<?php

/**
 * PHP IRC Client library
 * Copyright (C) 2008 Dan Fuhry. All rights reserved.
 */

/**
 * Version number
 * @const string
 */

define('REQUEST_IRC_VERSION', '0.1');

/**
 * The base class for an IRC session.
 */

class Request_IRC
{
  
  /**
   * Hostname
   * @var string
   */
  
  private $host = '';
  
  /**
   * Port number
   * @var int
   */
  
  private $port = 6667;
  
  /**
   * The socket for the connection.
   * @var resource
   */
  
  public $sock = false;
  
  /**
   * Channel objects, associative array
   * @var array
   */
  
  public $channels = array();
  
  /**
   * The function called when a private message is received.
   * @var string
   */
  
  private $privmsg_handler = false;
  
  /**
   * Switch to track if quitted or not. Helps avoid quitting the connection twice thus causing write errors.
   * @var bool
   * @access private
   */
  
  protected $quitted = false;
  
  /**
   * The nickname we're connected as. Not modified once connected.
   * @var string
   */
  
  public $nick = '';
  
  /**
   * The username we're connected as. Not modified once connected.
   * @var string
   */
  
  public $user = '';
  
  /**
   * Constructor.
   * @param string Hostname
   * @param int Port number, defaults to 6667
   */
  
  public function __construct($host, $port = 6667)
  {
    // Check hostname
    if ( !preg_match('/^(([a-z0-9-]+\.)*?)([a-z0-9-]+)$/', $host) )
      die(__CLASS__ . ': Invalid hostname');
    $this->host = $host;
    
    // Check port
    if ( is_int($port) && $port >= 1 && $port <= 65535 )
      $this->port = $port;
    else
      die(__CLASS__ . ': Invalid port');
  }
  
  /**
   * Sets parameters and opens the connection.
   * @param string Nick
   * @param string User
   * @param string Real name
   * @param string NickServ password
   * @param int Flags, defaults to 0.
   */
  
  public function connect($nick, $username, $realname, $pass, $flags = 0)
  {
    // Init connection
    $this->sock = fsockopen($this->host, $this->port);
    if ( !$this->sock )
      throw new Exception('Could not make socket connection to host.');
    
    stream_set_timeout($this->sock, 5);
    
    // Wait for initial ident messages
    while ( $msg = $this->get() )
    {
    }
    
    // Send nick and username
    $this->put("NICK $nick\r\n");
    $this->put("USER $username 0 * :$realname\r\n");
    
    // Wait for response and end of motd
    $motd = '';
    while ( $msg = $this->get() )
    {
      // Match particles
      $msg = trim($msg);
      $mc = preg_match('/^:([A-z0-9\.-]+) ([0-9]+) [A-z0-9_-]+ :(.+)$/', $msg, $match);
      if ( !$mc )
      {
        $mc = preg_match('/^:([A-z0-9_-]+)!([A-z0-9_-]+)@([A-z0-9_\.-]+) NOTICE [A-z0-9_-]+ :(.+)$/', $msg, $match);
        if ( !$mc )
          continue;
        // Look for a response from NickServ
        if ( $match[1] == 'NickServ' )
        {
          // Asking for auth?
          if ( strpos($match[4], 'IDENTIFY') )
          {
            // Yes, send password
            $this->privmsg('NickServ', "IDENTIFY $pass");
          }
        }
      }
      list(, $host, $stat, $msg) = $match;
      $motd .= "$msg";
    }
    
    $this->nick = $nick;
    $this->user = $username;
  }
  
  /**
   * Writes some data to the socket, abstracted for debugging purposes.
   * @param string Message to send, this should include a CRLF.
   */
  
  public function put($message)
  {
    if ( !$this->sock )
    {
      if ( defined('LIBIRC_DEBUG') )
        echo ">>> WRITE FAILED: $message";
      return false;
    }
    if ( defined('LIBIRC_DEBUG') )
      echo ">>> $message";
    fwrite($this->sock, $message);
  }
  
  /**
   * Reads from the socket...
   * @return string
   */
  
  public function get()
  {
    if ( !$this->sock )
    {
      if ( defined('LIBIRC_DEBUG') )
        echo "<<< READ FAILED\n";
      return false;
    }
    $out = fgets($this->sock, 4096);
    if ( defined('LIBIRC_DEBUG') )
      if ( !empty($out) )
        echo "<<< $out";
    return $out;
  }
  
  /**
   * Sends a message to a nick or channel.
   * @param string Nick or channel
   * @param string Message
   */
  
  public function privmsg($nick, $message)
  {
    $message = str_replace("\r\n", "\n", $message);
    $message = explode("\n", $message);
    foreach ( $message as $line )
    {
      $this->put("PRIVMSG $nick :$line\r\n");
    }
  }
  
  /**
   * The main event loop.
   */
  
  public function event_loop()
  {
    stream_set_timeout($this->sock, 0xFFFFFFFE);
    while ( $data = $this->get() )
    {
      $data_trim = trim($data);
      $match = self::parse_message($data_trim);
      if ( preg_match('/^PING :(.+?)$/', $data_trim, $pmatch) )
      {
        $this->put("PONG :{$pmatch[1]}\r\n");
      }
      else if ( $match )
      {
        // Received PRIVMSG or other mainstream action
        if ( $match['action'] == 'JOIN' )
          $channel =& $match['message'];
        else
          $channel =& $match['target'];
          
        if ( !preg_match('/^[#!&\+]/', $channel) )
        {
          // Private message from user
          $result = $this->handle_privmsg($data);
          stream_set_timeout($this->sock, 0xFFFFFFFE);
        }
        else if ( isset($this->channels[strtolower($channel)]) )
        {
          // Message into channel
          $chan =& $this->channels[strtolower($channel)];
          $func = $chan->get_handler();
          $result = @call_user_func($func, $data, $chan);
          stream_set_timeout($this->sock, 0xFFFFFFFE);
        }
        if ( $result == 'BREAK' )
        {
          break;
        }
      }
    }
  }
  
