package main

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

func handleConnection(conn net.Conn) error {
	buff := make([]byte, 4096)
	defer conn.Close()

	welcome := "=== Hola, Wikipedia! ==="
	conn.Write([]byte(welcome + "\n"))

	for {
		if n, err := conn.Read(buff); err != nil {
			return err
		} else if n == 0 {
			log.Println("Zero bytes, connection closed")
			break
		} else {
			msg := buff[0 : n-2] // trim "\r\n"
			log.Print(fmt.Sprintf("msg: %s", msg))

			resp := fmt.Sprintf("You said: \"%s\"\r\n", msg)
			if n, err := conn.Write([]byte(resp)); err != nil {
				return err
			} else if n == 0 {
				log.Println("zero bytes, closing connection")
				break
			}
		}
	}
	return nil
}

func startSever() error {
	if ln, err := net.Listen("tcp", ":8008"); err != nil {
		return err
	} else {
		for {
			if conn, err := ln.Accept(); err != nil {
				log.Printf("Error accepting connection", err)
				continue
			} else {
				log.Println("New connection accepted")
				go func() {
					if err := handleConnection(conn); err != nil {
						log.Println("Error handling connection", err)
					}
				}()
			}
		}
	}
}

func main() {
	if err := startSever(); err != nil {
		log.Fatal(err)
	}
}