"""
Weibo-HotSign 定时签到任务。

核心逻辑：
1. check_and_run_due_tasks (Beat 每 5 分钟触发)
   → 从 DB 读取所有 enabled Task
   → 用 croniter 判断是否到期
   → 对到期的 task 提交 execute_signin_task
2. execute_signin_task
   → 解密 cookie → 获取超话列表 → 逐个签到 → 写日志
"""

import os
import sys
import re
import asyncio
import time as _time
import logging
import redis
from datetime import datetime, timedelta
from typing import Dict, Any, List, Optional

from celery import current_task
from croniter import croniter
from sqlalchemy import select

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "../../.."))

from shared.models.base import Base
from shared.models.task import Task
from shared.models.account import Account
from shared.models.signin_log import SigninLog
from shared.crypto import decrypt_cookie, derive_key
from shared.config import shared_settings

from ..celery_app import celery_app
from ..config import settings

logger = logging.getLogger(__name__)


def _make_session():
    """
    每次创建新的 engine + session，避免 Celery worker fork 后
    复用主进程 event loop 绑定的连接池导致 'Future attached to a different loop' 错误。
    """
    from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
    from sqlalchemy.orm import sessionmaker

    engine_kwargs: dict = {"echo": False}
    if "sqlite" not in shared_settings.DATABASE_URL:
        engine_kwargs.update(pool_size=5, max_overflow=10, pool_pre_ping=True)

    eng = create_async_engine(shared_settings.DATABASE_URL, **engine_kwargs)
    factory = sessionmaker(eng, class_=AsyncSession, expire_on_commit=False)
    return factory, eng

WEIBO_HEADERS = {
    "User-Agent": (
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 "
        "(KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"
    ),
    "Referer": "https://weibo.com/",
    "Accept": "*/*",
    "Accept-Language": "zh-CN,zh;q=0.9,en;q=0.8",
}

# --------------- Redis 分布式锁 ---------------

_redis_client = None


def _get_redis():
    global _redis_client
    if not shared_settings.USE_REDIS:
        return None
    if _redis_client is None:
        try:
            _redis_client = redis.from_url(shared_settings.REDIS_URL, decode_responses=True)
        except Exception:
            return None
    return _redis_client


def _acquire_lock(key: str, ttl: int = 600) -> bool:
    r = _get_redis()
    if r:
        return bool(r.set(f"lock:{key}", "1", nx=True, ex=ttl))
    return True  # 无 Redis 时不加锁


def _release_lock(key: str):
    r = _get_redis()
    if r:
        r.delete(f"lock:{key}")


# --------------- 辅助函数 ---------------

def _parse_cookies(cookie_str: str) -> Dict[str, str]:
    cookies: Dict[str, str] = {}
    for pair in cookie_str.split(";"):
        pair = pair.strip()
        if "=" in pair:
            k, v = pair.split("=", 1)
            cookies[k.strip()] = v.strip()
    return cookies


def _run_async(coro):
    """在 Celery worker 线程中运行 async 函数"""
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    try:
        return loop.run_until_complete(coro)
    finally:
        loop.close()


# =============== Celery Tasks ===============

@celery_app.task
def check_and_run_due_tasks():
    """
    Beat 每分钟调用。
    对每个 enabled Task，用 croniter 算出下次触发时间，
    如果在 5 分钟内即将到期，则计算精确延迟后提交执行。
    已经过了触发时间但在 2 分钟内的也会立即执行（容错）。
    """
    return _run_async(_async_check_due())


async def _async_check_due():
    now = datetime.now()
    submitted = 0

    SessionFactory, eng = _make_session()
    try:
        async with SessionFactory() as session:
            stmt = (
                select(Task, Account)
                .join(Account, Task.account_id == Account.id)
                .where(Task.is_enabled == True)
                .where(Account.status.in_(["pending", "active"]))
            )
            result = await session.execute(stmt)
            pairs = result.all()
    finally:
        await eng.dispose()

    for task, account in pairs:
        try:
            if not croniter.is_valid(task.cron_expression):
                logger.warning(f"无效 cron: task={task.id}, expr={task.cron_expression}")
                continue

            cron = croniter(task.cron_expression, now)

            # 看下次触发时间
            next_fire = cron.get_next(datetime)
            # 也看上次触发时间（处理刚过期的情况）
            cron2 = croniter(task.cron_expression, now)
            prev_fire = cron2.get_prev(datetime)

            seconds_until = (next_fire - now).total_seconds()
            seconds_since = (now - prev_fire).total_seconds()

