from functools import cache

import redis
import redis.asyncio as async_redis
from sqlalchemy import create_engine
from sqlalchemy.engine import Engine

from config.main import BACKEND_DIR, config

# redis-py 8 defaults to RESP3. Keep the existing RESP2 wire contract so the
# client remains compatible with older Redis servers and proxies.
RedisPool = redis.ConnectionPool.from_url(config.REDIS_URL, protocol=2)
AsyncRedisPool = async_redis.ConnectionPool.from_url(config.REDIS_URL, protocol=2)
_db_engines: set[Engine] = set()


def get_redis_client():
    return redis.Redis(connection_pool=RedisPool)


def get_redis():
    with get_redis_client() as redis_conn:
        yield redis_conn


async def get_async_redis():
    redis_conn = async_redis.Redis(connection_pool=AsyncRedisPool)
    try:
        yield redis_conn
    finally:
        await redis_conn.aclose()


@cache
def get_db_engine(version='0'):
    db_path = BACKEND_DIR / 'dataFiles' / f'dcalc_{version}.db'
    engine = create_engine(f'sqlite:///{db_path}')
    _db_engines.add(engine)
    return engine


async def close_connection_pools() -> None:
    RedisPool.close()
    await AsyncRedisPool.aclose()
    for engine in _db_engines:
        engine.dispose()
    _db_engines.clear()
    get_db_engine.cache_clear()