<?php

/**
* phpagi.php : PHP AGI Functions for Asterisk
* Website: http://phpagi.sourceforge.net/
*
* $Id: phpagi.php,v 2.20 2010/09/30 02:21:00 masham Exp $
*
* Copyright (c) 2003 - 2010 Matthew Asham <matthew@ochrelabs.com>, David Eder <david@eder.us> and others
* All Rights Reserved.
*
* This software is released under the terms of the GNU Lesser General Public License v2.1
* A copy of which is available from http://www.gnu.org/copyleft/lesser.html
*
* We would be happy to list your phpagi based application on the phpagi
* website.  Drop me an Email if you'd like us to list your program.
* 
*
* Written for PHP 4.3.4, should work with older PHP 4.x versions.
*
* Please submit bug reports, patches, etc to http://sourceforge.net/projects/phpagi/
* Gracias. :)
*
*
* @package phpAGI
* @version 2.20
*/

if (!class_exists('AGI_AsteriskManager'))
{
    require_once(dirname(__FILE__) . DIRECTORY_SEPARATOR . 'phpagi-asmanager.php');
}

define('AST_CONFIG_DIR', '/etc/asterisk/');
define('AST_SPOOL_DIR', '/var/spool/asterisk/');
define('AST_TMP_DIR', AST_SPOOL_DIR . '/tmp/');
define('DEFAULT_PHPAGI_CONFIG', AST_CONFIG_DIR . '/phpagi.conf');

define('AST_DIGIT_ANY', '0123456789#*');

define('AGIRES_OK', 200);

define('AST_STATE_DOWN', 0);
define('AST_STATE_RESERVED', 1);
define('AST_STATE_OFFHOOK', 2);
define('AST_STATE_DIALING', 3);
define('AST_STATE_RING', 4);
define('AST_STATE_RINGING', 5);
define('AST_STATE_UP', 6);
define('AST_STATE_BUSY', 7);
define('AST_STATE_DIALING_OFFHOOK', 8);
define('AST_STATE_PRERING', 9);

define('AUDIO_FILENO', 3); // STDERR_FILENO + 1

/**
* AGI class
*
* @package phpAGI
* @link http://www.voip-info.org/wiki-Asterisk+agi
* @example examples/dtmf.php Get DTMF tones from the user and say the digits
* @example examples/input.php Get text input from the user and say it back
* @example examples/ping.php Ping an IP address
*/
class AGI
{
    /**
    * Request variables read in on initialization.
    *
    * Often contains any/all of the following:
    *   agi_request - name of agi script
    *   agi_channel - current channel
    *   agi_language - current language
    *   agi_type - channel type (SIP, ZAP, IAX, ...)
    *   agi_uniqueid - unique id based on unix time
    *   agi_callerid - callerID string
    *   agi_dnid - dialed number id
    *   agi_rdnis - referring DNIS number
    *   agi_context - current context
    *   agi_extension - extension dialed
    *   agi_priority - current priority
    *   agi_enhanced - value is 1.0 if started as an EAGI script
    *   agi_accountcode - set by SetAccount in the dialplan
    *   agi_network - value is yes if this is a fastagi
    *   agi_network_script - name of the script to execute
    *
    * NOTE: program arguments are still in $_SERVER['argv'].
    *
    * @var array
    * @access public
    */
    var $request;

    /**
    * Config variables
    *
    * @var array
    * @access public
    */
    var $config;

    /**
    * Asterisk Manager
    *
    * @var AGI_AsteriskManager
    * @access public
    */
    var $asmanager;

    /**
    * Input Stream
    *
    * @access private
    */
    var $in = NULL;

    /**
    * Output Stream
    *
    * @access private
    */
    var $out = NULL;

    /**
    * Audio Stream
    *
    * @access public
    */
    var $audio = NULL;


    /**
    * Application option delimiter
    * 
    * @access public
    */
    public $option_delim = ",";
    
    /**
    * Constructor
    *
    * @param string $config is the name of the config file to parse
    * @param array $optconfig is an array of configuration vars and vals, stuffed into $this->config['phpagi']
    */
    function __construct($config=NULL, $optconfig=array())
    {
        // load config
        if(!is_null($config) && file_exists($config))
          $this->config = parse_ini_file($config, true);
        elseif(file_exists(DEFAULT_PHPAGI_CONFIG))
          $this->config = parse_ini_file(DEFAULT_PHPAGI_CONFIG, true);

        // If optconfig is specified, stuff vals and vars into 'phpagi' config array.
        foreach($optconfig as $var=>$val)
          $this->config['phpagi'][$var] = $val;

        // add default values to config for uninitialized values
        if(!isset($this->config['phpagi']['error_handler'])) $this->config['phpagi']['error_handler'] = true;
        if(!isset($this->config['phpagi']['debug'])) $this->config['phpagi']['debug'] = false;
        if(!isset($this->config['phpagi']['admin'])) $this->config['phpagi']['admin'] = NULL;
        if(!isset($this->config['phpagi']['tempdir'])) $this->config['phpagi']['tempdir'] = AST_TMP_DIR;

        // festival TTS config
        if(!isset($this->config['festival']['text2wave'])) $this->config['festival']['text2wave'] = $this->which('text2wave');

        // swift TTS config
        if(!isset($this->config['cepstral']['swift'])) $this->config['cepstral']['swift'] = $this->which('swift');

        ob_implicit_flush(true);

        // open stdin & stdout
        $this->in = defined('STDIN') ? STDIN : fopen('php://stdin', 'r');
        $this->out = defined('STDOUT') ? STDOUT : fopen('php://stdout', 'w');

        // initialize error handler
        if($this->config['phpagi']['error_handler'] == true)
        {
          set_error_handler('phpagi_error_handler');
          global $phpagi_error_handler_email;
          $phpagi_error_handler_email = $this->config['phpagi']['admin'];
          error_reporting(E_ALL);
        }

        // make sure temp folder exists
        $this->make_folder($this->config['phpagi']['tempdir']);

        // read the request
        $str = fgets($this->in);
        while($str != "\n")
        {
          $this->request[substr($str, 0, strpos($str, ':'))] = trim(substr($str, strpos($str, ':') + 1));
          $str = fgets($this->in);
        }

        // open audio if eagi detected
        if($this->request['agi_enhanced'] == '1.0')
        {
          if(file_exists('/proc/' . getmypid() . '/fd/3'))
            $this->audio = fopen('/proc/' . getmypid() . '/fd/3', 'r');
          elseif(file_exists('/dev/fd/3'))
          {
            // may need to mount fdescfs
            $this->audio = fopen('/dev/fd/3', 'r');
          }
          else
            $this->conlog('Unable to open audio stream');

          if($this->audio) stream_set_blocking($this->audio, 0);
        }

        $this->conlog('AGI Request:');
        $this->conlog(print_r($this->request, true));
        $this->conlog('PHPAGI internal configuration:');
        $this->conlog(print_r($this->config, true));
    }

