package tcpserver

import (
	"IotAdmin/core/logger"
	"bufio"
	"crypto/tls"
	"crypto/x509"
	"fmt"
	"log"
	"net"
	"os"
	"sync"
	"time"
)

var (
	chanBuffSize = 32
)

type RestResult struct {
	Success bool   `json:"success"`
	Message string `json:"message"`
	Data    string `json:"data"`
	Stream  []byte `json:"stream"`
}
type Client struct {
	conn net.Conn
	//RD_chan   chan []byte
	//WR_chan   chan []byte
	//Exit_chan chan error // 异常退出通道
	//channel_rd  chan []byte
	rwLock     sync.RWMutex
	channelWr  chan []byte
	channelErr chan int
	rdChanFlag bool //读取buffRawRes通道标志位,true表示有线程等待读通道
	gRunFlag   bool //协程允许标记
	//towr        chan []byte
	tord        chan []byte
	clientId    string //客户端ID(SN)
	clientAddr  string //客户端地址
	buffRestRes chan RestResult
	buffRawRes  chan []byte //原始数据
	Server      *Server
	restCnt     int
}
type Server struct {
	address                   string
	config                    *tls.Config
	onNewClientCallback       func(c *Client)
	onClientConnectionClosed  func(c *Client, err error)
	onNewMessage              func(c *Client, msg []byte)
	onMsgClientCallback       func(c *Client, msg []byte) bool
	onMsgClientCallbackDefine func(c *Client, msg []byte) bool
}

// LockClient 锁定tcp通道,与解锁成对使用
func (c *Client) LockClient() {
	c.rwLock.Lock()
}

// UnLockClient 解锁tcp通道
func (c *Client) UnLockClient() {
	c.rwLock.Unlock()
}
func (c *Client) SetWaitRawRes() {
	c.rdChanFlag = true
}
func (c *Client) ClrWaitRawRes() {
	c.rdChanFlag = false
}
func (c *Client) GetWaitRawRes() bool {
	return c.rdChanFlag
}

// PutRestRes 以json格式推入
func (c *Client) PutRestRes(data RestResult) {
	//sync_lock
	//log.Println("PutRestRes:", data)
	c.buffRestRes <- data
}

// PutRawRes 或者以原始格式推入
func (c *Client) PutRawRes(data []byte) {
	//sync_lock
	//log.Printf("PutRestRes:%d\r\n", len(data))
	c.buffRawRes <- data
}

// GetRestRes 以json格式获取
func (c *Client) GetRestRes() (RestResult, bool) {
	//sync_lock
	var (
		ret bool = false
		res RestResult
	)
	select {
	case res = <-c.buffRestRes:
		ret = true
		//log.Println("GetRestRes:", res)
		//log.Printf("buffRestRes len:%d", len(c.buffRestRes))
	case <-time.After(time.Second * 10):
		ret = false
	}
	c.restCnt++
	return res, ret
}

func (c *Client) GetRestCnt() int {
	return c.restCnt
}

// GetRawRes 以原始格式获取
func (c *Client) GetRawRes() ([]byte, bool) {
	//sync_lock
	var (
		ret bool   = false
		res []byte = make([]byte, 0) //256)
	)
	select {
	case res = <-c.buffRawRes:
		ret = true
	case <-time.After(time.Second * 5):
		ret = false
	}
	c.restCnt++
	return res, ret
}

// ChanWrite 将数据写给User端
func (c *Client) ChanWrite(b []byte) int {
	//sync_lock
	c.channelWr <- b
	c.restCnt++
	return c.restCnt
}

func (c *Client) GetClientHost() string {
	return c.clientAddr
}
func (c *Client) GetClientRegisterID() string {
	return c.clientId
}
func (c *Client) SetClientRegisterID(id string) {
	c.clientId = id
}

// GetGRunFlag 协程运行标记
func (c *Client) GetGRunFlag() bool {
	return c.gRunFlag
}

func (c *Client) handleClient() {
	res := ""
	cnt := 0
	ro := make(chan int)
	//ctx, cancel := context.WithCancel(context.Background())
	//wo := make(chan int)
	//rexit := make(chan int)
	//wexit := make(chan int)
	go c.goRead(c.tord, ro)
	//go c.handleTaskTimer(ro)
	//go c.gowrite(c.towr, wo)
	c.clientAddr = c.Conn().RemoteAddr().String()
	c.Server.onNewClientCallback(c)
	c.restCnt = 0
	c.gRunFlag = true
	defer func() {
		c.closeClient()
		if res != "ro" {
			<-ro
		}
	}()
	for {
		select {
		case <-time.After(time.Minute * 2):
			cnt++
			if cnt > 2 {
				res = "over time"
				return //exit = true
			}
		case <-ro:
			res = "ro"
			return //exit = true
		case <-c.channelErr:
			res = "channel err"
			return //exit = true
		case wrData := <-c.channelWr:
			if _, err := c.conn.Write(wrData); err != nil { // && err != io.EOF {
				res = "wo"
				return //exit = true
			}
		case rData, ok := <-c.tord:
			if ok {
				cnt = 0
				c.Server.onNewMessage(c, rData)
			}
		}
	}
}

func (c *Client) closeClient() {
	var err error
	defer func(conn net.Conn) {
		_ = conn.Close()
	}(c.conn)
	c.gRunFlag = false
	c.Server.onClientConnectionClosed(c, err)
}

