import json
import asyncio
from typing import Any, Dict, Optional, Tuple

import httpx
from sqlalchemy import select, update
from sqlalchemy.ext.asyncio import AsyncSession
from datetime import datetime, timedelta

# 【改动1：引入自定义北京时间工具类】
from app.utils.datetime_util import (
    BEIJING_TZ,
    datetime_to_db_tz_str,
    db_tz_str_to_datetime
)
from app.models.user_oauth import UserOAuth
from app.models.user_oauth_app import UserOAuthApp
from app.models.base import async_session
from app.utils.redis import get_redis
from app.utils.logger import get_logger

logger = get_logger("douyin_request", "douyin_request")


class DouyinRequest:
    def __init__(self, platform: str = "douyin"):
        self._client: Optional[httpx.AsyncClient] = None
        self._platform = platform

    @property
    def client(self) -> httpx.AsyncClient:
        if not self._client:
            self._client = httpx.AsyncClient(
                timeout=httpx.Timeout(30.0),
                follow_redirects=True,
            )
        return self._client

    @property
    def _redis_key(self) -> str:
        return f"{self._platform}:tokens"

    async def close(self):
        if self._client:
            await self._client.aclose()
            self._client = None

    async def _get_redis_token(self, oauth_id: str) -> Optional[str]:
        """
        【核心改动：北京时间解析+脏缓存自动清理】
        1. 缓存格式异常/字段缺失：直接删除脏缓存
        2. Token过期则不返回，交由上层判断refresh是否过期决定是否删除缓存
        """
        redis = get_redis()
        if not redis:
            raise ValueError("Redis连接未配置")

        try:
            cache_str = await redis.hget(self._redis_key, oauth_id)
            if not cache_str:
                return None

            cache = json.loads(cache_str)
            token = cache.get("token")
            expired_at_str = cache.get("expired_at")

            # 脏缓存：关键字段缺失，直接删除
            if not (token and expired_at_str):
                await redis.hdel(self._redis_key, oauth_id)
                logger.warning(f"oauth_id:{oauth_id} Redis缓存字段缺失，已清理脏数据")
                return None

            # 【改动3：使用工具类解析带时区时间，不再强制覆盖UTC】
            expired_at = db_tz_str_to_datetime(expired_at_str)
            now_beijing = datetime.now(tz=BEIJING_TZ)

            if expired_at > now_beijing:
                return token

            # AccessToken已过期，返回None，上层会校验refresh_token状态决定是否清理缓存
            return None

        except json.JSONDecodeError:
            # JSON格式损坏，清理脏缓存
            await redis.hdel(self._redis_key, oauth_id)
            logger.error(f"oauth_id:{oauth_id} Redis缓存JSON格式异常，已清理脏数据")
            return None
        except Exception as e:
            raise ValueError(f"获取Redis缓存失败: {str(e)}")

    async def _set_redis_token(self, oauth_id: str, token: str, expired_at: datetime):
        redis = get_redis()
        if not redis:
            raise ValueError("Redis连接未配置")
        # 【改动4：统一转为北京时间序列化存入Redis，和数据库时区对齐】
        cache = {
            "token": token,
            "expired_at": datetime_to_db_tz_str(expired_at),
        }
        try:
            await redis.hset(self._redis_key, oauth_id, json.dumps(cache, ensure_ascii=False))
        except Exception as e:
            raise ValueError(f"设置Redis缓存失败: {str(e)}")

    async def _delete_redis_token(self, oauth_id: str):
        """删除单个oauth_id缓存（授权彻底失效时调用）"""
        redis = get_redis()
        if not redis:
            raise ValueError("Redis连接未配置")
        try:
            await redis.hdel(self._redis_key, oauth_id)
            logger.info(f"oauth_id:{oauth_id} 授权失效，已清理Redis缓存脏数据")
        except Exception as e:
            raise ValueError(f"删除Redis缓存失败: {str(e)}")

    async def get_access_token(self, oauth_id: str, force_refresh: bool = False) -> str:
        # 优先读取缓存
        if not force_refresh:
            token = await self._get_redis_token(oauth_id)
            if token:
                return token

        async with async_session() as db:
            oauth_data = await db.execute(
                select(UserOAuth).where(
                    UserOAuth.id == oauth_id,
                    UserOAuth.deleted_at.is_(None),
                ).limit(1)
            )
            oauth_data = oauth_data.scalar_one_or_none()

            if not oauth_data:
                raise ValueError("无效的oauth_id")

            # 【改动5：统一北京时间当前时间】
            now_beijing = datetime.now(tz=BEIJING_TZ)

            if force_refresh:
                # 强制刷新：先检查refresh_token是否为空
                if not oauth_data.refresh_token:
                    # RefreshToken为空 → 授权已失效，清理Redis脏缓存
                    await self._delete_redis_token(oauth_id)
                    raise ValueError("授权已过期，请重新授权登录")
                
