package main

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"hilo-userProxy/common"
	"hilo-userProxy/common/consul"
	"net"
	"net/http"
	_ "net/http/pprof"
	"runtime/debug"
	"strconv"
	"strings"
	"sync"
	"sync/atomic"
	"time"

	"hilo-userProxy/common/mylogrus"
	"hilo-userProxy/protocol/userCenter"
	"hilo-userProxy/protocol/userProxy"

	"github.com/golang/protobuf/proto"
	"github.com/gorilla/websocket"
	consulapi "github.com/hashicorp/consul/api"
	uuid "github.com/satori/go.uuid"
	log "github.com/sirupsen/logrus"
	"google.golang.org/grpc"
	"google.golang.org/grpc/keepalive"
	"google.golang.org/grpc/peer"
	"google.golang.org/grpc/resolver"
)

// 序号号，一个进程一个
var serialNum uint64 = 0

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
	CheckOrigin:     checkOrigin,
}

type ProtoData struct {
	MsgType uint32
	Data    []byte
}

var myAddress = ""
var m sync.RWMutex
var userChan = make(map[uint64]map[string]chan ProtoData)

/*  其中CheckOringin是一个函数，该函数用于拦截或放行跨域请求。函数返回值为bool类型，即true放行，false拦截。
如果请求不是跨域请求可以不赋值，我这里是跨域请求并且为了方便直接返回true
*/
func checkOrigin(r *http.Request) bool {
	return true
}

const (
	notLoginLimit      = 10.0
	heartBeatLossLimit = 30.0
)

type ConnectionInfo struct {
	RemoteAddr    string `json:"remote_addr"`
	ConnectTime   time.Time
	HeartbeatTime time.Time
	IsLogin       bool
	Uid           uint64 `json:"uid"`
	MsgId         uint64 `json:"msg_id"`
	ExternalId    string `json:"external_id"`
	Token         string `json:"token"`
}

func setupRoutes() {
	http.HandleFunc("/", homePage)
	http.HandleFunc("/ws", serverWebsocket)
}

func getShortToken(token string) string {
	s := strings.Split(token, ".")
	if len(s) == 0 {
		return token
	} else {
		return s[len(s)-1]
	}
}
func serverWebsocket(w http.ResponseWriter, r *http.Request) {
	ws, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		mylogrus.MyLog.Errorf("upgrade err:%v", err)
		return
	}

	now := time.Now()
	ci := ConnectionInfo{
		RemoteAddr:    ws.RemoteAddr().String(),
		ConnectTime:   now,
		HeartbeatTime: now,
		IsLogin:       false,
		Uid:           0,
		MsgId:         0,
		ExternalId:    "",
		Token:         "",
	}
	traceId := uuid.NewV4().String()
	logger := mylogrus.MyLog.WithFields(log.Fields{
		"addr":    ci.RemoteAddr,
		"token":   ci.Token,
		"traceId": traceId,
	})
	logger.Infof("Websocket client successfully Connected at %s", ci.ConnectTime.String())

	done := make(chan struct{})
	writeChan := make(chan ProtoData, 1000)

	ticker := time.NewTicker(time.Second * 2)
	defer ticker.Stop()

	go func() {
		defer common.CheckGoPanic()
		defer ws.Close()
		defer close(done)
		//defer close(writeChan) // 读断了就把写也断了
		for {
			messageType, message, err := ws.ReadMessage()
			if err != nil {
				logger.Infof("read error:%v", err)
				logger = logger.WithFields(log.Fields{
					"read_err": err.Error(),
				})
				break
			}

			if messageType != websocket.BinaryMessage {
				logger.Errorf("Unexpected messageType %d", messageType)
				continue
			}

			msgType, msgId, timeStamp, pbData, err := common.DecodeMessage(message)
			if err != nil {
				logger.Errorf("Decode error %s", err.Error())
				continue
			}

			if msgId <= ci.MsgId {
				logger.Infof("Discard outdated message msgId = %d <= %d, msgType = %d", msgId, ci.MsgId, msgType)
			} else {
				ci.MsgId = msgId