    // *********************************************************************************************************
    // **                             COMMANDS                                                                                            **
    // *********************************************************************************************************

    /**
    * Answer channel if not already in answer state.
    *
    * @link http://www.voip-info.org/wiki-answer
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    * @example examples/ping.php Ping an IP address
    *
    * @return array, see evaluate for return information.  ['result'] is 0 on success, -1 on failure.
    */
    function answer()
    {
        return $this->evaluate('ANSWER');
    }

    /**
    * Get the status of the specified channel. If no channel name is specified, return the status of the current channel.
    *
    * @link http://www.voip-info.org/wiki-channel+status
    * @param string $channel
    * @return array, see evaluate for return information. ['data'] contains description.
    */
    function channel_status($channel='')
    {
        $ret = $this->evaluate("CHANNEL STATUS $channel");
        switch($ret['result'])
        {
          case -1: $ret['data'] = trim("There is no channel that matches $channel"); break;
          case AST_STATE_DOWN: $ret['data'] = 'Channel is down and available'; break;
          case AST_STATE_RESERVED: $ret['data'] = 'Channel is down, but reserved'; break;
          case AST_STATE_OFFHOOK: $ret['data'] = 'Channel is off hook'; break;
          case AST_STATE_DIALING: $ret['data'] = 'Digits (or equivalent) have been dialed'; break;
          case AST_STATE_RING: $ret['data'] = 'Line is ringing'; break;
          case AST_STATE_RINGING: $ret['data'] = 'Remote end is ringing'; break;
          case AST_STATE_UP: $ret['data'] = 'Line is up'; break;
          case AST_STATE_BUSY: $ret['data'] = 'Line is busy'; break;
          case AST_STATE_DIALING_OFFHOOK: $ret['data'] = 'Digits (or equivalent) have been dialed while offhook'; break;
          case AST_STATE_PRERING: $ret['data'] = 'Channel has detected an incoming call and is waiting for ring'; break;
          default: $ret['data'] = "Unknown ({$ret['result']})"; break;
        }
        return $ret;
    }

    /**
    * Deletes an entry in the Asterisk database for a given family and key.
    *
    * @link http://www.voip-info.org/wiki-database+del
    * @param string $family
    * @param string $key
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise.
    */
    function database_del($family, $key)
    {
        return $this->evaluate("DATABASE DEL \"$family\" \"$key\"");
    }

    /**
    * Deletes a family or specific keytree within a family in the Asterisk database.
    *
    * @link http://www.voip-info.org/wiki-database+deltree
    * @param string $family
    * @param string $keytree
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise.
    */
    function database_deltree($family, $keytree='')
    {
        $cmd = "DATABASE DELTREE \"$family\"";
        if($keytree != '') $cmd .= " \"$keytree\"";
        return $this->evaluate($cmd);
    }

    /**
    * Retrieves an entry in the Asterisk database for a given family and key.
    *
    * @link http://www.voip-info.org/wiki-database+get
    * @param string $family
    * @param string $key
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 failure. ['data'] holds the value
    */
    function database_get($family, $key)
    {
        return $this->evaluate("DATABASE GET \"$family\" \"$key\"");
    }

    /**
    * Adds or updates an entry in the Asterisk database for a given family, key, and value.
    *
    * @param string $family
    * @param string $key
    * @param string $value
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise
    */
    function database_put($family, $key, $value)
    {
        $value = str_replace("\n", '\n', addslashes($value));
        return $this->evaluate("DATABASE PUT \"$family\" \"$key\" \"$value\"");
    }


    /**
    * Sets a global variable, using Asterisk 1.6 syntax.
    *
    * @link http://www.voip-info.org/wiki/view/Asterisk+cmd+Set
    *
    * @param string $pVariable
    * @param string|int|float $pValue
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise
    */
    function set_global_var($pVariable, $pValue)
    {
        if (is_numeric($pValue))
            return $this->evaluate("Set({$pVariable}={$pValue},g);");
        else
            return $this->evaluate("Set({$pVariable}=\"{$pValue}\",g);");
    }


    /**
    * Sets a variable, using Asterisk 1.6 syntax.
    *
    * @link http://www.voip-info.org/wiki/view/Asterisk+cmd+Set
    *
    * @param string $pVariable
    * @param string|int|float $pValue
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise
    */
    function set_var($pVariable, $pValue)
    {
        if (is_numeric($pValue))
            return $this->evaluate("Set({$pVariable}={$pValue});");
        else
            return $this->evaluate("Set({$pVariable}=\"{$pValue}\");");
    }


    /**
    * Executes the specified Asterisk application with given options.
    *
    * @link http://www.voip-info.org/wiki-exec
    * @link http://www.voip-info.org/wiki-Asterisk+-+documentation+of+application+commands
    * @param string $application
    * @param mixed $options
    * @return array, see evaluate for return information. ['result'] is whatever the application returns, or -2 on failure to find application
    */
    function exec($application, $options)
    {
        if(is_array($options)) $options = join('|', $options);
        return $this->evaluate("EXEC $application $options");
    }

    /**
    * Plays the given file and receives DTMF data.
    *
    * This is similar to STREAM FILE, but this command can accept and return many DTMF digits,
    * while STREAM FILE returns immediately after the first DTMF digit is detected.
    *
    * Asterisk looks for the file to play in /var/lib/asterisk/sounds by default.
    *
    * If the user doesn't press any keys when the message plays, there is $timeout milliseconds
    * of silence then the command ends. 
    *
    * The user has the opportunity to press a key at any time during the message or the
    * post-message silence. If the user presses a key while the message is playing, the
    * message stops playing. When the first key is pressed a timer starts counting for
    * $timeout milliseconds. Every time the user presses another key the timer is restarted.
    * The command ends when the counter goes to zero or the maximum number of digits is entered,
    * whichever happens first. 
    *
    * If you don't specify a time out then a default timeout of 2000 is used following a pressed
    * digit. If no digits are pressed then 6 seconds of silence follow the message. 
    *
    * If you don't specify $max_digits then the user can enter as many digits as they want. 
    *
    * Pressing the # key has the same effect as the timer running out: the command ends and
    * any previously keyed digits are returned. A side effect of this is that there is no
    * way to read a # key using this command.
    *
    * @example examples/ping.php Ping an IP address
    *
    * @link http://www.voip-info.org/wiki-get+data
    * @param string $filename file to play. Do not include file extension.
    * @param integer $timeout milliseconds
    * @param integer $max_digits
    * @return array, see evaluate for return information. ['result'] holds the digits and ['data'] holds the timeout if present.
    *
    * This differs from other commands with return DTMF as numbers representing ASCII characters.
    */
    function get_data($filename, $timeout=NULL, $max_digits=NULL)
    {
        return $this->evaluate(rtrim("GET DATA $filename $timeout $max_digits"));
    }

