package bilibili

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"live-gateway/bilibili/msg_handler"
	"live-gateway/live"
	"live-gateway/logger"
	"live-gateway/ws"
	"net/http"
	"time"
)

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

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

type LiveBilibili struct {
	Url               string
	GetRoomUrl        string
	RoomId            int64
	UserId            int64
	HeartbeatInterval time.Duration // 心跳间

	RoomInfo *RoomInfo
	Live     *live.Live

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

func NewLiveBilibili(config *Config) *live.Live {
	bl := &LiveBilibili{
		Url:               config.Url,
		GetRoomUrl:        config.GetRoomUrl,
		RoomId:            config.RoomId,
		UserId:            config.UserId,
		HeartbeatInterval: config.HeartbeatInterval * time.Second,
		msgHandlerMapper:  make(map[string]MsgHandler, 6),
		entered:           make(chan struct{}),
	}
	// 内置处理器
	bl.AddMessageHandler(
		msg_handler.NewDanmakuHandler(),
		//&msg_handler.InterActWordHandler{},
		//&msg_handler.SendGiftHandler{},
	)

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

	bl.Live = l
	return l
}

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

func (l *LiveBilibili) PreConnect() (url string, err error) {
	url = l.Url
	// 避免重复请求接口
	if l.RoomInfo != nil &&
		(l.RoomId == l.RoomInfo.RoomId || l.RoomId == l.RoomInfo.ShortId) {
		return
	}

	fetchUrl := fmt.Sprintf(`%s%d`, l.GetRoomUrl, l.RoomId)
	response, err := http.Get(fetchUrl)
	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
	//log.Debugf("获取房间数据: %+v\n", l.RoomInfo)
	//log.With("获取房间数据", l.RoomInfo)
	return
}

func (l *LiveBilibili) Init(conn *ws.NWebsocket) (err error) {
	if err = l.joinRoom(conn); err != nil {
		return
	}

	// 等待进入房间
	<-l.entered

	go l.heartbeat(conn, l.HeartbeatInterval)
	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 WsOpEnterRoomSuccess:
		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
			}
			handler, ok := l.msgHandlerMapper[cmd.CMD]
			if !ok {
				logger.SLog.Warnf("未发现 %s 处理器", cmd.CMD)
				return
			}
			handler.HandlerMessage(entry.data)
		}
	}
}

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

	data := &WsEntry{
		protoVer:   0,
		operation:  WsOpEnterRoom,
		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.Debug("heartbeat !!!")
		data := &WsEntry{
			protoVer:   0,
			operation:  WsOpHeartbeat,
			sequenceId: WsHeaderDefaultSequence,
			data:       nil,
		}
		err := conn.SendBinaryMessage(data)
		if err != nil {
			return
		}
	}
	hb(conn)

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