package bilibili

import (
	"encoding/json"
	"fmt"
	"git.noahlan.cn/northlan/ntools-go/logger"
	"github.com/go-ping/ping"
	"github.com/pkg/errors"
	"io/ioutil"
	"live-gateway/bilibili/msg_handler"
	"live-gateway/config"
	"live-gateway/live"
	"live-gateway/ws"
	"net/http"
	"strconv"
	"strings"
	"time"
)

type MsgHandler interface {
	HandlerMessage(data []byte)
	CMD() string
}

// 实现 live.Handler 接口
var _ live.Handler = (*LiveBilibili)(nil)

type (
	LiveBilibili struct {
		*live.Live
		sequenceId uint32

		roomInfo      *RoomInfo          // 房间信息
		webSocketInfo *WebsocketInfoResp // ws信息

		msgHandlerMapper map[string]MsgHandler
		entered          chan struct{} // 进入房间
	}
)

func NewLiveBilibili() *LiveBilibili {
	bl := &LiveBilibili{
		msgHandlerMapper: make(map[string]MsgHandler, 6),
		entered:          make(chan struct{}),
	}

	l := live.NewLive(
		live.WithWsOptions(
			ws.WithPacker(NewPackBilibili()),
		),
	)
	l.PreConnect(bl.preConnect)

	l.Init(bl.Init)
	l.Handler(bl)

	bl.Live = l
	return bl
}

func (l *LiveBilibili) registerMessageHandler(h ...MsgHandler) {
	for _, handler := range h {
		l.msgHandlerMapper[handler.CMD()] = handler
	}
}

func (l *LiveBilibili) preConnect() (url string, err error) {
	cfg := config.Config.Bilibili
	if err = l.initRoomInfo(); err != nil {
		return "", err
	}
	switch cfg.Type {
	case config.BilibiliTypeOfficial:
		err = l.initWebsocketInfo()
		if err != nil {
			logger.SLog.Errorf("获取wss信息失败, err:%+v", err)
			return "", err
		}
		if len(l.webSocketInfo.Ip) == 0 || len(l.webSocketInfo.WssPort) == 0 {
			return "", errors.New("获取到的wss信息中地址或端口为空")
		}
		logger.SLog.Info("正在寻找连接最快的API地址...")
		// 获取最快的地址
		var minDuration = 1 * time.Hour
		var minIdx = 0
		for i, ip := range l.webSocketInfo.Host {
			pinger, err := ping.NewPinger(ip)
			if err != nil {
				continue
			}
			pinger.SetPrivileged(true)
			pinger.Count = 3
			pinger.Interval = 100 * time.Nanosecond // 100ns /time
			pinger.Timeout = 200 * time.Millisecond // 200ms
			err = pinger.Run()
			if err != nil {
				continue
			}
			stat := pinger.Statistics()
			if stat.AvgRtt < minDuration {
				minDuration = stat.AvgRtt
				minIdx = i
			}
		}
		url = fmt.Sprintf("wss://%s:%d/sub", l.webSocketInfo.Host[minIdx], l.webSocketInfo.WssPort[0])

		logger.SLog.Info("找到当前最快的弹幕服务器地址 ", url, " 延迟:", minDuration)
		l.registerMessageHandler(
			msg_handler.NewDanmakuOfficialHandler(l.roomInfo.RoomId),
			msg_handler.NewGuardBuyOfficialHandler(l.roomInfo.RoomId),
			msg_handler.NewGiftOfficialHandler(l.roomInfo.RoomId),
		)
	case config.BilibiliTypeCustom:
		url = cfg.Custom.Url
		l.registerMessageHandler(
			msg_handler.NewDanmakuHandler(l.roomInfo.RoomId),
			msg_handler.NewSendGiftHandler(l.roomInfo.RoomId),
			msg_handler.NewGuardBuyHandler(l.roomInfo.RoomId),
			msg_handler.NewRedPocketHandler(l.roomInfo.RoomId),
		)
	}
	return
}

func (l *LiveBilibili) initRoomInfo() error {
	// 避免重复请求接口
	if l.roomInfo != nil {
		return nil
	}
	cfg := config.Config.Bilibili

	response, err := http.Get(fmt.Sprintf(`%s%d`, cfg.GetRoomUrl, cfg.RoomId))
	if err != nil {
		return err
	}
	res, err := ioutil.ReadAll(response.Body)
	if err != nil {
		return err
	}
	var getRoomInfoResp struct {
		Code    int       `json:"code"`
		Msg     string    `json:"msg"`
		Message string    `json:"message"`
		Data    *RoomInfo `json:"data"`
	}
	err = json.Unmarshal(res, &getRoomInfoResp)
	if err != nil {
		return err
	}
	l.roomInfo = getRoomInfoResp.Data
	logger.SLog.Infof("获取房间数据: %+v\n", l.roomInfo)

	return nil
}

func (l *LiveBilibili) initWebsocketInfo() error {
	cfg := config.Config.Bilibili