    /**
    * Fetch the value of a variable.
    *
    * Does not work with global variables. Does not work with some variables that are generated by modules.
    *
    * @link http://www.voip-info.org/wiki-get+variable
    * @link http://www.voip-info.org/wiki-Asterisk+variables
    * @param string $variable name
    * @param boolean $getvalue return the value only
    * @return array, see evaluate for return information. ['result'] is 0 if variable hasn't been set, 1 if it has. ['data'] holds the value. returns value if $getvalue is TRUE
    */
    function get_variable($variable,$getvalue=FALSE)
    {
        $res=$this->evaluate("GET VARIABLE $variable");

        if($getvalue==FALSE)
          return($res);

        return($res['data']);
    }


    /**
    * Fetch the value of a full variable.
    *
    *
    * @link http://www.voip-info.org/wiki/view/get+full+variable
    * @link http://www.voip-info.org/wiki-Asterisk+variables
    * @param string $variable name
    * @param string $channel channel
    * @param boolean $getvalue return the value only 
    * @return array, see evaluate for return information. ['result'] is 0 if variable hasn't been set, 1 if it has. ['data'] holds the value.  returns value if $getvalue is TRUE
    */
    function get_fullvariable($variable,$channel=FALSE,$getvalue=FALSE)
    {
      if($channel==FALSE){
        $req = $variable;
      } else {
        $req = $variable.' '.$channel;
      }
      
      $res=$this->evaluate('GET VARIABLE FULL '.$req);
      
      if($getvalue==FALSE)
        return($res);
      
      return($res['data']);
      
    }

    /**
    * Hangup the specified channel. If no channel name is given, hang up the current channel.
    *
    * With power comes responsibility. Hanging up channels other than your own isn't something
    * that is done routinely. If you are not sure why you are doing so, then don't.
    *
    * @link http://www.voip-info.org/wiki-hangup
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    * @example examples/ping.php Ping an IP address
    *
    * @param string $channel
    * @return array, see evaluate for return information. ['result'] is 1 on success, -1 on failure.
    */
    function hangup($channel='')
    {
        return $this->evaluate("HANGUP $channel");
    }

    /**
    * Does nothing.
    *
    * @link http://www.voip-info.org/wiki-noop
    * @return array, see evaluate for return information.
    */
    function noop($string="")
    {
        return $this->evaluate("NOOP \"$string\"");
    }

    /**
    * Receive a character of text from a connected channel. Waits up to $timeout milliseconds for
    * a character to arrive, or infinitely if $timeout is zero.
    *
    * @link http://www.voip-info.org/wiki-receive+char
    * @param integer $timeout milliseconds
    * @return array, see evaluate for return information. ['result'] is 0 on timeout or not supported, -1 on failure. Otherwise 
    * it is the decimal value of the DTMF tone. Use chr() to convert to ASCII.
    */
    function receive_char($timeout=-1)
    {
        return $this->evaluate("RECEIVE CHAR $timeout");
    }

    /**
    * Record sound to a file until an acceptable DTMF digit is received or a specified amount of
    * time has passed. Optionally the file BEEP is played before recording begins.
    *
    * @link http://www.voip-info.org/wiki-record+file
    * @param string $file to record, without extension, often created in /var/lib/asterisk/sounds
    * @param string $format of the file. GSM and WAV are commonly used formats. MP3 is read-only and thus cannot be used.
    * @param string $escape_digits
    * @param integer $timeout is the maximum record time in milliseconds, or -1 for no timeout.
    * @param integer $offset to seek to without exceeding the end of the file.
    * @param boolean $beep
    * @param integer $silence number of seconds of silence allowed before the function returns despite the 
    * lack of dtmf digits or reaching timeout.
    * @return array, see evaluate for return information. ['result'] is -1 on error, 0 on hangup, otherwise a decimal value of the 
    * DTMF tone. Use chr() to convert to ASCII.
    */
    function record_file($file, $format, $escape_digits='', $timeout=-1, $offset=NULL, $beep=false, $silence=NULL)
    {
        $cmd = trim("RECORD FILE $file $format \"$escape_digits\" $timeout $offset");
        if($beep) $cmd .= ' BEEP';
        if(!is_null($silence)) $cmd .= " s=$silence";
        return $this->evaluate($cmd);
    }

    /**
    * Say the given digit string, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+digits
    * @param integer $digits
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_digits($digits, $escape_digits='')
    {
        return $this->evaluate("SAY DIGITS $digits \"$escape_digits\"");
    }

    /**
    * Say the given number, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+number
    * @param integer $number
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_number($number, $escape_digits='')
    {
        return $this->evaluate("SAY NUMBER $number \"$escape_digits\"");
    }

    /**
    * Say the given character string, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+phonetic
    * @param string $text
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_phonetic($text, $escape_digits='')
    {
        return $this->evaluate("SAY PHONETIC $text \"$escape_digits\"");
    }

    /**
    * Say a given time, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+time
    * @param integer $time number of seconds elapsed since 00:00:00 on January 1, 1970, Coordinated Universal Time (UTC).
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_time($time=NULL, $escape_digits='')
    {
        if(is_null($time)) $time = time();
        return $this->evaluate("SAY TIME $time \"$escape_digits\"");
    }

    /**
    * Send the specified image on a channel.
    *
    * Most channels do not support the transmission of images.
    *
    * @link http://www.voip-info.org/wiki-send+image
    * @param string $image without extension, often in /var/lib/asterisk/images
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if the image is sent or 
    * channel does not support image transmission.
    */
    function send_image($image)
    {
        return $this->evaluate("SEND IMAGE $image");
    }

    /**
    * Send the given text to the connected channel.
    *
    * Most channels do not support transmission of text.
    *
    * @link http://www.voip-info.org/wiki-send+text
    * @param $text
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if the text is sent or 
    * channel does not support text transmission.
    */
    function send_text($text)
    {
        return $this->evaluate("SEND TEXT \"$text\"");
    }

    /**
    * Cause the channel to automatically hangup at $time seconds in the future.
    * If $time is 0 then the autohangup feature is disabled on this channel.
    *
    * If the channel is hungup prior to $time seconds, this setting has no effect.
    *
    * @link http://www.voip-info.org/wiki-set+autohangup
    * @param integer $time until automatic hangup
    * @return array, see evaluate for return information.
    */
    function set_autohangup($time=0)
    {
        return $this->evaluate("SET AUTOHANGUP $time");
    }