                # 清空同条件下所有账号缓存与数据库token
                where_cond = UserOAuth.deleted_at.is_(None)
                if oauth_data.appid:
                    where_cond = where_cond & (UserOAuth.appid == oauth_data.appid)
                if oauth_data.account_username:
                    where_cond = where_cond & (UserOAuth.account_username == oauth_data.account_username)
                if oauth_data.account_userid:
                    where_cond = where_cond & (UserOAuth.account_userid == oauth_data.account_userid)

                await db.execute(
                    update(UserOAuth).where(where_cond).values(
                        access_token=None,
                        access_token_expired=None,
                    )
                )
                await db.commit()

                related_oauth_ids = await db.execute(select(UserOAuth.id).where(where_cond))
                related_oauth_ids = [row[0] for row in related_oauth_ids.all()]
                for related_id in related_oauth_ids:
                    await self._delete_redis_token(related_id)

                new_token, new_expired_at = await self.refresh_access_token(db, oauth_id, oauth_data.appid, oauth_data.refresh_token)
                return new_token

            # 数据库AccessToken未过期，写入缓存直接返回
            if oauth_data.access_token_expired and oauth_data.access_token_expired > now_beijing:
                token = oauth_data.access_token
                expired_at = oauth_data.access_token_expired
                await self._set_redis_token(oauth_id, token, expired_at)
                return token

            # 查找同账号下未过期有效token复用
            where_cond = UserOAuth.deleted_at.is_(None)
            if oauth_data.appid:
                where_cond = where_cond & (UserOAuth.appid == oauth_data.appid)
            if oauth_data.account_username:
                where_cond = where_cond & (UserOAuth.account_username == oauth_data.account_username)
            if oauth_data.account_userid:
                where_cond = where_cond & (UserOAuth.account_userid == oauth_data.account_userid)

            related_oauths = await db.execute(
                select(UserOAuth.access_token, UserOAuth.access_token_expired).where(
                    where_cond,
                    UserOAuth.access_token_expired.is_not(None),
                    UserOAuth.access_token_expired > now_beijing,
                ).limit(1)
            )
            related_oauth = related_oauths.first()
            if related_oauth:
                token, expired_at = related_oauth
                await self._set_redis_token(oauth_id, token, expired_at)
                return token

            # =========【核心业务规则实现：判断RefreshToken是否过期】=========
            if not oauth_data.refresh_token:
                # RefreshToken为空 → 授权已失效，清理Redis脏缓存
                await self._delete_redis_token(oauth_id)
                raise ValueError("授权已过期，请重新授权登录")
            
            if oauth_data.refresh_token_expired and oauth_data.refresh_token_expired < now_beijing:
                # RefreshToken过期 → 授权彻底失效，清理Redis脏缓存
                await self._delete_redis_token(oauth_id)
                raise ValueError("授权已过期，请重新授权登录")

            # RefreshToken有效，执行刷新并更新缓存
            new_token, new_expired_at = await self.refresh_access_token(db, oauth_id, oauth_data.appid, oauth_data.refresh_token)
            return new_token

    async def refresh_access_token(self, db: AsyncSession, oauth_id: str, appid: str, refresh_token: str) -> Tuple[str, datetime]:
        oauth_info = await db.execute(
            select(UserOAuth.account_username, UserOAuth.account_userid).where(
                UserOAuth.id == oauth_id,
                UserOAuth.deleted_at.is_(None),
            ).limit(1)
        )
        oauth_info = oauth_info.first()
        if not oauth_info:
            raise ValueError("无效的oauth_id")

        account_username, account_userid = oauth_info

        result = await db.execute(
            select(UserOAuthApp.secret).where(
                UserOAuthApp.app_id == appid,
                UserOAuthApp.status == 1,
                UserOAuthApp.deleted_at.is_(None),
            ).limit(1)
        )
        app_secret = result.scalar_one_or_none()

        if not app_secret:
            raise ValueError("应用已被删除或禁用")

        response = await self.client.request(
            'POST',
            'https://api.oceanengine.com/open_api/oauth2/refresh_token/',
            data={
                'app_id': appid,
                'secret': app_secret,
                'refresh_token': refresh_token,
            },
        )
        response.raise_for_status()
        data = response.json()

        if 'code' not in data:
            raise ValueError("刷新access_token失败，接口未返回code")

        code = data.get('code', 0)
        if code != 0:
            #刷新token 
            raise ValueError(f"刷新access_token失败,接口返回：{data}")

        data = data.get('data', {})
        new_access_token = data.get('access_token', '')
        new_refresh_token = data.get('refresh_token', '')
        expires_in = data.get('expires_in', 0)
        refresh_token_expires_in = data.get('refresh_token_expires_in', 0)

