package main

import (
    "net"
    "log"
    "bufio"
    "fmt"
)

func main()  {
    ln, err := net.Listen("tcp", "192.168.1.254:8989")
    if err != nil {
        log.Println(err.Error())
    }
    log.Printf("Start pooling %v", ln)

    aconns := make(map[net.Conn]int)
    conns := make(chan net.Conn)
    dconns := make(chan net.Conn)
    msgs := make(chan string)
    names := make(map[net.Conn]string)
    i := 0

    go func() {
        for {
            conn, err := ln.Accept()
            if err != nil {
                log.Println(err.Error())
            }
            conn.Write([]byte("Enter your name\n"))
            rd := bufio.NewReader(conn)
            name, err := rd.ReadString('\n')
            if err != nil {
                conn.Write([]byte(err.Error()))
                return
            }
            conn.Write([]byte(fmt.Sprintf("Hello %v", name)))
            names[conn] = name
            conns <- conn
        }
    }()

    for {
        select {
        case conn := <- conns:
            aconns[conn] = i
            name := names[conn]
            log.Printf("Client %v %v connected", i, name)
            i++
            go func(conn net.Conn, i int) {
                rd := bufio.NewReader(conn)
                for {
                    m, err := rd.ReadString('\n')
                    if err != nil {
                        break
                    }
                    msgs <- fmt.Sprintf("Client %v: %v", i, m)
                }
                dconns <- conn
            }(conn, i)
        case msg := <- msgs:
            for conn := range aconns {
                conn.Write([]byte(msg))
            }

        case dconn := <- dconns:
            log.Printf("Client %v left the chat", aconns[dconn])
            delete(aconns, dconn)
            delete(names, dconn)
        }
    }
}