"""
Refactored preprocessing pipeline for all RAG methods.
Uses utils.py functions and supports multiple retrieval methods.

Directory Layout:
/data/         # Original PDFs, HTML
/embeddings/   # FAISS, Chroma, DPR vector stores  
/graph/        # Graph database files
/metadata/     # Image metadata (SQLite or MongoDB)
"""

import logging
from pathlib import Path

from config import *
from utils import (
    DocumentLoader, TextPreprocessor, VectorStoreManager, 
    ImageProcessor, ImageData
)

logger = logging.getLogger(__name__)

# Ensure all directories exist
ensure_directories()

def preprocess_for_method(method: str, documents: list):
    """Preprocess documents for a specific retrieval method."""
    
    print(f"\n{'='*50}")
    print(f"Preprocessing for method: {method}")
    print(f"{'='*50}")
    
    try:
        # Initialize processors
        text_processor = TextPreprocessor()
        vector_manager = VectorStoreManager()
        
        # Preprocess text chunks for this method
        chunks = text_processor.preprocess_for_method(documents, method)
        
        if method == 'vanilla':
            # Build FAISS index with OpenAI embeddings
            index, metadata = vector_manager.build_faiss_index(chunks, method="vanilla")
            vector_manager.save_index(index, metadata, method)
            
        elif method == 'dpr':
            # Build FAISS index with sentence transformer embeddings
            index, metadata = vector_manager.build_faiss_index(chunks, method="dpr")
            vector_manager.save_index(index, metadata, method)
            
        elif method == 'bm25':
            # Build BM25 index
            bm25_index = vector_manager.build_bm25_index(chunks)
            vector_manager.save_index(bm25_index, chunks, method)
            
        elif method == 'graph':
            # Build NetworkX graph
            graph = vector_manager.build_graph_index(chunks)
            vector_manager.save_index(graph, None, method)
            
        elif method == 'context_stuffing':
            # Save full documents for context stuffing
            vector_manager.save_index(None, chunks, method)
            
        else:
            raise ValueError(f"Unknown method: {method}")
            
        print(f"Successfully preprocessed for method '{method}'")
        
    except Exception as e:
        logger.error(f"Error preprocessing for {method}: {e}")
        raise


def extract_and_process_images(documents: list):
    """Extract images from documents and process them."""
    print("\n" + "="*50)
    print("Extracting and processing images...")
    print("="*50)
    
    image_processor = ImageProcessor()
    processed_count = 0
    filtered_count = 0
    filter_reasons = {}
    
    for doc in documents:
        if 'images' in doc and doc['images']:
            for image_info in doc['images']:
                try:
                    # Check if image should be filtered out
                    should_filter, reason = image_processor.should_filter_image(image_info['image_path'])
                    
                    if should_filter:
                        filtered_count += 1
                        filter_reasons[reason] = filter_reasons.get(reason, 0) + 1
                        print(f"  Filtered: {image_info['image_id']} - {reason}")
                        
                        # Optionally delete the filtered image file
                        try:
                            import os
                            os.remove(image_info['image_path'])
                            print(f"  Deleted: {image_info['image_path']}")
                        except Exception as e:
                            logger.warning(f"Could not delete filtered image {image_info['image_path']}: {e}")
                        
                        continue
                    
                    # Classify image
                    classification = image_processor.classify_image(image_info['image_path'])
                    
                    # Generate embedding (placeholder for now)
                    # embedding = embed_image_clip([image_info['image_path']])[0]
                    
                    # Create ImageData object
                    image_data = ImageData(
                        image_path=image_info['image_path'],
                        image_id=image_info['image_id'],
                        classification=classification,
                        metadata={
                            'source': doc['source'],
                            'page': image_info.get('page'),
                            'extracted_from': doc['path']
                        }
                    )
                    
                    # Store in database
                    image_processor.store_image_metadata(image_data)
                    processed_count += 1
                    
                except Exception as e:
                    logger.error(f"Error processing image {image_info['image_id']}: {e}")
                    continue
    
    # Print filtering summary
    if filtered_count > 0:
        print(f"\nImage Filtering Summary:")
        print(f"  Total filtered: {filtered_count}")
        for reason, count in filter_reasons.items():
            print(f"    {reason}: {count}")
        print()
    
    if processed_count > 0:
        print(f"Processed and stored metadata for {processed_count} images")
    else:
        print("No images found in documents")


def main():
    """Main preprocessing pipeline."""
    # Validate configuration
    try:
        validate_api_key()
    except ValueError as e:
        print(f"Error: {e}")
        return
    
    # Print configuration
    print_config()
    
    print("\nStarting preprocessing pipeline...")
    
    # Load documents using utils
    print("\nLoading documents...")
    loader = DocumentLoader()
    documents = loader.load_text_documents()
    
    print(f"Loaded {len(documents)} documents")
    
    # Define methods to preprocess
    methods = ['vanilla', 'dpr', 'bm25', 'graph', 'context_stuffing']
    
    # Preprocess for each method
    for method in methods:
        try:
            preprocess_for_method(method, documents)
        except Exception as e:
            print(f"Error preprocessing for {method}: {e}")
            import traceback
            traceback.print_exc()
    
    # Extract and process images
    try:
        extract_and_process_images(documents)
    except Exception as e:
        print(f"Error processing images: {e}")
        import traceback
        traceback.print_exc()
    
    print("\n" + "="*50)
    print("Preprocessing complete!")
    print("="*50)


if __name__ == "__main__":
    main()