app/cache.py

"""
Redis connection for Notification microservice.
Provides both sync cache and async pubsub for the worker queue.
"""
import redis
from typing import Optional, Any
import json
from app.core.config import settings
from app.core.logging import get_logger

logger = get_logger(__name__)

_redis_client: Optional[redis.Redis] = None


def get_redis() -> Optional[redis.Redis]:
    global _redis_client
    if _redis_client is None:
        pool_params = {
            "host": settings.REDIS_HOST,
            "port": settings.REDIS_PORT,
            "db": settings.REDIS_DB,
            "decode_responses": True,
            "max_connections": 20,
            "socket_keepalive": True,
            "socket_connect_timeout": 5,
            "retry_on_timeout": True,
            "health_check_interval": 30,
        }
        if settings.REDIS_PASSWORD:
            pool_params["password"] = settings.REDIS_PASSWORD
        pool = redis.ConnectionPool(**pool_params)
        _redis_client = redis.Redis(connection_pool=pool)
        logger.info(
            "Redis connected",
            extra={
                "event": "redis_connected",
                "redis_host": settings.REDIS_HOST,
                "redis_port": settings.REDIS_PORT,
                "redis_db": settings.REDIS_DB,
            },
        )
    return _redis_client


class CacheService:
    def __init__(self):
        self._client: Optional[redis.Redis] = None

    @property
    def client(self) -> redis.Redis:
        if self._client is None:
            self._client = get_redis()
        return self._client

    async def set(self, key: str, value: Any, ttl: int = 300) -> bool:
        try:
            v = json.dumps(value) if not isinstance(value, str) else value
            return self.client.setex(key, ttl, v)
        except Exception:
            logger.error("Cache set failed", exc_info=True, extra={"event": "cache_set_failure", "key": key})
            return False

    async def get(self, key: str) -> Optional[Any]:
        try:
            value = self.client.get(key)
            if value:
                try:
                    return json.loads(value)
                except json.JSONDecodeError:
                    return value
            return None
        except Exception:
            logger.error("Cache get failed", exc_info=True, extra={"event": "cache_get_failure", "key": key})
            return None

    async def delete(self, key: str) -> bool:
        try:
            return self.client.delete(key) > 0
        except Exception:
            logger.error(
                "Cache delete failed",
                exc_info=True,
                extra={"event": "cache_delete_failure", "key": key},
            )
            return False


cache_service = CacheService()