"""验证任务队列 - 解耦爬取与验证，支持背压控制和持久化"""
import asyncio
from typing import Optional
from app.models.domain import ProxyRaw
from app.repositories.task_repo import ValidationTaskRepository
from app.core.db import get_db
from app.core.log import logger


class ValidationQueue:
    """代理验证队列（支持持久化到 SQLite）

    工作流程：
    1. 爬虫将原始代理 submit() 到队列（写入数据库 + 内存信号）
    2. Worker 池从数据库消费并验证
    3. 验证通过的代理写入数据库
    4. 服务重启时自动恢复未完成的 pending 任务
    """

    def __init__(
        self,
        validator,
        proxy_repo,
        worker_count: int = 50,
        score_valid: int = 10,
        score_invalid: int = -5,
        score_min: int = 0,
        score_max: int = 100,
    ):
        self.validator = validator
        self.proxy_repo = proxy_repo
        self.task_repo = ValidationTaskRepository()
        self.worker_count = worker_count
        self.score_valid = score_valid
        self.score_invalid = score_invalid
        self.score_min = score_min
        self.score_max = score_max

        self._signal: asyncio.Queue[None] = asyncio.Queue()
        self._workers: list[asyncio.Task] = []
        self._running = False
        self._db_lock = asyncio.Lock()

        # 统计
        self.valid_count = 0
        self.invalid_count = 0

    async def start(self):
        if self._running:
            return
        self._running = True

        # 恢复之前中断的 processing 任务
        async with get_db() as db:
            recovered = await self.task_repo.reset_processing(db)
            pending = await self.task_repo.get_pending_count(db)
        if recovered:
            logger.info(f"ValidationQueue recovered {recovered} interrupted tasks")
        if pending:
            logger.info(f"ValidationQueue has {pending} pending tasks to process")

        for i in range(self.worker_count):
            self._workers.append(asyncio.create_task(self._worker_loop(i)))

        # 唤醒 Worker 处理恢复的 pending 任务
        if pending:
            for _ in range(min(pending, self.worker_count)):
                self._signal.put_nowait(None)

        logger.info(f"ValidationQueue started with {self.worker_count} workers")

    async def stop(self):
        if not self._running:
            return
        self._running = False
        for _ in self._workers:
            self._signal.put_nowait(None)  # sentinel
        if self._workers:
            await asyncio.gather(*self._workers, return_exceptions=True)
        self._workers.clear()
        logger.info("ValidationQueue stopped")

    async def submit(self, proxies: list[ProxyRaw]):
        """提交代理到验证队列（持久化 + 唤醒 Worker）"""
        async with self._db_lock:
            async with get_db() as db:
                inserted = await self.task_repo.insert_batch(db, proxies)
        if inserted:
            for _ in range(min(inserted, self.worker_count)):
                self._signal.put_nowait(None)

    async def submit_one(self, proxy: ProxyRaw):
        await self.submit([proxy])

    async def drain(self):
        """等待队列中当前所有 pending 任务处理完毕"""
        while True:
            async with get_db() as db:
                count = await self.task_repo.get_pending_count(db)
            if count == 0:
                break
            await asyncio.sleep(0.5)

    async def _worker_loop(self, worker_id: int):
        while True:
            await self._signal.get()
            self._signal.task_done()
            if not self._running:
                break
            await self._process_one_task(worker_id)

    async def _process_one_task(self, worker_id: int):
        """从数据库取一个任务并验证"""
        async with self._db_lock:
            async with get_db() as db:
                task = await self.task_repo.acquire_pending(db)
        if not task:
            return

        proxy = ProxyRaw(task["ip"], task["port"], task["protocol"])
        try:
            is_valid, latency = await self.validator.validate(
                proxy.ip, proxy.port, proxy.protocol
            )
        except Exception as e:
            logger.error(f"Worker {worker_id} validation error: {e}")
            is_valid, latency = False, 0.0

        async with self._db_lock:
            async with get_db() as db:
                if is_valid:
                    await self.proxy_repo.insert_or_update(
                        db, proxy.ip, proxy.port, proxy.protocol, score=self.score_valid
                    )
                    if latency:
                        await self.proxy_repo.update_response_time(
                            db, proxy.ip, proxy.port, latency
                        )
                    await self.task_repo.complete_task(db, task["id"], True, latency)
                    self.valid_count += 1
                    logger.debug(f"ValidationQueue: valid {proxy.ip}:{proxy.port}")
                else:
                    await self.task_repo.complete_task(db, task["id"], False, 0.0)
                    self.invalid_count += 1
                    logger.debug(f"ValidationQueue: invalid {proxy.ip}:{proxy.port}")

    def reset_stats(self):
        self.valid_count = 0
        self.invalid_count = 0