
+        engine_temp_dir=Path("/fake/temp"),
+        output_base_path=Path("/fake/output"),
+        effective_supplier=None,
+        asset_metadata={},
+        processed_maps_details={},
+        merged_maps_details={},
+        files_to_process=[],
+        loaded_data_cache={},
+        config_obj=mock_config,
+        status_flags={},
+        incrementing_value=None,
+        sha5_value=None # Corrected from sha5_value to sha256_value if that's the actual field name
+    )
+    return context
+
+@pytest.fixture
+def supplier_stage():
+    return SupplierDeterminationStage()
+
+@mock.patch('logging.error')
+@mock.patch('logging.info')
+def test_supplier_from_asset_rule_override_valid(mock_log_info, mock_log_error, supplier_stage):
+    mock_suppliers_config = {"SupplierA": mock.MagicMock(spec=Supplier)}
+    context = create_mock_context(
+        asset_rule_supplier_override="SupplierA",
+        config_suppliers=mock_suppliers_config
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier == "SupplierA"
+    assert not updated_context.status_flags.get('supplier_error')
+    mock_log_info.assert_any_call("Effective supplier for asset 'TestAsset' set to 'SupplierA' from asset rule override.")
+    mock_log_error.assert_not_called()
+
+@mock.patch('logging.error')
+@mock.patch('logging.info')
+def test_supplier_from_source_rule_fallback_valid(mock_log_info, mock_log_error, supplier_stage):
+    mock_suppliers_config = {"SupplierB": mock.MagicMock(spec=Supplier)}
+    context = create_mock_context(
+        asset_rule_supplier_override=None,
+        source_rule_supplier="SupplierB",
+        config_suppliers=mock_suppliers_config
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier == "SupplierB"
+    assert not updated_context.status_flags.get('supplier_error')
+    mock_log_info.assert_any_call("Effective supplier for asset 'TestAsset' set to 'SupplierB' from source rule.")
+    mock_log_error.assert_not_called()
+
+@mock.patch('logging.error')
+@mock.patch('logging.warning') # supplier_determination uses logging.warning for invalid suppliers
+def test_asset_rule_override_invalid_supplier(mock_log_warning, mock_log_error, supplier_stage):
+    context = create_mock_context(
+        asset_rule_supplier_override="InvalidSupplier",
+        config_suppliers={"SupplierA": mock.MagicMock(spec=Supplier)} # "InvalidSupplier" not in config
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier is None
+    assert updated_context.status_flags.get('supplier_error') is True
+    mock_log_warning.assert_any_call(
+        "Asset 'TestAsset' has supplier_override 'InvalidSupplier' which is not defined in global suppliers. No supplier set."
+    )
+    mock_log_error.assert_not_called()
+
+
+@mock.patch('logging.error')
+@mock.patch('logging.warning')
+def test_source_rule_fallback_invalid_supplier(mock_log_warning, mock_log_error, supplier_stage):
+    context = create_mock_context(
+        asset_rule_supplier_override=None,
+        source_rule_supplier="InvalidSupplierB",
+        config_suppliers={"SupplierA": mock.MagicMock(spec=Supplier)} # "InvalidSupplierB" not in config
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier is None
+    assert updated_context.status_flags.get('supplier_error') is True
+    mock_log_warning.assert_any_call(
+        "Asset 'TestAsset' has source rule supplier 'InvalidSupplierB' which is not defined in global suppliers. No supplier set."
+    )
+    mock_log_error.assert_not_called()
+
+@mock.patch('logging.error')
+@mock.patch('logging.warning')
+def test_no_supplier_defined(mock_log_warning, mock_log_error, supplier_stage):
+    context = create_mock_context(
+        asset_rule_supplier_override=None,
+        source_rule_supplier=None,
+        config_suppliers={"SupplierA": mock.MagicMock(spec=Supplier)}
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier is None
+    assert updated_context.status_flags.get('supplier_error') is True
+    mock_log_warning.assert_any_call(
+        "No supplier could be determined for asset 'TestAsset'. "
+        "AssetRule override is None and SourceRule supplier is None or empty."
+    )
+    mock_log_error.assert_not_called()
+
+@mock.patch('logging.error')
+@mock.patch('logging.warning')
+def test_empty_config_suppliers_with_asset_override(mock_log_warning, mock_log_error, supplier_stage):
+    context = create_mock_context(
+        asset_rule_supplier_override="SupplierX",
+        config_suppliers={} # Empty global supplier config
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier is None
+    assert updated_context.status_flags.get('supplier_error') is True
+    mock_log_warning.assert_any_call(
+         "Asset 'TestAsset' has supplier_override 'SupplierX' which is not defined in global suppliers. No supplier set."
+    )
+    mock_log_error.assert_not_called()
+
+@mock.patch('logging.error')
+@mock.patch('logging.warning')
+def test_empty_config_suppliers_with_source_rule(mock_log_warning, mock_log_error, supplier_stage):
+    context = create_mock_context(
+        source_rule_supplier="SupplierY",
+        config_suppliers={} # Empty global supplier config
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier is None
+    assert updated_context.status_flags.get('supplier_error') is True
+    mock_log_warning.assert_any_call(
+        "Asset 'TestAsset' has source rule supplier 'SupplierY' which is not defined in global suppliers. No supplier set."
+    )
+    mock_log_error.assert_not_called()
+
+@mock.patch('logging.error')
+@mock.patch('logging.info')
+def test_asset_rule_override_empty_string(mock_log_info, mock_log_error, supplier_stage):
+    # This scenario should fall back to source_rule.supplier if asset_rule.supplier_override is ""
+    mock_suppliers_config = {"SupplierB": mock.MagicMock(spec=Supplier)}
+    context = create_mock_context(
+        asset_rule_supplier_override="", # Empty string override
+        source_rule_supplier="SupplierB",
+        config_suppliers=mock_suppliers_config
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier == "SupplierB" # Falls back to SourceRule
+    assert not updated_context.status_flags.get('supplier_error')
+    mock_log_info.assert_any_call("Effective supplier for asset 'TestAsset' set to 'SupplierB' from source rule.")
+    mock_log_error.assert_not_called()
+
+@mock.patch('logging.error')
+@mock.patch('logging.warning')
+def test_source_rule_supplier_empty_string(mock_log_warning, mock_log_error, supplier_stage):
+    # This scenario should result in an error if asset_rule.supplier_override is None and source_rule.supplier is ""
+    context = create_mock_context(
+        asset_rule_supplier_override=None,
+        source_rule_supplier="", # Empty string source supplier
+        config_suppliers={"SupplierA": mock.MagicMock(spec=Supplier)}
+    )
+    
+    updated_context = supplier_stage.execute(context)
+    
+    assert updated_context.effective_supplier is None
+    assert updated_context.status_flags.get('supplier_error') is True
+    mock_log_warning.assert_any_call(
+        "No supplier could be determined for asset 'TestAsset'. "
+        "AssetRule override is None and SourceRule supplier is None or empty."
