package wechat

import (
	"context"
	"github.com/gogf/gf/v2/encoding/gjson"
	"io"
	"os"
	"server/internal/consts"
	"server/utility/ecode"
	"sync"
	"time"

	"github.com/go-resty/resty/v2"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/os/glog"
	"github.com/google/uuid"
)

type weChatClient struct {
	AppId        string
	AppSecret    string
	TicketExpire int
	Token        string
	accessToken  string
	expiresIn    int
	lastUpdated  time.Time
	mu           sync.RWMutex
}

var (
	instance *weChatClient
	once     sync.Once
)

func (c *weChatClient) loadCachedToken(ctx context.Context) bool {
	val, err := g.Redis().Get(ctx, consts.WechatAccessTokenKey)
	if err != nil || val.IsEmpty() {
		return false
	}

	var data struct {
		Token     string `json:"token"`
		ExpiresAt int64  `json:"expires_at"`
	}
	if err := gjson.DecodeTo(val.String(), &data); err != nil {
		return false
	}

	// 如果当前时间超过过期时间 - 5分钟，则视为即将过期
	if time.Now().Unix() >= data.ExpiresAt-300 {
		return false
	}

	c.mu.Lock()
	c.accessToken = data.Token
	c.expiresIn = int(data.ExpiresAt - time.Now().Unix())
	c.lastUpdated = time.Now()
	c.mu.Unlock()

	glog.Infof(ctx, "[loadCachedToken] 成功加载 Redis 中的 access_token: %s", data.Token)
	return true
}

func GetWeChatClient() *weChatClient {
	return instance
}
func init() {
	once.Do(func() {
		ctx := context.Background()
		instance = &weChatClient{
			AppId:        g.Config().MustGet(ctx, "wechat.appId").String(),
			AppSecret:    g.Config().MustGet(ctx, "wechat.appSecret").String(),
			TicketExpire: g.Config().MustGet(ctx, "wechat.ticketExpire").Int(),
			Token:        g.Config().MustGet(ctx, "wechat.token").String(),
		}

		go instance.autoRefreshToken(ctx)
	})
}

func (c *weChatClient) getAccessToken() error {
	ctx := context.Background()

	result := struct {
		AccessToken string `json:"access_token"`
		ExpiresIn   int    `json:"expires_in"` // 一般为 7200 秒
	}{}

	url := "https://api.weixin.qq.com/cgi-bin/token"

	resp, err := resty.New().R().
		SetQueryParams(g.MapStrStr{
			"grant_type": "client_credential",
			"appid":      c.AppId,
			"secret":     c.AppSecret,
		}).
		SetResult(&result).
		Get(url)

	if err != nil {
		glog.Errorf(ctx, "[getAccessToken] 请求异常, URL: %s, err: %+v", url, err)
		return ecode.Fail.Sub("发起 get access_token 请求出现异常")
	}
	if resp.IsError() {
		glog.Errorf(ctx, "[getAccessToken] 响应错误, 状态: %s, 内容: %s", resp.Status(), resp.String())
		return ecode.Fail.Sub("获取 access_token 失败")
	}

	// 写入内存
	c.mu.Lock()
	c.accessToken = result.AccessToken
	c.expiresIn = result.ExpiresIn
	c.lastUpdated = time.Now()
	c.mu.Unlock()

	// 写入 Redis
	expiresAt := time.Now().Unix() + int64(result.ExpiresIn)
	cacheData := g.Map{
		"token":      result.AccessToken,
		"expires_at": expiresAt,
	}
	jsonStr, _ := gjson.Encode(cacheData)

	ttl := result.ExpiresIn - 300
	if ttl < 60 {
		ttl = 60
	}

	err = g.Redis().SetEX(ctx, consts.WechatAccessTokenKey, jsonStr, int64(ttl))
	if err != nil {
		glog.Warningf(ctx, "[getAccessToken] Redis 缓存失败: %+v", err)
	} else {
		glog.Infof(ctx, "[getAccessToken] 成功写入 Redis，expires_in: %ds", result.ExpiresIn)
	}

	glog.Infof(ctx, "[getAccessToken] 成功获取 access_token: %s，expires_in: %ds", result.AccessToken, result.ExpiresIn)
	return nil
}

func (c *weChatClient) autoRefreshToken(ctx context.Context) {
	if c.loadCachedToken(ctx) {
		glog.Infof(ctx, "[autoRefreshToken] 成功加载缓存 token")
	} else {
		if err := c.getAccessToken(); err != nil {
			glog.Errorf(ctx, "[autoRefreshToken] 初次获取 token 失败: %+v", err)
			time.Sleep(1 * time.Minute)
		}
	}

	for {
		c.mu.RLock()
		expiresIn := c.expiresIn
		c.mu.RUnlock()