            # 情况1: 下次触发在 5 分钟内 → 延迟到精确时间执行
            # 情况2: 上次触发在 2 分钟内 → 立即执行（刚好到期或略过）
            fire_time = None
            delay_seconds = 0

            if seconds_until <= 300:
                fire_time = next_fire
                delay_seconds = max(0, int(seconds_until))
            elif seconds_since <= 120:
                fire_time = prev_fire
                delay_seconds = 0

            if fire_time is not None:
                lock_key = f"due:{task.id}:{fire_time.strftime('%Y%m%d%H%M')}"
                if _acquire_lock(lock_key, ttl=3600):
                    if delay_seconds > 0:
                        execute_signin_task.apply_async(
                            args=[str(task.id), str(account.id)],
                            countdown=delay_seconds,
                        )
                        logger.info(
                            f"📤 预约任务: task={task.id}, account={account.weibo_user_id}, "
                            f"{delay_seconds}秒后执行 (cron={task.cron_expression})"
                        )
                    else:
                        execute_signin_task.delay(str(task.id), str(account.id))
                        logger.info(
                            f"📤 立即执行: task={task.id}, account={account.weibo_user_id}, "
                            f"cron={task.cron_expression}"
                        )
                    submitted += 1
        except Exception as e:
            logger.error(f"检查任务 {task.id} 出错: {e}")

    if submitted > 0:
        logger.info(f"✅ 本轮提交了 {submitted} 个任务")
    return {"checked": len(pairs), "submitted": submitted}


@celery_app.task(bind=True, max_retries=2, default_retry_delay=120)
def execute_signin_task(self, task_id: str, account_id: str):
    """执行单个账号的全量超话签到"""
    lock_key = f"signin:{task_id}:{account_id}"
    if not _acquire_lock(lock_key, ttl=600):
        logger.warning(f"⏭️ 签到任务正在执行中: task={task_id}")
        return {"status": "skipped", "reason": "already running"}

    try:
        logger.info(f"🎯 开始签到: task={task_id}, account={account_id}")
        result = _run_async(_async_do_signin(account_id))
        logger.info(f"✅ 签到完成: task={task_id}, result={result}")
        return result
    except Exception as exc:
        logger.error(f"❌ 签到失败: task={task_id}, error={exc}")
        _release_lock(lock_key)
        if self.request.retries < 2:
            raise self.retry(exc=exc)
        raise
    finally:
        _release_lock(lock_key)


# =============== 签到核心逻辑 ===============

async def _async_do_signin(account_id: str) -> Dict[str, Any]:
    """直接操作数据库和微博 API 完成签到"""
    import httpx

    SessionFactory, eng = _make_session()
    try:
        async with SessionFactory() as session:
            stmt = select(Account).where(Account.id == account_id)
            result = await session.execute(stmt)
            account = result.scalar_one_or_none()
            if not account:
                raise Exception(f"Account {account_id} not found")

            if account.status not in ("pending", "active"):
                return {"status": "skipped", "reason": f"status={account.status}"}

            # 解密 cookie
            key = derive_key(shared_settings.COOKIE_ENCRYPTION_KEY)
            try:
                cookie_str = decrypt_cookie(account.encrypted_cookies, account.iv, key)
            except Exception:
                account.status = "invalid_cookie"
                await session.commit()
                return {"status": "failed", "reason": "cookie decryption failed"}

            cookies = _parse_cookies(cookie_str)

            # 获取超话列表
            topics = await _fetch_topics(cookies)
            if not topics:
                return {"status": "completed", "signed": 0, "message": "no topics"}

            # 逐个签到
            signed = already = failed = 0
            for topic in topics:
                await asyncio.sleep(1.5)
                r = await _do_single_signin(cookies, topic)

                if r["status"] == "success":
                    s = "success"
                    signed += 1
                elif r["status"] == "already_signed":
                    s = "failed_already_signed"
                    already += 1
                else:
                    s = "failed_network"
                    failed += 1

                log = SigninLog(
                    account_id=account.id,
                    topic_title=topic["title"],
                    status=s,
                    reward_info={"message": r["message"]},
                    signed_at=datetime.now(),
                )
                session.add(log)

            account.last_checked_at = datetime.now()
            if account.status != "active":
                account.status = "active"
            await session.commit()

            logger.info(
                f"签到结果: account={account_id}, "
                f"signed={signed}, already={already}, failed={failed}"
            )
            return {
                "status": "completed",
                "signed": signed,
                "already_signed": already,
                "failed": failed,
                "total_topics": len(topics),
            }
    finally:
        await eng.dispose()


async def _fetch_topics(cookies: Dict[str, str]) -> List[dict]:
    """获取关注的超话列表"""
    import httpx

    topics: List[dict] = []
    async with httpx.AsyncClient(timeout=15, follow_redirects=True) as client:
        await client.get("https://weibo.com/", headers=WEIBO_HEADERS, cookies=cookies)
        xsrf = client.cookies.get("XSRF-TOKEN", "")
        headers = {**WEIBO_HEADERS, "X-Requested-With": "XMLHttpRequest"}
        if xsrf:
            headers["X-XSRF-TOKEN"] = xsrf