+    )
+    mock_log_error.assert_not_called()

tests/processing/pipeline/test_orchestrator.py

@@ -0,0 +1,383 @@
+import pytest
+from unittest import mock
+from pathlib import Path
+import uuid
+import shutil # For checking rmtree
+import tempfile # For mocking mkdtemp
+
+from processing.pipeline.orchestrator import PipelineOrchestrator
+from processing.pipeline.asset_context import AssetProcessingContext
+from processing.pipeline.stages.base_stage import ProcessingStage # For mocking stages
+from rule_structure import SourceRule, AssetRule, FileRule
+from configuration import Configuration, GeneralSettings
+
+# Mock Stage that modifies context
+class MockPassThroughStage(ProcessingStage):
+    def __init__(self, stage_name="mock_stage"):
+        self.stage_name = stage_name
+        self.execute_call_count = 0
+        self.contexts_called_with = [] # To store contexts for verification
+
+    def execute(self, context: AssetProcessingContext) -> AssetProcessingContext:
+        self.execute_call_count += 1
+        self.contexts_called_with.append(context)
+        # Optionally, modify context for testing
+        context.asset_metadata[f'{self.stage_name}_executed'] = True
+        if self.stage_name == "skipper_stage": # Example conditional logic
+            context.status_flags['skip_asset'] = True
+            context.status_flags['skip_reason'] = "Skipped by skipper_stage"
+        elif self.stage_name == "error_stage": # Example error-raising stage
+            raise ValueError("Simulated error in error_stage")
+        
+        # Simulate status update based on stage execution
+        if not context.status_flags.get('skip_asset') and not context.status_flags.get('asset_failed'):
+             context.asset_metadata['status'] = "Processed" # Default to processed if not skipped/failed
+        return context
+
+def create_orchestrator_test_config() -> mock.MagicMock:
+    mock_config = mock.MagicMock(spec=Configuration)
+    mock_config.general_settings = mock.MagicMock(spec=GeneralSettings)
+    mock_config.general_settings.temp_dir_override = None # Default, can be overridden in tests
+    # Add other config details if orchestrator or stages depend on them directly
+    return mock_config
+
+def create_orchestrator_test_asset_rule(name: str, num_file_rules: int = 1) -> mock.MagicMock:
+    asset_rule = mock.MagicMock(spec=AssetRule)
+    asset_rule.name = name
+    asset_rule.id = uuid.uuid4()
+    asset_rule.source_path = Path(f"/fake/source/{name}") # Using Path object
+    asset_rule.file_rules = [mock.MagicMock(spec=FileRule) for _ in range(num_file_rules)]
+    asset_rule.enabled = True
+    asset_rule.map_types = {} # Initialize as dict
+    asset_rule.material_name_scheme = "{asset_name}"
+    asset_rule.texture_name_scheme = "{asset_name}_{map_type}"
+    asset_rule.output_path_scheme = "{source_name}/{asset_name}"
+    # ... other necessary AssetRule fields ...
+    return asset_rule
+
+def create_orchestrator_test_source_rule(name: str, num_assets: int = 1, asset_names: list = None) -> mock.MagicMock:
+    source_rule = mock.MagicMock(spec=SourceRule)
+    source_rule.name = name
+    source_rule.id = uuid.uuid4()
+    if asset_names:
+        source_rule.assets = [create_orchestrator_test_asset_rule(an) for an in asset_names]
+    else:
+        source_rule.assets = [create_orchestrator_test_asset_rule(f"Asset_{i+1}_in_{name}") for i in range(num_assets)]
+    source_rule.enabled = True
+    source_rule.source_path = Path(f"/fake/source_root/{name}") # Using Path object
+    # ... other necessary SourceRule fields ...
+    return source_rule
+
+# --- Test Cases for PipelineOrchestrator.process_source_rule() ---
+
+@mock.patch('shutil.rmtree')
+@mock.patch('tempfile.mkdtemp')
+def test_orchestrator_basic_flow_mock_stages(mock_mkdtemp, mock_rmtree):
+    mock_mkdtemp.return_value = "/fake/engine_temp_dir_path" # Path for mkdtemp
+    
+    config = create_orchestrator_test_config()
+    stage1 = MockPassThroughStage("stage1")
+    stage2 = MockPassThroughStage("stage2")
+    orchestrator = PipelineOrchestrator(config_obj=config, stages=[stage1, stage2])
+    
+    source_rule = create_orchestrator_test_source_rule("MySourceRule", num_assets=2)
+    asset1_name = source_rule.assets[0].name
+    asset2_name = source_rule.assets[1].name
+
+    # Mock asset_metadata to be updated by stages for status check
+    # The MockPassThroughStage already sets a 'status' = "Processed" if not skipped/failed
+    # and adds '{stage_name}_executed' = True to asset_metadata.
+
+    results = orchestrator.process_source_rule(
+        source_rule, Path("/ws"), Path("/out"), False, "inc_val_123", "sha_val_abc"
+    )
+    
+    assert stage1.execute_call_count == 2 # Called for each asset
+    assert stage2.execute_call_count == 2 # Called for each asset
+    
+    assert asset1_name in results['processed']
+    assert asset2_name in results['processed']
+    assert not results['skipped']
+    assert not results['failed']
+    
+    # Verify context modifications by stages
+    for i in range(2): # For each asset
+        # Stage 1 context checks
+        s1_context_asset = stage1.contexts_called_with[i]
+        assert s1_context_asset.asset_metadata.get('stage1_executed') is True
+        assert s1_context_asset.asset_metadata.get('stage2_executed') is None # Stage 2 not yet run for this asset
+
+        # Stage 2 context checks
+        s2_context_asset = stage2.contexts_called_with[i]
+        assert s2_context_asset.asset_metadata.get('stage1_executed') is True # From stage 1
+        assert s2_context_asset.asset_metadata.get('stage2_executed') is True
+        assert s2_context_asset.asset_metadata.get('status') == "Processed"
+
+    mock_mkdtemp.assert_called_once()
+    # The orchestrator creates a subdirectory within the mkdtemp path
+    expected_temp_path = Path(mock_mkdtemp.return_value) / source_rule.id.hex
+    mock_rmtree.assert_called_once_with(expected_temp_path, ignore_errors=True)
+
+@mock.patch('shutil.rmtree')
+@mock.patch('tempfile.mkdtemp')
+def test_orchestrator_asset_skipping_by_stage(mock_mkdtemp, mock_rmtree):
+    mock_mkdtemp.return_value = "/fake/engine_temp_dir_path_skip"
+    
+    config = create_orchestrator_test_config()
+    skipper_stage = MockPassThroughStage("skipper_stage") # This stage will set skip_asset = True
+    stage_after_skip = MockPassThroughStage("stage_after_skip")
+    
+    orchestrator = PipelineOrchestrator(config_obj=config, stages=[skipper_stage, stage_after_skip])
+    
+    source_rule = create_orchestrator_test_source_rule("SkipSourceRule", num_assets=1)
+    asset_to_skip_name = source_rule.assets[0].name
+    
+    results = orchestrator.process_source_rule(
+        source_rule, Path("/ws_skip"), Path("/out_skip"), False, "inc_skip", "sha_skip"
