// inspired from:
// https://github.com/mactsouk/opensource.com.git
// and
// https://coderwall.com/p/wohavg/creating-a-simple-tcp-server-in-go

package main

import "bufio"
// import "fmt"
import "math/rand"
import "net"
// import "os"
import "strconv"
import "strings"
import "time"
import "log"

const MIN = 1
const MAX = 100

const (
	CONN_HOST = "localhost"
	CONN_PORT = "3333"
	CONN_TYPE = "tcp"
)

func main() {
	// // Listen for incoming connections.
	l, err := net.Listen(CONN_TYPE, CONN_HOST+":"+CONN_PORT)
	if err != nil {
		log.Println("Error listening:", err.Error())
		return
	}

	// Close the listener when the application closes.
	defer l.Close()

	log.Println("Listening on " + CONN_HOST + ":" + CONN_PORT)

	rand.Seed(time.Now().Unix())

	for {
		// Listen for an incoming connection.
		conn, err := l.Accept()
		if err != nil {
			log.Println("Error accepting: ", err.Error())
			return
		}

		// Handle connections in a new goroutine.
		go handleConnection(conn)
	}
}


func random() int {
	return rand.Intn(MAX-MIN) + MIN
}

func handleConnection(c net.Conn) {
	log.Printf("Serving %s\n", c.RemoteAddr().String())
	for {
		netData, err := bufio.NewReader(c).ReadString('\n')
		if err != nil {
			log.Println(err)
			return
		}

		temp := strings.TrimSpace(string(netData))
		if temp == "STOP" {
			break
		}
		log.Println("Recieved: ", temp)

		result := strconv.Itoa(random()) + "\n"
		c.Write([]byte(string(result)))
	}
	c.Close()
}