"""代理验证服务 - 支持 HTTP/HTTPS/SOCKS4/SOCKS5"""
import asyncio
import random
import time
import aiohttp
import aiohttp_socks
from typing import Tuple, Optional

from app.core.config import settings as app_settings
from app.core.log import logger


class ValidatorService:
    """代理验证器

    支持动态读取配置，实现设置热更新。
    """

    # 测试 URL
    TEST_URLS = {
        "http": ["http://httpbin.org/ip", "http://api.ipify.org"],
        "https": ["https://httpbin.org/ip", "https://api.ipify.org"],
    }

    def __init__(
        self,
        timeout: Optional[float] = None,
        connect_timeout: Optional[float] = None,
        max_concurrency: Optional[int] = None,
    ):
        # 初始化时使用传入值或默认值，但运行期会动态读取 settings
        self._init_timeout = timeout or app_settings.validator_timeout
        self._init_connect_timeout = connect_timeout or app_settings.validator_connect_timeout
        self._init_max_concurrency = max_concurrency or app_settings.validator_max_concurrency

        self._http_connector: Optional[aiohttp.TCPConnector] = None
        self._http_session: Optional[aiohttp.ClientSession] = None
        self._semaphore: Optional[asyncio.Semaphore] = None
        self._lock = asyncio.Lock()

    @property
    def timeout(self) -> float:
        return float(self._init_timeout)

    @property
    def connect_timeout(self) -> float:
        return float(self._init_connect_timeout)

    @property
    def max_concurrency(self) -> int:
        return int(self._init_max_concurrency)

    def _ensure_session(self) -> aiohttp.ClientSession:
        """懒加载共享 HTTP session"""
        if self._http_session is None or self._http_session.closed:
            connector = aiohttp.TCPConnector(
                ssl=False,
                limit=self.max_concurrency,
                limit_per_host=self.max_concurrency,
                force_close=False,
            )
            timeout = aiohttp.ClientTimeout(
                total=self.timeout, connect=self.connect_timeout
            )
            self._http_connector = connector
            self._http_session = aiohttp.ClientSession(
                connector=connector,
                timeout=timeout,
            )
        return self._http_session

    def _ensure_semaphore(self) -> asyncio.Semaphore:
        if self._semaphore is None:
            self._semaphore = asyncio.Semaphore(self.max_concurrency)
        return self._semaphore

    def _get_test_url(self, protocol: str) -> str:
        urls = self.TEST_URLS.get(protocol.lower(), self.TEST_URLS["http"])
        return random.choice(urls)

    async def validate(self, ip: str, port: int, protocol: str = "http") -> Tuple[bool, float]:
        """验证单个代理，返回 (是否有效, 延迟毫秒)"""
        protocol = protocol.lower()
        semaphore = self._ensure_semaphore()

        async with semaphore:
            start = time.time()
            try:
                if protocol in ("socks4", "socks5"):
                    return await self._validate_socks(ip, port, protocol, start)
                else:
                    return await self._validate_http(ip, port, protocol, start)
            except asyncio.TimeoutError:
                logger.debug(f"Validation timeout: {ip}:{port} ({protocol})")
                return False, 0.0
            except Exception as e:
                logger.debug(f"Validation error {ip}:{port} ({protocol}): {e}")
                return False, 0.0

    async def _validate_http(self, ip: str, port: int, protocol: str, start: float) -> Tuple[bool, float]:
        proxy_url = f"http://{ip}:{port}"
        test_url = self._get_test_url(protocol)
        session = self._ensure_session()

        async with session.get(test_url, proxy=proxy_url, allow_redirects=True) as response:
            if response.status in (200, 301, 302):
                latency = round((time.time() - start) * 1000, 2)
                logger.info(f"HTTP valid: {ip}:{port} ({protocol}) {latency}ms")
                return True, latency
            return False, 0.0

    async def _validate_socks(self, ip: str, port: int, protocol: str, start: float) -> Tuple[bool, float]:
        proxy_type = (
            aiohttp_socks.ProxyType.SOCKS4
            if protocol == "socks4"
            else aiohttp_socks.ProxyType.SOCKS5
        )
        connector = aiohttp_socks.ProxyConnector(
            proxy_type=proxy_type,
            host=ip,
            port=port,
            rdns=True,
            ssl=False,
        )
        timeout = aiohttp.ClientTimeout(total=self.timeout, connect=self.connect_timeout)
        test_url = self._get_test_url("http")

        async with aiohttp.ClientSession(connector=connector, timeout=timeout) as session:
            async with session.get(test_url, allow_redirects=True) as response:
                if response.status in (200, 301, 302):
                    latency = round((time.time() - start) * 1000, 2)
                    logger.info(f"SOCKS valid: {ip}:{port} ({protocol}) {latency}ms")
                    return True, latency
                return False, 0.0

    async def close(self) -> None:
        """关闭共享的 HTTP ClientSession"""
        if self._http_session and not self._http_session.closed:
            await self._http_session.close()
            self._http_session = None
        self._http_connector = None