				// 统计时延
				now := time.Now()
				us := now.UnixNano()/1000 - int64(timeStamp)
				if us > 200000 {
					logger.Infof("Message take %d us to come here.", us)
				}

				if msgType == common.MsgTypeLogin {
					if ci.IsLogin {
						logger.Infof("Connection already logged in %+v", ci)
					} else {
						var rsp *userProxy.LoginRsp
						ci.Token, ci.Uid, rsp, err = processLogin(logger, ci.RemoteAddr, pbData)
						if err == nil && rsp != nil {
							logger = logger.WithFields(log.Fields{
								"addr":   ci.RemoteAddr,
								"userId": ci.Uid,
								"sToken": getShortToken(ci.Token),
							})

							if buffer, err := proto.Marshal(rsp); err == nil {
								writeChan <- ProtoData{
									MsgType: common.MsgTypeLoginRsp,
									Data:    buffer,
								}
							}
							if rsp.Status == common.Login_success {
								ci.IsLogin = true
								ci.HeartbeatTime = now

								logger.Infof("Bind to channel %v", writeChan)
								setUserChan(ci.Uid, ci.RemoteAddr, writeChan)
							}
						}
					}
				} else if msgType == common.MsgTypeHeartBeat {
					status, extUid, err := processHeartBeat(pbData)
					logger.Infof("heartbeat")
					if err == nil {
						ci.HeartbeatTime = time.Now()
						if len(ci.ExternalId) == 0 {
							logger.Infof("Received first heartbeat")

							ci.ExternalId = extUid

							logger = logger.WithFields(log.Fields{
								"addr":       ci.RemoteAddr,
								"userId":     ci.Uid,
								"sToken":     getShortToken(ci.Token),
								"externalId": ci.ExternalId,
							})
						}
						msg := &userProxy.HeartBeatRsp{
							Status: status,
						}
						if buffer, err := proto.Marshal(msg); err == nil {
							writeChan <- ProtoData{
								MsgType: common.MsgTypeHeartBeatRsp,
								Data:    buffer,
							}
						}
					}
				} else if msgType == common.MsgTypeGlobalGiftBannerRsp {
					logger = logger.WithFields(log.Fields{
						"addr":       ci.RemoteAddr,
						"userId":     ci.Uid,
						"sToken":     getShortToken(ci.Token),
						"externalId": ci.ExternalId,
					})
					rsp := &userProxy.GlobalGiftBannerRsp{}
					err := proto.Unmarshal(pbData, rsp)
					if err == nil {
						logger.Infof("GlobalGiftBannerRsp, msgType = %d, %v", msgType, rsp)
					} else {
						logger.Errorf("Unmarshal error")
					}
				} else if msgType == common.MsgTypeBiz {
					logger = logger.WithFields(log.Fields{
						"addr":   ci.RemoteAddr,
						"userId": ci.Uid,
					})
					rsp, err := processBizRequest(logger, ci.Uid, pbData)
					if err == nil && rsp != nil {
						logger.Infof("processBizRequest rsp %+v", rsp)

						if buffer, err := proto.Marshal(rsp); err == nil {
							writeChan <- ProtoData{
								MsgType: common.MsgTypeBizRsp,
								Data:    buffer,
							}
						}
					}
				} else {
					logger.Warnf("Unknown message type %d", msgType)
				}

				if err != nil {
					logger.Infof("process message error %s", err.Error())
				}
			}
		}
		logger.Infof("exiting read loop for token %s, user %d", ci.Token, ci.Uid)
		sz := removeUserChan(ci.Uid, ci.RemoteAddr)

		b, _ := json.Marshal(ci)
		logger.Infof("exiting read loop for %s, size = %d", string(b), sz)

		if ci.IsLogin {
			err, status := doLogout(ci.RemoteAddr, ci.Uid)
			if err == nil {
				logger.Printf("logout result %d", status)
			} else {
				logger.Printf("Logout failed, %s", err.Error())
			}
			ci.IsLogin = false
		}
	}()

