import os
import json
import redis
from config import logger

_REDIS_CLIENT = None

def get_redis():
    global _REDIS_CLIENT
    if _REDIS_CLIENT is not None:
        return _REDIS_CLIENT
        
    redis_url = os.getenv("REDIS_URL", "redis://localhost:6379/0")
    try:
        _REDIS_CLIENT = redis.Redis.from_url(redis_url, decode_responses=True)
        # Test connection
        _REDIS_CLIENT.ping()
        logger.info("Successfully connected to Redis cache.")
    except Exception as e:
        logger.warning(f"Failed to connect to Redis at {redis_url}: {e}. Falling back to in-memory mock.")
        _REDIS_CLIENT = MockRedis()
        
    return _REDIS_CLIENT

class MockRedis:
    """Fallback if Redis server is down"""
    def __init__(self):
        self._data = {}
    def get(self, key):
        return self._data.get(key)
    def setex(self, key, time, value):
        self._data[key] = value
    def delete(self, key):
        self._data.pop(key, None)
    def ping(self):
        return True

def cache_get_json(key):
    client = get_redis()
    val = client.get(key)
    if val:
        return json.loads(val)
    return None

def cache_set_json(key, value, ttl=300):
    client = get_redis()
    client.setex(key, ttl, json.dumps(value))