app/vectorstore_interface.py

from abc import ABC, abstractmethod
from typing import List, Dict, Any, Optional
from gradio_client import Client
import logging
import os
from pathlib import Path
from dotenv import load_dotenv
from .utils import get_auth, process_content
load_dotenv()


class VectorStoreInterface(ABC):
    """Abstract interface for different vector store implementations."""
    
    @abstractmethod
    def search(self, query: str, top_k: int, **kwargs) -> List[Dict[str, Any]]:
        """Search for similar documents."""
        pass


class HuggingFaceSpacesVectorStore(VectorStoreInterface):
    """Vector store implementation for Hugging Face Spaces with MCP endpoints."""
    
    def __init__(self, url: str, collection_name: str, api_key: Optional[str] = None):
        repo_id = url
            
        logging.info(f"Connecting to Hugging Face Space: {repo_id}")
        
        if api_key:
            self.client = Client(repo_id, hf_token=api_key)
        else:
            self.client = Client(repo_id)
            
        self.collection_name = collection_name
        
    def search(self, query: str, top_k: int, **kwargs) -> List[Dict[str, Any]]:
        """Search using Hugging Face Spaces MCP API."""
        try:
            # Use the /search_text endpoint as documented in the API
            result = self.client.predict(
                query=query,
                collection_name=self.collection_name,
                model_name=kwargs.get('model_name'),
                top_k=top_k,
                api_name="/search_text"
            )
            
            logging.info(f"Successfully retrieved {len(result) if result else 0} documents")
            return result
            
        except Exception as e:
            logging.error(f"Error searching Hugging Face Spaces: {str(e)}")
            raise e

class QdrantVectorStore(VectorStoreInterface):
    """Vector store implementation for direct Qdrant connection."""
    
    def __init__(self, url: str, collection_name: str, api_key: Optional[str] = None):
        from qdrant_client import QdrantClient
        from sentence_transformers import SentenceTransformer

        self.client = QdrantClient(host = url,
                                # very important that port to be used for python client
                                port=443,
                                https=True,
                                # api_key = QDRANT_API_KEY_READ,
                                ## this is for write access
                                api_key = api_key,
                                timeout=120,)
        
        #self.client = QdrantClient(
        #    url=url,  # Use url parameter which handles full URLs with protocol
        #    api_key=api_key
        #)
        
        self.collection_name = collection_name
        # Initialize embedding model as None - will be loaded on first use
        self._embedding_model = None
        self._current_model_name = None
        
    def _get_embedding_model(self, model_name: str = None):
        """Lazy load embedding model to avoid loading if not needed."""
        if model_name is None:
            model_name = "BAAI/bge-m3"  # Default from config
            
        # Only reload if model name changed
        if self._embedding_model is None or self._current_model_name != model_name:
            logging.info(f"Loading embedding model: {model_name}")
            from sentence_transformers import SentenceTransformer

            cache_folder = Path(os.getenv("HF_HUB_CACHE", "/tmp/hf_cache"))
            cache_folder.mkdir(parents=True, exist_ok=True)

            self._embedding_model = SentenceTransformer(
                model_name,
                cache_folder=str(cache_folder)
            )
            # self._embedding_model = SentenceTransformer(model_name)
            self._current_model_name = model_name
            logging.info(f"Successfully loaded embedding model: {model_name}")
            
        return self._embedding_model
        
    def search(self, query: str, top_k: int, **kwargs) -> List[Dict[str, Any]]:
        """Search using direct Qdrant connection."""
        try:
            # Get embedding model
            model_name = kwargs.get('model_name')
            embedding_model = self._get_embedding_model(model_name)
            
            # Convert query to embedding
            logging.info(f"Converting query to embedding using model: {self._current_model_name}")
            query_embedding = embedding_model.encode(query).tolist()
            
            # Get filter from kwargs if provided
            filter_obj = kwargs.get('filter', None)
            
            # Perform vector search
            logging.info(f"Searching Qdrant collection '{self.collection_name}' for top {top_k} results")
            search_result = self.client.search(
                collection_name=self.collection_name,
                query_vector=query_embedding,
                query_filter=filter_obj,  # Add filter support
                limit=top_k,
                with_payload=True,
                with_vectors=False
            )
            logging.info(search_result)
            # Format results to match expected output format
            results = []
            for hit in search_result:
                raw_content = hit.payload.get('text', '')
                # Process content to handle malformed nested list structures
                processed_content = process_content(raw_content)
                
                result_dict = {
                    'answer': processed_content,
                    'answer_metadata': hit.payload.get('metadata', {}),
                    'score': hit.score
                }
                results.append(result_dict)
            
            logging.info(f"Successfully retrieved {len(results)} documents from Qdrant")
            return results
            
        except Exception as e:
            logging.error(f"Error searching Qdrant: {str(e)}")
            raise e

def create_vectorstore(config: Any) -> VectorStoreInterface:
    """Factory function to create appropriate vector store based on configuration."""
    vectorstore_type = config.get("vectorstore", "PROVIDER")
    
    # Get authentication config based on provider
    auth_config = get_auth(vectorstore_type.lower())
    
    if vectorstore_type.lower() == "huggingface":
        url = config.get("vectorstore", "URL")
        collection_name = config.get("vectorstore", "COLLECTION_NAME")
        api_key = auth_config["api_key"]
        return HuggingFaceSpacesVectorStore(url, collection_name, api_key)
    
    elif vectorstore_type.lower() == "qdrant":
        url = config.get("vectorstore", "URL")  # Use the full URL
        collection_name = config.get("vectorstore", "COLLECTION_NAME")
        api_key = auth_config["api_key"]
        # Remove port parameter since it's included in the URL
        return QdrantVectorStore(url, collection_name, api_key)
    
    else:
        raise ValueError(f"Unsupported vector store type: {vectorstore_type}")