	req := &WebsocketInfoReq{
		RoomId: l.roomInfo.RoomId,
	}
	content, _ := json.Marshal(req)
	header := &CommonHeader{
		ContentType:       JsonType,
		ContentAcceptType: JsonType,
		Timestamp:         strconv.FormatInt(time.Now().Unix(), 10),
		SignatureMethod:   HmacSha256,
		SignatureVersion:  BiliVersion,
		Authorization:     "",
		Nonce:             strconv.FormatInt(time.Now().UnixNano(), 10),
		AccessKeyId:       cfg.Official.AkId,
		ContentMD5:        Md5(string(content)),
	}
	header.Authorization = CreateSignature(header, cfg.Official.AkSecret)

	request, err := http.NewRequest("POST", fmt.Sprintf("%s/v1/common/websocketInfo", cfg.Official.Api), strings.NewReader(string(content)))
	if err != nil {
		return err
	}
	for k, v := range header.ToMap() {
		request.Header.Add(k, v)
	}
	response, err := http.DefaultClient.Do(request)
	if err != nil {
		return err
	}
	res, err := ioutil.ReadAll(response.Body)
	if err != nil {
		return err
	}
	var baseResp BaseResp
	err = json.Unmarshal(res, &baseResp)
	if err != nil {
		return err
	}
	if baseResp.Code != 0 {
		return errors.New(fmt.Sprintf("调用API失败, result: %+v", baseResp))
	}
	var infoData WebsocketInfoResp
	err = json.Unmarshal(baseResp.Data, &infoData)
	if err != nil {
		return err
	}
	l.webSocketInfo = &infoData
	logger.SLog.Debugf("获取到wss信息为: %+v", infoData)
	return nil
}

func (l *LiveBilibili) Init(conn *ws.NWebsocket) (err error) {
	cfg := config.Config.Bilibili
	switch cfg.Type {
	case config.BilibiliTypeOfficial:
		if err = l.auth(conn); err != nil {
			logger.SLog.Error(err)
			return
		}
	case config.BilibiliTypeCustom:
		if err = l.joinRoom(conn); err != nil {
			logger.SLog.Error(err)
			return
		}
	}

	// 等待进入房间或登录成功
	<-l.entered

	go l.heartbeat(conn, cfg.HeartbeatInterval*time.Second)
	return
}

func (l *LiveBilibili) HandlerMessage(v interface{}) {
	entry, ok := v.(*WsEntry)
	if !ok {
		logger.SLog.Warn("读取消息错误, 数据类型不匹配 WsEntry")
		return
	}
	// 处理消息
	switch entry.operation {
	case WsOpEnterRoomOrAuthReply:
		go func() {
			select {
			case l.entered <- struct{}{}:
			}
		}()
	case WsOpHeartbeatReply:
	// TODO 心跳回复(房间人数)
	case WsOpMessage:
		// message with operation
		if entry.protoVer == WsVerPlain {
			var cmd CMD
			err := json.Unmarshal(entry.data, &cmd)
			if err != nil {
				logger.SLog.Error("读取消息CMD错误")
				return
			}
			// 暂时忽略CMD错误
			if strings.Contains(cmd.CMD, "DANMU_MSG") {
				cmd.CMD = "DANMU_MSG"
			}
			handler, ok := l.msgHandlerMapper[cmd.CMD]
			if !ok {
				logger.SLog.Debugf("未发现 %s 处理器", cmd.CMD)
				return
			}
			handler.HandlerMessage(entry.data)
		}
	}
}

func (l *LiveBilibili) auth(conn *ws.NWebsocket) error {
	if l.webSocketInfo == nil {
		return errors.New("websocket信息未获取成功，不能登录")
	}
	data := &WsEntry{
		operation: WsOpEnterRoomOrAuth,
		data:      []byte(l.webSocketInfo.AuthBody),
	}
	l.sequenceId++
	err := conn.SendBinaryMessage(data)
	if err != nil {
		return errors.Wrap(err, "发送AUTH消息到wss失败")
	}
	return nil
}

func (l *LiveBilibili) joinRoom(conn *ws.NWebsocket) error {
	cfg := config.Config.Bilibili
	msg := JoinRoomReq{
		Platform: "web",
		ProtoVer: 1,
		RoomId:   l.roomInfo.RoomId,
		Uid:      cfg.UserId,
		Type:     2,
	}
	body, err := json.Marshal(msg)
	if err != nil {
		return err
	}

	data := &WsEntry{
		protoVer:   0,
		operation:  WsOpEnterRoomOrAuth,
		sequenceId: WsHeaderDefaultSequence,
		data:       body,
	}
	if err = conn.SendBinaryMessage(data); err != nil {
		return err
	}
	return nil
}

func (l *LiveBilibili) heartbeat(conn *ws.NWebsocket, t time.Duration) {
	hb := func(conn *ws.NWebsocket) {
		//logger.SLog.Info("heartbeat !!!")
		data := &WsEntry{
			protoVer:   0,
			operation:  WsOpHeartbeat,
			sequenceId: l.sequenceId,
			data:       nil,
		}
		l.sequenceId++
		err := conn.SendBinaryMessage(data)
		if err != nil {
			return
		}
	}
	hb(conn)

	ticker := time.NewTicker(t)
	defer ticker.Stop()
	for {
		select {
		case <-ticker.C:
			hb(conn)
		}
	}
}