import (
    "fmt"
    "log"
    "net"
    "strconv"
)

func handleConnection(conn net.Conn, talkChan map[int]chan string) {
    //fmt.Printf("%p\n", talkChan)  //用以檢查是否是傳過(guò)來(lái)的指針

    /*
        定義當(dāng)前用戶的uid
    */
    var curUid int

    var err error

    /*
        定義關(guān)閉通道
    */
    var closed = make(chan bool)

    defer func() {
        fmt.Println("defer do : conn closed")
        conn.Close()
        fmt.Printf("delete userid [%v] from talkChan", curUid)
        delete(talkChan, curUid)
    }()

    /**
     * 提示用戶設(shè)置自己的uid， 如果沒(méi)設(shè)置，則不朝下執(zhí)行
     */
    for {
        //提示客戶端設(shè)置用戶id
        _, err = conn.Write([]byte("請(qǐng)?jiān)O(shè)置用戶uid"))
        if err != nil {
            return
        }
        data := make([]byte, 1024)
        c, err := conn.Read(data)
        if err != nil {
            //closed <- true  //這樣會(huì)阻塞 | 后面取closed的for循環(huán)，沒(méi)有執(zhí)行到。
            return
        }
        sUid := string(data[0:c])

        //轉(zhuǎn)成int類型
        uid, _ := strconv.Atoi(sUid)
        if uid < 1 {
            continue
        }
        curUid = uid
        talkChan[uid] = make(chan string)
        //fmt.Println(conn, "have set uid ", uid, "can talk")

        _, err = conn.Write([]byte("have set uid "+sUid+" can talk"))
        if err != nil {
            return
        }
        break
    }

    fmt.Println("err 3")

    //當(dāng)前所有的連接
    fmt.Println(talkChan)

    //讀取客戶端傳過(guò)來(lái)的數(shù)據(jù)
    go func() {
        for {
            //不停的讀客戶端傳過(guò)來(lái)的數(shù)據(jù)
            data := make([]byte, 1024)
            c, err := conn.Read(data)
            if err != nil {
                fmt.Println("have no client write", err)
                closed <- true //這里可以使用 | 因?yàn)槭怯糜玫膅o 新開的線程去處理的。 |  即便chan阻塞，后面的也會(huì)執(zhí)行去讀 closed 這個(gè)chan
            }

            clientString := string(data[0:c])

            //將客戶端過(guò)來(lái)的數(shù)據(jù)，寫到相應(yīng)的chan里
            if curUid == 3 {
                talkChan[4] <- clientString
            } else {
                talkChan[3] <- clientString
            }

        }
    }()

    /*
        從chan 里讀出給這個(gè)客戶端的數(shù)據(jù) 然后寫到該客戶端里
    */
    go func() {
        for {
            talkString := <-talkChan[curUid]
            _, err = conn.Write([]byte(talkString))
            if err != nil {
                closed <- true
            }
        }
    }()

    /*
       檢查是否已經(jīng)關(guān)閉連接 如果關(guān)閉則推出該線程  去執(zhí)行defer語(yǔ)句
    */
    for {
        if <-closed {
            return
        }
    }
}

func main() {

    /**
    建立監(jiān)聽(tīng)鏈接
    */
    ln, err := net.Listen("tcp", "127.0.0.1:6010")
    if err != nil {
        panic(err)
    }

    //創(chuàng)建一個(gè)管道

    //talkChan := map[f]
    talkChan := make(map[int]chan string)

    fmt.Printf("%p\n", talkChan)

    /*
       監(jiān)聽(tīng)是否有客戶端過(guò)來(lái)的連接請(qǐng)求
    */
    for {
        fmt.Println("wait connect...")
        conn, err := ln.Accept()
        if err != nil {
            log.Fatal("get client connection error: ", err)
        }

        go handleConnection(conn, talkChan)
    }
}

import (
    "fmt"
    "math/rand"
    "net"
)

func main() {
    conn, err := net.Dial("tcp", "127.0.0.1:6010")
    if err != nil {
        panic(err)
    }

    fmt.Fprintf(conn, "hello server\n")

    defer conn.Close()
    go writeFromServer(conn)

    for {
        var talkContent string
        fmt.Scanln(&talkContent)

        if len(talkContent) > 0 {
            _, err = conn.Write([]byte(talkContent))
            if err != nil {
                fmt.Println("write to server error")
                return
            }
        }
    }
}

func connect() {
    conn, err := net.Dial("tcp", "127.0.0.1:6010")
    if err != nil {
        panic(err)
    }

    fmt.Fprintf(conn, "hello server\n")

    defer conn.Close()
    go writeFromServer(conn)

    for {
        var talkContent string
        fmt.Scanln(&talkContent)

        if len(talkContent) > 0 {
            _, err = conn.Write([]byte(talkContent))
            if err != nil {
                fmt.Println("write to server error")
                return
            }
        }
    }
}

func writeFromServer(conn net.Conn) {
    defer conn.Close()
    for {
        data := make([]byte, 1024)
        c, err := conn.Read(data)
        if err != nil {
            fmt.Println("rand", rand.Intn(10), "have no server write", err)
            return
        }
        fmt.Println(string(data[0:c]) + "\n ")
    }
}