package irc

import (
	"log"
	"net"
	"strings"
)

type Server struct {
	ch chan Message
	users map[string]*Client
	nicks map[string]*Client
}

func NewServer() *Server {
	server := Server{make(chan Message), make(map[string]*Client), make(map[string]*Client)}
	go server.Receive()
	return &server
}

func (s *Server) Listen(addr string) {
	listener, err := net.Listen("tcp", addr)
	if err != nil {
		log.Fatal("Server.Listen: ", err)
	}

	for {
		conn, err := listener.Accept()
		if err != nil {
			log.Print("Server.Listen: ", err)
			continue
		}
		go NewClient(conn).Communicate(s)
	}
}

func (s *Server) Receive() {
	for message := range s.ch {
		log.Printf("C -> S: %s %s", message.command, message.args)
		switch message.command {
		case "PING":
			message.client.Send("PONG")
		case "PASS":
			s.PassCommand(message.client, message.args)
		case "USER":
			s.UserCommand(message.client, message.args)
		case "NICK":
			s.NickCommand(message.client, message.args)
		default:
			message.client.Send(ErrUnknownCommand(message.client.nick, message.command))
		}
	}
}

func (s *Server) Send(m Message) {
	s.ch <- m
}

// commands

func (s *Server) PassCommand(c *Client, args string) {
}

func (s *Server) UserCommand(c *Client, args string) {
	parts := strings.SplitN(args, " ", 4)
	username, _, _, realname := parts[0], parts[1], parts[2], parts[3]
	if s.users[username] != nil {
		c.Send(ErrAlreadyRegistered(c.nick))
		return
	}
	c.username, c.realname = username, realname
	s.users[username] = c
	if c.nick != "" {
		c.Send(
			ReplyWelcome(c.nick, c.username, "localhost"),
			ReplyYourHost(c.nick, "irc.jlatt.com"),
			ReplyCreated(c.nick, "2012/04/07"),
			ReplyMyInfo(c.nick, "irc.jlatt.com"))
	}
}

func (s *Server) NickCommand(c *Client, nick string) {
	if s.nicks[nick] != nil {
		c.Send(ErrNickNameInUse(nick))
		return
	}
	c.nick = nick
	s.nicks[nick] = c
}