Loop:
	for {
		select {
		case <-done:
			break Loop
		case <-ticker.C:
			timeDiff := time.Since(ci.HeartbeatTime)
			if ci.IsLogin {
				if timeDiff.Seconds() > heartBeatLossLimit/2 {
					logger.Infof("Heartbeat lost for %f seconds", timeDiff.Seconds())
				}

				if timeDiff.Seconds() > heartBeatLossLimit {
					logger.Warnln("Heartbeat lost, terminate!")

					err := ws.WriteControl(websocket.CloseMessage,
						websocket.FormatCloseMessage(websocket.ClosePolicyViolation, "heartbeat loss"),
						time.Now().Add(time.Second))
					if err != nil {
						logger.Println("write close:", err)
					}
					ws.Close()
					break Loop
				}
			} else {
				if timeDiff.Seconds() > notLoginLimit {
					logger.Infof("Not loggined for %f seconds, kick!", timeDiff.Seconds())

					err := ws.WriteControl(websocket.CloseMessage,
						websocket.FormatCloseMessage(websocket.ClosePolicyViolation, "no login"),
						time.Now().Add(time.Second))
					if err != nil {
						logger.Println("write close:", err)
					}
					_ = ws.Close()
					break Loop
				}
			}
		case d := <-writeChan:
			if d.MsgType == common.MsgTypeKickUser {
				// 特殊消息，用于踢走用户
				logger.Infof("Login from another device, kick!")

				// 取消登录态，避免readloop结束时发logout消息，把新记录也清了
				ci.IsLogin = false

				err := ws.WriteControl(websocket.CloseMessage,
					websocket.FormatCloseMessage(websocket.ClosePolicyViolation, "double login"),
					time.Now().Add(time.Second*3))
				if err != nil {
					logger.Println("write close:", err)
					break
				}
				_ = ws.Close()
				break Loop
			}

			atomic.AddUint64(&serialNum, 1)
			logger.Infof("About to send msgType = %d, size = %d", d.MsgType, len(d.Data))
			data := common.EncodeMessage(d.MsgType, serialNum, d.Data)
			err = ws.WriteMessage(websocket.BinaryMessage, data)
			if err != nil {
				logger.Println("write close:", err)
			}
		}
	}
	b, _ := json.Marshal(ci)
	logger.Infof("exiting write loop:%s", string(b))
}

func processLogin(logger *log.Entry, clientAddr string, pbData []byte) (string, uint64, *userProxy.LoginRsp, error) {
	rsp := &userProxy.LoginRsp{}
	//logger := log.WithFields(log.Fields{
	//	"addr": clientAddr,
	//})

	loginMsg := &userProxy.Login{}
	var loginUid uint64 = 0
	err := proto.Unmarshal(pbData, loginMsg)

	if err == nil {
		logger := logger.WithFields(log.Fields{
			"addr":  clientAddr,
			"token": loginMsg.Token,
		})
		logger.Info(loginMsg.String())

		err, rsp.Status, loginUid = doLogin(loginMsg.Token, clientAddr)
		if err == nil {
			logger.Infof("login status = %d, uid = %d,proxyAddr:%s,clientAddr:%s", rsp.Status, loginUid, myAddress, clientAddr)
		} else {
			logger.Warnf("login RPC failed for %d, %v", rsp.Status, err)
		}
		return loginMsg.Token, loginUid, rsp, err
	} else {
		logger.Warn("unmarshal error")
		return loginMsg.Token, 0, rsp, err
	}
}