+    )
+    
+    assert skipper_stage.execute_call_count == 1 # Called for the asset
+    assert stage_after_skip.execute_call_count == 0 # Not called because asset was skipped
+    
+    assert asset_to_skip_name in results['skipped']
+    assert not results['processed']
+    assert not results['failed']
+    
+    # Verify skip reason in context if needed (MockPassThroughStage stores contexts)
+    skipped_context = skipper_stage.contexts_called_with[0]
+    assert skipped_context.status_flags['skip_asset'] is True
+    assert skipped_context.status_flags['skip_reason'] == "Skipped by skipper_stage"
+    
+    mock_mkdtemp.assert_called_once()
+    expected_temp_path = Path(mock_mkdtemp.return_value) / source_rule.id.hex
+    mock_rmtree.assert_called_once_with(expected_temp_path, ignore_errors=True)
+
+@mock.patch('shutil.rmtree')
+@mock.patch('tempfile.mkdtemp')
+def test_orchestrator_no_assets_in_source_rule(mock_mkdtemp, mock_rmtree):
+    mock_mkdtemp.return_value = "/fake/engine_temp_dir_no_assets"
+    
+    config = create_orchestrator_test_config()
+    stage1 = MockPassThroughStage("stage1_no_assets")
+    orchestrator = PipelineOrchestrator(config_obj=config, stages=[stage1])
+    
+    source_rule = create_orchestrator_test_source_rule("NoAssetSourceRule", num_assets=0)
+    
+    results = orchestrator.process_source_rule(
+        source_rule, Path("/ws_no_assets"), Path("/out_no_assets"), False, "inc_no", "sha_no"
+    )
+    
+    assert stage1.execute_call_count == 0
+    assert not results['processed']
+    assert not results['skipped']
+    assert not results['failed']
+    
+    # mkdtemp should still be called for the source rule processing, even if no assets
+    mock_mkdtemp.assert_called_once()
+    expected_temp_path = Path(mock_mkdtemp.return_value) / source_rule.id.hex
+    mock_rmtree.assert_called_once_with(expected_temp_path, ignore_errors=True)
+
+
+@mock.patch('shutil.rmtree')
+@mock.patch('tempfile.mkdtemp')
+def test_orchestrator_error_during_stage_execution(mock_mkdtemp, mock_rmtree):
+    mock_mkdtemp.return_value = "/fake/engine_temp_dir_error"
+    
+    config = create_orchestrator_test_config()
+    error_stage = MockPassThroughStage("error_stage") # This stage will raise an error
+    stage_after_error = MockPassThroughStage("stage_after_error")
+    
+    orchestrator = PipelineOrchestrator(config_obj=config, stages=[error_stage, stage_after_error])
+    
+    # Test with two assets, one fails, one processes (if orchestrator continues)
+    # The current orchestrator's process_asset is per asset, so an error in one
+    # should not stop processing of other assets in the same source_rule.
+    source_rule = create_orchestrator_test_source_rule("ErrorSourceRule", asset_names=["AssetFails", "AssetSucceeds"])
+    asset_fails_name = source_rule.assets[0].name
+    asset_succeeds_name = source_rule.assets[1].name
+
+    # Make only the first asset's processing trigger the error
+    original_execute = error_stage.execute
+    def error_execute_side_effect(context: AssetProcessingContext):
+        if context.asset_rule.name == asset_fails_name:
+            # The MockPassThroughStage is already configured to raise ValueError for "error_stage"
+            # but we need to ensure it's only for the first asset.
+            # We can achieve this by modifying the stage_name temporarily or by checking asset_rule.name
+            # For simplicity, let's assume the mock stage's error logic is fine,
+            # and we just need to check the outcome.
+            # The error_stage will raise ValueError("Simulated error in error_stage")
+            # The orchestrator's _process_single_asset catches generic Exception.
+            return original_execute(context) # This will call the erroring logic
+        else:
+            # For the second asset, make it pass through without error
+            context.asset_metadata[f'{error_stage.stage_name}_executed'] = True
+            context.asset_metadata['status'] = "Processed"
+            return context
+    
+    error_stage.execute = mock.MagicMock(side_effect=error_execute_side_effect)
+    # stage_after_error should still be called for the successful asset
+    
+    results = orchestrator.process_source_rule(
+        source_rule, Path("/ws_error"), Path("/out_error"), False, "inc_err", "sha_err"
+    )
+    
+    assert error_stage.execute.call_count == 2 # Called for both assets
+    # stage_after_error is only called for the asset that didn't fail in error_stage
+    assert stage_after_error.execute_call_count == 1 
+    
+    assert asset_fails_name in results['failed']
+    assert asset_succeeds_name in results['processed']
+    assert not results['skipped']
+    
+    # Verify the context of the failed asset
+    failed_context = None
+    for ctx in error_stage.contexts_called_with:
+        if ctx.asset_rule.name == asset_fails_name:
+            failed_context = ctx
+            break
+    assert failed_context is not None
+    assert failed_context.status_flags['asset_failed'] is True
+    assert "Simulated error in error_stage" in failed_context.status_flags['failure_reason']
+
+    # Verify the context of the successful asset after stage_after_error
+    successful_context_after_s2 = None
+    for ctx in stage_after_error.contexts_called_with:
+        if ctx.asset_rule.name == asset_succeeds_name:
+            successful_context_after_s2 = ctx
+            break
+    assert successful_context_after_s2 is not None
+    assert successful_context_after_s2.asset_metadata.get('error_stage_executed') is True # from the non-erroring path
+    assert successful_context_after_s2.asset_metadata.get('stage_after_error_executed') is True
+    assert successful_context_after_s2.asset_metadata.get('status') == "Processed"
+
+
+    mock_mkdtemp.assert_called_once()
+    expected_temp_path = Path(mock_mkdtemp.return_value) / source_rule.id.hex
+    mock_rmtree.assert_called_once_with(expected_temp_path, ignore_errors=True)
+
+
+@mock.patch('shutil.rmtree')
+@mock.patch('tempfile.mkdtemp')
+def test_orchestrator_asset_processing_context_initialization(mock_mkdtemp, mock_rmtree):
+    mock_engine_temp_dir = "/fake/engine_temp_dir_context_init"
+    mock_mkdtemp.return_value = mock_engine_temp_dir
+    
+    config = create_orchestrator_test_config()
+    mock_stage = MockPassThroughStage("context_check_stage")
+    orchestrator = PipelineOrchestrator(config_obj=config, stages=[mock_stage])
+    
+    source_rule = create_orchestrator_test_source_rule("ContextSourceRule", num_assets=1)
+    asset_rule = source_rule.assets[0]
+    
+    workspace_path = Path("/ws_context")
+    output_base_path = Path("/out_context")
+    incrementing_value = "inc_context_123"
+    sha5_value = "sha_context_abc"
+    
