"""
HTTP Client Manager - 永久連線池管理
=====================================
統帥鐵律: 禁止 subprocess+curl，必須用 httpx AsyncClient

Features:
- Lifespan 管理 (startup/shutdown)
- 連線池復用 (Connection Pooling)
- 強制 trust_env=False (禁止 HTTP_PROXY 干擾)
- ClickHouse/SignOz 專用 Client
"""

import httpx
import structlog

from src.core.config import settings

logger = structlog.get_logger(__name__)


# =============================================================================
# Singleton Clients
# =============================================================================

_clickhouse_client: httpx.AsyncClient | None = None
_general_client: httpx.AsyncClient | None = None


# =============================================================================
# ClickHouse Client (SignOz Backend)
# =============================================================================

async def get_clickhouse_client() -> httpx.AsyncClient:
    """
    取得 ClickHouse HTTP Client

    配置:
    - base_url: 192.168.0.188:8123 (ClickHouse HTTP API)
    - trust_env: False (禁止 HTTP_PROXY 干擾)
    - timeout: 30 秒
    - 連線池: limits=100
    """
    global _clickhouse_client
    if _clickhouse_client is None or _clickhouse_client.is_closed:
        _clickhouse_client = httpx.AsyncClient(
            base_url=settings.CLICKHOUSE_URL.rstrip("/"),
            timeout=httpx.Timeout(30.0, connect=10.0),
            trust_env=False,  # 🔧 關鍵: 禁止讀取 HTTP_PROXY
            limits=httpx.Limits(max_connections=100, max_keepalive_connections=20),
            headers={
                "Content-Type": "text/plain",  # ClickHouse 需要 plain text
            },
        )
        logger.info(
            "clickhouse_client_initialized",
            base_url=settings.CLICKHOUSE_URL,
            trust_env=False,
        )
    return _clickhouse_client


async def init_clickhouse_client() -> httpx.AsyncClient:
    """
    初始化 ClickHouse Client (在 Lifespan 啟動時調用)
    """
    return await get_clickhouse_client()


async def close_clickhouse_client() -> None:
    """
    關閉 ClickHouse Client (在 Lifespan 關閉時調用)
    """
    global _clickhouse_client
    if _clickhouse_client and not _clickhouse_client.is_closed:
        await _clickhouse_client.aclose()
        logger.info("clickhouse_client_closed")
    _clickhouse_client = None


# =============================================================================
# General HTTP Client
# =============================================================================

async def get_general_client() -> httpx.AsyncClient:
    """
    取得通用 HTTP Client (Ollama, Gemini, Claude)
    """
    global _general_client
    if _general_client is None or _general_client.is_closed:
        _general_client = httpx.AsyncClient(
            timeout=httpx.Timeout(float(settings.OPENCLAW_TIMEOUT), connect=10.0),
            trust_env=False,
            limits=httpx.Limits(max_connections=50, max_keepalive_connections=10),
        )
        logger.info(
            "general_client_initialized",
            timeout=settings.OPENCLAW_TIMEOUT,
        )
    return _general_client


async def init_general_client() -> httpx.AsyncClient:
    """初始化通用 Client"""
    return await get_general_client()


async def close_general_client() -> None:
    """關閉通用 Client"""
    global _general_client
    if _general_client and not _general_client.is_closed:
        await _general_client.aclose()
        logger.info("general_client_closed")
    _general_client = None


# =============================================================================
# All Clients Lifecycle
# =============================================================================

async def init_all_http_clients() -> None:
    """
    初始化所有 HTTP Clients (在 Lifespan 調用)
    """
    await init_clickhouse_client()
    await init_general_client()
    logger.info("all_http_clients_initialized")


async def close_all_http_clients() -> None:
    """
    關閉所有 HTTP Clients (在 Lifespan 調用)
    """
    await close_clickhouse_client()
    await close_general_client()
    logger.info("all_http_clients_closed")