#!/usr/bin/php -q
<?php
	/***********************
	* Sample AGI script
	* @author Cory Forsyth
	* @date Mar 27 2007
	* This is a script used in
	* an Asterisk Primer Lecture
	* 
	* This file is located at /var/lib/asterisk/agi-bin/
	* and it requires phpagi.php, php-asmanager.php and JSON.php to be in the same directory
	*************************/
	
	/*
	 * Note that the first line of this file contains the shebang line that 
	 * specifies what script interpreter to run the file in
	 * You can't just use the open <?php tag because when Asterisk runs this
	 * AGI it doesn't know it is written in PHP. That's why you specify it.
	*/

	// Require the phpagi library -- this simplifies communication via stdin/stdout
	// with asterisk
	require('phpagi.php');

	// load the JSON library -- this is used to decode a JSON response from twitter
	// into a PHP Object.  (Easier to use this external library and get a JSON response 
	// from twitter than to get XML from twitter and write our own XML parser)
	require( 'JSON.php' );

	// instantiate the AGI class variable we will use to talk to asterisk
	$agi = new AGI();

	// instantiate the JSON class variable that we will use to decode twitter's JSON response
	$services_json = new Services_JSON();

	
	// This is my twitter username and password
	$username = "bantic";
	$password = "xxx";
	
	// This is the twiter API url
	$url = "http://$username:$password@twitter.com/statuses/friends.json";
	
	// get the json from twitter
	$json = file_get_contents( $url );
	
	// decode the json into a PHP Object
	$obj = $services_json->decode($json);
	
	// This array will hold the decoded "tweets"
	$twitters = array();

	// Loop through the Object and decode the latest twitters
	foreach ( $obj as $twitter_obj ) {
		$screenname 	= $twitter_obj->screen_name;
		$name 			= $twitter_obj->name;
		$status			= $twitter_obj->status;
		$status_text	= $status->text;
		$status_rel_created_at = $status->relative_created_at;
		$status_timestamp		= $status->created_at;
		
		// Twitter includes a "+0000" string in the timestamp they return that throws off PHP's strtotime function that we
		// use in cmp_twitters below, so we'll just strip it out. This may or may not hold up well in case twitter's format
		// changes down the road
		$status_timestamp = str_replace("+0000","",$status_timestamp);
		
		$twitters[] = array( "screenname" => $screenname, "name" => $name, "status" => $status_text, "status_rel_created_at" => $status_rel_created_at, "status_timestamp" => $status_timestamp);
	}
	
	/**
	 * This is a function we use to compare the timestamp of the twitters ("tweets"). It is used by usort below
	 * to sort the tweets into reverse chrono order so we can play back the latest ones
	 */
	function cmp_twitters( $a, $b ) {
		$a_ts = strtotime($a['status_timestamp']);
		$b_ts = strtotime($b['status_timestamp']);
		if ( $a_ts == $b_ts ) {
	       return 0;
	   }
	   return ($a_ts < $b_ts) ? 1 : -1;
	}
	
	// Sort the twitters array using the function "cmp_twitters" -- puts the array into reverse chrono order
	usort( $twitters, "cmp_twitters");

	// Now we just set the following 9 variables in Asterisk -- we'll use them to read back the tweets when this script
	// ends and we continue with the dialplan
	$agi->set_variable("TWITTER_NAME", $twitters[0]['screenname']);
	$agi->set_variable("TWITTER_TEXT", $twitters[0]['status']);
	$agi->set_variable("TWITTER_TIME", $twitters[0]['status_rel_created_at']);

	$agi->set_variable("TWITTER_NAME1", $twitters[1]['screenname']);
	$agi->set_variable("TWITTER_TEXT1", $twitters[1]['status']);
	$agi->set_variable("TWITTER_TIME1", $twitters[1]['status_rel_created_at']);

	$agi->set_variable("TWITTER_NAME2", $twitters[2]['screenname']);
	$agi->set_variable("TWITTER_TEXT2", $twitters[2]['status']);
	$agi->set_variable("TWITTER_TIME2", $twitters[2]['status_rel_created_at']);
?>