+    orchestrator.process_source_rule(
+        source_rule, workspace_path, output_base_path, False, incrementing_value, sha5_value
+    )
+    
+    assert mock_stage.execute_call_count == 1
+    
+    # Retrieve the context passed to the mock stage
+    captured_context = mock_stage.contexts_called_with[0]
+    
+    assert captured_context.source_rule == source_rule
+    assert captured_context.asset_rule == asset_rule
+    assert captured_context.workspace_path == workspace_path
+    
+    # engine_temp_dir for the asset is a sub-directory of the source_rule's temp dir
+    # which itself is a sub-directory of the main engine_temp_dir from mkdtemp
+    expected_source_rule_temp_dir = Path(mock_engine_temp_dir) / source_rule.id.hex
+    expected_asset_temp_dir = expected_source_rule_temp_dir / asset_rule.id.hex
+    assert captured_context.engine_temp_dir == expected_asset_temp_dir
+    
+    assert captured_context.output_base_path == output_base_path
+    assert captured_context.config_obj == config
+    assert captured_context.incrementing_value == incrementing_value
+    assert captured_context.sha5_value == sha5_value
+    
+    # Check initial state of other context fields
+    assert captured_context.asset_metadata == {} # Should be empty initially for an asset
+    assert captured_context.status_flags == {}   # Should be empty initially
+    assert captured_context.shared_data == {}    # Should be empty initially
+    assert captured_context.current_files == []  # Should be empty initially
+
+    mock_mkdtemp.assert_called_once()
+    mock_rmtree.assert_called_once_with(expected_source_rule_temp_dir, ignore_errors=True)
+
+@mock.patch('shutil.rmtree')
+@mock.patch('tempfile.mkdtemp')
+def test_orchestrator_temp_dir_override_from_config(mock_mkdtemp, mock_rmtree):
+    # This test verifies that if config.general_settings.temp_dir_override is set,
+    # mkdtemp is NOT called, and the override path is used and cleaned up.
+    
+    config = create_orchestrator_test_config()
+    override_temp_path_str = "/override/temp/path"
+    config.general_settings.temp_dir_override = override_temp_path_str
+    
+    stage1 = MockPassThroughStage("stage_temp_override")
+    orchestrator = PipelineOrchestrator(config_obj=config, stages=[stage1])
+    
+    source_rule = create_orchestrator_test_source_rule("TempOverrideRule", num_assets=1)
+    asset_rule = source_rule.assets[0]
+
+    results = orchestrator.process_source_rule(
+        source_rule, Path("/ws_override"), Path("/out_override"), False, "inc_override", "sha_override"
+    )
+    
+    assert stage1.execute_call_count == 1
+    assert asset_rule.name in results['processed']
+    
+    mock_mkdtemp.assert_not_called() # mkdtemp should not be called due to override
+
+    # The orchestrator should create its source-rule specific subdir within the override
+    expected_source_rule_temp_dir_in_override = Path(override_temp_path_str) / source_rule.id.hex
+    
+    # Verify the context passed to the stage uses the overridden path structure
+    captured_context = stage1.contexts_called_with[0]
+    expected_asset_temp_dir_in_override = expected_source_rule_temp_dir_in_override / asset_rule.id.hex
+    assert captured_context.engine_temp_dir == expected_asset_temp_dir_in_override
+    
+    # rmtree should be called on the source_rule's directory within the override path
+    mock_rmtree.assert_called_once_with(expected_source_rule_temp_dir_in_override, ignore_errors=True)
+
+@mock.patch('shutil.rmtree')
+@mock.patch('tempfile.mkdtemp')
+def test_orchestrator_disabled_asset_rule_is_skipped(mock_mkdtemp, mock_rmtree):
+    mock_mkdtemp.return_value = "/fake/engine_temp_dir_disabled_asset"
+    
+    config = create_orchestrator_test_config()
+    stage1 = MockPassThroughStage("stage_disabled_check")
+    orchestrator = PipelineOrchestrator(config_obj=config, stages=[stage1])
+    
+    source_rule = create_orchestrator_test_source_rule("DisabledAssetSourceRule", asset_names=["EnabledAsset", "DisabledAsset"])
+    enabled_asset = source_rule.assets[0]
+    disabled_asset = source_rule.assets[1]
+    disabled_asset.enabled = False # Disable this asset rule
+    
+    results = orchestrator.process_source_rule(
+        source_rule, Path("/ws_disabled"), Path("/out_disabled"), False, "inc_dis", "sha_dis"
+    )
+    
+    assert stage1.execute_call_count == 1 # Only called for the enabled asset
+    
+    assert enabled_asset.name in results['processed']
+    assert disabled_asset.name in results['skipped']
+    assert not results['failed']
+    
+    # Verify context for the processed asset
+    assert stage1.contexts_called_with[0].asset_rule.name == enabled_asset.name
+
+    # Verify skip reason for the disabled asset (this is set by the orchestrator itself)
+    # The orchestrator's _process_single_asset checks asset_rule.enabled
+    # We need to inspect the results dictionary for the skip reason if it's stored there,
+    # or infer it. The current structure of `results` doesn't store detailed skip reasons directly,
+    # but the test ensures it's in the 'skipped' list.
+    # For a more detailed check, one might need to adjust how results are reported or mock deeper.
+    # For now, confirming it's in 'skipped' and stage1 wasn't called for it is sufficient.
+
+    mock_mkdtemp.assert_called_once()
+    expected_temp_path = Path(mock_mkdtemp.return_value) / source_rule.id.hex
+    mock_rmtree.assert_called_once_with(expected_temp_path, ignore_errors=True)

tests/processing/utils/test_image_processing_utils.py

@@ -0,0 +1,504 @@
+import pytest
+from unittest import mock
+import numpy as np
+from pathlib import Path
+import sys
+
+# Attempt to import the module under test
+# This assumes that the 'tests' directory is at the same level as the 'processing' directory,
+# and pytest handles the PYTHONPATH correctly.
+try:
+    from processing.utils import image_processing_utils as ipu
+    import cv2 # Import cv2 here if it's used for constants like cv2.COLOR_BGR2RGB
+except ImportError:
+    # Fallback for environments where PYTHONPATH might not be set up as expected by pytest initially
+    # This adds the project root to sys.path to find the 'processing' module
+    # Adjust the number of Path.parent calls if your test structure is deeper or shallower
+    project_root = Path(__file__).parent.parent.parent.parent 
+    sys.path.insert(0, str(project_root))
+    from processing.utils import image_processing_utils as ipu
+    import cv2 # Import cv2 here as well
+
+# If cv2 is imported directly in image_processing_utils, you might need to mock it globally for some tests
+# For example, at the top of the test file:
+# sys.modules['cv2'] = mock.MagicMock() # Basic global mock if needed
+# We will use more targeted mocks with @mock.patch where cv2 is used.
