import json
import time
from utils.config import config

# Try to import redis, but handle if not available
try:
    import redis
    REDIS_AVAILABLE = True
except ImportError:
    REDIS_AVAILABLE = False
    redis = None

def get_redis_client():
    """Create and return Redis client with retry logic"""
    if not REDIS_AVAILABLE:
        return None
        
    last_exception = None
    
    for attempt in range(config.redis_retries + 1):
        try:
            # Handle empty username/password gracefully
            redis_client = redis.Redis(
                host=config.redis_host,
                port=config.redis_port,
                username=config.redis_username if config.redis_username else None,
                password=config.redis_password if config.redis_password else None,
                decode_responses=True,
                socket_connect_timeout=5,
                socket_timeout=5
            )
            # Test the connection
            redis_client.ping()
            return redis_client
        except Exception as e:
            last_exception = e
            if attempt < config.redis_retries:
                time.sleep(config.redis_retry_delay * (2 ** attempt))  # Exponential backoff
            continue
            
    return None

# Initialize Redis connection with better error handling
redis_client = None
try:
    redis_client = get_redis_client()
    if redis_client is None and REDIS_AVAILABLE:
        print("Warning: Could not connect to Redis - using in-memory storage")
except Exception as e:
    print(f"Warning: Redis initialization failed: {e}")

def save_user_state(user_id: str, state: dict):
    """Save user state to Redis with fallback to in-memory storage"""
    global redis_client
    if not redis_client:
        # Fallback: use in-memory storage (will not persist across restarts)
        print("Redis not available, using in-memory storage for user state")
        return False
        
    try:
        redis_client.hset(f"user:{user_id}", mapping=state)
        return True
    except Exception as e:
        print(f"Error saving user state: {e}")
        return False

def load_user_state(user_id: str):
    """Load user state from Redis with fallback"""
    global redis_client
    if not redis_client:
        print("Redis not available, returning empty state")
        return {}
        
    try:
        return redis_client.hgetall(f"user:{user_id}")
    except Exception as e:
        print(f"Error loading user state: {e}")
        return {}

def check_redis_health():
    """Check if Redis is healthy"""
    global redis_client
    if not redis_client:
        return False
    try:
        redis_client.ping()
        return True
    except:
        return False