services/utils/chat_cache.py

from services.config.valkey_config import get_redis_client, is_connection_available
import json

redis_client = get_redis_client()
CHAT_HISTORY_TTL = 3600  # 1 hour session expiry

def get_chat_history(username: str) -> list:
    """Get cached chat history for a user"""
    if not is_connection_available() or not redis_client:
        print(f"Chat cache DISABLED for {username} - returning empty history")
        return []
    
    try:
        key = f"chat:history:{username}"
        history = redis_client.get(key)
        if history:
            try:
                parsed = json.loads(history)
                print(f"Retrieved chat history for {username}: {len(parsed)} messages")
                return parsed
            except Exception as e:
                print(f"Error parsing chat history: {str(e)}")
                return []
        return []
    except Exception as e:
        print(f"Chat cache ERROR for {username}: {e}")
        return []

def append_chat_message(username: str, message: str, is_user: bool):
    """Add a new message to user's chat history"""
    if not is_connection_available() or not redis_client:
        print(f"Chat cache DISABLED for {username} - cannot save message")
        return
    
    try:
        key = f"chat:history:{username}"
        history = get_chat_history(username)
        history.append({
            "content": message,
            "is_user": is_user
        })
        redis_client.setex(key, CHAT_HISTORY_TTL, json.dumps(history))
    except Exception as e:
        print(f"Chat cache ERROR saving message for {username}: {e}")

def clear_user_chat_history(username: str):
    """Clear chat history for a user"""
    if not is_connection_available() or not redis_client:
        print(f"Chat cache DISABLED for {username} - cannot clear history")
        return
    
    try:
        key = f"chat:history:{username}"
        redis_client.delete(key)
        print(f"Cleared chat history for {username}")
    except Exception as e:
        print(f"Chat cache ERROR clearing history for {username}: {e}")