"""
Tests for the processing pipeline.
"""

import pytest
import numpy as np
import cv2
from unittest.mock import Mock, patch, MagicMock
from pathlib import Path

from api.pipeline import (
    ProcessingPipeline,
    PipelineConfig,
    PipelineResult,
    ProcessingMode,
    PipelineStage
)


class TestPipelineConfig:
    """Test pipeline configuration."""
    
    def test_default_config(self):
        """Test default configuration values."""
        config = PipelineConfig()
        assert config.mode == ProcessingMode.PHOTO
        assert config.quality_preset == "high"
        assert config.use_gpu == True
        assert config.enable_cache == True
    
    def test_custom_config(self):
        """Test custom configuration."""
        config = PipelineConfig(
            mode=ProcessingMode.VIDEO,
            quality_preset="ultra",
            use_gpu=False,
            batch_size=4
        )
        assert config.mode == ProcessingMode.VIDEO
        assert config.quality_preset == "ultra"
        assert config.use_gpu == False
        assert config.batch_size == 4


class TestProcessingPipeline:
    """Test the main processing pipeline."""
    
    @pytest.fixture
    def mock_pipeline(self, pipeline_config):
        """Create a pipeline with mocked components."""
        with patch('api.pipeline.ModelFactory') as mock_factory:
            with patch('api.pipeline.DeviceManager') as mock_device:
                mock_device.return_value.get_device.return_value = 'cpu'
                mock_factory.return_value.load_model.return_value = Mock()
                
                pipeline = ProcessingPipeline(pipeline_config)
                return pipeline
    
    def test_pipeline_initialization(self, mock_pipeline):
        """Test pipeline initialization."""
        assert mock_pipeline is not None
        assert mock_pipeline.config is not None
        assert mock_pipeline.current_stage == PipelineStage.INITIALIZATION
    
    def test_process_image_success(self, mock_pipeline, sample_image, sample_background):
        """Test successful image processing."""
        # Mock the processing methods
        mock_pipeline._segment_image = Mock(return_value=np.ones((512, 512), dtype=np.uint8) * 255)
        mock_pipeline.alpha_matting.process = Mock(return_value={
            'alpha': np.ones((512, 512), dtype=np.float32),
            'confidence': 0.95
        })
        
        result = mock_pipeline.process_image(sample_image, sample_background)
        
        assert result is not None
        assert isinstance(result, PipelineResult)
        assert result.success == True
        assert result.output_image is not None
    
    def test_process_image_with_effects(self, mock_pipeline, sample_image):
        """Test image processing with effects."""
        mock_pipeline.config.apply_effects = ['bokeh', 'vignette']
        
        # Mock processing
        mock_pipeline._segment_image = Mock(return_value=np.ones((512, 512), dtype=np.uint8) * 255)
        mock_pipeline.alpha_matting.process = Mock(return_value={
            'alpha': np.ones((512, 512), dtype=np.float32),
            'confidence': 0.95
        })
        
        result = mock_pipeline.process_image(sample_image, None)
        
        assert result is not None
        assert result.success == True
    
    def test_process_image_failure(self, mock_pipeline, sample_image):
        """Test image processing failure handling."""
        # Mock segmentation to fail
        mock_pipeline._segment_image = Mock(side_effect=Exception("Segmentation failed"))
        
        result = mock_pipeline.process_image(sample_image, None)
        
        assert result is not None
        assert result.success == False
        assert len(result.errors) > 0
    
    @pytest.mark.parametrize("quality", ["low", "medium", "high", "ultra"])
    def test_quality_presets(self, mock_pipeline, sample_image, quality):
        """Test different quality presets."""
        mock_pipeline.config.quality_preset = quality
        
        # Mock processing
        mock_pipeline._segment_image = Mock(return_value=np.ones((512, 512), dtype=np.uint8) * 255)
        mock_pipeline.alpha_matting.process = Mock(return_value={
            'alpha': np.ones((512, 512), dtype=np.float32),
            'confidence': 0.95
        })
        
        result = mock_pipeline.process_image(sample_image, None)
        
        assert result is not None
        assert result.success == True
    
    def test_batch_processing(self, mock_pipeline, sample_image):
        """Test batch processing of multiple images."""
        images = [sample_image] * 3
        
        # Mock processing
        mock_pipeline.process_image = Mock(return_value=PipelineResult(
            success=True,
            output_image=sample_image,
            quality_score=0.9
        ))
        
        results = mock_pipeline.process_batch(images)
        
        assert len(results) == 3
        assert all(r.success for r in results)
    
    def test_progress_callback(self, mock_pipeline, sample_image):
        """Test progress callback functionality."""
        progress_values = []
        
        def progress_callback(value, message):
            progress_values.append(value)
        
        mock_pipeline.config.progress_callback = progress_callback
        
        # Mock processing
        mock_pipeline._segment_image = Mock(return_value=np.ones((512, 512), dtype=np.uint8) * 255)
        mock_pipeline.alpha_matting.process = Mock(return_value={
            'alpha': np.ones((512, 512), dtype=np.float32),
            'confidence': 0.95
        })
        
        result = mock_pipeline.process_image(sample_image, None)
        
        assert len(progress_values) > 0
        assert 0.0 <= max(progress_values) <= 1.0
    
    def test_cache_functionality(self, mock_pipeline, sample_image):
        """Test caching functionality."""
        mock_pipeline.config.enable_cache = True
        
        # Mock processing
        mock_pipeline._segment_image = Mock(return_value=np.ones((512, 512), dtype=np.uint8) * 255)
        mock_pipeline.alpha_matting.process = Mock(return_value={
            'alpha': np.ones((512, 512), dtype=np.float32),
            'confidence': 0.95
        })
        