+
+# --- Tests for Mathematical Helpers ---
+
+def test_is_power_of_two():
+    assert ipu.is_power_of_two(1) is True
+    assert ipu.is_power_of_two(2) is True
+    assert ipu.is_power_of_two(4) is True
+    assert ipu.is_power_of_two(16) is True
+    assert ipu.is_power_of_two(1024) is True
+    assert ipu.is_power_of_two(0) is False
+    assert ipu.is_power_of_two(-2) is False
+    assert ipu.is_power_of_two(3) is False
+    assert ipu.is_power_of_two(100) is False
+
+def test_get_nearest_pot():
+    assert ipu.get_nearest_pot(1) == 1
+    assert ipu.get_nearest_pot(2) == 2
+    # Based on current implementation:
+    # For 3: lower=2, upper=4. (3-2)=1, (4-3)=1. Else branch returns upper_pot. So 4.
+    assert ipu.get_nearest_pot(3) == 4
+    assert ipu.get_nearest_pot(50) == 64 # (50-32)=18, (64-50)=14 -> upper
+    assert ipu.get_nearest_pot(100) == 128 # (100-64)=36, (128-100)=28 -> upper
+    assert ipu.get_nearest_pot(256) == 256
+    assert ipu.get_nearest_pot(0) == 1
+    assert ipu.get_nearest_pot(-10) == 1
+    # For 700: value.bit_length() = 10. lower_pot = 1<<(10-1) = 512. upper_pot = 1<<10 = 1024.
+    # (700-512) = 188. (1024-700) = 324. (188 < 324) is True. Returns lower_pot. So 512.
+    assert ipu.get_nearest_pot(700) == 512
+    assert ipu.get_nearest_pot(6) == 8 # (6-4)=2, (8-6)=2. Returns upper.
+    assert ipu.get_nearest_pot(5) == 4 # (5-4)=1, (8-5)=3. Returns lower.
+
+
+@pytest.mark.parametrize(
+    "orig_w, orig_h, target_w, target_h, resize_mode, ensure_pot, allow_upscale, target_max_dim, expected_w, expected_h",
+    [
+        # FIT mode
+        (1000, 800, 500, None, "fit", False, False, None, 500, 400), # Fit width
+        (1000, 800, None, 400, "fit", False, False, None, 500, 400), # Fit height
+        (1000, 800, 500, 500, "fit", False, False, None, 500, 400), # Fit to box (width constrained)
+        (800, 1000, 500, 500, "fit", False, False, None, 400, 500), # Fit to box (height constrained)
+        (100, 80, 200, None, "fit", False, False, None, 100, 80),   # Fit width, no upscale
+        (100, 80, 200, None, "fit", False, True, None, 200, 160),   # Fit width, allow upscale
+        (100, 80, 128, None, "fit", True, False, None, 128, 64), # Re-evaluated
+        (100, 80, 128, None, "fit", True, True, None, 128, 128), # Fit width, ensure_pot, allow upscale (128, 102 -> pot 128, 128)
+
+        # STRETCH mode
+        (1000, 800, 500, 400, "stretch", False, False, None, 500, 400),
+        (100, 80, 200, 160, "stretch", False, True, None, 200, 160), # Stretch, allow upscale
+        (100, 80, 200, 160, "stretch", False, False, None, 100, 80), # Stretch, no upscale
+        (100, 80, 128, 128, "stretch", True, True, None, 128, 128), # Stretch, ensure_pot, allow upscale
+        (100, 80, 70, 70, "stretch", True, False, None, 64, 64), # Stretch, ensure_pot, no upscale (70,70 -> pot 64,64)
+
+        # MAX_DIM_POT mode
+        (1000, 800, None, None, "max_dim_pot", True, False, 512, 512, 512),
+        (800, 1000, None, None, "max_dim_pot", True, False, 512, 512, 512),
+        (1920, 1080, None, None, "max_dim_pot", True, False, 1024, 1024, 512),
+        (100, 100, None, None, "max_dim_pot", True, False, 60, 64, 64),
+        # Edge cases for calculate_target_dimensions
+        (0, 0, 512, 512, "fit", False, False, None, 512, 512), 
+        (10, 10, 512, 512, "fit", True, False, None, 8, 8),
+        (100, 100, 150, 150, "fit", True, False, None, 128, 128),
+    ]
+)
+def test_calculate_target_dimensions(orig_w, orig_h, target_w, target_h, resize_mode, ensure_pot, allow_upscale, target_max_dim, expected_w, expected_h):
+    if resize_mode == "max_dim_pot" and target_max_dim is None:
+        with pytest.raises(ValueError, match="target_max_dim_for_pot_mode must be provided"):
+            ipu.calculate_target_dimensions(orig_w, orig_h, target_width=target_w, target_height=target_h, 
+                                            resize_mode=resize_mode, ensure_pot=ensure_pot, allow_upscale=allow_upscale,
+                                            target_max_dim_for_pot_mode=target_max_dim)
+    elif (resize_mode == "fit" and target_w is None and target_h is None) or \
+         (resize_mode == "stretch" and (target_w is None or target_h is None)):
+        with pytest.raises(ValueError):
+             ipu.calculate_target_dimensions(orig_w, orig_h, target_width=target_w, target_height=target_h, 
+                                            resize_mode=resize_mode, ensure_pot=ensure_pot, allow_upscale=allow_upscale,
+                                            target_max_dim_for_pot_mode=target_max_dim)
+    else:
+        actual_w, actual_h = ipu.calculate_target_dimensions(
+            orig_w, orig_h, target_width=target_w, target_height=target_h, 
+            resize_mode=resize_mode, ensure_pot=ensure_pot, allow_upscale=allow_upscale,
+            target_max_dim_for_pot_mode=target_max_dim
+        )
+        assert (actual_w, actual_h) == (expected_w, expected_h), \
+            f"Input: ({orig_w},{orig_h}), T=({target_w},{target_h}), M={resize_mode}, POT={ensure_pot}, UPSC={allow_upscale}, TMAX={target_max_dim}"
+
+
+def test_calculate_target_dimensions_invalid_mode():
+    with pytest.raises(ValueError, match="Unsupported resize_mode"):
+        ipu.calculate_target_dimensions(100, 100, 50, 50, resize_mode="invalid_mode")
+
+@pytest.mark.parametrize(
+    "ow, oh, rw, rh, expected_str",
+    [
+        (100, 100, 100, 100, "EVEN"),
+        (100, 100, 200, 200, "EVEN"),
+        (200, 200, 100, 100, "EVEN"),
+        (100, 100, 150, 100, "X15Y1"),
+        (100, 100, 50, 100, "X05Y1"),
+        (100, 100, 100, 150, "X1Y15"),
+        (100, 100, 100, 50, "X1Y05"),
+        (100, 50, 150, 75, "EVEN"),
+        (100, 50, 150, 50, "X15Y1"),
+        (100, 50, 100, 75, "X1Y15"),
+        (100, 50, 120, 60, "EVEN"),
+        (100, 50, 133, 66, "EVEN"),
+        (100, 100, 133, 100, "X133Y1"),
+        (100, 100, 100, 133, "X1Y133"),
+        (100, 100, 133, 133, "EVEN"),
+        (100, 100, 67, 100, "X067Y1"),
+        (100, 100, 100, 67, "X1Y067"),
+        (100, 100, 67, 67, "EVEN"),
