<?php

/**
Copyright (c) 2011, NullWarez All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 * The name of the author may not be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/

/**
*
* @package PHP DC++ Library (Non Threads)
* @version 1.1.3a
* @author NullWarez
* @copyright Copyright (c) 2011, NullWarez
* @license 3-clause BSD
*
*/


class PHPDClib
{
    private $handle_connection;
    private $options = array(
        'host'                => 'localhost',
        'port'                => '411',
        'bind_ip'             => '0.0.0.0',

        'nickname'            => 'PHPDClib',
        'password'            => '',
        'description'         => 'DC++ Library sf.net/projects/phpdclibrary',
        'email'               => '',
        'connection'          => 'LAN(T1)',
        'tag'                 => '<PHPDCLib++ V:1.1.3a,M:P,H:1/0/0,S:10>',
        'sharesize'           => '0',

        'userlist'            => 0,

        'debug'               => 0,
        'frequency_low'       => 300000,
        'frequency_high'      => 1000,
        'read_buffer_size'    => 256000,

        'func_chat_public'    => 'chat_public',
        'func_chat_private'   => 'chat_private',
        'func_event_handler'  => 'event_handler'
    );
    private $control = array(
        'connected'     => false
    );

    public $hub_info = array(
        'hubname'   => '',
        'userlist' => array()
    );

    private $curent_buffer = null;
    private $read_buffer = null;
    private $read_buffer_array = array();

    private $socket_tcp_recvspace = 0;

    private $frequency = 0;

    /**
     * Main function to connect
     *
     * @access public
     * @param array $optionArray
     */
    public function connect($optionArray)
    {
        $this->options = array_merge($this->options, $optionArray);
        $this->reconnect();

        while(1)
        {
            usleep($this->frequency);

            if($this->sock_error_trigger())
            {
                $this->reconnect();
                continue;
            }

            if($this->read_buffer_array || $this->read_buffer !== null)
            {
                if($this->frequency != $this->options['frequency_high'])
                    $this->frequency = $this->options['frequency_high'];
            }
            else
            {
                if($this->frequency != $this->options['frequency_low'])
                    $this->frequency = $this->options['frequency_low'];
            }

            if($this->read_socket())
                continue;

            if(!$this->read_buffer_array)
                continue;

            $this->curent_buffer = array_shift($this->read_buffer_array);
            $this->_debug("RX: $this->curent_buffer");
            $temp_cmd = $this->get_cmd();

            do
            {
                if('MyINFO' === $temp_cmd)
                {
                        if(!$this->control['connected']) break;
                        if(!$this->options['userlist']) break;

                        $str_pos = strpos($this->curent_buffer, 'L ');
                        $tmp = substr($this->curent_buffer, $str_pos+2);
                        $str_pos = strpos($tmp, ' ');
                        $tmp = substr($tmp, 0, $str_pos);

                        $this->hub_info['userlist'][$tmp] = '';

                }
                else if('$CHAT' === $temp_cmd)
                {
                        if(!$this->control['connected']) break;

                        $msg_array = $this->get_public_message();

                        if($msg_array !== false)
                            $this->options['func_chat_public']($msg_array[0], $msg_array[1], $this);
                }
                else if('Hello' === $temp_cmd)
                {
                        if($this->control['connected']) break;

                        $nickname = substr($this->curent_buffer, strpos($this->curent_buffer, ' ')+1);
                        if($nickname != $this->options['nickname'])
                        {
                            $this->options['func_event_handler']('>BadNick', $this);
                            break;
                        }

                        $this->write_socket('$Version 1,0091');
                        $this->write_socket('$MyINFO $ALL '.$this->options['nickname'].' '.$this->options['description'].$this->options['tag'].'$ $'.$this->options['connection'].'1$'.$this->options['email'].'$'.$this->options['sharesize'].'$');

                        if($this->options['userlist'])
                            $this->write_socket('$GetNickList');

                        $this->control['connected'] = true;

                }
                else if('Quit' === $temp_cmd)
                {
                        if(!$this->control['connected']) break;
                        if(!$this->options['userlist']) break;

                        $tmp = substr($this->curent_buffer, 6);

                        if(isset($this->hub_info['userlist'][$tmp]))
                            unset($this->hub_info['userlist'][$tmp]);

                }
                else if('To:' === $temp_cmd)
                {
                        if(!$this->control['connected']) break;

                        $msg_array = $this->get_private_message();

                        if($msg_array !== false)
                            $this->options['func_chat_private']($msg_array[0], $msg_array[1], $this);

                }
                else if('UserCommand' === $temp_cmd)
                {
                    break;
                }
                else if('Lock' === $temp_cmd)
                {
                        if($this->control['connected']) break;