        # First call
        result1 = mock_pipeline.process_image(sample_image, None)
        
        # Second call (should use cache)
        result2 = mock_pipeline.process_image(sample_image, None)
        
        assert result1.success == result2.success
        # Verify segmentation was only called once (cache hit on second call)
        assert mock_pipeline._segment_image.call_count == 1
    
    def test_memory_management(self, mock_pipeline):
        """Test memory management and cleanup."""
        initial_cache_size = len(mock_pipeline.cache)
        
        # Process multiple images to fill cache
        for i in range(10):
            image = np.random.randint(0, 255, (512, 512, 3), dtype=np.uint8)
            mock_pipeline.cache[f"test_{i}"] = PipelineResult(success=True)
        
        # Clear cache
        mock_pipeline.clear_cache()
        
        assert len(mock_pipeline.cache) == 0
    
    def test_statistics_tracking(self, mock_pipeline, sample_image):
        """Test statistics tracking."""
        # Mock processing
        mock_pipeline._segment_image = Mock(return_value=np.ones((512, 512), dtype=np.uint8) * 255)
        mock_pipeline.alpha_matting.process = Mock(return_value={
            'alpha': np.ones((512, 512), dtype=np.float32),
            'confidence': 0.95
        })
        
        # Process image
        result = mock_pipeline.process_image(sample_image, None)
        
        # Get statistics
        stats = mock_pipeline.get_statistics()
        
        assert 'total_processed' in stats
        assert stats['total_processed'] > 0
        assert 'avg_time' in stats


class TestPipelineIntegration:
    """Integration tests for the pipeline."""
    
    @pytest.mark.integration
    @pytest.mark.slow
    def test_end_to_end_processing(self, sample_image, sample_background, temp_dir):
        """Test end-to-end processing pipeline."""
        config = PipelineConfig(
            use_gpu=False,
            quality_preset="medium",
            enable_cache=False
        )
        
        # Create pipeline (will use real components if available)
        try:
            pipeline = ProcessingPipeline(config)
        except Exception:
            pytest.skip("Models not available for integration test")
        
        # Process image
        result = pipeline.process_image(sample_image, sample_background)
        
        if result.success:
            assert result.output_image is not None
            assert result.output_image.shape == sample_image.shape
            assert result.quality_score > 0
            
            # Save output
            output_path = temp_dir / "test_output.png"
            cv2.imwrite(str(output_path), result.output_image)
            assert output_path.exists()
    
    @pytest.mark.integration
    @pytest.mark.slow
    def test_video_frame_processing(self, sample_video, temp_dir):
        """Test processing video frames."""
        config = PipelineConfig(
            mode=ProcessingMode.VIDEO,
            use_gpu=False,
            quality_preset="low"
        )
        
        try:
            pipeline = ProcessingPipeline(config)
        except Exception:
            pytest.skip("Models not available for integration test")
        
        # Open video
        cap = cv2.VideoCapture(sample_video)
        processed_frames = []
        
        # Process first 5 frames
        for i in range(5):
            ret, frame = cap.read()
            if not ret:
                break
            
            result = pipeline.process_image(frame, None)
            if result.success:
                processed_frames.append(result.output_image)
        
        cap.release()
        
        assert len(processed_frames) > 0
        
        # Save as video
        if processed_frames:
            output_path = temp_dir / "test_video_out.mp4"
            fourcc = cv2.VideoWriter_fourcc(*'mp4v')
            out = cv2.VideoWriter(str(output_path), fourcc, 30.0, 
                                (processed_frames[0].shape[1], processed_frames[0].shape[0]))
            
            for frame in processed_frames:
                out.write(frame)
            
            out.release()
            assert output_path.exists()


class TestPipelinePerformance:
    """Performance tests for the pipeline."""
    
    @pytest.mark.slow
    def test_processing_speed(self, mock_pipeline, sample_image, performance_timer):
        """Test processing speed."""
        # Mock processing
        mock_pipeline._segment_image = Mock(return_value=np.ones((512, 512), dtype=np.uint8) * 255)
        mock_pipeline.alpha_matting.process = Mock(return_value={
            'alpha': np.ones((512, 512), dtype=np.float32),
            'confidence': 0.95
        })
        
        with performance_timer as timer:
            result = mock_pipeline.process_image(sample_image, None)
        
        assert result.success == True
        assert timer.elapsed < 1.0  # Should process in under 1 second
    
    @pytest.mark.slow
    def test_batch_processing_speed(self, mock_pipeline, sample_image, performance_timer):
        """Test batch processing speed."""
        images = [sample_image] * 10
        
        # Mock processing
        mock_pipeline.process_image = Mock(return_value=PipelineResult(
            success=True,
            output_image=sample_image,
            quality_score=0.9
        ))
        
        with performance_timer as timer:
            results = mock_pipeline.process_batch(images)
        
        assert len(results) == 10
        assert timer.elapsed < 5.0  # Should process 10 images in under 5 seconds
    
    def test_memory_usage(self, mock_pipeline, sample_image):
        """Test memory usage during processing."""
        import psutil
        import os
        
        process = psutil.Process(os.getpid())
        initial_memory = process.memory_info().rss / 1024 / 1024  # MB
        
        # Process multiple images
        for _ in range(10):
            mock_pipeline.process_image(sample_image, None)
        
        final_memory = process.memory_info().rss / 1024 / 1024  # MB
        memory_increase = final_memory - initial_memory
        
        # Memory increase should be reasonable (less than 500MB for 10 images)
        assert memory_increase < 500