"""
Image processing functions for the Image Tagger application.
"""

import os
import traceback
import glob


def process_image(image_path, model, thresholds, metadata, threshold_profile, active_threshold, active_category_thresholds, min_confidence=0.1):
    """
    Process a single image and return the tags.
    
    Args:
        image_path: Path to the image
        model: The image tagger model
        thresholds: Thresholds dictionary
        metadata: Metadata dictionary
        threshold_profile: Selected threshold profile
        active_threshold: Overall threshold value
        active_category_thresholds: Category-specific thresholds
        min_confidence: Minimum confidence to include in results
        
    Returns:
        Dictionary with tags, all probabilities, and other info
    """
    try:
        # Run inference directly using the model's predict method
        if threshold_profile in ["Category-specific", "High Precision", "High Recall"]:
            results = model.predict(
                image_path=image_path,
                category_thresholds=active_category_thresholds
            )
        else:
            results = model.predict(
                image_path=image_path,
                threshold=active_threshold
            )
        
        # Extract and organize all probabilities
        all_probs = {}
        probs = results['refined_probabilities'][0]  # Remove batch dimension
        
        for idx in range(len(probs)):
            prob_value = probs[idx].item()
            if prob_value >= min_confidence:
                tag, category = model.dataset.get_tag_info(idx)
                
                if category not in all_probs:
                    all_probs[category] = []
                
                all_probs[category].append((tag, prob_value))
        
        # Sort tags by probability within each category
        for category in all_probs:
            all_probs[category] = sorted(
                all_probs[category], 
                key=lambda x: x[1], 
                reverse=True
            )
        
        # Get the filtered tags based on the selected threshold
        tags = {}
        for category, cat_tags in all_probs.items():
            threshold = active_category_thresholds.get(category, active_threshold) if active_category_thresholds else active_threshold
            tags[category] = [(tag, prob) for tag, prob in cat_tags if prob >= threshold]
        
        # Create a flat list of all tags above threshold
        all_tags = []
        for category, cat_tags in tags.items():
            for tag, _ in cat_tags:
                all_tags.append(tag)
        
        return {
            'tags': tags,
            'all_probs': all_probs,
            'all_tags': all_tags,
            'success': True
        }
    
    except Exception as e:
        print(f"Error processing {image_path}: {str(e)}")
        traceback.print_exc()
        return {
            'tags': {},
            'all_probs': {},
            'all_tags': [],
            'success': False,
            'error': str(e)
        }

def apply_category_limits(result, category_limits):
    """
    Apply category limits to a result dictionary.
    
    Args:
        result: Result dictionary containing tags and all_tags
        category_limits: Dictionary mapping categories to their tag limits
                         (0 = exclude category, -1 = no limit/include all)
        
    Returns:
        Updated result dictionary with limits applied
    """
    if not category_limits or not result['success']:
        return result
    
    # Get the filtered tags
    filtered_tags = result['tags']
    
    # Apply limits to each category
    for category, cat_tags in list(filtered_tags.items()):
        # Get limit for this category, default to -1 (no limit)
        limit = category_limits.get(category, -1)
        
        if limit == 0:
            # Exclude this category entirely
            del filtered_tags[category]
        elif limit > 0 and len(cat_tags) > limit:
            # Limit to top N tags for this category
            filtered_tags[category] = cat_tags[:limit]
    
    # Regenerate all_tags list after applying limits
    all_tags = []
    for category, cat_tags in filtered_tags.items():
        for tag, _ in cat_tags:
            all_tags.append(tag)
    
    # Update the result with limited tags
    result['tags'] = filtered_tags
    result['all_tags'] = all_tags
    
    return result

def batch_process_images(folder_path, model, thresholds, metadata, threshold_profile, active_threshold, 
                        active_category_thresholds, save_dir=None, progress_callback=None, 
                        min_confidence=0.1, batch_size=1, category_limits=None):
    """
    Process all images in a folder with optional batching for improved performance.
    
    Args:
        folder_path: Path to folder containing images
        model: The image tagger model
        thresholds: Thresholds dictionary
        metadata: Metadata dictionary
        threshold_profile: Selected threshold profile
        active_threshold: Overall threshold value
        active_category_thresholds: Category-specific thresholds
        save_dir: Directory to save tag files (if None uses default)
        progress_callback: Optional callback for progress updates
        min_confidence: Minimum confidence threshold
        batch_size: Number of images to process at once (default: 1)
        category_limits: Dictionary mapping categories to their tag limits (0 = unlimited)
        
    Returns:
        Dictionary with results for each image
    """
    from .file_utils import save_tags_to_file  # Import here to avoid circular imports
    import torch
    from PIL import Image
    import time
    
    print(f"Starting batch processing on {folder_path} with batch size {batch_size}")
    start_time = time.time()
    
    # Find all image files in the folder
    image_extensions = ['*.jpg', '*.jpeg', '*.png']
    image_files = []

    for ext in image_extensions:
        image_files.extend(glob.glob(os.path.join(folder_path, ext)))
        image_files.extend(glob.glob(os.path.join(folder_path, ext.upper())))