		refreshAfter := time.Duration(expiresIn-300) * time.Second
		if refreshAfter <= 0 {
			refreshAfter = 5 * time.Minute
		}

		time.Sleep(refreshAfter)

		if err := c.getAccessToken(); err != nil {
			glog.Errorf(ctx, "[autoRefreshToken] 刷新 token 失败: %+v", err)
			time.Sleep(1 * time.Minute)
		}
	}
}

func (c *weChatClient) GetTicket(sceneId string) (string, error) {
	ctx := context.Background()
	body := map[string]interface{}{
		"expire_seconds": c.TicketExpire,
		"action_name":    "QR_STR_SCENE",
		"action_info": map[string]interface{}{
			"scene": map[string]string{
				"scene_str": sceneId,
			},
		},
	}
	result := struct {
		Errcode       int    `json:"errcode"`
		Ticket        string `json:"ticket"`
		ExpireSeconds int    `json:"expire_seconds"`
		Url           string `json:"url"`
	}{}

	resp, err := resty.New().R().
		SetQueryParams(g.MapStrStr{"access_token": c.accessToken}).
		SetBody(body).
		SetResult(&result).
		Post("https://api.weixin.qq.com/cgi-bin/qrcode/create")

	if err != nil {
		glog.Errorf(ctx, "[GetTicket] 请求异常: %+v", err)
		return "", ecode.Fail.Sub("发起 get ticket 请求出现异常")
	}
	if resp.IsError() {
		glog.Errorf(ctx, "[GetTicket] 响应错误，状态: %s，内容: %s", resp.Status(), resp.String())
		return "", ecode.Fail.Sub("获取微信 ticket 失败")
	}
	if result.Errcode == 40001 {
		if err := c.getAccessToken(); err != nil {
			glog.Errorf(ctx, "[GetTicket] 刷新 token 失败: %+v", err)
			return "", ecode.Fail.Sub("刷新 access_token 失败")
		}
		return c.GetTicket(sceneId)
	}
	glog.Infof(ctx, "[GetTicket] 成功获取 ticket: %s, 过期时间: %ds", result.Ticket, result.ExpireSeconds)
	return result.Ticket, nil
}

func (c *weChatClient) GetQrCode(ticket string) (string, error) {
	ctx := context.Background()
	url := "https://mp.weixin.qq.com/cgi-bin/showqrcode"
	resp, err := resty.New().R().
		SetDoNotParseResponse(true).
		SetQueryParams(g.MapStrStr{"ticket": ticket}).
		Get(url)

	if err != nil {
		glog.Errorf(ctx, "[GetQrCode] 请求失败: %+v", err)
		return "", ecode.Fail.Sub("获取二维码图片请求失败")
	}
	if resp.IsError() {
		glog.Errorf(ctx, "[GetQrCode] 响应异常, 状态: %s", resp.Status())
		return "", ecode.Fail.Sub("获取二维码图片失败")
	}

	imagePath := uuid.New().String() + ".jpg"
	data, readErr := io.ReadAll(resp.RawBody())
	defer resp.RawBody().Close()

	if readErr != nil {
		glog.Errorf(ctx, "[GetQrCode] 读取图片失败: %+v", readErr)
		return "", ecode.Fail.Sub("读取二维码图片失败")
	}

	writeErr := os.WriteFile(imagePath, data, 0644)
	if writeErr != nil {
		glog.Errorf(ctx, "[GetQrCode] 保存图片失败: %+v", writeErr)
		return "", ecode.Fail.Sub("保存二维码图片失败")
	}

	glog.Infof(ctx, "[GetQrCode] 二维码保存成功: %s", imagePath)
	return imagePath, nil
}

func (c *weChatClient) GetToken() string {
	return c.Token
}

func (c *weChatClient) GetUserUnionId(ctx context.Context, openid string) (unionId string, err error) {

	// TODO 获取唯一UnionId
	//result := struct {
	//	UnionId string `json:"unionid"`
	//}{}
	//
	//resp, err := resty.New().R().
	//	SetQueryParams(g.MapStrStr{"access_token": c.accessToken}).SetQueryParam("openid", openid).
	//	SetResult(&result).
	//	Get("https://api.weixin.qq.com/cgi-bin/user/info")
	//
	//if err != nil {
	//	glog.Errorf(ctx, "发起 get ticket 请求出现异常: %+v", err)
	//	return "", ecode.Fail.Sub("发起 get ticket 请求出现异常")
	//}
	//if resp.StatusCode() != 200 {
	//	glog.Errorf(ctx, "获取微信 ticket 响应异常: %+v", resp.Status())
	//	return "", ecode.Fail.Sub("获取微信 ticket 失败")
	//}
	return openid, nil
}