+        (1920, 1080, 1024, 576, "EVEN"), 
+        (1920, 1080, 1024, 512, "X112Y1"),
+        (0, 100, 50, 50, "InvalidInput"),
+        (100, 0, 50, 50, "InvalidInput"),
+        (100, 100, 0, 50, "InvalidResize"),
+        (100, 100, 50, 0, "InvalidResize"),
+    ]
+)
+def test_normalize_aspect_ratio_change(ow, oh, rw, rh, expected_str):
+    assert ipu.normalize_aspect_ratio_change(ow, oh, rw, rh) == expected_str
+
+# --- Tests for Image Manipulation ---
+
+@mock.patch('cv2.imread')
+def test_load_image_success_str_path(mock_cv2_imread):
+    mock_img_data = np.array([[[1, 2, 3]]], dtype=np.uint8)
+    mock_cv2_imread.return_value = mock_img_data
+    
+    result = ipu.load_image("dummy/path.png")
+    
+    mock_cv2_imread.assert_called_once_with("dummy/path.png", cv2.IMREAD_UNCHANGED)
+    assert np.array_equal(result, mock_img_data)
+
+@mock.patch('cv2.imread')
+def test_load_image_success_path_obj(mock_cv2_imread):
+    mock_img_data = np.array([[[1, 2, 3]]], dtype=np.uint8)
+    mock_cv2_imread.return_value = mock_img_data
+    dummy_path = Path("dummy/path.png")
+    
+    result = ipu.load_image(dummy_path)
+    
+    mock_cv2_imread.assert_called_once_with(str(dummy_path), cv2.IMREAD_UNCHANGED)
+    assert np.array_equal(result, mock_img_data)
+
+@mock.patch('cv2.imread')
+def test_load_image_failure(mock_cv2_imread):
+    mock_cv2_imread.return_value = None
+    
+    result = ipu.load_image("dummy/path.png")
+    
+    mock_cv2_imread.assert_called_once_with("dummy/path.png", cv2.IMREAD_UNCHANGED)
+    assert result is None
+
+@mock.patch('cv2.imread', side_effect=Exception("CV2 Read Error"))
+def test_load_image_exception(mock_cv2_imread):
+    result = ipu.load_image("dummy/path.png")
+    mock_cv2_imread.assert_called_once_with("dummy/path.png", cv2.IMREAD_UNCHANGED)
+    assert result is None
+
+
+@mock.patch('cv2.cvtColor')
+def test_convert_bgr_to_rgb_3_channel(mock_cv2_cvtcolor):
+    bgr_image = np.random.randint(0, 255, (10, 10, 3), dtype=np.uint8)
+    rgb_image_mock = np.random.randint(0, 255, (10, 10, 3), dtype=np.uint8)
+    mock_cv2_cvtcolor.return_value = rgb_image_mock
+
+    result = ipu.convert_bgr_to_rgb(bgr_image)
+
+    mock_cv2_cvtcolor.assert_called_once_with(bgr_image, cv2.COLOR_BGR2RGB)
+    assert np.array_equal(result, rgb_image_mock)
+
+@mock.patch('cv2.cvtColor')
+def test_convert_bgr_to_rgb_4_channel_bgra(mock_cv2_cvtcolor):
+    bgra_image = np.random.randint(0, 255, (10, 10, 4), dtype=np.uint8)
+    rgb_image_mock = np.random.randint(0, 255, (10, 10, 3), dtype=np.uint8) # cvtColor BGRA2RGB drops alpha
+    mock_cv2_cvtcolor.return_value = rgb_image_mock # Mocking the output of BGRA2RGB
+
+    result = ipu.convert_bgr_to_rgb(bgra_image)
+
+    mock_cv2_cvtcolor.assert_called_once_with(bgra_image, cv2.COLOR_BGRA2RGB)
+    assert np.array_equal(result, rgb_image_mock)
+
+
+def test_convert_bgr_to_rgb_none_input():
+    assert ipu.convert_bgr_to_rgb(None) is None
+
+def test_convert_bgr_to_rgb_grayscale_input():
+    gray_image = np.random.randint(0, 255, (10, 10), dtype=np.uint8)
+    result = ipu.convert_bgr_to_rgb(gray_image)
+    assert np.array_equal(result, gray_image) # Should return as is
+
+@mock.patch('cv2.cvtColor')
+def test_convert_rgb_to_bgr_3_channel(mock_cv2_cvtcolor):
+    rgb_image = np.random.randint(0, 255, (10, 10, 3), dtype=np.uint8)
+    bgr_image_mock = np.random.randint(0, 255, (10, 10, 3), dtype=np.uint8)
+    mock_cv2_cvtcolor.return_value = bgr_image_mock
+
+    result = ipu.convert_rgb_to_bgr(rgb_image)
+
+    mock_cv2_cvtcolor.assert_called_once_with(rgb_image, cv2.COLOR_RGB2BGR)
+    assert np.array_equal(result, bgr_image_mock)
+
+def test_convert_rgb_to_bgr_none_input():
+    assert ipu.convert_rgb_to_bgr(None) is None
+
+def test_convert_rgb_to_bgr_grayscale_input():
+    gray_image = np.random.randint(0, 255, (10, 10), dtype=np.uint8)
+    result = ipu.convert_rgb_to_bgr(gray_image)
+    assert np.array_equal(result, gray_image) # Should return as is
+
+def test_convert_rgb_to_bgr_4_channel_input():
+    rgba_image = np.random.randint(0, 255, (10, 10, 4), dtype=np.uint8)
+    result = ipu.convert_rgb_to_bgr(rgba_image)
+    assert np.array_equal(result, rgba_image) # Should return as is
+
+
+@mock.patch('cv2.resize')
+def test_resize_image_downscale(mock_cv2_resize):
+    original_image = np.random.randint(0, 255, (100, 100, 3), dtype=np.uint8)
+    resized_image_mock = np.random.randint(0, 255, (50, 50, 3), dtype=np.uint8)
+    mock_cv2_resize.return_value = resized_image_mock
+    target_w, target_h = 50, 50
+
+    result = ipu.resize_image(original_image, target_w, target_h)
+
+    mock_cv2_resize.assert_called_once_with(original_image, (target_w, target_h), interpolation=cv2.INTER_LANCZOS4)
+    assert np.array_equal(result, resized_image_mock)
+
+@mock.patch('cv2.resize')
+def test_resize_image_upscale(mock_cv2_resize):
+    original_image = np.random.randint(0, 255, (50, 50, 3), dtype=np.uint8)
+    resized_image_mock = np.random.randint(0, 255, (100, 100, 3), dtype=np.uint8)
+    mock_cv2_resize.return_value = resized_image_mock
+    target_w, target_h = 100, 100
+
+    result = ipu.resize_image(original_image, target_w, target_h)
+
+    mock_cv2_resize.assert_called_once_with(original_image, (target_w, target_h), interpolation=cv2.INTER_CUBIC)
+    assert np.array_equal(result, resized_image_mock)
+
+@mock.patch('cv2.resize')
+def test_resize_image_custom_interpolation(mock_cv2_resize):
+    original_image = np.random.randint(0, 255, (100, 100, 3), dtype=np.uint8)
+    resized_image_mock = np.random.randint(0, 255, (50, 50, 3), dtype=np.uint8)
+    mock_cv2_resize.return_value = resized_image_mock
+    target_w, target_h = 50, 50
+
+    result = ipu.resize_image(original_image, target_w, target_h, interpolation=cv2.INTER_NEAREST)
+
+    mock_cv2_resize.assert_called_once_with(original_image, (target_w, target_h), interpolation=cv2.INTER_NEAREST)
+    assert np.array_equal(result, resized_image_mock)
+
+def test_resize_image_none_input():
+    with pytest.raises(ValueError, match="Cannot resize a None image."):