    # Use a set to remove duplicate files (Windows filesystems are case-insensitive)
    if os.name == 'nt':  # Windows
        # Use lowercase paths for comparison on Windows
        unique_paths = set()
        unique_files = []
        for file_path in image_files:
            normalized_path = os.path.normpath(file_path).lower()
            if normalized_path not in unique_paths:
                unique_paths.add(normalized_path)
                unique_files.append(file_path)
        image_files = unique_files
    
    # Sort files for consistent processing order
    image_files.sort()
    
    if not image_files:
        return {
            'success': False,
            'error': f"No images found in {folder_path}",
            'results': {}
        }
    
    print(f"Found {len(image_files)} images to process")
    
    # Use the provided save directory or create a default one
    if save_dir is None:
        app_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
        save_dir = os.path.join(app_dir, "saved_tags")
    
    # Ensure the directory exists
    os.makedirs(save_dir, exist_ok=True)
    
    # Process images in batches
    results = {}
    total_images = len(image_files)
    processed = 0
    
    # Process in batches
    for i in range(0, total_images, batch_size):
        batch_start = time.time()
        # Get current batch of images
        batch_files = image_files[i:i+batch_size]
        batch_size_actual = len(batch_files)
        
        print(f"Processing batch {i//batch_size + 1}/{(total_images + batch_size - 1)//batch_size}: {batch_size_actual} images")
        
        if batch_size > 1:
            # True batch processing for multiple images at once
            try:
                # Using batch processing if batch_size > 1
                batch_results = process_image_batch(
                    image_paths=batch_files,
                    model=model,
                    thresholds=thresholds,
                    metadata=metadata,
                    threshold_profile=threshold_profile,
                    active_threshold=active_threshold,
                    active_category_thresholds=active_category_thresholds,
                    min_confidence=min_confidence
                )
                
                # Process and save results for each image in the batch
                for j, image_path in enumerate(batch_files):
                    # Update progress if callback provided
                    if progress_callback:
                        progress_callback(processed + j, total_images, image_path)
                    
                    if j < len(batch_results):
                        result = batch_results[j]
                        
                        # Apply category limits if specified
                        if category_limits and result['success']:
                            # Use the apply_category_limits function instead of the inline code
                            result = apply_category_limits(result, category_limits)
                            
                            # Debug print if you want
                            print(f"Applied limits for {os.path.basename(image_path)}, remaining tags: {len(result['all_tags'])}")
                        
                        # Save the tags to a file
                        if result['success']:
                            output_path = save_tags_to_file(
                                image_path=image_path,
                                all_tags=result['all_tags'],
                                custom_dir=save_dir,
                                overwrite=True
                            )
                            result['output_path'] = str(output_path)
                        
                        # Store the result
                        results[image_path] = result
                    else:
                        # Handle case where batch processing returned fewer results than expected
                        results[image_path] = {
                            'success': False,
                            'error': 'Batch processing error: missing result',
                            'all_tags': []
                        }
                
            except Exception as e:
                print(f"Batch processing error: {str(e)}")
                traceback.print_exc()
                
                # Fall back to processing images one by one in this batch
                for j, image_path in enumerate(batch_files):
                    if progress_callback:
                        progress_callback(processed + j, total_images, image_path)
                    
                    result = process_image(
                        image_path=image_path,
                        model=model,
                        thresholds=thresholds,
                        metadata=metadata,
                        threshold_profile=threshold_profile,
                        active_threshold=active_threshold,
                        active_category_thresholds=active_category_thresholds,
                        min_confidence=min_confidence
                    )
                    
                    # Apply category limits if specified
                    if category_limits and result['success']:
                        # Use the apply_category_limits function
                        result = apply_category_limits(result, category_limits)
                    
                    if result['success']:
                        output_path = save_tags_to_file(
                            image_path=image_path,
                            all_tags=result['all_tags'],
                            custom_dir=save_dir,
                            overwrite=True
                        )
                        result['output_path'] = str(output_path)
                    
                    results[image_path] = result
        else:
            # Process one by one if batch_size is 1
            for j, image_path in enumerate(batch_files):
                if progress_callback:
                    progress_callback(processed + j, total_images, image_path)
                
                result = process_image(
                    image_path=image_path,
                    model=model,
                    thresholds=thresholds,
                    metadata=metadata,
                    threshold_profile=threshold_profile,
                    active_threshold=active_threshold,
                    active_category_thresholds=active_category_thresholds,
                    min_confidence=min_confidence
                )
                
                # Apply category limits if specified
                if category_limits and result['success']:
                    # Use the apply_category_limits function
                    result = apply_category_limits(result, category_limits)
                
                if result['success']:
                    output_path = save_tags_to_file(
                        image_path=image_path,
                        all_tags=result['all_tags'],
                        custom_dir=save_dir,
                        overwrite=True
                    )
                    result['output_path'] = str(output_path)
                
                results[image_path] = result
        
        # Update processed count
        processed += batch_size_actual
        
        # Calculate batch timing
        batch_end = time.time()
        batch_time = batch_end - batch_start
        print(f"Batch processed in {batch_time:.2f} seconds ({batch_time/batch_size_actual:.2f} seconds per image)")
        
    # Final progress update
    if progress_callback:
        progress_callback(total_images, total_images, None)
    
    end_time = time.time()
    total_time = end_time - start_time
    print(f"Batch processing finished. Total time: {total_time:.2f} seconds, Average: {total_time/total_images:.2f} seconds per image")
    
    return {
        'success': True,
        'total': total_images,
        'processed': len(results),
        'results': results,
        'save_dir': save_dir,
        'time_elapsed': end_time - start_time
    }

def process_image_batch(image_paths, model, thresholds, metadata, threshold_profile, active_threshold, active_category_thresholds, min_confidence=0.1):
    """
    Process a batch of images at once.
    