        page = 1
        while page <= 10:
            resp = await client.get(
                "https://weibo.com/ajax/profile/topicContent",
                params={"tabid": "231093_-_chaohua", "page": str(page)},
                headers=headers, cookies=cookies,
            )
            data = resp.json()
            if data.get("ok") != 1:
                break
            topic_list = data.get("data", {}).get("list", [])
            if not topic_list:
                break
            for item in topic_list:
                title = item.get("topic_name", "") or item.get("title", "")
                containerid = ""
                for field in ("oid", "scheme"):
                    m = re.search(r"100808[0-9a-fA-F]+", item.get(field, ""))
                    if m:
                        containerid = m.group(0)
                        break
                if title and containerid:
                    topics.append({"title": title, "containerid": containerid})
            if page >= data.get("data", {}).get("max_page", 1):
                break
            page += 1
    return topics


async def _do_single_signin(cookies: Dict[str, str], topic: dict) -> dict:
    """签到单个超话"""
    import httpx

    try:
        async with httpx.AsyncClient(timeout=15, follow_redirects=True) as client:
            await client.get("https://weibo.com/", headers=WEIBO_HEADERS, cookies=cookies)
            xsrf = client.cookies.get("XSRF-TOKEN", "")
            h = {
                **WEIBO_HEADERS,
                "Referer": f"https://weibo.com/p/{topic['containerid']}/super_index",
                "X-Requested-With": "XMLHttpRequest",
            }
            if xsrf:
                h["X-XSRF-TOKEN"] = xsrf

            resp = await client.get(
                "https://weibo.com/p/aj/general/button",
                params={
                    "ajwvr": "6",
                    "api": "http://i.huati.weibo.com/aj/super/checkin",
                    "texta": "签到", "textb": "已签到",
                    "status": "0",
                    "id": topic["containerid"],
                    "location": "page_100808_super_index",
                    "timezone": "GMT+0800",
                    "lang": "zh-cn",
                    "plat": "Win32",
                    "ua": WEIBO_HEADERS["User-Agent"],
                    "screen": "1920*1080",
                    "__rnd": str(int(_time.time() * 1000)),
                },
                headers=h, cookies=cookies,
            )
            data = resp.json()
            code = str(data.get("code", ""))
            msg = data.get("msg", "")

            if code == "100000":
                tip = ""
                if isinstance(data.get("data"), dict):
                    tip = data["data"].get("alert_title", "") or data["data"].get("tipMessage", "")
                return {"status": "success", "message": tip or "签到成功"}
            elif code == "382004":
                return {"status": "already_signed", "message": msg or "今日已签到"}
            else:
                return {"status": "failed", "message": f"code={code}, msg={msg}"}
    except Exception as e:
        return {"status": "failed", "message": str(e)}


# =============== 日志清理 ===============

# 保留天数，可通过环境变量覆盖
SIGNIN_LOG_RETAIN_DAYS = int(os.getenv("SIGNIN_LOG_RETAIN_DAYS", "30"))
# 每批删除条数，避免长时间锁表
CLEANUP_BATCH_SIZE = 1000


@celery_app.task
def cleanup_old_signin_logs():
    """
    清理超过 N 天的签到日志。
    分批删除，每批最多 CLEANUP_BATCH_SIZE 条，避免锁表。
    """
    logger.info(f"🧹 开始清理 {SIGNIN_LOG_RETAIN_DAYS} 天前的签到日志...")
    return _run_async(_async_cleanup())


async def _async_cleanup():
    from sqlalchemy import delete, func

    cutoff = datetime.now() - timedelta(days=SIGNIN_LOG_RETAIN_DAYS)
    total_deleted = 0

    SessionFactory, eng = _make_session()
    try:
        async with SessionFactory() as session:
            while True:
                # 分批删除：先查出一批 id，再按 id 删除
                stmt = (
                    select(SigninLog.id)
                    .where(SigninLog.signed_at < cutoff)
                    .limit(CLEANUP_BATCH_SIZE)
                )
                result = await session.execute(stmt)
                ids = [row[0] for row in result.all()]

                if not ids:
                    break

                del_stmt = delete(SigninLog).where(SigninLog.id.in_(ids))
                await session.execute(del_stmt)
                await session.commit()
                total_deleted += len(ids)
                logger.info(f"🧹 已删除 {total_deleted} 条...")

                # 如果本批不满，说明已经删完
                if len(ids) < CLEANUP_BATCH_SIZE:
                    break
    finally:
        await eng.dispose()

    logger.info(f"✅ 日志清理完成，共删除 {total_deleted} 条（截止 {cutoff.strftime('%Y-%m-%d')}）")
    return {"deleted": total_deleted, "cutoff": cutoff.isoformat()}