"""MySQL / Redis 连接工厂。"""

from functools import lru_cache

import redis
from sqlalchemy import create_engine
from sqlalchemy.engine import Engine

from app.config.settings import settings


def _mysql_url(database: str) -> str:
    pwd = settings.mysql_password
    auth = f"{settings.mysql_user}:{pwd}" if pwd else settings.mysql_user
    return (
        f"mysql+pymysql://{auth}@{settings.mysql_host}:{settings.mysql_port}"
        f"/{database}?charset=utf8mb4"
    )


@lru_cache
def get_agent_engine() -> Engine:
    return create_engine(_mysql_url(settings.mysql_database), pool_pre_ping=True)


@lru_cache
def get_core_engine() -> Engine:
    return create_engine(_mysql_url(settings.mysql_core_database), pool_pre_ping=True)


def _redis_kwargs() -> dict:
    """RESP2：兼容 Windows Redis 3.x（无 HELLO）；Redis 7 Docker 同样可用。"""
    return {
        "decode_responses": True,
        "protocol": 2,
        "socket_timeout": 1,
        "socket_connect_timeout": 0.5,
    }


@lru_cache
def get_redis_client() -> redis.Redis:
    """Redis 单例客户端（客服线 VisitorMemory / ProfileHotCache 用）。"""
    return redis.from_url(settings.redis_url, **_redis_kwargs())