package main

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"git.qianqiusoft.com/library/glog"
	"git.qianqiusoft.com/qianqiusoft/go-uuid/uuid"
	"net"
	"sync"
	"time"
)

const (
	__KEY = "Light#dauth-@*I2"

	CMD_NEW = "new"
	CMD_REMOVE = "remove"
	CMD_PINGPONG = "pg"
	CMD_PINGPONG_RESP = "pg_resp"
)

/**
 * 数据包获取接口，跟业务无关
 */
type Getter interface {
	/**
	 * @brief: 包解析器接口
	 * @param1 bytess: 当前接收到的数据
	 * @param2 conn: 当前conn
	 * @return1: 获取出来包内容，多个
	 * @return2: 剩余数据
	 * @return3: 错误信息
	 */
	Get(bytess []byte, tcpConn *TcpConn)([][]byte, []byte, error)
}

/**
 * 包解析器
 */
type Parser interface {
	/**
	 * @brief: 包解析器
	 * @param1 bytess: 包数据
	 * @param2 tcpConn: 当前连接
	 */
	Parse(bytess []byte, tcpConn *TcpConn)
}

/**
 * 连接回调接口
 */
type TcpConnCallback interface {
	/**
	 * @brief: 新连接回调
	 * @param1 conn: 连接
	 */
	OnConnected(conn *TcpConn)               //
	/**
	 * @brief: 连接断开回调
	 * @param1 conn: 连接
	 * @param2 err: 错误信息，正常关闭的为nil
	 */
	OnDisconnected(conn *TcpConn) //
	/**
	 * @brief: 错误回调
	 * @param1 conn: 连接
	 * @param2 err: 错误信息
	 */
	OnError(conn *TcpConn, err error)
}

/**
 * tcp 配置信息
 */
type Config struct {
	Ip           string          // ip
	Port         string          // 端口
	Network      string          // 默认tcp, The network must be "tcp", "tcp4", "tcp6", "unix" or "unixpacket".
	Interval     time.Duration   // 心跳间隔
	Timeout      time.Duration   // 超时时间
	BufferSize   int             // 接收缓冲区大小
	SendChanSize int             // 发送通道大小
	RecvChanSize int             // 接收通道大小
	Getter       Getter          // tcp 连接处理接口
	Parser       Parser          // 包解析器
	ConnCallback TcpConnCallback // 连接回调接口
}

/**
 * tcp 连接
 */
type TcpConn struct {
	id         string             // id
	conn       net.Conn           // 连接
	sendChan   chan []byte        // 发送数据chan
	recvChan   chan []byte        // 接收数组chan
	done       chan bool          // 完成chan
	ctx        context.Context    // 上下文
	cancel     context.CancelFunc // 取消函数
	reqTime    time.Time          // 最后请求时间
	timer      *time.Ticker       // 超时检查定时器
	interval   time.Duration      // 心跳时间间隔
	timeout    time.Duration      // 超时时间
	bufferSize int                // 接收缓冲区大小
	tcpServer  *TcpServer         // 服务端
	Getter     Getter             // 包解析器
	Parser     Parser             // 包解析器
	Tag        interface{}        // 连接标识
}

/**
 * @brief: 发送接口
 * @param1 data: 数据
 */
func (tc *TcpConn)Send(data []byte){
	if data == nil{
		fmt.Println("发送数据为nil")
		return
	}

	tc.sendChan <- data
}

/**
 * @brief: 取消
 */
func (tc *TcpConn)Cancel(){
	glog.Infoln("tcp conn cancel")

	if tc.timer != nil{
		tc.timer.Stop()
	}
	if tc.cancel != nil{
		tc.cancel()
	}

	tc.conn.Close()
}

/**
 * @brief: 启动超时
 */
func (tc *TcpConn)startTimeoutCheckProcess(){
	go func() {
		if int64(tc.interval) <= 0{
			glog.Infoln("时间间隔小于等于0，不启动超时检测定时器")
			return
		}

		tc.timer = time.NewTicker(tc.interval)

		defer func() {
			tc.timer.Stop()
			glog.Infoln("startTimeoutCheckProcess end")
		}()

		for {
			select {
			case <-tc.ctx.Done():
				glog.Infoln("startTimeoutCheckProcess ctx.cancel")
				return
			case <-tc.timer.C:
				now := time.Now()
				if now.Sub(tc.reqTime) > tc.timeout {
					glog.Errorln(tc.conn, "heartbeat timeout exit", now.Format("2006-01-02 15:04:05"), tc.reqTime.Format("2006-01-02 15:04:05"))
					tc.Cancel()
					return
				}
			}
		}
	}()
}

