<?php
/**
 * The SocketHandler class will handle a single socket.
 * It takes care of the very basic socket functions.
 * @author jpt
 * @package Socket
 */
class Socket_SocketHandler {

	/**
	 * Socket ressource
	 * @var ressource
	 */
	protected $socket;

	/**
	 * @var boolean
	 */
	protected $is_connected;

	/**
	 * @var boolean
	 */
	protected $is_bound;

	/**
	 * @var boolean
	 */
	protected $is_listening;

	/**
	 * Default constructor. Sets the socket.
	 * @throws Exception_SocketException
	 * @param ressource $socket
	 * @return void
	 */
	function __construct($socket) {
		if(is_resource($socket) === FALSE) throw new Exception_SocketException("Invalid socket ressource!", 1289663108);
		$this->socket = $socket;
		$this->is_bound = FALSE;
		$this->is_connected = FALSE;
		$this->is_listening = FALSE;
	}

	/**
	 * Destructor. Closes socket.
	 * @return void
	 */
	function __destruct() {
		$this->close();
	}

	/**
	 * Returns socket
	 * @return ressource
	 */
	public function getSocket() {
		return $this->socket;
	}

	/**
	 * @return boolean
	 */
	public function isConnected() {
		return $this->is_connected;
	}

	/**
	 * @return boolean
	 */
	public function isListening() {
		return $this->is_listening;
	}

	/**
	 * Connects to a specified address.
	 * @throws Exception_SocketException
	 * @param string $address
	 * @param int $port
	 * @return void
	 */
	public function connect($address, $port) {
		if($this->is_connected === TRUE) throw new Exception_SocketException("Socket is already connected!", 1289663170);
		$result = socket_connect($this->socket, $address, $port);
		if($result === FALSE) $this->error();
		$this->is_connected = TRUE;
	}

	/**
	 * Binds the socket to an address + port.
	 * @throws Exception_SocketException
	 * @param string $address
	 * @param int $port
	 * @return void
	 */
	public function bind($address, $port) {
		if($this->is_bound === TRUE) throw new Exception_SocketException("Socket is already bound!", 1289663212);
		$result = socket_set_option($this->socket, SOL_SOCKET, SO_REUSEADDR, 1);
		if($result === FALSE) $this->error();
		$result = socket_bind($this->socket, $address, $port);
		if($result === FALSE) $this->error();
		$this->is_bound = TRUE;
	}

	/**
	 * Let's the socket listen for incoming connections.
	 * @throws Exception_SocketException
	 * @return void
	 */
	public function listen() {
		if($this->is_bound === FALSE) throw new Exception_SocketException("Cannot listen on unbound socket!", 1289663220);
		$result = socket_listen($this->socket);
		if($result === FALSE) $this->error();
		$this->is_listening = TRUE;
	}

	/**
	 * Tells the SocketHandler that he got accepted.
	 * @return void
	 */
	public function hasBeenAccepted() {
		$this->is_connected = TRUE;
	}

	/**
	 * Accepts a connection to a socket that is bound and listens
	 * The ressource has to be added to the SocketPool manually
	 * @throws Exception_SocketException
	 * @return ressource
	 */
	public function accept() {
		if($this->is_bound === FALSE) throw new Exception_SocketException("Cannot accept connections from unbound socket!", 1289663239);
		if($this->is_listening === FALSE) throw new Exception_SocketException("Cannot accept connections from socket that is not listening!", 1289663241);
		$accept = socket_accept($this->socket);
		if($accept === FALSE) $this->error();
		return $accept;
	}

	/**
	 * Returns ip + port of the remote socket.
	 * @throws Exception_SocketException
	 * @return string
	 */
	public function getRemoteName() {
		if($this->is_connected === FALSE) throw new Exception_SocketException("Socket not connected, cannot retrieve remote name!", 1289928192);
		$result = socket_getpeername($this->socket, $address, $port);
		if($result === FALSE) $this->error();
		return $address . ":" . $port;
	}

	/**
	 * Returns ip + port of the local socket.
	 * @throws Exception_SocketException
	 * @return string
	 */
	public function getLocalName() {
		if($this->is_bound === FALSE ^ $this->is_connected === FALSE) throw new Exception_SocketException("Socket is not bound or connected, no local name available!", 1289928256);
		$result = socket_getsockname($this->socket, $address, $port);
		if($result === FALSE) $this->error();
		return $address . ":" . $port;
	}

	/**
	 * Writes data to the socket.
	 * @throws Exception_SocketException
	 * @param string $data
	 * @return void
	 */
	public function write($data) {
		$result = socket_write($this->socket, $data);
		if($result === FALSE) $this->error();
	}

	/**
	 * Reads data from the socket.
	 * @throws Exception_SocketException
	 * @param int $length
	 * @return string
	 */
	public function read($length = 16384) {
		$result = socket_read($this->socket, $length, PHP_BINARY_READ);
		if($result === FALSE) $this->error();
		return $result;
	}

	/**
	 * Shuts the socket down after waiting a bit (waiting might be optional).
	 * @throws Exception_SocketException
	 * @return void
	 */
	public function close() {
		usleep(100000);
		if($this->is_connected === TRUE) {
			$result = socket_shutdown($this->socket);
			if($result === FALSE) $this->error();
		}
		if(is_resource($this->socket)) {
			$result = socket_close($this->socket);
			if($result === FALSE) $this->error();
		}
		$this->is_connected = FALSE;
	}

	/**
	 * Gets last error from socket.
	 * @throws Exception_SocketException
	 */
	protected function error() {
		$errno = socket_last_error($this->socket);
		$error = socket_strerror($errno);
		socket_clear_error();
		$errormsg = "[" . $errno . "] " . $error;
		throw new Exception_SocketException("A socket error occured: " . $errormsg, 1289663360);
	}
}
?>