func processHeartBeat(pbData []byte) (uint32, string, error) {
	heartBeat := &userProxy.HeartBeat{}
	err := proto.Unmarshal(pbData, heartBeat)
	if err == nil {
		// FIXME: 增加heartbeat过频控制
		return 0, heartBeat.ExternalUid, err
	}
	return 0, "", err
}

func processBizRequest(logger *log.Entry, uid uint64, pbData []byte) (*userProxy.BizResponse, error) {
	//logger := log.WithFields(log.Fields{
	//	"uid": uid,
	//})

	rsp := &userProxy.BizResponse{}

	msg := &userProxy.BizRequest{}
	err := proto.Unmarshal(pbData, msg)

	if err == nil {
		logger.Infof("doBizRequest msgType = %d, msg: %s", msg.Type, msg.PayLoad)

		rsp.Status, err = doBizRequest(uid, msg.Type, msg.PayLoad)
		if err != nil {
			logger.Warnf("doBizRequest RPC failed for %d, %v, uid = %d", uid, rsp.Status, err)
		}
		return rsp, err
	} else {
		logger.Warn("unmarshal error")
		return rsp, err
	}
}

// 直接发匹配成功消息，调试用
func homePage(w http.ResponseWriter, r *http.Request) {
	rsp := "Home Page"
	var targetUserId uint64 = 0
	fromUserId := ""
	toUserId := ""
	if r.ParseForm() == nil {
		targetUserId, _ = strconv.ParseUint(r.FormValue("target"), 10, 64)
		fromUserId = r.FormValue("from")
		toUserId = r.FormValue("to")
	}

	if targetUserId == 0 || len(fromUserId) == 0 || len(toUserId) == 0 {
		rsp = "targetUserId or fromUserId or toUserId is missing."
	} else {
		m := getChans(targetUserId)
		if m == nil {
			rsp = "User not found"
		} else {
			for i, c := range m {
				rsp += fmt.Sprintf("address %d bound to channel %v", i, c)
			}
		}
	}
	fmt.Fprint(w, rsp)
}

func setUserChan(uid uint64, addr string, c chan ProtoData) {
	m.Lock()
	defer m.Unlock()
	if userChan[uid] == nil {
		userChan[uid] = make(map[string]chan ProtoData)
	}
	userChan[uid][addr] = c
}

func getUserChan(uid uint64, addr string) chan ProtoData {
	m.RLock()
	defer m.RUnlock()
	if userChan[uid] == nil {
		return nil
	} else {
		return userChan[uid][addr]
	}
}

func getChans(uid uint64) map[string]chan ProtoData {
	m.RLock()
	defer m.RUnlock()
	return userChan[uid]
}

func removeUserChan(uid uint64, addr string) int {
	m.Lock()
	defer m.Unlock()
	if chs, ok := userChan[uid]; ok {
		delete(chs, addr)
		if len(chs) == 0 {
			delete(userChan, uid)
		}
	}
	return len(userChan)
}

const (
	rpcListenPortBase = 50050
)

type server struct {
	userCenter.UnimplementedRouterServer
}

func (s *server) Route(ctx context.Context, in *userCenter.RouteMessage) (*userCenter.RouteMessageRsp, error) {
	defer func() {
		if r := recover(); r != nil {
			//打印错误堆栈信息
			mylogrus.MyLog.Errorf("Route SYSTEM ACTION PANIC: %v, stack: %v", r, string(debug.Stack()))
		}
	}()
	peerInfo, _ := peer.FromContext(ctx)
	mylogrus.MyLog.Infof("Received Route request from %s: msgType = %d, uid = %d, payload size = %d",
		peerInfo.Addr.String(), in.GetMsgType(), in.GetUid(), len(in.GetPayLoad()))