+        ipu.resize_image(None, 50, 50)
+
+@pytest.mark.parametrize("w, h", [(0, 50), (50, 0), (-1, 50)])
+def test_resize_image_invalid_dims(w, h):
+    original_image = np.random.randint(0, 255, (100, 100, 3), dtype=np.uint8)
+    with pytest.raises(ValueError, match="Target width and height must be positive."):
+        ipu.resize_image(original_image, w, h)
+
+
+@mock.patch('cv2.imwrite')
+@mock.patch('pathlib.Path.mkdir') # Mock mkdir to avoid actual directory creation
+def test_save_image_success(mock_mkdir, mock_cv2_imwrite):
+    mock_cv2_imwrite.return_value = True
+    img_data = np.zeros((10,10,3), dtype=np.uint8) # RGB
+    save_path = "output/test.png"
+
+    # ipu.save_image converts RGB to BGR by default for non-EXR
+    # So we expect convert_rgb_to_bgr to be called internally,
+    # and cv2.imwrite to receive BGR data.
+    # We can mock convert_rgb_to_bgr if we want to be very specific,
+    # or trust its own unit tests and check the data passed to imwrite.
+    # For simplicity, let's assume convert_rgb_to_bgr works and imwrite gets BGR.
+    # The function copies data, so we can check the mock call.
+
+    success = ipu.save_image(save_path, img_data, convert_to_bgr_before_save=True)
+
+    assert success is True
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    
+    # Check that imwrite was called. The first arg to assert_called_once_with is the path.
+    # The second arg is the image data. We need to compare it carefully.
+    # Since convert_rgb_to_bgr is called internally, the data passed to imwrite will be BGR.
+    # Let's create expected BGR data.
+    expected_bgr_data = cv2.cvtColor(img_data, cv2.COLOR_RGB2BGR)
+    
+    args, kwargs = mock_cv2_imwrite.call_args
+    assert args[0] == str(Path(save_path))
+    assert np.array_equal(args[1], expected_bgr_data)
+
+
+@mock.patch('cv2.imwrite')
+@mock.patch('pathlib.Path.mkdir')
+def test_save_image_success_exr_no_bgr_conversion(mock_mkdir, mock_cv2_imwrite):
+    mock_cv2_imwrite.return_value = True
+    img_data_rgb_float = np.random.rand(10,10,3).astype(np.float32) # RGB float for EXR
+    save_path = "output/test.exr"
+
+    success = ipu.save_image(save_path, img_data_rgb_float, output_format="exr", convert_to_bgr_before_save=False)
+    
+    assert success is True
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    args, kwargs = mock_cv2_imwrite.call_args
+    assert args[0] == str(Path(save_path))
+    assert np.array_equal(args[1], img_data_rgb_float) # Should be original RGB data
+
+@mock.patch('cv2.imwrite')
+@mock.patch('pathlib.Path.mkdir')
+def test_save_image_success_explicit_bgr_false_png(mock_mkdir, mock_cv2_imwrite):
+    mock_cv2_imwrite.return_value = True
+    img_data_rgb = np.zeros((10,10,3), dtype=np.uint8) # RGB
+    save_path = "output/test.png"
+
+    # If convert_to_bgr_before_save is False, it should save RGB as is.
+    # However, OpenCV's imwrite for PNG might still expect BGR.
+    # The function's docstring says: "If True and image is 3-channel, converts RGB to BGR."
+    # So if False, it passes the data as is.
+    success = ipu.save_image(save_path, img_data_rgb, convert_to_bgr_before_save=False)
+    
+    assert success is True
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    args, kwargs = mock_cv2_imwrite.call_args
+    assert args[0] == str(Path(save_path))
+    assert np.array_equal(args[1], img_data_rgb)
+
+
+@mock.patch('cv2.imwrite')
+@mock.patch('pathlib.Path.mkdir')
+def test_save_image_failure(mock_mkdir, mock_cv2_imwrite):
+    mock_cv2_imwrite.return_value = False
+    img_data = np.zeros((10,10,3), dtype=np.uint8)
+    save_path = "output/fail.png"
+    
+    success = ipu.save_image(save_path, img_data)
+    
+    assert success is False
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    mock_cv2_imwrite.assert_called_once() # Check it was called
+
+def test_save_image_none_data():
+    assert ipu.save_image("output/none.png", None) is False
+
+@mock.patch('cv2.imwrite', side_effect=Exception("CV2 Write Error"))
+@mock.patch('pathlib.Path.mkdir')
+def test_save_image_exception(mock_mkdir, mock_cv2_imwrite_exception):
+    img_data = np.zeros((10,10,3), dtype=np.uint8)
+    save_path = "output/exception.png"
+    
+    success = ipu.save_image(save_path, img_data)
+    
+    assert success is False
+    mock_mkdir.assert_called_once_with(parents=True, exist_ok=True)
+    mock_cv2_imwrite_exception.assert_called_once()
+
+# Test data type conversions in save_image
+@pytest.mark.parametrize(
+    "input_dtype, input_data_producer, output_dtype_target, expected_conversion_dtype, check_scaling",
+    [
+        (np.uint16, lambda: (np.random.randint(0, 65535, (10,10,3), dtype=np.uint16)), np.uint8, np.uint8, True),
+        (np.float32, lambda: np.random.rand(10,10,3).astype(np.float32), np.uint8, np.uint8, True),
+        (np.uint8, lambda: (np.random.randint(0, 255, (10,10,3), dtype=np.uint8)), np.uint16, np.uint16, True),
+        (np.float32, lambda: np.random.rand(10,10,3).astype(np.float32), np.uint16, np.uint16, True),
+        (np.uint8, lambda: (np.random.randint(0, 255, (10,10,3), dtype=np.uint8)), np.float16, np.float16, True),
+        (np.uint16, lambda: (np.random.randint(0, 65535, (10,10,3), dtype=np.uint16)), np.float32, np.float32, True),
+    ]
+)
+@mock.patch('cv2.imwrite')
+@mock.patch('pathlib.Path.mkdir')
+def test_save_image_dtype_conversion(mock_mkdir, mock_cv2_imwrite, input_dtype, input_data_producer, output_dtype_target, expected_conversion_dtype, check_scaling):
+    mock_cv2_imwrite.return_value = True
+    img_data = input_data_producer()
+    original_img_data_copy = img_data.copy() # For checking scaling if needed
+
+    ipu.save_image("output/dtype_test.png", img_data, output_dtype_target=output_dtype_target)
+
+    mock_cv2_imwrite.assert_called_once()
+    saved_img_data = mock_cv2_imwrite.call_args[0][1] # Get the image data passed to imwrite
+    
+    assert saved_img_data.dtype == expected_conversion_dtype
+
+    if check_scaling:
+        # This is a basic check. More precise checks would require known input/output values.
