package logic

import (
	"bytes"
	"encoding/json"
	"fmt"
	"fusenapi/constants"
	"fusenapi/server/websocket/internal/types"
	"fusenapi/utils/auth"
	"github.com/google/uuid"
	"github.com/gorilla/websocket"
	"net/http"
	"sync"
	"time"

	"context"

	"fusenapi/server/websocket/internal/svc"
	"github.com/zeromicro/go-zero/core/logx"
)

type DataTransferLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewDataTransferLogic(ctx context.Context, svcCtx *svc.ServiceContext) *DataTransferLogic {
	return &DataTransferLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

var (
	//临时缓存对象池
	buffPool = sync.Pool{
		New: func() interface{} {
			return bytes.Buffer{}
		},
	}
	//升级websocket
	upgrade = websocket.Upgrader{
		ReadBufferSize: 1024 * 10, //最大可读取大小 10M
		//握手超时时间15s
		HandshakeTimeout: time.Second * 15,
		//允许跨域
		CheckOrigin: func(r *http.Request) bool {
			return true
		},
		WriteBufferPool:   &buffPool,
		EnableCompression: true,
	}
	//连接map池
	mapConnPool = sync.Map{}
)

// 每个连接的连接基本属性
type wsConnectItem struct {
	conn           *websocket.Conn //websocket的连接
	closeChan      chan struct{}   //ws连接关闭chan
	isClose        bool            //是否已经关闭
	flag           string          //ws连接唯一标识
	inChan         chan []byte     //接受消息缓冲通道
	outChan        chan []byte     //发送回客户端的消息
	mutex          sync.Mutex      //互斥锁
	renderProperty renderProperty  //扩展云渲染属性
}

func (l *DataTransferLogic) DataTransfer(svcCtx *svc.ServiceContext, w http.ResponseWriter, r *http.Request) {
	//升级websocket
	conn, err := upgrade.Upgrade(w, r, nil)
	if err != nil {
		logx.Error("http upgrade websocket err:", err)
		return
	}
	defer conn.Close()
	w.Header().Set("Connection", "Upgrade")
	rsp := types.DataTransferData{}
	//鉴权不成功10秒后断开
	if !l.checkAuth(svcCtx, r) {
		time.Sleep(time.Second) //兼容下火狐
		rsp.T = constants.WEBSOCKET_UNAUTH
		b, _ := json.Marshal(rsp)
		//先发一条正常信息
		_ = conn.WriteMessage(websocket.TextMessage, b)
		//发送关闭信息
		_ = conn.WriteMessage(websocket.CloseMessage, nil)
		return
	}
	//生成连接唯一标识
	flag := uuid.New().String() + "<date=" + time.Now().Format("2006-01-02-15-04-05") + ">"
	ws := wsConnectItem{
		conn:      conn,
		flag:      flag,
		closeChan: make(chan struct{}, 1),
		inChan:    make(chan []byte, 100),
		outChan:   make(chan []byte, 100),
		renderProperty: renderProperty{
			renderImageTask:        make(map[string]struct{}),
			renderImageTaskCtlChan: make(chan renderImageControlChanItem, 100),
		},
	}
	//保存连接
	mapConnPool.Store(flag, ws)
	defer ws.close()
	//把连接成功消息发回去
	time.Sleep(time.Second) //兼容下火狐
	rsp.T = constants.WEBSOCKET_CONNECT_SUCCESS
	rsp.D = flag
	b, _ := json.Marshal(rsp)
	_ = conn.WriteMessage(websocket.TextMessage, b)
	//循环读客户端信息
	go ws.readLoop()
	//循环把数据发送给客户端
	go ws.writeLoop()
	//推消息到云渲染
	go ws.sendLoop()
	//操作连接中渲染任务的增加/删除
	go ws.operationRenderTask()
	//心跳
	ws.heartbeat()
}

// 鉴权
func (l *DataTransferLogic) checkAuth(svcCtx *svc.ServiceContext, r *http.Request) bool {
	// 解析JWT token,并对空用户进行判断
	claims, err := svcCtx.ParseJwtToken(r)
	// 如果解析JWT token出错,则返回未授权的JSON响应并记录错误消息
	if err != nil {
		return false
	}
	if claims != nil {
		// 从token中获取对应的用户信息
		_, err = auth.GetUserInfoFormMapClaims(claims)
		// 如果获取用户信息出错,则返回未授权的JSON响应并记录错误消息
		if err != nil {
			return false
		}
	} else {
		return false
	}
	return true
}

// 心跳
func (w *wsConnectItem) heartbeat() {
	tick := time.Tick(time.Second * 5)
	for {
		select {
		case <-w.closeChan:
			return
		case <-tick:
			//发送心跳信息
			if err := w.conn.WriteMessage(websocket.PongMessage, nil); err != nil {
				logx.Error("发送心跳信息异常，关闭连接:", w.flag, err)
				w.close()
				return
			}
		}
	}
}

// 关闭连接
func (w *wsConnectItem) close() {
	w.mutex.Lock()
	defer w.mutex.Unlock()
	logx.Info("websocket:", w.flag, " is closing...")
	//发送关闭信息
	_ = w.conn.WriteMessage(websocket.CloseMessage, nil)
	w.conn.Close()
	mapConnPool.Delete(w.flag)
	if !w.isClose {
		w.isClose = true
		close(w.closeChan)
	}
	logx.Info("websocket:", w.flag, " is closed")
}

// 读取输出返回给客户端
func (w *wsConnectItem) writeLoop() {
	for {
		select {
		case <-w.closeChan: //如果关闭了
			return
		case data := <-w.outChan:
			if err := w.conn.WriteMessage(websocket.TextMessage, data); err != nil {
				logx.Error("websocket write loop err:", err)
				w.close()
				return
			}
		}
	}
}

// 接受客户端发来的消息
func (w *wsConnectItem) readLoop() {
	for {
		select {
		case <-w.closeChan: //如果关闭了
			return
		default:
			msgType, data, err := w.conn.ReadMessage()
			if err != nil {
				logx.Error("接受信息错误:", err)
				//关闭连接
				w.close()
				return
			}
			//ping的消息不处理
			if msgType != websocket.PingMessage {
				//消息传入缓冲通道
				w.inChan <- data
			}
		}
	}
}

// 把收到的消息发往不同的地方处理
func (w *wsConnectItem) sendLoop() {
	for {
		select {
		case <-w.closeChan:
			return
		case data := <-w.inChan:
			w.dealwithReciveData(data)
		}
	}
}

// 把要传递给客户端的数据放入outchan
func (w *wsConnectItem) sendToOutChan(data []byte) {
	select {
	case <-w.closeChan:
		return
	case w.outChan <- data:
		logx.Info("notify send render result to out chan")
	}
}

// 获取需要渲染图片的map key
func (w *wsConnectItem) getRenderImageMapKey(productId, sizeId, templateId int64) string {
	return fmt.Sprintf("%d-%d-%d", productId, sizeId, templateId)
}

// 处理接受到的数据
func (w *wsConnectItem) dealwithReciveData(data []byte) {
	var parseInfo types.DataTransferData
	if err := json.Unmarshal(data, &parseInfo); err != nil {
		logx.Error("invalid format of websocket message")
		return
	}
	d, _ := json.Marshal(parseInfo.D)
	//分消息类型给到不同逻辑处理，可扩展
	switch parseInfo.T {
	//图片渲染
	case constants.WEBSOCKET_RENDER_IMAGE:
		go w.SendToCloudRender(d)
	default:

	}
}