from pathlib import Path
from typing import Any, Dict, List, Optional

from ..embedding.embedding_service import EmbeddingService
from ..vector_store.vector_db import VectorDatabase
from .document_chunker import DocumentChunker
from .document_parser import DocumentParser


class IngestionPipeline:
    """Complete ingestion pipeline for processing document corpus with embeddings"""

    def __init__(
        self,
        chunk_size: int = 1000,
        overlap: int = 200,
        seed: int = 42,
        store_embeddings: bool = True,
        vector_db: Optional[VectorDatabase] = None,
        embedding_service: Optional[EmbeddingService] = None,
    ):
        """
        Initialize the ingestion pipeline

        Args:
            chunk_size: Size of text chunks
            overlap: Overlap between chunks
            seed: Random seed for reproducibility
            store_embeddings: Whether to generate and store embeddings
            vector_db: Vector database instance for storing embeddings
            embedding_service: Embedding service for generating embeddings
        """
        self.parser = DocumentParser()
        self.chunker = DocumentChunker(
            chunk_size=chunk_size, overlap=overlap, seed=seed
        )
        self.seed = seed
        self.store_embeddings = store_embeddings

        # Initialize embedding components if storing embeddings
        if store_embeddings:
            self.embedding_service = embedding_service or EmbeddingService()
            if vector_db is None:
                from ..config import COLLECTION_NAME, VECTOR_DB_PERSIST_PATH

                self.vector_db = VectorDatabase(
                    persist_path=VECTOR_DB_PERSIST_PATH, collection_name=COLLECTION_NAME
                )
            else:
                self.vector_db = vector_db
        else:
            self.embedding_service = None
            self.vector_db = None

    def process_directory(self, directory_path: str) -> List[Dict[str, Any]]:
        """
        Process all supported documents in a directory (backward compatible)

        Args:
            directory_path: Path to directory containing documents

        Returns:
            List of processed chunks with metadata
        """
        directory = Path(directory_path)
        if not directory.exists():
            raise FileNotFoundError(f"Directory not found: {directory_path}")

        all_chunks = []

        # Process each supported file
        for file_path in directory.iterdir():
            if (
                file_path.is_file()
                and file_path.suffix.lower() in self.parser.SUPPORTED_FORMATS
            ):
                try:
                    chunks = self.process_file(str(file_path))
                    all_chunks.extend(chunks)
                except Exception as e:
                    print(f"Warning: Failed to process {file_path}: {e}")
                    continue

        return all_chunks

    def process_directory_with_embeddings(self, directory_path: str) -> Dict[str, Any]:
        """
        Process all supported documents in a directory with embeddings and enhanced
        reporting

        Args:
            directory_path: Path to directory containing documents

        Returns:
            Dictionary with processing results and statistics
        """
        import time

        start_time = time.time()

        directory = Path(directory_path)
        if not directory.exists():
            raise FileNotFoundError(f"Directory not found: {directory_path}")

        all_chunks = []
        processed_files = 0
        failed_files = []
        embeddings_stored = 0

        # Process each supported file
        for file_path in directory.iterdir():
            if (
                file_path.is_file()
                and file_path.suffix.lower() in self.parser.SUPPORTED_FORMATS
            ):
                try:
                    chunks = self.process_file(str(file_path))
                    all_chunks.extend(chunks)
                    processed_files += 1
                except Exception as e:
                    print(f"Warning: Failed to process {file_path}: {e}")
                    failed_files.append({"file": str(file_path), "error": str(e)})
                    continue

        # Generate and store embeddings if enabled
        if (
            self.store_embeddings
            and all_chunks
            and self.embedding_service
            and self.vector_db
        ):
            try:
                embeddings_stored = self._store_embeddings_batch(all_chunks)
            except Exception as e:
                print(f"Warning: Failed to store embeddings: {e}")

        return {
            "status": "success",
            "chunks_processed": len(all_chunks),
            "files_processed": processed_files,
            "failed_files": failed_files,
            "embeddings_stored": embeddings_stored,
            "store_embeddings": self.store_embeddings,
            "processing_time_seconds": time.time() - start_time,
            "chunks": all_chunks,  # Include chunks for backward compatibility
        }

    def process_file(self, file_path: str) -> List[Dict[str, Any]]:
        """
        Process a single file through the complete pipeline

        Args:
            file_path: Path to the file to process

        Returns:
            List of chunks from the file
        """
        # Parse document
        parsed_doc = self.parser.parse_document(file_path)

        # Chunk the document
        chunks = self.chunker.chunk_document(
            parsed_doc["content"], parsed_doc["metadata"]
        )

        return chunks

    def _store_embeddings_batch(self, chunks: List[Dict[str, Any]]) -> int:
        """
        Generate embeddings and store chunks in vector database

        Args:
            chunks: List of text chunks with metadata

        Returns:
            Number of embeddings stored successfully
        """
        if not self.embedding_service or not self.vector_db:
            return 0

        stored_count = 0
        batch_size = 32  # Process in batches for memory efficiency

        for i in range(0, len(chunks), batch_size):
            batch = chunks[i : i + batch_size]

            try:
                # Extract texts and prepare data for vector storage
                texts = [chunk["content"] for chunk in batch]
                chunk_ids = [chunk["metadata"]["chunk_id"] for chunk in batch]
                metadatas = [chunk["metadata"] for chunk in batch]

                # Generate embeddings for the batch
                embeddings = self.embedding_service.embed_texts(texts)

                # Store in vector database
                self.vector_db.add_embeddings(
                    embeddings=embeddings,
                    chunk_ids=chunk_ids,
                    documents=texts,
                    metadatas=metadatas,
                )

                stored_count += len(batch)
                print(
                    f"Stored embeddings for batch {i // batch_size + 1}: "
                    f"{len(batch)} chunks"
                )

            except Exception as e:
                print(f"Warning: Failed to store batch {i // batch_size + 1}: {e}")
                continue

        return stored_count