    /**
    * Changes the caller ID of the current channel.
    *
    * @link http://www.voip-info.org/wiki-set+callerid
    * @param string $cid example: "John Smith"<1234567>
    * This command will let you take liberties with the <caller ID specification> but the format shown in the example above works 
    * well: the name enclosed in double quotes followed immediately by the number inside angle brackets. If there is no name then
    * you can omit it. If the name contains no spaces you can omit the double quotes around it. The number must follow the name
    * immediately; don't put a space between them. The angle brackets around the number are necessary; if you omit them the
    * number will be considered to be part of the name.
    * @return array, see evaluate for return information.
    */
    function set_callerid($cid)
    {
        return $this->evaluate("SET CALLERID $cid");
    }

    /**
    * Sets the context for continuation upon exiting the application.
    *
    * Setting the context does NOT automatically reset the extension and the priority; if you want to start at the top of the new 
    * context you should set extension and priority yourself. 
    *
    * If you specify a non-existent context you receive no error indication (['result'] is still 0) but you do get a 
    * warning message on the Asterisk console.
    *
    * @link http://www.voip-info.org/wiki-set+context
    * @param string $context 
    * @return array, see evaluate for return information.
    */
    function set_context($context)
    {
        return $this->evaluate("SET CONTEXT $context");
    }

    /**
    * Set the extension to be used for continuation upon exiting the application.
    *
    * Setting the extension does NOT automatically reset the priority. If you want to start with the first priority of the 
    * extension you should set the priority yourself. 
    *
    * If you specify a non-existent extension you receive no error indication (['result'] is still 0) but you do 
    * get a warning message on the Asterisk console.
    *
    * @link http://www.voip-info.org/wiki-set+extension
    * @param string $extension
    * @return array, see evaluate for return information.
    */
    function set_extension($extension)
    {
        return $this->evaluate("SET EXTENSION $extension");
    }

    /**
    * Enable/Disable Music on hold generator.
    *
    * @link http://www.voip-info.org/wiki-set+music
    * @param boolean $enabled
    * @param string $class
    * @return array, see evaluate for return information.
    */
    function set_music($enabled=true, $class='')
    {
        $enabled = ($enabled) ? 'ON' : 'OFF';
        return $this->evaluate("SET MUSIC $enabled $class");
    }

    /**
    * Set the priority to be used for continuation upon exiting the application.
    *
    * If you specify a non-existent priority you receive no error indication (['result'] is still 0)
    * and no warning is issued on the Asterisk console.
    *
    * @link http://www.voip-info.org/wiki-set+priority
    * @param integer $priority
    * @return array, see evaluate for return information.
    */
    function set_priority($priority)
    {
        return $this->evaluate("SET PRIORITY $priority");
    }

    /**
    * Sets a variable to the specified value. The variables so created can later be used by later using ${<variablename>}
    * in the dialplan.
    *
    * These variables live in the channel Asterisk creates when you pickup a phone and as such they are both local and temporary. 
    * Variables created in one channel can not be accessed by another channel. When you hang up the phone, the channel is deleted 
    * and any variables in that channel are deleted as well.
    *
    * @link http://www.voip-info.org/wiki-set+variable
    * @param string $variable is case sensitive
    * @param string $value
    * @return array, see evaluate for return information.
    */
    function set_variable($variable, $value)
    {
        $value = str_replace("\n", '\n', addslashes($value));
        return $this->evaluate("SET VARIABLE $variable \"$value\"");
    }

    /**
    * Play the given audio file, allowing playback to be interrupted by a DTMF digit. This command is similar to the GET DATA 
    * command but this command returns after the first DTMF digit has been pressed while GET DATA can accumulated any number of 
    * digits before returning.
    *
    * @example examples/ping.php Ping an IP address
    *
    * @link http://www.voip-info.org/wiki-stream+file
    * @param string $filename without extension, often in /var/lib/asterisk/sounds
    * @param string $escape_digits
    * @param integer $offset
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function stream_file($filename, $escape_digits='', $offset=0)
    {
        return $this->evaluate("STREAM FILE $filename \"$escape_digits\" $offset");
    }

    /**
    * Enable or disable TDD transmission/reception on the current channel.
    *
    * @link http://www.voip-info.org/wiki-tdd+mode
    * @param string $setting can be on, off or mate
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 if the channel is not TDD capable.
    */
    function tdd_mode($setting)
    {
        return $this->evaluate("TDD MODE $setting");
    }

    /**
    * Sends $message to the Asterisk console via the 'verbose' message system.
    *
    * If the Asterisk verbosity level is $level or greater, send $message to the console.
    *
    * The Asterisk verbosity system works as follows. The Asterisk user gets to set the desired verbosity at startup time or later 
    * using the console 'set verbose' command. Messages are displayed on the console if their verbose level is less than or equal 
    * to desired verbosity set by the user. More important messages should have a low verbose level; less important messages 
    * should have a high verbose level.
    *
    * @link http://www.voip-info.org/wiki-verbose
    * @param string $message
    * @param integer $level from 1 to 4
    * @return array, see evaluate for return information.
    */
    function verbose($message, $level=1)
    {
        foreach(explode("\n", str_replace("\r\n", "\n", print_r($message, true))) as $msg)
        {
          @syslog(LOG_WARNING, $msg);
          $ret = $this->evaluate("VERBOSE \"$msg\" $level");
        }
        return $ret;
    }

    /**
    * Waits up to $timeout milliseconds for channel to receive a DTMF digit.
    *
    * @link http://www.voip-info.org/wiki-wait+for+digit
    * @param integer $timeout in millisecons. Use -1 for the timeout value if you want the call to wait indefinitely.
    * @return array, see evaluate for return information. ['result'] is 0 if wait completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function wait_for_digit($timeout=-1)
    {
        return $this->evaluate("WAIT FOR DIGIT $timeout");
    }


    // *********************************************************************************************************
    // **                             APPLICATIONS                                                                                        **
    // *********************************************************************************************************

    /**
    * Set absolute maximum time of call.
    *
    * Note that the timeout is set from the current time forward, not counting the number of seconds the call has already been up. 
    * Each time you call AbsoluteTimeout(), all previous absolute timeouts are cancelled. 
    * Will return the call to the T extension so that you can playback an explanatory note to the calling party (the called party 
    * will not hear that)
    *
    * @link http://www.voip-info.org/wiki-Asterisk+-+documentation+of+application+commands
    * @link http://www.dynx.net/ASTERISK/AGI/ccard/agi-ccard.agi
    * @param $seconds allowed, 0 disables timeout
    * @return array, see evaluate for return information.
    */
    function exec_absolutetimeout($seconds=0)
    {
        return $this->exec('AbsoluteTimeout', $seconds);
    }

