Pusher.php

<?php

/* 
		Pusher PHP Library
	/////////////////////////////////
	This was a very simple PHP library to the Pusher API.

		$pusher = new Pusher(APIKEY, SECRET, APP_ID, CHANNEL, [Debug: true/false, HOST, PORT]);
		$pusher->trigger('my_event', 'test_channel', [socket_id, Debug: true/false]);
		$pusher->socket_auth('socket_id');

	Copyright 2010, Squeeks. Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php

	Contrbutors:
		+ Paul44 (http://github.com/Paul44)
		+ Ben Pickles (http://github.com/benpickles)
		+ Mastercoding (http://www.mastercoding.nl)

*/

class Pusher
{

	private $settings = array ();

	/**
	* PHP5 Constructor. 
	* 
	* Initializes a new Pusher instance with key, secret , app ID and channel. 
	* You can optionally turn on debugging for all requests by setting debug to true.
	* 
	* @param string $auth_key
	* @param string $secret
	* @param int $app_id
	* @param string $channel [optional]
	* @param bool $debug [optional]
	* @param string $host [optional]
	* @param int $port [optional]
	* @param int $timeout [optional]
	*/
	public function __construct( $auth_key, $secret, $app_id, $channel = '', $debug = false, $host = 'http://api.pusherapp.com', $port = '80', $timeout = 30 )
	{

		// Check compatibility, disable for speed improvement
		$this->check_compatibility();

		// Setup defaults
		$this->settings['server']	= $host;
		$this->settings['port']		= $port;
		$this->settings['auth_key']	= $auth_key;
		$this->settings['secret']	= $secret;
		$this->settings['app_id']	= $app_id;
		$this->settings['channel']	= $channel;
		$this->settings['url']		= '/apps/' . $this->settings['app_id'];
		$this->settings['debug']	= $debug;
		$this->settings['timeout']	= $timeout;

	}

	/**
	* Check if the current PHP setup is sufficient to run this class
	*/
	private function check_compatibility()
	{

		// Check for dependent PHP extensions (JSON, cURL)
		if ( ! extension_loaded( 'curl' ) || ! extension_loaded( 'json' ) )
		{
			die( 'There is missing dependant extensions - please ensure both cURL and JSON modules are installed' );
		}

		# Supports SHA256?
		if ( ! in_array( 'sha256', hash_algos() ) )
		{
			die( 'SHA256 appears to be unsupported - make sure you have support for it, or upgrade your version of PHP.' );
		}

	}

	/**
	* Trigger an event by providing event name and payload. 
	* Optionally provide a socket ID to exclude a client (most likely the sender).
	* 
	* @param string $event
	* @param mixed $payload
	* @param int $socket_id [optional]
	* @param string $channel [optional]
	* @param bool $debug [optional]
	* @return bool|string
	*/
	public function trigger( $event, $payload, $socket_id = null, $channel = '', $debug = false )
	{

		# Check if we can initialize a cURL connection
		$ch = curl_init();
		if ( $ch === false )
		{
			die( 'Could not initialise cURL!' );
		}

		# Add channel to URL..
		$s_url = $this->settings['url'] . '/channels/' . ($channel != '' ? $channel : $this->settings['channel']) . '/events';

		# Build the request
		$signature = "POST\n" . $s_url . "\n";
		$payload_encoded = json_encode( $payload );
		$query = "auth_key=" . $this->settings['auth_key'] . "&auth_timestamp=" . time() . "&auth_version=1.0&body_md5=" . md5( $payload_encoded ) . "&name=" . $event;

		# Socket ID set?
		if ( $socket_id !== null )
		{
			$query .= "&socket_id=" . $socket_id;
		}

		# Create the signed signature...
		$auth_signature = hash_hmac( 'sha256', $signature . $query, $this->settings['secret'], false );
		$signed_query = $query . "&auth_signature=" . $auth_signature;
		$full_url = $this->settings['server'] . ':' . $this->settings['port'] . $s_url . '?' . $signed_query;

		# Set cURL opts and execute request
		curl_setopt( $ch, CURLOPT_URL, $full_url );
		curl_setopt( $ch, CURLOPT_HTTPHEADER, array ( "Content-Type: application/json" ) );
		curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );
		curl_setopt( $ch, CURLOPT_POST, 1 );
		curl_setopt( $ch, CURLOPT_POSTFIELDS, $payload_encoded );
		curl_setopt( $ch, CURLOPT_TIMEOUT, $this->settings['timeout'] );

		$response = curl_exec( $ch );

		curl_close( $ch );

		if ( $response == "202 ACCEPTED\n" && $debug == false )
		{
			return true;
		}
		elseif ( $debug == true || $this->settings['debug'] == true )
		{
			return $response;
		}
		else
		{
			return false;
		}

	}

	/**
	* Creates a socket signature
	* 
	* @param int $socket_id
	* @return string
	*/
	public function socket_auth( $socket_id )
	{

		$signature = hash_hmac( 'sha256', $socket_id . ':' . $this->settings['channel'], $this->settings['secret'], false );
		$signature = array ( 'auth' => $this->settings['auth_key'] . ':' . $signature );
		return json_encode( $signature );

	}


}

?>