package main

import (
	"net";
	"log";
	"strings";
	"irc";
	"bufio";
)

var (
    users = make(map[net.Conn]map[string]string);
    sem = make(chan int, 1);
)

const welcomeMessage = "Welcome to the IRC Server\n"

func getConnections(listener *net.TCPListener, ch chan net.Conn) {
	for {
		tmp, _ := listener.Accept();
		ch <- tmp;
	}
}



func getConnFromUsername(username string) net.Conn {
	for key, value := range users {
		if value["nickname"] == username {
			return key
		}
	}
	return nil;
}

func registerNickname(nickname string, conn net.Conn) {
	sem <- 1;
	users[conn] = map[string]string{"nickname": nickname};
    log.Stdoutf("%s HAS REGISTERED A NICK\n", users[conn]["nickname"]);
	<-sem;
}

func sendMessage(message string, conn net.Conn, sendNickname string) {
	conn.Write(strings.Bytes(":" + sendNickname + " PRIVMSG :" + message))
}

func parseLine(line string, conn net.Conn) {
	msg := irc.ParseMessage(line);
	switch msg.Command {
	case "PRIVMSG":
		nickname := msg.Args[0];
		message := msg.LastArg;
		otherUserConn := getConnFromUsername(nickname);
		senderNickname := users[conn]["nickname"];
		sendMessage(message, otherUserConn, senderNickname);
	case "NICK":
		nickname := msg.Args[0];
		registerNickname(nickname, conn);
	}
}

func handleConnection(conn net.Conn) {
	//registerUser(conn);
    buf := bufio.NewReader(conn);
    buf.ReadString('\n');
    nick, _ := buf.ReadString('\n');
    nick = nick[0:len(nick) - 2];
    registerNickname(strings.Split(nick, " ", 0)[1], conn);
	for {
		line, err := buf.ReadString('\n');
        line = line[0:len(line) - 2]; 
		if err == nil {
			parseLine(users[conn]["nickname"] + " " + line, conn);
		} else {
            log.Stdoutf("ERROR READING FROM CONNECTION %v: %s\n", conn, err);
			break;
		}
	}
}

func main() {
	addr, _ := net.ResolveTCPAddr("localhost:6667");
	listener, _ := net.ListenTCP("tcp", addr);
	conChan := make(chan net.Conn);
	log.Stdout("STARTING SERVER...");
	go getConnections(listener, conChan);
	for {
		con := <-conChan;
		log.Stdout("Connection accepted:", con.RemoteAddr().String());
		go handleConnection(con);
	}
}