main.go

package main

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

func main() {
	msgs := make(chan string)
	conns := make(chan net.Conn)
	aconns := make(map[net.Conn]int)
	dconns := make(chan net.Conn)
	i := 0
	ln, err := net.Listen("tcp", "127.0.0.1:8080")
	defer ln.Close()
	if err != nil {
		log.Println(err.Error())
	}
	// Accept connections for ever
	go func() {
		for {
			conn, err := ln.Accept()
			if err != nil {
				log.Println(err.Error())
			}
			conns <- conn
		}
	}()
	for {
		select {
		// Read incoming connections
		case conn := <-conns:
			log.Printf("Received new connection, ID = %v\n", i)
			aconns[conn] = i
			i++
			go func(conn net.Conn, i int) {
				r := bufio.NewReader(conn)
				for {
					t, err := r.ReadString('\n')
					if err != nil {
						log.Println(err.Error())
						break
					}
					msgs <- fmt.Sprintf("Client %v: %v", i, t)

				}
				dconns <- conn
			}(conn, i)
		// Read incoming messages
		case msg := <-msgs:
			for conn := range aconns {
				go func(conn net.Conn, msg string) {
					_, err := conn.Write([]byte(msg))
					if err != nil {
						dconns <- conn
					}

				}(conn, msg)
			}
		case dconn := <-dconns:
			log.Printf("Closing connection %v\n", aconns[dconn])
			dconn.Close()
			delete(aconns, dconn)
		}
	}
}