    /**
    * Executes an AGI compliant application.
    *
    * @param string $command
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or if application requested hangup, or 0 on non-hangup exit.
    * @param string $args
    */
    function exec_agi($command, $args)
    {
        return $this->exec("AGI $command", $args);
    }

    /**
    * Set Language.
    *
    * @param string $language code
    * @return array, see evaluate for return information.
    */
    function exec_setlanguage($language='en')
    {
        return $this->exec('Set', 'CHANNEL(language)='. $language);
    }

    /**
    * Do ENUM Lookup.
    *
    * Note: to retrieve the result, use
    *   get_variable('ENUM');
    *
    * @param $exten
    * @return array, see evaluate for return information.
    */
    function exec_enumlookup($exten)
    {
        return $this->exec('EnumLookup', $exten);
    }

    /**
    * Dial.
    *
    * Dial takes input from ${VXML_URL} to send XML Url to Cisco 7960
    * Dial takes input from ${ALERT_INFO} to set ring cadence for Cisco phones
    * Dial returns ${CAUSECODE}: If the dial failed, this is the errormessage.
    * Dial returns ${DIALSTATUS}: Text code returning status of last dial attempt.
    *
    * @link http://www.voip-info.org/wiki-Asterisk+cmd+Dial
    * @param string $type
    * @param string $identifier
    * @param integer $timeout
    * @param string $options
    * @param string $url
    * @return array, see evaluate for return information.
    */
    function exec_dial($type, $identifier, $timeout=NULL, $options=NULL, $url=NULL)
    {
        return $this->exec('Dial', trim("$type/$identifier".$this->option_delim.$timeout.$this->option_delim.$options.$this->option_delim.$url, $this->option_delim));
    }

    /**
    * Goto.
    *
    * This function takes three arguments: context,extension, and priority, but the leading arguments
    * are optional, not the trailing arguments.  Thuse goto($z) sets the priority to $z.
    *
    * @param string $a
    * @param string $b;
    * @param string $c;
    * @return array, see evaluate for return information.
    */
    function exec_goto($a, $b=NULL, $c=NULL)
    {
        return $this->exec('Goto', trim($a.$this->option_delim.$b.$this->option_delim.$c, $this->option_delim));
    }


    // *********************************************************************************************************
    // **                             FAST PASSING                                                                                        **
    // *********************************************************************************************************

    /**
    * Say the given digit string, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+digits
    * @param string $buffer
    * @param integer $digits
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function fastpass_say_digits(&$buffer, $digits, $escape_digits='')
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->say_digits($digits, $escape_digits);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
    }

    /**
    * Say the given number, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+number
    * @param string $buffer
    * @param integer $number
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function fastpass_say_number(&$buffer, $number, $escape_digits='')
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->say_number($number, $escape_digits);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
    }

    /**
    * Say the given character string, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+phonetic
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function fastpass_say_phonetic(&$buffer, $text, $escape_digits='')
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->say_phonetic($text, $escape_digits);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
    }

    /**
    * Say a given time, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+time
    * @param string $buffer
    * @param integer $time number of seconds elapsed since 00:00:00 on January 1, 1970, Coordinated Universal Time (UTC).
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function fastpass_say_time(&$buffer, $time=NULL, $escape_digits='')
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->say_time($time, $escape_digits);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
    }

    /**
    * Play the given audio file, allowing playback to be interrupted by a DTMF digit. This command is similar to the GET DATA
    * command but this command returns after the first DTMF digit has been pressed while GET DATA can accumulated any number of
    * digits before returning.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-stream+file
    * @param string $buffer
    * @param string $filename without extension, often in /var/lib/asterisk/sounds
    * @param string $escape_digits
    * @param integer $offset
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function fastpass_stream_file(&$buffer, $filename, $escape_digits='', $offset=0)
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->stream_file($filename, $escape_digits, $offset);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}), 'endpos'=>0);
    }

    /**
    * Use festival to read text.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.cstr.ed.ac.uk/projects/festival/
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function fastpass_text2wav(&$buffer, $text, $escape_digits='', $frequency=8000)
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->text2wav($text, $escape_digits, $frequency);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}), 'endpos'=>0);
    }

    /**
    * Use Cepstral Swift to read text.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.cepstral.com/
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function fastpass_swift(&$buffer, $text, $escape_digits='', $frequency=8000, $voice=NULL)
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->swift($text, $escape_digits, $frequency, $voice);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}), 'endpos'=>0);
    }

    /**
    * Say Puncutation in a string.
    * Return early if $buffer is adequate for request.
    *
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function fastpass_say_punctuation(&$buffer, $text, $escape_digits='', $frequency=8000)
    {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
         if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
           $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
         $res = $this->say_punctuation($text, $escape_digits, $frequency);
         if($res['code'] == AGIRES_OK && $res['result'] > 0)
           $buffer .= chr($res['result']);
         return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
    }

    /**
    * Plays the given file and receives DTMF data.
    * Return early if $buffer is adequate for request.
    *
    * This is similar to STREAM FILE, but this command can accept and return many DTMF digits,
    * while STREAM FILE returns immediately after the first DTMF digit is detected.
    *
    * Asterisk looks for the file to play in /var/lib/asterisk/sounds by default.
    *
    * If the user doesn't press any keys when the message plays, there is $timeout milliseconds
    * of silence then the command ends.
    *
    * The user has the opportunity to press a key at any time during the message or the
    * post-message silence. If the user presses a key while the message is playing, the
    * message stops playing. When the first key is pressed a timer starts counting for
    * $timeout milliseconds. Every time the user presses another key the timer is restarted.
    * The command ends when the counter goes to zero or the maximum number of digits is entered,
    * whichever happens first.
    *
    * If you don't specify a time out then a default timeout of 2000 is used following a pressed
    * digit. If no digits are pressed then 6 seconds of silence follow the message.
    *
    * If you don't specify $max_digits then the user can enter as many digits as they want.
    *
    * Pressing the # key has the same effect as the timer running out: the command ends and
    * any previously keyed digits are returned. A side effect of this is that there is no
    * way to read a # key using this command.
    *
    * @link http://www.voip-info.org/wiki-get+data
    * @param string $buffer
    * @param string $filename file to play. Do not include file extension.
    * @param integer $timeout milliseconds
    * @param integer $max_digits
    * @return array, see evaluate for return information. ['result'] holds the digits and ['data'] holds the timeout if present.
    *
    * This differs from other commands with return DTMF as numbers representing ASCII characters.
    */
    function fastpass_get_data(&$buffer, $filename, $timeout=NULL, $max_digits=NULL)
    {
     if(is_null($max_digits) || strlen($buffer) < $max_digits)
     {
         if($buffer == '')
         {
           $res = $this->get_data($filename, $timeout, $max_digits);
           if($res['code'] == AGIRES_OK)
             $buffer .= $res['result'];
           return $res;
         }
         else
         {
           while(is_null($max_digits) || strlen($buffer) < $max_digits)
           {
             $res = $this->wait_for_digit();
             if($res['code'] != AGIRES_OK) return $res;
             if($res['result'] == ord('#')) break;
             $buffer .= chr($res['result']);
           }
         }
     }
     return array('code'=>AGIRES_OK, 'result'=>$buffer);
    }