                        preg_match("/Lock (.*) Pk/i", $this->curent_buffer, $lock);

                        if($this->options['userlist'])
                            $this->write_socket('$Supports NoHello');

                        $this->write_socket('$Key '.$this->lock2key($lock[1]));
                        $this->write_socket('$ValidateNick '.$this->options['nickname']);

                        if(!empty($this->options['password']))
                            $this->write_socket('$MyPass '.$this->options['password']);

                }
                else if('HubName' === $temp_cmd)
                {
                        if($this->control['connected']) break;

                        $this->hub_info['hubname'] = substr($this->curent_buffer, 9);

                }
                else if('GetPass' === $temp_cmd)
                {
                        if($this->control['connected']) break;

                        $this->options['func_event_handler']('GetPass', $this);

                }
                else if('ForceMove' === $temp_cmd)
                {

                    $this->options['func_event_handler']($this->curent_buffer, $this);

                }
                else if('HubIsFull' === $temp_cmd)
                {

                    $this->disconnect();
                    $this->options['func_event_handler']('$HubIsFull', $this);

                }

            }while(0);

            // Free the memory
            if($this->curent_buffer !== null)
            {
                $this->curent_buffer = null;
                $temp_cmd = null;
            }
        }
    }

    /**
     * Function to send public messages. Can be used in Callback functions
     *
     * @access public
     * @param string $msg
     */
    public function send_public_message($msg)
    {
        $this->write_socket('<'.$this->options['nickname'].'> '.$this->nmdcspecialchars($msg, true));
    }

    /**
     * Function to send private messages. Can be used in Callback functions
     *
     * @access public
     * @param string $to
     * @param string $msg
     */
    public function send_private_message($to, $msg)
    {
        $this->write_socket('$To: '.$to.' From: '. $this->options['nickname'].' $<'.$this->options['nickname'].'> '.$this->nmdcspecialchars($msg, true));
    }

    /**
     * Function of receiving commands, protocol NMDC
     *
     * @access private
     */
    private function get_cmd()
    {
        if($this->curent_buffer[0] === '<')
            return '$CHAT';
        elseif($this->curent_buffer[0] !== '$')
            return false;

        return substr($this->curent_buffer, 1, strpos($this->curent_buffer, ' ')-1);
    }

    /**
     * Function for receiving public messages
     *
     * @access private
     */
    private function get_public_message()
    {
        $str_pos = strpos($this->curent_buffer, '>');
        $msg_array[0] = substr($this->curent_buffer, 1, $str_pos-1);

        if($msg_array[0] === $this->options['nickname'])
            return false;

        $msg_array[1] = $this->nmdcspecialchars(substr($this->curent_buffer, $str_pos+2), false);

        return $msg_array;
    }

    /**
     * Function for receiving private messages
     *
     * @access private
     */
    private function get_private_message()
    {
        $str_pos_first = strpos($this->curent_buffer, '<');
        $str_pos_last = strpos($this->curent_buffer, '>', $str_pos_first);

        $msg_array[0] = substr($this->curent_buffer, $str_pos_first+1, $str_pos_last - $str_pos_first -1);

        if($msg_array[0] === $this->options['nickname'])
            return false;

        $msg_array[1] = $this->nmdcspecialchars(substr($this->curent_buffer, $str_pos_last+2), false);

        return $msg_array;
    }

    /**
     * Function, character by character to read from socket
     *
     * @access private
     */
    private function read_socket()
    {
        while(1)
        {
            $return_data = socket_read($this->handle_connection, $this->socket_tcp_recvspace, PHP_BINARY_READ);

            if($return_data === false)
            {
                return false;
            }
            else if($return_data === '')
            {
                $this->reconnect();
                return true;
            }

            $this->read_buffer .= $return_data;

            unset($return_data);

            $position = strrpos($this->read_buffer, '|');

            if($position === false)
                return false;

            $raw_data = explode('|', substr($this->read_buffer, 0, $position));

            foreach ($raw_data as $val)
            {
                $this->read_buffer_array[] = $val;
            }

            $raw_buffer = substr($this->read_buffer, $position+1);

            unset($position, $raw_data);

            if($raw_buffer === false)
            {
                $this->read_buffer = null;
                return false;
            }

            if(strlen($this->read_buffer) < $this->options['read_buffer_size'])
            {
                $this->read_buffer = $raw_buffer;
                return false;
            }

            $this->_debug('SYS(BUFFER OVERFLOW) - size: '.strlen($this->read_buffer).' max_size: '.$this->options['read_buffer_size']);
            $this->options['func_event_handler']('sysbufoverflow', $this);
            return false;
        }
    }

