package netProgram

import (
	"encoding/gob"
	"errors"
	"fmt"
	"io"
	"log"
	"math/rand"
	"net"
	"sync"
	"time"
)

// 客户端
func TcpClient() {
	// tcp服务端地址
	//serverAddress := "127.0.0.1:5678"

	// tcp协议类型
	serverAddress := "[::1]:5678" // IPv6
	//serverAddress := "127.0.0.1:5678" // IPv4

	// 模拟多客户端
	// 并发的客户端请求
	num := 10
	wg := sync.WaitGroup{}
	wg.Add(num)
	for i := 0; i < num; i++ {
		// 并发请求
		go func(wg *sync.WaitGroup) {
			defer wg.Done()
			// A. 建立连接
			conn, err := net.Dial(tcp, serverAddress)
			if err != nil {
				log.Println(err)
				return
			}
			// 保证关闭
			defer conn.Close()
			log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())
		}(&wg)
	}

	wg.Wait()
}

func TcpTimeoutClient() {
	// tcp服务端地址
	serverAddress := "192.168.110.123:5678" // IPv6 4

	// 模拟多客户端
	// 并发的客户端请求
	num := 10
	wg := sync.WaitGroup{}
	wg.Add(num)
	for i := 0; i < num; i++ {
		// 并发请求
		go func(wg *sync.WaitGroup) {
			defer wg.Done()
			// A. 建立连接
			conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
			//conn, err := net.Dial(tcp, serverAddress)
			if err != nil {
				log.Println(err)
				return
			}
			// 保证关闭
			defer conn.Close()
			log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())
		}(&wg)
	}

	wg.Wait()
}

func TcpBacklogClient() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4

	// 模拟多客户端
	// 并发的客户端请求
	num := 256
	wg := sync.WaitGroup{}
	wg.Add(num)
	for i := 0; i < num; i++ {
		// 并发请求
		go func(wg *sync.WaitGroup, no int) {
			defer wg.Done()
			// A. 建立连接
			conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
			//conn, err := net.Dial(tcp, serverAddress)
			if err != nil {
				log.Println(err)
				return
			}
			// 保证关闭
			defer conn.Close()
			log.Printf("%d: connection is establish, client addr is %s\n", no, conn.LocalAddr())
		}(&wg, i)

		time.Sleep(30 * time.Millisecond)
	}

	wg.Wait()
}

func TcpClientRW() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4

	// A. 建立连接
	conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
	//conn, err := net.Dial(tcp, serverAddress)
	if err != nil {
		log.Println(err)
		return
	}
	// 保证关闭
	defer conn.Close()
	log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())

	// B.从服务端接收数据，SerRead
	buf := make([]byte, 1024)
	rn, err := conn.Read(buf)
	if err != nil {
		log.Println(err)
	}
	log.Println("received from server data is:", string(buf[:rn]))

	// C.向服务器端发送数据，SerWrite
	wn, err := conn.Write([]byte("send some data from client" + "\n"))
	if err != nil {
		log.Println(err)
	}
	log.Printf("client write len is %d\n", wn)
}

func TcpWClient() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4

	// A. 建立连接
	conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
	//conn, err := net.Dial(tcp, serverAddress)
	if err != nil {
		log.Println(err)
		return
	}
	// 保证关闭
	defer conn.Close()
	log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())
	//
	//select {}

	// 1. 阻塞Read
	//buf := make([]byte, 1024)
	//rn, err := conn.SerRead(buf)
	//if err != nil {
	//	log.Println(err)
	//}
	//log.Println("received from server data is:", string(buf[:rn]))

	// 2. 循环读
	conn.SetReadDeadline(time.Now().Add(10 * time.Second))
	for {

		buf := make([]byte, 10)
		rn, err := conn.Read(buf)
		if err != nil {
			log.Println(err)
			break
		}
		log.Println("received from server data is:", string(buf[:rn]))
	}
}

func TcpClientRWConcurrency() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4

	// A. 建立连接
	conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
	//conn, err := net.Dial(tcp, serverAddress)
	if err != nil {
		log.Println(err)
		return
	}
	// 保证关闭
	defer conn.Close()
	log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())

	wg := sync.WaitGroup{}
	// 并发的写
	wg.Add(1)
	go CliWrite(conn, &wg)

	// 并发的读
	wg.Add(1)
	go CliRead(conn, &wg)

	wg.Wait()
}

func CliWrite(conn net.Conn, wg *sync.WaitGroup) {
	defer wg.Done()
	for {
		// B.向客户端发送数据，SerWrite
		wn, err := conn.Write([]byte("send some data from client" + "\n"))
		if err != nil {
			log.Println(err)
		}
		log.Printf("client write len is %d\n", wn)
		time.Sleep(3 * time.Second)
	}

}

func CliRead(conn net.Conn, wg *sync.WaitGroup) {
	defer wg.Done()
	for {
		// C.从客户端接收数据，SerRead
		buf := make([]byte, 1024)
		rn, err := conn.Read(buf)
		if err != nil {
			log.Println(err)
		}
		log.Println("received from server data is:", string(buf[:rn]))
	}
}

func TcpClientFormat() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4

	// A. 建立连接
	conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
	//conn, err := net.Dial(tcp, serverAddress)
	if err != nil {
		log.Println(err)
		return
	}
	// 保证关闭
	defer conn.Close()
	log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())

	wg := sync.WaitGroup{}

	// 接收端
	wg.Add(1)
	go CliReadFormat(conn, &wg)

	wg.Wait()
}

func CliReadFormat(conn net.Conn, wg *sync.WaitGroup) {
	defer wg.Done()
	for {
		// 从客户端接收数据
		// 接收到数据后，先解码