    // *********************************************************************************************************
    // **                             DERIVED                                                                                             **
    // *********************************************************************************************************

    /**
    * Menu.
    *
    * This function presents the user with a menu and reads the response
    *
    * @param array $choices has the following structure:
    *   array('1'=>'*Press 1 for this', // festival reads if prompt starts with *
    *           '2'=>'some-gsm-without-extension',
    *           '*'=>'*Press star for help');
    * @return mixed key pressed on sucess, -1 on failure
    */
    function menu($choices, $timeout=2000)
    {
        $keys = join('', array_keys($choices));
        $choice = NULL;
        while(is_null($choice))
        {
          foreach($choices as $prompt)
          {
            if($prompt{0} == '*')
                $ret = $this->text2wav(substr($prompt, 1), $keys);
            else
                $ret = $this->stream_file($prompt, $keys);

            if($ret['code'] != AGIRES_OK || $ret['result'] == -1)
            {
                $choice = -1;
                break;
            }

            if($ret['result'] != 0)
            {
                $choice = chr($ret['result']);
                break;
            }
          }

          if(is_null($choice))
          {
            $ret = $this->get_data('beep', $timeout, 1);
            if($ret['code'] != AGIRES_OK || $ret['result'] == -1)
                $choice = -1;
            elseif($ret['result'] != '' && strpos(' '.$keys, $ret['result']))
                $choice = $ret['result'];
          }
        }
        return $choice;
    }

    /**
    * setContext - Set context, extension and priority.
    *
    * @param string $context
    * @param string $extension
    * @param string $priority
    */
    function setContext($context, $extension='s', $priority=1)
    {
        $this->set_context($context);
        $this->set_extension($extension);
        $this->set_priority($priority);
    }

    /**
    * Parse caller id.
    *
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    *
    * "name" <proto:user@server:port>
    *
    * @param string $callerid
    * @return array('Name'=>$name, 'Number'=>$number)
    */
    function parse_callerid($callerid=NULL)
    {
        if(is_null($callerid))
          $callerid = $this->request['agi_callerid'];

        $ret = array('name'=>'', 'protocol'=>'', 'username'=>'', 'host'=>'', 'port'=>'');
        $callerid = trim($callerid);

        if($callerid{0} == '"' || $callerid{0} == "'")
        {
          $d = $callerid{0};
          $callerid = explode($d, substr($callerid, 1));
          $ret['name'] = array_shift($callerid);
          $callerid = join($d, $callerid);
        }

        $callerid = explode('@', trim($callerid, '<> '));
        $username  = explode(':', array_shift($callerid));
        if(count($username) == 1)
          $ret['username'] = $username[0];
        else
        {
          $ret['protocol'] = array_shift($username);
          $ret['username'] = join(':', $username);
        }

        $callerid = join('@', $callerid);
        $host = explode(':', $callerid);
        if(count($host) == 1)
          $ret['host'] =  $host[0];
        else
        {
          $ret['host'] = array_shift($host);
          $ret['port'] = join(':', $host);
        }

        return $ret;
    }

    /**
    * Use festival to read text.
    *
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    * @example examples/ping.php Ping an IP address
    *
    * @link http://www.cstr.ed.ac.uk/projects/festival/
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function text2wav($text, $escape_digits='', $frequency=8000)
    {
        $text = trim($text);
        if($text == '') return true;

        $hash = md5($text);
        $fname = $this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR;
        $fname .= 'text2wav_' . $hash;

        // create wave file
        if(!file_exists("$fname.wav"))
        {
          // write text file
          if(!file_exists("$fname.txt"))
          {
            $fp = fopen("$fname.txt", 'w');
            fputs($fp, $text);
            fclose($fp);
          }

          shell_exec("{$this->config['festival']['text2wave']} -F $frequency -o $fname.wav $fname.txt");
        }
        else
        {
          touch("$fname.txt");
          touch("$fname.wav");
        }

        // stream it
        $ret = $this->stream_file($fname, $escape_digits);

        // clean up old files
        $delete = time() - 2592000; // 1 month
        foreach(glob($this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR . 'text2wav_*') as $file)
          if(filemtime($file) < $delete)
            unlink($file);

        return $ret;
    }

    /**
    * Use Cepstral Swift to read text.
    *
    * @link http://www.cepstral.com/
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function swift($text, $escape_digits='', $frequency=8000, $voice=NULL)
    {
        if(!is_null($voice))
          $voice = "-n $voice";
        elseif(isset($this->config['cepstral']['voice']))
          $voice = "-n {$this->config['cepstral']['voice']}";

        $text = trim($text);
        if($text == '') return true;

        $hash = md5($text);
        $fname = $this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR;
        $fname .= 'swift_' . $hash;

        // create wave file
        if(!file_exists("$fname.wav"))
        {
          // write text file
          if(!file_exists("$fname.txt"))
          {
            $fp = fopen("$fname.txt", 'w');
            fputs($fp, $text);
            fclose($fp);
          }

          shell_exec("{$this->config['cepstral']['swift']} -p audio/channels=1,audio/sampling-rate=$frequency $voice -o $fname.wav -f $fname.txt");
        }

        // stream it
        $ret = $this->stream_file($fname, $escape_digits);

        // clean up old files
        $delete = time() - 2592000; // 1 month
        foreach(glob($this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR . 'swift_*') as $file)
          if(filemtime($file) < $delete)
            unlink($file);