    /**
     * Function write in socket
     *
     * @access private
     */
    private function write_socket($cmd)
    {
        $this->_debug("TX: $cmd");

        $cmd .='|';
        $len = strlen($cmd);
        $offset = 0;

        while ($offset < $len)
        {
            $sent = socket_write($this->handle_connection, substr($cmd, $offset), $len-$offset);
            if($sent === false) {
                // Error occurred, break the while loop
                break;
            }
            $offset += $sent;

            if($offset < $len)
                $this->_debug('SOCKET_WRITE FRAG: len:'.$len.' writed: '.$offset);
        }
        if ($offset < $len)
        {
            $this->_debug('SOCKET_WRITE ERROR: '.socket_last_error());
            return false;
        }

        return true;
    }

    /**
     * Function for immediate reconnection
     *
     * @access private
     */
    public function reconnect()
    {
        if($this->control['connected'])
        {
            socket_close($this->handle_connection);
        }

        $this->control['connected'] = false;
        $this->hub_info['userlist'] = array();
        $this->curent_buffer = null;
        $this->read_buffer = null;
        $this->read_buffer_array = array();

        $this->handle_connection = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
        socket_bind($this->handle_connection, $this->options['bind_ip']);

        $this->socket_tcp_recvspace = socket_get_option($this->handle_connection, SOL_SOCKET, SO_RCVBUF);

        socket_connect($this->handle_connection, $this->options['host'], $this->options['port']);
        socket_set_nonblock($this->handle_connection);

        if($this->frequency != $this->options['frequency_low'])
            $this->frequency = $this->options['frequency_low'];
    }

    /**
     * Function to disconnect
     *
     * @access public
     */
    public function disconnect()
    {
        $this->write_socket('$Quit');
        $this->control['connected'] = false;
        $this->hub_info['userlist'] = array();
        socket_close($this->handle_connection);
    }

    /**
     * Function to send raw commands
     *
     * @access public
     * @param string $command
     */
    public function send_raw_command($command)
    {
        $this->write_socket($command);
    }

    /**
     * Convert special characters in NMDC protocol
     *
     * @access private
     * @param string $str
     * @param bool $reverse
     */
    private function nmdcspecialchars($str, $reverse)
    {
        if($reverse)
        {
            $search = array('&#36;', '&#124;', '&amp;');
            $replace = array('$', '|', '&');

            return str_replace($search, $replace, $str);
        }
        else
        {
            $search = array('&amp;', '&#36', '&#124;', '$', '|');
            $replace = array('&amp;amp;', '&amp;#36', '&amp;#124;', '&#36;', '&#124;');

            return str_replace($search, $replace, $str);
        }
    }

    /**
     * Function generation lock2key key to the protocol specification NMDC
     *
     * @access private
     * @param string $_LOCK
     */
    private function lock2key($_LOCK)
    {
        $lockLength = strlen($_LOCK);
        $LockToKey = '';

        for ($j = 0; $j < strlen($_LOCK); $j++)
        {
            if($j == 0) {
                $h = ord($_LOCK{0}) ^ ord( $_LOCK{ $lockLength - 1} ) ^ ord( $_LOCK{ $lockLength - 2} ) ^ 5;
            }
            else {
                $h = ord($_LOCK{$j}) ^ ord($_LOCK{$j-1});
            }

            $h = $h % 256;

            $a = (($h<<4) & 240) | (($h>>4) & 15);

            if($a == '126' or $a == '124' or $a == '96' or $a == '36' or $a == '5' or $a == '0') {
                $LockToKey .= '/%DCN';

                  if ($a < 100) $LockToKey .= "0";
                  if ($a < 10) $LockToKey .= "0";

                  $LockToKey .= $a.'%/';
            }
            else {
                  $LockToKey .= chr($a);
            }
        }

        return $LockToKey;
    }

    /**
     * Function debugging, to monitor incoming and outgoing data
     *
     * @access private
     * @param string $str
     */
    private function _debug($str)
    {
        if(!$this->options['debug'])
            return;

        echo $str."\n\n";
    }

    /**
     * Function check error codes.
     *
     * @access private
     */
    private function sock_error_trigger()
    {
        $err_num = socket_last_error($this->handle_connection);

        if($err_num === 0) // *nix, Windows (In non-blocking mode when the connection is not established, but we're trying to read data from socket)
            return false;
        else if($err_num === 35) // *nix (tested on FreeBSD)
            return false;
        else if($err_num === 10035) // Windows (tested on Windows 7)
            return false;
        else
            return true;
    }
}

?>