	var status uint32 = common.ROUTE_SUCCESS
	m := getChans(in.GetUid())
	if len(m) > 0 {
		for i, c := range m {
			mylogrus.MyLog.Infof("Route to user %d, addr %s, channel %v", in.Uid, i, c)
			c <- ProtoData{
				MsgType: in.GetMsgType(),
				Data:    in.GetPayLoad(),
			}
		}
	} else {
		status = common.ROUTE_CHANNEL_NOT_FOUND
		mylogrus.MyLog.Warnf("No write channel for user %d", in.GetUid())
	}
	return &userCenter.RouteMessageRsp{Status: status}, nil
}

func (s *server) KickUser(ctx context.Context, in *userCenter.KickMessage) (*userCenter.KickMessageRsp, error) {
	peerInfo, _ := peer.FromContext(ctx)
	logger := mylogrus.MyLog.WithFields(log.Fields{
		"uid":  in.Uid,
		"addr": in.Addr,
	})
	logger.Infof("Received KickUser request from %s", peerInfo.Addr.String())

	c := getUserChan(in.Uid, in.Addr)
	if c == nil {
		logger.Infof("No write channel")
	} else {
		c <- ProtoData{
			MsgType: common.MsgTypeKickUser,
		}
	}
	return &userCenter.KickMessageRsp{Status: 0}, nil
}

var userClient userCenter.UserClient

func doLogin(token string, clientAddr string) (error, uint32, uint64) {
	ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)
	defer cancel()

	r, err := userClient.Login(ctx, &userCenter.LoginMessage{
		Token:      token,
		ProxyAddr:  myAddress,
		ClientAddr: clientAddr,
	})
	if err == nil && r != nil {
		return err, r.Status, r.Uid
	} else {
		return err, 0, 0
	}
}

func doLogout(addr string, uid uint64) (error, uint32) {
	ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)
	defer cancel()
	r, err := userClient.Logout(ctx, &userCenter.LogoutMessage{
		ClientAddr: addr,
		Uid:        uid,
	})
	if err == nil && r != nil {
		return err, r.Status
	} else {
		return err, 0
	}
}

func doBizRequest(uid uint64, msgType uint32, payLoad string) (uint32, error) {
	ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)
	defer cancel()

	r, err := userClient.Transmit(ctx, &userCenter.BizMessage{
		Uid:     uid,
		MsgType: msgType,
		PayLoad: payLoad,
	})
	if err == nil && r != nil {
		return r.Status, err
	} else {
		return 0, err
	}
}

var kacp = keepalive.ClientParameters{
	Time:                10 * time.Second, // send pings every 10 seconds if there is no activity
	Timeout:             time.Second,      // wait 1 second for ping ack before considering the connection dead
	PermitWithoutStream: true,             // send pings even without active streams
}

var (
	defaultUserCenterAddr = "127.0.0.1:50040" // userCenter default addr
	userCenterAddr        = defaultUserCenterAddr
	userCenterConsulName  = "userCenter"
)

// grpc服务发现
type Builder struct {
	addrs map[string][]string

	cc resolver.ClientConn
}

func (b *Builder) Scheme() string {
	return "uc" // userCenter
}

type Resolver struct {
}

func (r Resolver) ResolveNow(options resolver.ResolveNowOptions) {}

func (r Resolver) Close() {}

func (b *Builder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
	r := &Resolver{}
	paths := b.addrs[target.URL.Path]
	addrs := make([]resolver.Address, len(paths))
	for i, s := range paths {
		addrs[i] = resolver.Address{Addr: s}
	}
	cc.UpdateState(resolver.State{Addresses: addrs})
	b.cc = cc
	return r, nil
}

func (b *Builder) UpdateState(addrs []string) {
	as := make([]resolver.Address, len(addrs))
	for i, s := range addrs {
		as[i] = resolver.Address{Addr: s}
	}
	b.cc.UpdateState(resolver.State{Addresses: as})
}

var certFile = flag.String("certFile", "ws.faceline.live.pem", "cert file")
var keyFile = flag.String("keyFile", "ws.faceline.live.key", "key file")
var listenPort = flag.String("port", "8081", "listen port")