func (c *Client) ExitClient() {
	c.channelErr <- 0 //errors.New("exit")
}

func (c *Client) goRead(buff chan<- []byte, out chan<- int) {
	size := (int)(32 * 1024)
	data := make([]byte, size)
	reader := bufio.NewReader(c.conn)
	for {
		n, err := reader.Read(data) //c.conn.Read(data) //
		if err != nil {
			close(buff)
			out <- 0
			return
		} else {
			if n > 0 && n < size-1 {
				buff <- data[:n]
			}
		}
	}
}

func SendTo(cli *Client, date []byte) (res []byte, ok bool) {
	var (
		en = false
	)
	ok = true
	cli.LockClient()
	cnt := cli.ChanWrite(date)
	select {
	case <-time.After(time.Millisecond * 800):
	}
	for {
		res, ok = cli.GetRawRes()
		nCnt := cli.GetRestCnt()
		if !ok {
			break
		}
		if nCnt == cnt+1 {
			break
		}
		if nCnt > cnt+1 {
			ok = false
			break
		}
		if en {
			break
		}
		en = true
	}
	cli.UnLockClient()
	return
}

func (c *Client) Send(msg string) error {
	_, err := c.conn.Write([]byte(msg))
	return err
}
func (c *Client) SendBytes(msg []byte) error {
	_, err := c.conn.Write(msg)
	return err
}
func (c *Client) Conn() net.Conn {
	return c.conn
}
func (c *Client) Close() error {
	return c.conn.Close()
}

func (s *Server) OnNewClient(callback func(c *Client)) {
	s.onNewClientCallback = callback
}
func (s *Server) OnClientConnectionClosed(callback func(c *Client, err error)) {
	s.onClientConnectionClosed = callback
}
func (s *Server) OnNewMessage(callback func(c *Client, msg []byte)) {
	s.onNewMessage = callback
}

func (s *Server) OnMsgClientCallbackDefine(callback func(c *Client, msg []byte) bool) {
	s.onMsgClientCallbackDefine = callback
}
func (s *Server) OnMsgClientCallback(callback func(c *Client, msg []byte) bool) {
	s.onMsgClientCallback = callback
}

func (s *Server) Listen() {
	var listener net.Listener
	var err error
	if s.config == nil {
		listener, err = net.Listen("tcp", s.address)
	} else {
		listener, err = tls.Listen("tcp", s.address, s.config)
	}
	if err != nil {
		log.Fatal("Error starting TCP server")
	}
	defer func(listener net.Listener) {
		_ = listener.Close()
	}(listener)
	for {
		conn, _ := listener.Accept()
		if tcpConn, ok := conn.(*net.TCPConn); ok {
			if err := tcpConn.SetKeepAlive(false); err != nil {
				//fmt.Println("close keepalive fail")
			} else {
				//fmt.Println("close keepalive ok")
			}
		}
		Client := &Client{
			conn:   conn,
			Server: s,
			//towr:       make(chan []byte),
			tord:      make(chan []byte),
			channelWr: make(chan []byte, chanBuffSize),
			//channel_rd:  make(chan []byte, chanBuffSize),
			channelErr:  make(chan int),
			buffRestRes: make(chan RestResult, chanBuffSize),
			buffRawRes:  make(chan []byte, chanBuffSize),
			clientId:    "",
			clientAddr:  "",
			rdChanFlag:  false,
			gRunFlag:    false,
			//reConn: make(chan bool),
		}
		go Client.handleClient()
		//go Client.listen()
	}
}

func New(address string) *Server {
	logger.Infof("创建TCP服务,端口 [%s]", address)
	server := &Server{
		address: address,
		config:  nil,
	}
	server.OnNewClient(func(c *Client) {})
	server.OnNewMessage(func(c *Client, msg []byte) {})
	server.OnClientConnectionClosed(func(c *Client, err error) {})
	return server
}

func NewWithTLS(address, certFile, keyFile string) *Server {
	logger.Infof("创建TCP服务,端口 [%s]", address)
	conf, err := serverTLSConf(certFile, keyFile)
	// sconf.ClientAuth = tls.RequireAndVerifyClientCert
	if err != nil {
		fmt.Println("创建TCP服务失败", err)
		return nil
	}
	//conf.MaxVersion = tls.VersionTLS12
	conf.BuildNameToCertificate()
	server := &Server{
		address: address,
		config:  conf,
	}
	server.OnNewClient(func(c *Client) {})
	server.OnNewMessage(func(c *Client, msg []byte) {})
	server.OnClientConnectionClosed(func(c *Client, err error) {})
	return server
}

func serverTLSConf(certFile, keyFile string) (*tls.Config, error) {
	cacert, _ := os.ReadFile("./cert/ca.crt")
	pool := x509.NewCertPool()
	pool.AppendCertsFromPEM(cacert)

	tlsConf := new(tls.Config)
	//tlsConf.PreferServerCipherSuites = true
	tlsConf.ClientCAs = pool
	tlsConf.ClientAuth = tls.NoClientCert //RequireAndVerifyClientCert
	// support http2
	//tlsConf.NextProtos = append(tlsConf.NextProtos, "h2", "http/1.1")
	// 准备证书
	tlsConf.Certificates = make([]tls.Certificate, 1)
	var err error
	tlsConf.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile)
	if err != nil {
		return nil, err
	}
	// tlsConf.KeyLogWriter = handsh.KeyLog("server")
	return tlsConf, nil
}