  /**
   * Processor for when a private message is received.
   * @access private
   */
  
  private function handle_privmsg($message)
  {
    $message = self::parse_message($message);
    $ph = $this->privmsg_handler;
    if ( @function_exists($ph) )
      return @call_user_func($ph, $message);
  }
  
  /**
   * Changes the function called upon receipt of a private message.
   * @param string Function to call, will be passed a parsed message.
   */
  
  function set_privmsg_handler($func)
  {
    if ( !function_exists($func) )
      return false;
    $this->privmsg_handler = $func;
    return true;
  }
  
  /**
   * Parses a message line.
   * @param string Message text
   * @return array Associative with keys: nick, user, host, action, target, message
   */
   
  public static function parse_message($message)
  {
    // Indices:          12       3       4        5        67                         8
    $mc = preg_match('/^:(([^ ]+)!([^ ]+)@([^ ]+)) ([A-Z]+) (([#!&\+]*[A-z0-9_-]+) )?:?(.*?)$/', $message, $match);
    if ( !$mc )
    {
      return false;
    }
    // Indices: 0 1 2      3      4      5        6 7        8
    list(       , , $nick, $user, $host, $action, , $target, $message) = $match;
    return array(
        'nick' => $nick,
        'user' => $user,
        'host' => $host,
        'action' => $action,
        'target' => $target,
        'message' => trim($message)
      );
  }
  
  /**
   * Joins a channel, and returns a Request_IRC_Channel object.
   * @param string Channel name (remember # prefix)
   * @param string Event handler function, will be called with param 0 = socket output and param 1 = channel object
   * @return object
   */
  
  function join($channel, $handler)
  {
    $chan = new Request_IRC_Channel(strtolower($channel), $handler, $this);
    $this->channels[strtolower($channel)] = $chan;
    return $chan;
  }
  
  /**
   * Closes the connection and quits.
   * @param string Optional part message
   */
  
  public function close($partmsg = false)
  {
    if ( $this->quitted )
      return true;
    
    $this->quitted = true;
    // Part all channels
    if ( !$partmsg )
      $partmsg = 'IRC bot powered by PHP/' . PHP_VERSION . ' libirc/' . REQUEST_IRC_VERSION;
    
    foreach ( $this->channels as $channel )
    {
      $channel->part($partmsg);
    }
    
    $this->put("QUIT\r\n");
    
    while ( $msg = $this->get() )
    {
      // Do nothing.
    }
    
    fclose($this->sock);
  }
  
}

/**
 * Wrapper for channels.
 */

class Request_IRC_Channel extends Request_IRC
{
  
  /**
   * The name of the channel
   * @var string
   */
  
  private $channel_name = '';
  
  /**
   * The event handler function.
   * @var string
   */
  
  private $handler = '';
  
  /**
   * The parent connection.
   * @var object
   */
  
  public $parent = false;
  
  /**
   * Whether the channel has been parted or not, used to kill the destructor.
   * @var bool
   */
  
  protected $parted = false;
  
  /**
   * Constructor.
   * @param string Channel name
   * @param string Handler function
   * @param object IRC connection (Request_IRC object)
   */
  
  function __construct($channel, $handler, $parent)
  {
    $this->parent = $parent;
    $this->parent->put("JOIN $channel\r\n");
    stream_set_timeout($this->parent->sock, 3);
    while ( $msg = $this->parent->get() )
    {
      // Do nothing
    }
    $this->channel_name = $channel;
    $this->handler = $handler;
  }
  
  /**
   * Returns the channel name
   * @return string
   */
  
  function get_channel_name()
  {
    return $this->channel_name;
  }
  
  /**
   * Returns the handler function
   * @return string
   */
  
  function get_handler()
  {
    return $this->handler;
  }
  
  /**
   * Sends a message.
   * @param string message
   * @param bool If true, will fire a message event when the message is sent.
   */
  
  function msg($msg, $fire_event = false)
  {
    $this->parent->privmsg($this->channel_name, $msg);
    if ( $fire_event )
    {
      $func = $this->get_handler();
      // format: :nick!user@host PRIVMSG #channel :msg.
      $lines = explode("\n", $msg);
      foreach ( $lines as $line )
      {
        $data = ":{$this->parent->nick}!{$this->parent->user}@localhost PRIVMSG {$this->channel_name} :$line";
        $result = @call_user_func($func, $data, $this);
        stream_set_timeout($this->parent->sock, 0xFFFFFFFE);
      }
    }
  }
  
  /**
   * Destructor, automatically parts the channel.
   */
  
  function __destruct()
  {
    if ( !$this->parted )
      $this->part('IRC bot powered by PHP/' . PHP_VERSION . ' libirc/' . REQUEST_IRC_VERSION);
  }
  
  /**
   * Parts the channel.
   * @param string Optional message
   */
  
  function part($msg = '')
  {
    $this->parent->put("PART {$this->channel_name} :$msg\r\n");
    $this->parted = true;
    unset($this->parent->channels[$this->channel_name]);
  }
  
}

?>