func main() {
	flag.Parse()

	client, err := consulapi.NewClient(consulapi.DefaultConfig()) //非默认情况下需要设置实际的参数
	if client == nil {
		mylogrus.MyLog.Fatalln("Fail to get consul client.")
	}

	myIp, myNodeName := consul.GetAgentInfo(client)
	myLocalIp, err := common.GetClientIpV2()
	if err != nil {
		mylogrus.MyLog.Fatal(err)
	}
	mylogrus.MyLog.Infof("myIp is %s, myNodeName: %s, localIp is %s", myIp, myNodeName, myLocalIp)

	cataLog := client.Catalog()
	if cataLog == nil {
		mylogrus.MyLog.Fatalln("No catalog.")
	}
	services, _, err := cataLog.Service(userCenterConsulName, "", nil)
	if err != nil {
		mylogrus.MyLog.Fatalln(err)
	}
	if len(services) == 0 {
		mylogrus.MyLog.Fatalln("userCenter not found.")
	}

	var addrs []string
	bd := &Builder{addrs: map[string][]string{"/api": {userCenterAddr}}}
	for _, s := range services {
		addrs = append(addrs, fmt.Sprintf("%s:%d", s.ServiceAddress, s.ServicePort))
	}
	if len(addrs) > 0 {
		bd = &Builder{addrs: map[string][]string{"/api": addrs}}
		userCenterAddr = "uc:///api"
	}
	mylogrus.MyLog.Infof("userCenterAddr:%v,addr:%v", userCenterAddr, addrs)
	// 服务发现
	resolver.Register(bd)
	go func() {
		consul.RegisterWatcher(userCenterConsulName, func(addr []string) {
			if len(addr) > 0 {
				bd.UpdateState(addr) // 更新新的注册名
			}
		})
	}()

	// Set up a connection to the userCenter.
	conn, err := grpc.Dial(userCenterAddr, grpc.WithInsecure(), grpc.WithBlock(), grpc.WithKeepaliveParams(kacp),
		grpc.WithDefaultServiceConfig(fmt.Sprintf(`{"LoadBalancingPolicy":"%s"}`, "round_robin")))
	if err != nil {
		mylogrus.MyLog.Fatalf("did not connect: %v", err)
	}
	//defer conn.Close()
	userClient = userCenter.NewUserClient(conn)
	if userClient == nil {
		mylogrus.MyLog.Fatalln("userClient null")
	}

	go func() {
		var i int
		var lis net.Listener
		var err error
		for i = 0; i < 10; i++ {
			addr := ":" + strconv.Itoa(rpcListenPortBase+i)
			lis, err = net.Listen("tcp", addr)
			if err == nil {
				mylogrus.MyLog.Infof("Go RPC listening on %s", lis.Addr().String())
				break
			}
		}
		if i >= 10 {
			mylogrus.MyLog.Fatalln("No RPC Listen port available.")
		}
		myAddress = myLocalIp + ":" + strconv.Itoa(rpcListenPortBase+i)

		mylogrus.MyLog.Infof("My address is %s", myAddress)

		s := grpc.NewServer()
		userCenter.RegisterRouterServer(s, &server{})
		if err := s.Serve(lis); err != nil {
			mylogrus.MyLog.Fatalf("failed to serve: %v", err)
		}
	}()

	setupRoutes()

	addr := ":" + *listenPort
	mylogrus.MyLog.Infof("Go Websocket listening on %s", addr)
	// http ws
	mux := http.NewServeMux()
	mux.HandleFunc("/ws", serverWebsocket)
	go http.ListenAndServe(":8082", mux)

	// https wss
	mylogrus.MyLog.Infof("certFile = %s, keyFile = %s", *certFile, *keyFile)
	mylogrus.MyLog.Printf("%s", http.ListenAndServeTLS(addr, *certFile, *keyFile, nil).Error())
}