        return $ret;
    }

    /**
    * Text Input.
    *
    * Based on ideas found at http://www.voip-info.org/wiki-Asterisk+cmd+DTMFToText
    *
    * Example:
    *                  UC   H     LC   i        ,     SP   h     o        w    SP   a    r        e     SP   y        o        u     ?
    *   $string = '*8'.'44*'.'*5'.'444*'.'00*'.'0*'.'44*'.'666*'.'9*'.'0*'.'2*'.'777*'.'33*'.'0*'.'999*'.'666*'.'88*'.'0000*';
    *
    * @link http://www.voip-info.org/wiki-Asterisk+cmd+DTMFToText
    * @example examples/input.php Get text input from the user and say it back
    *
    * @return string
    */
    function text_input($mode='NUMERIC')
    {
        $alpha = array( 'k0'=>' ', 'k00'=>',', 'k000'=>'.', 'k0000'=>'?', 'k00000'=>'0',
                            'k1'=>'!', 'k11'=>':', 'k111'=>';', 'k1111'=>'#', 'k11111'=>'1',
                            'k2'=>'A', 'k22'=>'B', 'k222'=>'C', 'k2222'=>'2',
                            'k3'=>'D', 'k33'=>'E', 'k333'=>'F', 'k3333'=>'3',
                            'k4'=>'G', 'k44'=>'H', 'k444'=>'I', 'k4444'=>'4',
                            'k5'=>'J', 'k55'=>'K', 'k555'=>'L', 'k5555'=>'5',
                            'k6'=>'M', 'k66'=>'N', 'k666'=>'O', 'k6666'=>'6',
                            'k7'=>'P', 'k77'=>'Q', 'k777'=>'R', 'k7777'=>'S', 'k77777'=>'7',
                            'k8'=>'T', 'k88'=>'U', 'k888'=>'V', 'k8888'=>'8',
                            'k9'=>'W', 'k99'=>'X', 'k999'=>'Y', 'k9999'=>'Z', 'k99999'=>'9');
        $symbol = array('k0'=>'=',
                            'k1'=>'<', 'k11'=>'(', 'k111'=>'[', 'k1111'=>'{', 'k11111'=>'1',
                            'k2'=>'@', 'k22'=>'$', 'k222'=>'&', 'k2222'=>'%', 'k22222'=>'2',
                            'k3'=>'>', 'k33'=>')', 'k333'=>']', 'k3333'=>'}', 'k33333'=>'3',
                            'k4'=>'+', 'k44'=>'-', 'k444'=>'*', 'k4444'=>'/', 'k44444'=>'4',
                            'k5'=>"'", 'k55'=>'`', 'k555'=>'5',
                            'k6'=>'"', 'k66'=>'6',
                            'k7'=>'^', 'k77'=>'7',
                            'k8'=>"\\",'k88'=>'|', 'k888'=>'8',
                            'k9'=>'_', 'k99'=>'~', 'k999'=>'9');
        $text = '';
        do
        {
          $command = false;
          $result = $this->get_data('beep');
          foreach(explode('*', $result['result']) as $code)
          {
            if($command)
            {
                switch($code{0})
                {
                  case '2': $text = substr($text, 0, strlen($text) - 1); break; // backspace
                  case '5': $mode = 'LOWERCASE'; break;
                  case '6': $mode = 'NUMERIC'; break;
                  case '7': $mode = 'SYMBOL'; break;
                  case '8': $mode = 'UPPERCASE'; break;
                  case '9': $text = explode(' ', $text); unset($text[count($text)-1]); $text = join(' ', $text); break; // backspace a word
                }
                $code = substr($code, 1);
                $command = false;
            }
            if($code == '')
                $command = true;
            elseif($mode == 'NUMERIC')
                $text .= $code;
            elseif($mode == 'UPPERCASE' && isset($alpha['k'.$code]))
                $text .= $alpha['k'.$code];
            elseif($mode == 'LOWERCASE' && isset($alpha['k'.$code]))
                $text .= strtolower($alpha['k'.$code]);
            elseif($mode == 'SYMBOL' && isset($symbol['k'.$code]))
                $text .= $symbol['k'.$code];
          }
          $this->say_punctuation($text);
        } while(substr($result['result'], -2) == '**');
        return $text;
    }

    /**
    * Say Puncutation in a string.
    *
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function say_punctuation($text, $escape_digits='', $frequency=8000)
    {
        $ret="";
        for($i = 0; $i < strlen($text); $i++)
        {
          switch($text{$i})
          {
            case ' ': $ret .= 'SPACE ';
            case ',': $ret .= 'COMMA '; break;
            case '.': $ret .= 'PERIOD '; break;
            case '?': $ret .= 'QUESTION MARK '; break;
            case '!': $ret .= 'EXPLANATION POINT '; break;
            case ':': $ret .= 'COLON '; break;
            case ';': $ret .= 'SEMICOLON '; break;
            case '#': $ret .= 'POUND '; break;
            case '=': $ret .= 'EQUALS '; break;
            case '<': $ret .= 'LESS THAN '; break;
            case '(': $ret .= 'LEFT PARENTHESIS '; break;
            case '[': $ret .= 'LEFT BRACKET '; break;
            case '{': $ret .= 'LEFT BRACE '; break;
            case '@': $ret .= 'AT '; break;
            case '$': $ret .= 'DOLLAR SIGN '; break;
            case '&': $ret .= 'AMPERSAND '; break;
            case '%': $ret .= 'PERCENT '; break;
            case '>': $ret .= 'GREATER THAN '; break;
            case ')': $ret .= 'RIGHT PARENTHESIS '; break;
            case ']': $ret .= 'RIGHT BRACKET '; break;
            case '}': $ret .= 'RIGHT BRACE '; break;
            case '+': $ret .= 'PLUS '; break;
            case '-': $ret .= 'MINUS '; break;
            case '*': $ret .= 'ASTERISK '; break;
            case '/': $ret .= 'SLASH '; break;
            case "'": $ret .= 'SINGLE QUOTE '; break;
            case '`': $ret .= 'BACK TICK '; break;
            case '"': $ret .= 'QUOTE '; break;
            case '^': $ret .= 'CAROT '; break;
            case "\\": $ret .= 'BACK SLASH '; break;
            case '|': $ret .= 'BAR '; break;
            case '_': $ret .= 'UNDERSCORE '; break;
            case '~': $ret .= 'TILDE '; break;
            default: $ret .= $text{$i} . ' '; break;
          }
        }
        return $this->text2wav($ret, $escape_digits, $frequency);
    }

    /**
    * Create a new AGI_AsteriskManager.
    */
    function &new_AsteriskManager()
    {
        $this->asm = new AGI_AsteriskManager(NULL, $this->config);
        $this->asm->pagi =& $this;
        $this->config =& $this->asm->config;
        return $this->asm;
    }


    // *********************************************************************************************************
    // **                             PRIVATE                                                                                             **
    // *********************************************************************************************************


    /**
    * Evaluate an AGI command.
    *
    * @access private
    * @param string $command
    * @return array ('code'=>$code, 'result'=>$result, 'data'=>$data)
    */
    function evaluate($command)
    {
        $broken = array('code'=>500, 'result'=>-1, 'data'=>'');

        // write command
        if(!@fwrite($this->out, trim($command) . "\n")) return $broken;
        fflush($this->out);