        # 【改动6：北京时间计算过期时间】
        now_beijing = datetime.now(tz=BEIJING_TZ)
        new_expired_at = now_beijing + timedelta(seconds=expires_in)
        new_refresh_expired = now_beijing + timedelta(seconds=refresh_token_expires_in)

        where_cond = UserOAuth.deleted_at.is_(None)
        if appid:
            where_cond = where_cond & (UserOAuth.appid == appid)
        if account_username:
            where_cond = where_cond & (UserOAuth.account_username == account_username)
        if account_userid:
            where_cond = where_cond & (UserOAuth.account_userid == account_userid)

        await db.execute(
            update(UserOAuth).where(where_cond).values(
                access_token=new_access_token,
                refresh_token=new_refresh_token,
                access_token_expired=new_expired_at,
                refresh_token_expired=new_refresh_expired,
            )
        )
        await db.commit()

        related_oauth_ids = await db.execute(select(UserOAuth.id).where(where_cond))
        related_oauth_ids = [row[0] for row in related_oauth_ids.all()]

        for related_id in related_oauth_ids:
            await self._set_redis_token(related_id, new_access_token, new_expired_at)

        return new_access_token, new_expired_at

    async def request_with_token_with_context(
        self,
        oauth_id: str,
        url: str,
        method: str = 'GET',
        options: Optional[Dict[str, Any]] = None,
        request_count: int = 1,
    ) -> Any:
        options = options or {}
        token = await self.get_access_token(oauth_id)
        resp_data: Optional[Dict[str, Any]] = None

        for i in range(1, request_count + 1):
            try:
                headers = options.get('headers', {}).copy()
                headers['Access-Token'] = token

                has_files = 'files' in options
                if has_files:
                    headers.pop('Content-Type', None)
                else:
                    headers.setdefault('Content-Type', 'application/json')

                options['headers'] = headers
                response = await self.client.request(method, url, **options)
                response.raise_for_status()

                try:
                    resp_data = response.json()
                except json.JSONDecodeError:
                    resp_data = {'code': 0, 'data': response.text, 'msg': 'JSON解析失败'}

                if 'code' not in resp_data:
                    await asyncio.sleep(i * 5)
                    continue

                code = resp_data.get('code', 0)
                if code in [40102, 40104]:
                    await asyncio.sleep(i * 5)
                    token = await self.get_access_token(oauth_id, force_refresh=True)
                    continue
                if code in [40100, 40110]:
                    wait_time = min(2 * (2 ** (i - 1)), 10)
                    await asyncio.sleep(wait_time)
                    continue
                if code == 50000:
                    await asyncio.sleep(i * 10)
                    continue

                return resp_data

            except (httpx.HTTPStatusError, httpx.RequestError):
                await asyncio.sleep(i * 10)
                continue

        # 重试耗尽，日志记录
        options_log = {}
        for key, value in options.items():
            if key == 'files':
                options_log[key] = {k: (v[0], 'bytes_content', v[2]) for k, v in value.items()}
            else:
                options_log[key] = value

        res = json.dumps(resp_data, ensure_ascii=False) if resp_data else ''
        logger.error(
            f'DouYin API request failed after {request_count} retries. '
            f'url:{url};method:{method};oauth_id:{oauth_id};options:{json.dumps(options_log, ensure_ascii=False)};response:{res}'
        )

        if resp_data and resp_data.get("code", 0) != 0:
            raise ValueError(f'接口返回错误[code:{resp_data.get("code")}]{resp_data.get("message", "接口异常")}')
        raise ValueError("网络请求失败，请稍后重试")

    async def request_with_context(
        self,
        url: str,
        method: str = 'GET',
        options: Optional[Dict[str, Any]] = None,
    ) -> Dict[str, Any]:
        options = options or {}
        resp_data: Optional[Dict[str, Any]] = None

        for i in range(1, 3):
            try:
                headers = options.get('headers', {}).copy()
                headers.setdefault('Content-Type', 'application/json')
                options['headers'] = headers

                response = await self.client.request(method, url, **options)
                response.raise_for_status()

                try:
                    resp_data = response.json()
                except json.JSONDecodeError:
                    resp_data = {'code': 0, 'data': response.text}

                if 'code' not in resp_data:
                    await asyncio.sleep(i * 5)
                    continue
                if resp_data.get("code", 0) >= 50000:
                    await asyncio.sleep(i * 10)
                    continue
                return resp_data

            except (httpx.HTTPStatusError, httpx.RequestError):
                await asyncio.sleep(i * 10)
                continue

        res = json.dumps(resp_data, ensure_ascii=False) if resp_data else ''
        raise RuntimeError(
            f'DouYin API request failed after 2 retries. '
            f'url:{url};options:{json.dumps(options, ensure_ascii=False)};response:{res}'
        )