"""
全局 httpx 客户端 - 连接池复用
"""

import httpx
from typing import Optional

DEFAULT_TIMEOUT = 60.0
MAX_CONNECTIONS = 10
MAX_KEEPALIVE_CONNECTIONS = 5
KEEPALIVE_EXPIRY = 30.0

_http_client: Optional[httpx.AsyncClient] = None


def get_http_client() -> httpx.AsyncClient:
    """获取全局 httpx 客户端单例"""
    global _http_client
    if _http_client is None:
        limits = httpx.Limits(
            max_connections=MAX_CONNECTIONS,
            max_keepalive_connections=MAX_KEEPALIVE_CONNECTIONS,
            keepalive_expiry=KEEPALIVE_EXPIRY,
        )
        _http_client = httpx.AsyncClient(
            timeout=DEFAULT_TIMEOUT,
            limits=limits,
            follow_redirects=True,
        )
    return _http_client


async def close_http_client():
    """关闭全局客户端（应用关闭时调用）"""
    global _http_client
    if _http_client is not None:
        await _http_client.aclose()
        _http_client = None