        // Read result.  Occasionally, a command return a string followed by an extra new line.
        // When this happens, our script will ignore the new line, but it will still be in the
        // buffer.  So, if we get a blank line, it is probably the result of a previous
        // command.  We read until we get a valid result or asterisk hangs up.  One offending
        // command is SEND TEXT.
        $count = 0;
        do
        {
          $str = trim(fgets($this->in, 4096));
        } while($str == '' && $count++ < 5);

        if($count >= 5)
        {
    //          $this->conlog("evaluate error on read for $command");
          return $broken;
        }

        // parse result
        $ret['code'] = substr($str, 0, 3);
        $str = trim(substr($str, 3));

        if($str{0} == '-') // we have a multiline response!
        {
          $count = 0;
          $str = substr($str, 1) . "\n";
          $line = fgets($this->in, 4096);
          while(substr($line, 0, 3) != $ret['code'] && $count < 5)
          {
            $str .= $line;
            $line = fgets($this->in, 4096);
            $count = (trim($line) == '') ? $count + 1 : 0;
          }
          if($count >= 5)
          {
    //            $this->conlog("evaluate error on multiline read for $command");
            return $broken;
          }
        }

        $ret['result'] = NULL;
        $ret['data'] = '';
        if($ret['code'] != AGIRES_OK) // some sort of error
        {
          $ret['data'] = $str;
          $this->conlog(print_r($ret, true));
        }
        else // normal AGIRES_OK response
        {
          $parse = explode(' ', trim($str));
          $in_token = false;
          foreach($parse as $token)
          {
            if($in_token) // we previously hit a token starting with ')' but not ending in ')'
            {
                $ret['data'] .= ' ' . trim($token, '() ');
                if($token{strlen($token)-1} == ')') $in_token = false;
            }
            elseif($token{0} == '(')
            {
                if($token{strlen($token)-1} != ')') $in_token = true;
                $ret['data'] .= ' ' . trim($token, '() ');
            }
            elseif(strpos($token, '='))
            {
                $token = explode('=', $token);
                $ret[$token[0]] = $token[1];
            }
            elseif($token != '')
                $ret['data'] .= ' ' . $token;
          }
          $ret['data'] = trim($ret['data']);
        }

        // log some errors
        if($ret['result'] < 0)
          $this->conlog("$command returned {$ret['result']}");

        return $ret;
    }

    /**
    * Log to console if debug mode.
    *
    * @example examples/ping.php Ping an IP address
    *
    * @param string $str
    * @param integer $vbl verbose level
    */
    function conlog($str, $vbl=1)
    {
        static $busy = false;

        if($this->config['phpagi']['debug'] != false)
        {
          if(!$busy) // no conlogs inside conlog!!!
          {
            $busy = true;
            $this->verbose($str, $vbl);
            $busy = false;
          }
        }
    }

    /**
    * Find an execuable in the path.
    *
    * @access private
    * @param string $cmd command to find
    * @param string $checkpath path to check
    * @return string the path to the command
    */
    function which($cmd, $checkpath=NULL)
    {
        global $_ENV;
        $chpath = is_null($checkpath) ? @$_ENV['PATH'] : $checkpath;

        foreach(explode(':', $chpath) as $path)
          if(is_executable("$path/$cmd"))
            return "$path/$cmd";

        if(is_null($checkpath))
          return $this->which($cmd, '/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:'.
                                            '/usr/X11R6/bin:/usr/local/apache/bin:/usr/local/mysql/bin');
        return false;
    }

    /**
    * Make a folder recursively.
    *
    * @access private
    * @param string $folder
    * @param integer $perms
    * @return boolean 
    */
    function make_folder($folder, $perms=0755)
    {
        $f = explode(DIRECTORY_SEPARATOR, $folder);
        $base = '';
        for($i = 0; $i < count($f); $i++)
        {
          $base .= $f[$i];
          if($f[$i] != '' && !file_exists($base)) {
            if(mkdir($base, $perms)==FALSE){
              return(FALSE);
            }
          }
          $base .= DIRECTORY_SEPARATOR;
        }
        return(TRUE);
    }	

}


/**
 * error handler for phpagi.
 *
 * @param integer $level PHP error level
 * @param string $message error message
 * @param string $file path to file
 * @param integer $line line number of error
 * @param array $context variables in the current scope
 */
  function phpagi_error_handler($level, $message, $file, $line, $context)
  {
    if(ini_get('error_reporting') == 0) return; // this happens with an @

    @syslog(LOG_WARNING, $file . '[' . $line . ']: ' . $message);

    global $phpagi_error_handler_email;
    if(function_exists('mail') && !is_null($phpagi_error_handler_email)) // generate email debugging information
    {
        // decode error level
        switch($level)
        {
          case E_WARNING:
          case E_USER_WARNING:
            $level = "Warning";
            break;
          case E_NOTICE:
          case E_USER_NOTICE:
            $level = "Notice";
            break;
          case E_USER_ERROR:
            $level = "Error";
            break;
        }

        // build message
        $basefile = basename($file);
        $subject = "$basefile/$line/$level: $message";
        $message = "$level: $message in $file on line $line\n\n";

        if(function_exists('mysql_errno') && strpos(' '.strtolower($message), 'mysql'))
          $message .= 'MySQL error ' . mysql_errno() . ": " . mysql_error() . "\n\n";

        // figure out who we are
        if(function_exists('socket_create'))
        {
          $addr = NULL;
          $port = 80;
          $socket = @socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
          @socket_connect($socket, '64.0.0.0', $port);
          @socket_getsockname($socket, $addr, $port);
          @socket_close($socket);
          $message .= "\n\nIP Address: $addr\n";
        }

        // include variables
        $message .= "\n\nContext:\n" . print_r($context, true);
        $message .= "\n\nGLOBALS:\n" . print_r($GLOBALS, true);
        $message .= "\n\nBacktrace:\n" . print_r(debug_backtrace(), true);

        // include code fragment
        if(file_exists($file))
        {
          $message .= "\n\n$file:\n";
          $code = @file($file);
          for($i = max(0, $line - 10); $i < min($line + 10, count($code)); $i++)
            $message .= ($i + 1)."\t$code[$i]";
        }

        // make sure message is fully readable (convert unprintable chars to hex representation)
        $ret = '';
        for($i = 0; $i < strlen($message); $i++)
        {
          $c = ord($message{$i});
          if($c == 10 || $c == 13 || $c == 9)
            $ret .= $message{$i};
          elseif($c < 16)
            $ret .= '\x0' . dechex($c);
          elseif($c < 32 || $c > 127)
            $ret .= '\x' . dechex($c);
          else
            $ret .= $message{$i};
        }
        $message = $ret;

        // send the mail if less than 5 errors
        static $mailcount = 0;
        if($mailcount < 5)
          @mail($phpagi_error_handler_email, $subject, $message);
        $mailcount++;
    }
  }

  $phpagi_error_handler_email = NULL;

