/*
goircd -- minimalistic simple Internet Relay Chat (IRC) server
Copyright (C) 2014 Sergey Matveev <stargrave@stargrave.org>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
package main

import (
	"bytes"
	"log"
	"net"
	"strings"
	"time"
)

const (
	CRLF     = "\x0d\x0a"
	BUF_SIZE = 1380
)

type Client struct {
	hostname   string
	conn       net.Conn
	registered bool
	ping_sent  bool
	timestamp  time.Time
	nickname   string
	username   string
	realname   string
}

func (client Client) String() string {
	return client.nickname + "!" + client.username + "@" + client.conn.RemoteAddr().String()
}

func NewClient(hostname string, conn net.Conn) *Client {
	return &Client{hostname: hostname, conn: conn, nickname: "*"}
}

// Client processor blockingly reads everything remote client sends,
// splits messages by CRLF and send them to Daemon gorouting for processing
// it futher. Also it can signalize that client is unavailable (disconnected).
func (client *Client) Processor(sink chan ClientEvent) {
	var buf_net []byte
	buf := make([]byte, 0)
	log.Println("New client", client)
	sink <- ClientEvent{client, EVENT_NEW, ""}
	for {
		buf_net = make([]byte, BUF_SIZE)
		_, err := client.conn.Read(buf_net)
		if err != nil {
			log.Println(client, "connection lost", err)
			sink <- ClientEvent{client, EVENT_DEL, ""}
			break
		}
		client.timestamp = time.Now()
		client.ping_sent = false
		buf_net = bytes.TrimRight(buf_net, "\x00")
		buf = append(buf, buf_net...)
		if !bytes.HasSuffix(buf, []byte(CRLF)) {
			continue
		}
		for _, msg := range bytes.Split(buf[:len(buf)-2], []byte(CRLF)) {
			if len(msg) > 0 {
				sink <- ClientEvent{client, EVENT_MSG, string(msg)}
			}
		}
		buf = []byte{}
	}
}

// Send message as is with CRLF appended.
func (client *Client) Msg(text string) {
	client.conn.Write([]byte(text + CRLF))
}

// Send message from server. It has ": servername" prefix.
func (client *Client) Reply(text string) {
	client.Msg(":" + client.hostname + " " + text)
}

// Send server message, concatenating all provided text parts and
// prefix the last one with ":".
func (client *Client) ReplyParts(code string, text ...string) {
	parts := []string{code}
	for _, t := range text {
		parts = append(parts, t)
	}
	parts[len(parts)-1] = ":" + parts[len(parts)-1]
	client.Reply(strings.Join(parts, " "))
}

// Send nicknamed server message. After servername it always has target
// client's nickname. The last part is prefixed with ":".
func (client *Client) ReplyNicknamed(code string, text ...string) {
	client.ReplyParts(code, append([]string{client.nickname}, text...)...)
}

// Reply "461 not enough parameters" error for given command.
func (client *Client) ReplyNotEnoughParameters(command string) {
	client.ReplyNicknamed("461", command, "Not enough parameters")
}

// Reply "403 no such channel" error for specified channel.
func (client *Client) ReplyNoChannel(channel string) {
	client.ReplyNicknamed("403", channel, "No such channel")
}

func (client *Client) ReplyNoNickChan(channel string) {
	client.ReplyNicknamed("401", channel, "No such nick/channel")
}