import logging
from typing import Dict, Any, Optional
from langchain.chains import ConversationChain

logger = logging.getLogger(__name__)

# In-memory storage for user sessions
user_sessions: Dict[str, Dict[str, Any]] = {}

def initialize_session(
    session_id: str, 
    user_id: str, 
    collection_name: Optional[str] = None
) -> None:
    """
    Initialize a new chat session
    
    Args:
        session_id: Session ID
        user_id: User ID
        collection_name: Vector store collection name (optional)
    """
    logger.info(f"Initializing session {session_id} for user {user_id}")
    
    user_sessions[session_id] = {
        "user_id": user_id,
        "collection_name": collection_name or "default",
        "chat_history": [],
        "rag_chain": None
    }

def get_session(session_id: str) -> Dict[str, Any]:
    """
    Get a session by ID
    
    Args:
        session_id: Session ID
        
    Returns:
        Dict: Session data
    """
    return user_sessions.get(session_id)

def create_rag_chain(session_id: str) -> ConversationChain:
    """
    Create a RAG chain for a session
    
    Args:
        session_id: Session ID
        
    Returns:
        ConversationChain: The created RAG chain
    """
    # Implementation for creating RAG chain
    # This would be replaced with actual implementation
    logger.info(f"Creating RAG chain for session {session_id}")
    
    # Placeholder for RAG chain creation
    rag_chain = ConversationChain()
    
    # Store the chain in the session
    if session_id in user_sessions:
        user_sessions[session_id]["rag_chain"] = rag_chain
    
    return rag_chain

def clear_chat_history(session_id: str) -> None:
    """
    Clear chat history for a session
    
    Args:
        session_id: Session ID
    """
    logger.info(f"Clearing chat history for session {session_id}")
    
    if session_id in user_sessions:
        user_sessions[session_id]["chat_history"] = []

def update_chat_history(session_id: str, user_message: str, ai_message: str) -> None:
    """
    Update chat history for a session
    
    Args:
        session_id: Session ID
        user_message: User message
        ai_message: AI response message
    """
    if session_id in user_sessions:
        user_sessions[session_id]["chat_history"].append({
            "user": user_message,
            "ai": ai_message
        })