    Args:
        image_paths: List of paths to the images
        model: The image tagger model
        thresholds: Thresholds dictionary
        metadata: Metadata dictionary
        threshold_profile: Selected threshold profile
        active_threshold: Overall threshold value
        active_category_thresholds: Category-specific thresholds
        min_confidence: Minimum confidence to include in results
        
    Returns:
        List of dictionaries with tags, all probabilities, and other info for each image
    """
    try:
        import torch
        from PIL import Image
        import torchvision.transforms as transforms
        
        # Identify the model type we're using for better error handling
        model_type = model.__class__.__name__
        print(f"Running batch processing with model type: {model_type}")
        
        # Prepare the transformation for the images
        transform = transforms.Compose([
            transforms.Resize((512, 512)),  # Adjust based on your model's expected input
            transforms.ToTensor(),
        ])
        
        # Get model information
        device = next(model.parameters()).device
        dtype = next(model.parameters()).dtype
        print(f"Model is using device: {device}, dtype: {dtype}")
        
        # Load and preprocess all images
        batch_tensor = []
        valid_images = []
        
        for img_path in image_paths:
            try:
                img = Image.open(img_path).convert('RGB')
                img_tensor = transform(img)
                img_tensor = img_tensor.to(device=device, dtype=dtype)
                batch_tensor.append(img_tensor)
                valid_images.append(img_path)
            except Exception as e:
                print(f"Error loading image {img_path}: {str(e)}")
        
        if not batch_tensor:
            return []
        
        # Stack all tensors into a single batch
        batch_input = torch.stack(batch_tensor)
        
        # Process entire batch at once
        with torch.no_grad():
            try:
                # Forward pass on the whole batch
                output = model(batch_input)
                
                # Handle tuple output format
                if isinstance(output, tuple):
                    probs_batch = torch.sigmoid(output[1])
                else:
                    probs_batch = torch.sigmoid(output)
                
                # Process each image's results
                results = []
                for i, img_path in enumerate(valid_images):
                    probs = probs_batch[i].unsqueeze(0)  # Add batch dimension back
                    
                    # Extract and organize all probabilities
                    all_probs = {}
                    for idx in range(probs.size(1)):
                        prob_value = probs[0, idx].item()
                        if prob_value >= min_confidence:
                            tag, category = model.dataset.get_tag_info(idx)
                            
                            if category not in all_probs:
                                all_probs[category] = []
                            
                            all_probs[category].append((tag, prob_value))
                    
                    # Sort tags by probability
                    for category in all_probs:
                        all_probs[category] = sorted(all_probs[category], key=lambda x: x[1], reverse=True)
                    
                    # Get filtered tags
                    tags = {}
                    for category, cat_tags in all_probs.items():
                        threshold = active_category_thresholds.get(category, active_threshold) if active_category_thresholds else active_threshold
                        tags[category] = [(tag, prob) for tag, prob in cat_tags if prob >= threshold]
                    
                    # Create a flat list of all tags above threshold
                    all_tags = []
                    for category, cat_tags in tags.items():
                        for tag, _ in cat_tags:
                            all_tags.append(tag)
                    
                    results.append({
                        'tags': tags,
                        'all_probs': all_probs,
                        'all_tags': all_tags,
                        'success': True
                    })
                
                return results
                
            except RuntimeError as e:
                # If we encounter CUDA out of memory or another runtime error, 
                # fall back to processing one by one
                print(f"Error in batch processing: {str(e)}")
                print("Falling back to one-by-one processing...")
                
                # Process one by one as fallback
                results = []
                for i, (img_tensor, img_path) in enumerate(zip(batch_tensor, valid_images)):
                    try:
                        input_tensor = img_tensor.unsqueeze(0)
                        output = model(input_tensor)
                        
                        if isinstance(output, tuple):
                            probs = torch.sigmoid(output[1])
                        else:
                            probs = torch.sigmoid(output)
                        
                        # Same post-processing as before...
                        # [Code omitted for brevity]
                        
                    except Exception as e:
                        print(f"Error processing image {img_path}: {str(e)}")
                        results.append({
                            'tags': {},
                            'all_probs': {},
                            'all_tags': [],
                            'success': False,
                            'error': str(e)
                        })
                
                return results
                
    except Exception as e:
        print(f"Error in batch processing: {str(e)}")
        import traceback
        traceback.print_exc()