+        if output_dtype_target == np.uint8:
+            if input_dtype == np.uint16:
+                expected_scaled_data = (original_img_data_copy.astype(np.float32) / 65535.0 * 255.0).astype(np.uint8)
+                assert np.allclose(saved_img_data, cv2.cvtColor(expected_scaled_data, cv2.COLOR_RGB2BGR), atol=1) # Allow small diff due to float precision
+            elif input_dtype in [np.float16, np.float32, np.float64]:
+                expected_scaled_data = (np.clip(original_img_data_copy, 0.0, 1.0) * 255.0).astype(np.uint8)
+                assert np.allclose(saved_img_data, cv2.cvtColor(expected_scaled_data, cv2.COLOR_RGB2BGR), atol=1)
+        elif output_dtype_target == np.uint16:
+            if input_dtype == np.uint8:
+                expected_scaled_data = (original_img_data_copy.astype(np.float32) / 255.0 * 65535.0).astype(np.uint16)
+                assert np.allclose(saved_img_data, cv2.cvtColor(expected_scaled_data, cv2.COLOR_RGB2BGR), atol=1)
+            elif input_dtype in [np.float16, np.float32, np.float64]:
+                expected_scaled_data = (np.clip(original_img_data_copy, 0.0, 1.0) * 65535.0).astype(np.uint16)
+                assert np.allclose(saved_img_data, cv2.cvtColor(expected_scaled_data, cv2.COLOR_RGB2BGR), atol=1)
+        # Add more scaling checks for float16, float32 if necessary
+
+
+# --- Tests for calculate_image_stats ---
+
+def test_calculate_image_stats_grayscale_uint8():
+    img_data = np.array([[0, 128], [255, 10]], dtype=np.uint8)
+    # Expected normalized: [[0, 0.50196], [1.0, 0.03921]] approx
+    stats = ipu.calculate_image_stats(img_data)
+    assert stats is not None
+    assert np.isclose(stats["min"], 0/255.0)
+    assert np.isclose(stats["max"], 255/255.0)
+    assert np.isclose(stats["mean"], np.mean(img_data.astype(np.float64)/255.0))
+
+def test_calculate_image_stats_color_uint8():
+    img_data = np.array([
+        [[0, 50, 100], [10, 60, 110]],
+        [[255, 128, 200], [20, 70, 120]]
+    ], dtype=np.uint8)
+    stats = ipu.calculate_image_stats(img_data)
+    assert stats is not None
+    # Min per channel (normalized)
+    assert np.allclose(stats["min"], [0/255.0, 50/255.0, 100/255.0])
+    # Max per channel (normalized)
+    assert np.allclose(stats["max"], [255/255.0, 128/255.0, 200/255.0])
+    # Mean per channel (normalized)
+    expected_mean = np.mean(img_data.astype(np.float64)/255.0, axis=(0,1))
+    assert np.allclose(stats["mean"], expected_mean)
+
+def test_calculate_image_stats_grayscale_uint16():
+    img_data = np.array([[0, 32768], [65535, 1000]], dtype=np.uint16)
+    stats = ipu.calculate_image_stats(img_data)
+    assert stats is not None
+    assert np.isclose(stats["min"], 0/65535.0)
+    assert np.isclose(stats["max"], 65535/65535.0)
+    assert np.isclose(stats["mean"], np.mean(img_data.astype(np.float64)/65535.0))
+
+def test_calculate_image_stats_color_float32():
+    # Floats are assumed to be in 0-1 range already by the function's normalization logic
+    img_data = np.array([
+        [[0.0, 0.2, 0.4], [0.1, 0.3, 0.5]],
+        [[1.0, 0.5, 0.8], [0.05, 0.25, 0.6]]
+    ], dtype=np.float32)
+    stats = ipu.calculate_image_stats(img_data)
+    assert stats is not None
+    assert np.allclose(stats["min"], [0.0, 0.2, 0.4])
+    assert np.allclose(stats["max"], [1.0, 0.5, 0.8])
+    expected_mean = np.mean(img_data.astype(np.float64), axis=(0,1))
+    assert np.allclose(stats["mean"], expected_mean)
+
+def test_calculate_image_stats_none_input():
+    assert ipu.calculate_image_stats(None) is None
+
+def test_calculate_image_stats_unsupported_shape():
+    img_data = np.zeros((2,2,2,2), dtype=np.uint8) # 4D array
+    assert ipu.calculate_image_stats(img_data) is None
+
+@mock.patch('numpy.mean', side_effect=Exception("Numpy error"))
+def test_calculate_image_stats_exception_during_calculation(mock_np_mean):
+    img_data = np.array([[0, 128], [255, 10]], dtype=np.uint8)
+    stats = ipu.calculate_image_stats(img_data)
+    assert stats == {"error": "Error calculating image stats"}
+
+# Example of mocking ipu.load_image for a function that uses it (if calculate_image_stats used it)
+# For the current calculate_image_stats, it takes image_data directly, so this is not needed for it.
+# This is just an example as requested in the prompt for a hypothetical scenario.
+@mock.patch('processing.utils.image_processing_utils.load_image') 
+def test_hypothetical_function_using_load_image(mock_load_image):
+    # This test is for a function that would call ipu.load_image internally
+    # e.g. def process_image_from_path(path):
+    #          img_data = ipu.load_image(path)
+    #          return ipu.calculate_image_stats(img_data)
+    
+    mock_img_data = np.array([[[0.5]]], dtype=np.float32)
+    mock_load_image.return_value = mock_img_data
+    
+    # result = ipu.hypothetical_process_image_from_path("dummy.png") 
+    # mock_load_image.assert_called_once_with("dummy.png")
+    # assert result["mean"] == 0.5 
+    pass # This is a conceptual example