/**
 * @brief: 发送处理流程
 */
func (tc *TcpConn)startSendProcess() {
	go func() {
		glog.Infoln(tc.conn, "startSendProcess start")
		defer func() {
			tc.done <- true
			glog.Infoln(tc.conn, "startSendProcess end.")
		}()

		for {
			select {
			case <-tc.ctx.Done():
				glog.Infoln("startSendProcess ctx.cancel")
				return
			case data := <-tc.sendChan:
				tc.conn.SetWriteDeadline(time.Now().Add(5 * time.Second))
				if _, err := tc.conn.Write(data); err != nil {
					glog.Errorln(tc.conn, "conn.Write", err.Error())
					return
				}
			}
		}
	}()
}

/**
 * @brief: 接收处理流程
 */
func (tc *TcpConn)startRecvProcess(){
	go func() {
		glog.Infoln(tc.conn, "startRecvProcess start")
		lastRecvDataTime := time.Now()

		defer func() {
			glog.Errorln(tc.conn, "last recv time:", lastRecvDataTime.Format("2006-01-02 15:04:05"), "now time:", time.Now().Format("2006-01-02 15:04:05"))
			tc.done <- true
			glog.Infoln(tc.conn, "startRecvProcess end.")
		}()

		ok, err := checkSign(tc.conn)	// 校验
		if err != nil{
			fmt.Println("校验key异常, 关闭连接", err.Error())
			tc.Cancel()
			return
		}
		if !ok{
			fmt.Println("key错误, 关闭连接", err.Error())
			tc.Cancel()
			return
		}
		err = writeString(tc.conn, "ok")	// 应答ok
		if err != nil{
			fmt.Println("应答ok错误, 关闭连接", err.Error())
			tc.Cancel()
			return
		}

		// 验证成功后直接同步
		mmap := tc.tcpServer.store.All()
		for _, v := range mmap{
			tc.Send(cmdContentToBytes(CMD_NEW, v))
		}

		for {
			cmd, err := readString(tc.conn)
			if err != nil{
				glog.Errorln(tc.conn, "读取cmd错误:", err.Error())
				break
			}
			if cmd == CMD_NEW{
				err = tc.newHandler()
			}else if cmd == CMD_REMOVE{
				err = tc.removeHandler()
			} else if cmd == CMD_PINGPONG{
				err = tc.pingpongHandler()
			} else{
				glog.Errorln("未知cmd", CMD_NEW)
				continue
			}
			if err != nil{
				glog.Errorln(tc.conn, "处理错误:", cmd, err.Error())
				break
			}
		}
	}()
}

// 处理新建
func (tc *TcpConn)newHandler()error{
	fmt.Println("处理新建")
	_, err := readUInt32(tc.conn) // 读取主体长度，这个忽略掉
	if err != nil{
		glog.Errorln(tc.conn, "读取token错误:", err.Error())
		return err
	}
	tokenStr, err := readString(tc.conn)	// d读取token
	if err != nil{
		glog.Errorln(tc.conn, "读取token错误:", err.Error())
		return err
	}
	fmt.Println("处理新建1", tokenStr)
	tokenBytes, err := readBytes(tc.conn)
	if err != nil{
		glog.Errorln(tc.conn, "读取token bytes错误:", err.Error())
		return err
	}
	fmt.Println("处理新建2")
	fmt.Println(tokenBytes)
	tc.tcpServer.store.Set(tokenStr, tokenBytes)
	tc.tcpServer.Broadcast(tc.id, CMD_NEW, tokenBytes)
	return nil
}

