"""
Redis connection and cache instance.
Provides Redis client for caching and session management.
"""
import redis.asyncio as redis
from insightfy_utils.logging import get_logger
from app.core.config import settings

logger = get_logger(__name__)

# Redis client instance
redis_client: redis.Redis = None

# Settings mapping
CACHE_URL = settings.REDIS_URL
CACHE_URI = f"{settings.REDIS_HOST}:{settings.REDIS_PORT}"
CACHE_K = settings.REDIS_PASSWORD
CACHE_DB = settings.REDIS_DB


def create_redis_connection(**kwargs) -> redis.Redis:
    """Create a Redis client with the provided kwargs."""
    return redis.Redis(**kwargs)


def _redis_from_settings() -> redis.Redis:
    """Create Redis client from settings."""
    cache_url = (CACHE_URL or "").strip()
    if cache_url:
        if cache_url.startswith(("redis://", "rediss://", "unix://")):
            return redis.from_url(
                cache_url,
                decode_responses=True,
                socket_timeout=5,
                socket_connect_timeout=5,
                retry_on_timeout=True,
                health_check_interval=30,
            )
        logger.warning(
            "Invalid REDIS_URL scheme; falling back to REDIS_HOST/REDIS_PORT",
            extra={"redis_url": cache_url},
        )

    try:
        host, port_str = CACHE_URI.split(":")
        port = int(port_str)
    except Exception:
        raise ValueError("Invalid CACHE_URI format. Expected 'host:port'.")

    return create_redis_connection(
        host=host,
        port=port,
        password=CACHE_K or None,
        db=CACHE_DB,
        decode_responses=True,
        socket_timeout=5,
        socket_connect_timeout=5,
        retry_on_timeout=True,
        health_check_interval=30,
    )


async def connect_to_redis():
    """
    Establish connection to Redis.
    Called during application startup.
    """
    global redis_client
    try:
        redis_client = _redis_from_settings()
        logger.info("Redis client initialized", extra={
            "service": "cuatrolabs-spa-ms"
        })

        # Test the connection
        await redis_client.ping()
        logger.info("Successfully connected to Redis")
    except Exception as e:
        logger.error("Failed to initialize Redis client", exc_info=e)
        raise


async def close_redis_connection():
    """
    Close Redis connection.
    Called during application shutdown.
    """
    global redis_client
    if redis_client:
        logger.info("Closing Redis connection")
        await redis_client.close()
        logger.info("Redis connection closed")


def get_redis() -> redis.Redis:
    """
    Get Redis client instance.
    
    Returns:
        redis.Redis: Redis client instance
    """
    return redis_client