// +build ignore

package main

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

func main() {
	// listening on tcp://0.0.0.0:8080
	ln, err := net.Listen("tcp", "0.0.0.0:8080")
	if err != nil {
		log.Fatalln(err)
	}
	fmt.Println("listening on", ln.Addr())
	// assign a unique id to each incoming connection
	for id := 0; ; id++ {
		if conn, err := ln.Accept(); err == nil {
			fmt.Printf("client[%d] connected from %s\n", id, conn.RemoteAddr())
			// handle the connection
			go echo(conn, id)
		}
	}
}

func echo(conn io.ReadWriteCloser, id int) {
	// close the conn on EOF
	defer func() {
		fmt.Printf("client[%d] disconnected: read: EOF\n", id)
		conn.Close()
	}()

	// for each line, do ...
	for scanner := bufio.NewScanner(conn); scanner.Scan(); {
		// get line
		line := scanner.Text()

		// echo back to client
		if _, err := io.WriteString(conn, fmt.Sprintln(line)); err != nil {
			fmt.Printf("client[%d] disconnected: write: %s\n", id, err.Error())
			break
		}

		// server-side log
		fmt.Println(fmt.Sprintf("client[%d]: %s", id, line))
	}
}