// 处理移除
func (tc *TcpConn)removeHandler()error{
	fmt.Println("处理删除")
	tokenStr, err := readString(tc.conn)
	if err != nil{
		glog.Errorln(tc.conn, "读取token错误:", err.Error())
		return err
	}
	tc.tcpServer.store.Remove(tokenStr)
	tc.tcpServer.Broadcast(tc.id, CMD_NEW, []byte(tokenStr))
	return nil
}

// 处理心跳
func (tc *TcpConn)pingpongHandler()error{
	fmt.Println("处理心跳")
	buf := bytes.NewBuffer([]byte{})

	bytess := []byte(CMD_PINGPONG_RESP)
	size := len(bytess)

	buf.Write(uint32ToBytes(uint32(size)))
	buf.Write(bytess)

	tc.Send(buf.Bytes())

	return nil
}

type TcpServer struct {
	config  *Config             // 配置
	connMap sync.Map // 连接列表
	store   IStore
}

func NewTcpServer(config *Config, store IStore)*TcpServer{
	return &TcpServer{
		config: config,
		store:  store,
	}
}

/**
 * @brief: 处理新连接
 * @param1 conn: 新连接
 * @param2 config: 配置
 */
func (ts *TcpServer)handleConn(conn net.Conn, config *Config){
	ctx, cancel := context.WithCancel(context.Background())
	tcpConn := &TcpConn{
		id: uuid.New(),
		conn:       conn,
		sendChan:   make(chan []byte, config.SendChanSize),
		recvChan:   make(chan []byte, config.RecvChanSize),
		done:       make(chan bool, 1),
		ctx:        ctx,
		cancel:     cancel,
		reqTime:    time.Now(),
		interval:   config.Interval,
		timeout:    config.Timeout,
		bufferSize: ts.config.BufferSize,
		tcpServer:  ts,
		Getter:     config.Getter,
		Parser:     config.Parser,
		Tag:        nil,
	}

	ts.connMap.Store(tcpConn.id, tcpConn)

	defer func() {
		glog.Infoln(tcpConn.conn, "handleConn end -> conn.Close()")
		err := tcpConn.conn.Close()
		if err != nil {
			glog.Errorln(tcpConn.conn, "conn.Close()", err.Error())
		}
		glog.Infoln(tcpConn.conn, "handleConn end -> cancel()")
		tcpConn.cancel()
	}()

	tcpConn.startSendProcess()
	tcpConn.startRecvProcess()

	if ts.config.ConnCallback != nil{
		// 新连接回调
		ts.config.ConnCallback.OnConnected(tcpConn)
	}

	<-tcpConn.done

	if ts.config.ConnCallback != nil{
		// 关闭回调
		ts.config.ConnCallback.OnDisconnected(tcpConn)
	}

	ts.connMap.Delete(tcpConn.id)
}

/**
 * @brief: 广播
 * @param1 exceptConnId: 不包含连接kkey
 * @param2 cmd: 命令
 * @param3 content: 内容
 */
func (ts *TcpServer)Broadcast(exceptConnId, cmd string, content []byte){
	fmt.Println("广播", exceptConnId, cmd)
	bytess := cmdContentToBytes(cmd, content)

	ts.connMap.Range(func(k, v interface{})bool{
		con := v.(*TcpConn)
		if con.id != exceptConnId{
			con.Send(bytess)
		}
		return true
	})
}

/**
 * @brief: 启动服务端
 * @param1 config: tcp配置
 * @return1 错误信息
 */
func (ts *TcpServer)StartServer()error{
	if ts.config == nil{
		return errors.New("参数config为nil")
	}
	glog.Infoln(ts.config)

	network := ts.config.Network
	if network == ""{
		network = "tcp"
	}
	listen, err := net.Listen(network, ts.config.Ip + ":" + ts.config.Port)
	if err != nil {
		glog.Errorln("监听端口失败：", err.Error())
		return err
	}

	glog.Infoln("启动dauth服务")

	go func() {
		for {
			conn, err := listen.Accept()
			if err != nil {
				glog.Errorln("接受TCP连接异常:", err.Error())
				continue
			}
			glog.Infoln("TCP连接来自:", conn.RemoteAddr().String(), conn)

			go ts.handleConn(conn, ts.config)
		}
	}()

	return nil
}