		// 传递的消息类型
		type Message struct {
			ID      uint   `json:"id,omitempty"`
			Code    string `json:"code,omitempty"`
			Content string `json:"content,omitempty"`
		}
		message := Message{}

		// 1, JSON解码
		//// 创建解码器
		//decoder := json.NewDecoder(conn)
		//// 利用解码器进行解码
		//// 解码操作，从conn中读取内容，成功会将解码后的结果，赋值到message变量
		//if err := decoder.Decode(&message); err != nil {
		//	log.Println(err)
		//	continue
		//}
		//log.Println(message)

		// 2, GOB解码
		// 创建解码器
		decoder := gob.NewDecoder(conn)
		// 利用解码器进行解码
		// 解码操作，从conn中读取内容，成功会将解码后的结果，赋值到message变量
		if err := decoder.Decode(&message); err != nil {
			log.Println(err)
			continue
		}
		log.Println(message)

	}
}

// 短连接示例
func TcpClientSort() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4
	// A. 建立连接
	conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
	if err != nil {
		log.Println(err)
		return
	}
	// 保证关闭
	defer conn.Close()
	log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())

	wg := sync.WaitGroup{}

	// 接收端
	wg.Add(1)
	go CliReadSort(conn, &wg)

	wg.Wait()
}

func CliReadSort(conn net.Conn, wg *sync.WaitGroup) {
	defer wg.Done()
	// 传递的消息类型
	type Message struct {
		ID      uint   `json:"id,omitempty"`
		Code    string `json:"code,omitempty"`
		Content string `json:"content,omitempty"`
	}
	message := Message{}
	for {
		// 从客户端接收数据
		// 接收到数据后，先解码
		// GOB解码
		// 创建解码器
		decoder := gob.NewDecoder(conn)
		// 利用解码器进行解码
		// 解码操作，从conn中读取内容，成功会将解码后的结果，赋值到message变量
		err := decoder.Decode(&message)
		// 错误 io.EOF 时，表示连接被给关闭
		if err != nil && errors.Is(err, io.EOF) {
			log.Println(err)
			log.Println("link was closed")
			break
		}
		log.Println(message)
	}
}

// 响应服务端的心跳检测
func TcpClientHB() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4
	// A. 建立连接
	conn, err := net.DialTimeout(tcp, serverAddress, time.Second)
	if err != nil {
		log.Println(err)
		return
	}
	// 保证关闭
	defer conn.Close()
	log.Printf("connection is establish, client addr is %s\n", conn.LocalAddr())

	wg := sync.WaitGroup{}
	// 接收端
	wg.Add(1)
	go CliReadPing(conn, &wg)

	wg.Wait()
}

// 传递的消息类型
type MessageHB struct {
	ID      uint      `json:"id,omitempty"`
	Code    string    `json:"code,omitempty"`
	Content string    `json:"content,omitempty"`
	Time    time.Time `json:"time,omitempty"`
}

func CliReadPing(conn net.Conn, wg *sync.WaitGroup) {
	defer wg.Done()
	// 传递的消息类型
	message := MessageHB{}
	for {
		// GOB解码
		decoder := gob.NewDecoder(conn)
		// 解码操作，从conn中读取内容，成功会将解码后的结果，赋值到message变量
		err := decoder.Decode(&message)
		// 错误 io.EOF 时，表示连接被给关闭
		if err != nil && errors.Is(err, io.EOF) {
			log.Println(err)
			break
		}
		// 判断是为为 ping 类型消息
		if message.Code == "PING-SERVER" {
			log.Println("receive ping from", conn.RemoteAddr())
			CliWritePong(conn, message)
		}
	}
}

func CliWritePong(conn net.Conn, pingMsg MessageHB) {
	pongMsg := MessageHB{
		ID:      uint(rand.Int()),
		Code:    "PONG-CLIENT",
		Content: fmt.Sprintf("pingID:%d", pingMsg.ID),
		Time:    time.Now(),
	}

	// GOB, 二进制编码
	// 创建编码器
	encoder := gob.NewEncoder(conn)
	// 利用编码器进行编码
	// encode 成功后，会写入到conn，已经完成了conn.Write()
	if err := encoder.Encode(pongMsg); err != nil {
		log.Println(err)
		return
	}
	log.Println("pong was send to", conn.RemoteAddr())
	return
}

// 连接池使用
func TcpClientPool() {
	// tcp服务端地址
	serverAddress := "127.0.0.1:5678" // IPv6 4
	// A，建立连接池
	pool, err := NewTcpPool(serverAddress, PoolConfig{
		Factory:     &TcpConnFactory{},
		InitConnNum: 4,
	})
	if err != nil {
		log.Fatalln(err)
	}
	log.Println(pool, len(pool.idleList))

	wg := sync.WaitGroup{}
	clientNum := 50
	wg.Add(clientNum)
	// B, 复用连接池中的连接
	for i := 0; i < clientNum; i++ {
		// goroutine 模拟独立的客户端
		go func(wg *sync.WaitGroup) {
			defer wg.Done()
			// 获取连接
			conn, err := pool.Get()
			if err != nil {
				log.Println(err)
				return
			}
			//log.Println(conn)
			// 回收连接
			pool.Put(conn)
		}(&wg)
	}
	wg.Wait()
}