<?php
/**
 * ManiaPlanet dedicated server Xml-RPC client
 *
 * @license     http://www.gnu.org/licenses/lgpl.html LGPL License 3
 */

namespace Maniaplanet\DedicatedServer\Xmlrpc;

class GbxRemote
{
	const MAX_REQUEST_SIZE = 0x400000; // 4MB
	const MAX_RESPONSE_SIZE = 0x400000; // 4MB

	public static $received;
	public static $sent;

	private $socket;
	private $readTimeout = ['sec' => 5, 'usec' => 0];
	private $writeTimeout = ['sec' => 5, 'usec' => 0];
	private $requestHandle;
	private $callbacksBuffer = [];
	private $multicallBuffer = [];
	private $lastNetworkActivity = 0;

	/**
	 * @param string $host
	 * @param int $port
	 * @param int $timeout Timeout when opening connection
	 */
	function __construct($host, $port, $timeout = 5)
	{
		$this->requestHandle = (int)0x80000000;
		$this->connect($host, $port, $timeout);
	}

	/**
	 * @param string $host
	 * @param int $port
	 * @param int $timeout
	 * @throws TransportException
	 */
	private function connect($host, $port, $timeout)
	{
		$this->socket = @fsockopen($host, $port, $errno, $errstr, $timeout);
		if (!$this->socket) {
			throw new TransportException('Cannot open socket', TransportException::NOT_INITIALIZED);
		}

		stream_set_read_buffer($this->socket, 0);
		stream_set_write_buffer($this->socket, 0);

		// handshake
		$header = $this->read(15);
		if ($header === false) {
			if (!is_resource($this->socket)) {
				$this->onIoFailure('socket closed during handshake');
			}
			$this->onIoFailure(sprintf('during handshake (%s)', socket_strerror(socket_last_error())));
		}

		extract(unpack('Vsize/a*protocol', $header));
		/** @var $size int */
		/** @var $protocol string */
		if ($size != 11 || $protocol != 'GBXRemote 2') {
			throw new TransportException('Wrong protocol header', TransportException::WRONG_PROTOCOL);
		}
		$this->lastNetworkActivity = time();
	}

	/**
	 * @param int $size
	 * @return boolean|string
	 */
	private function read($size)
	{
		@stream_set_timeout($this->socket, $this->readTimeout['sec'], $this->readTimeout['usec']);

		$data = '';
		while (strlen($data) < $size) {
			$buf = @fread($this->socket, $size - strlen($data));
			if ($buf === '' || $buf === false) {
				return false;
			}
			$data .= $buf;
		}

		self::$received += $size;
		return $data;
	}

	/**
	 * @param string $when
	 * @throws TransportException
	 */
	private function onIoFailure($when)
	{
		$meta = stream_get_meta_data($this->socket);
		if ($meta['timed_out']) {
			throw new TransportException('Connection timed out ' . $when, TransportException::TIMED_OUT);
		}
		throw new TransportException('Connection interrupted ' . $when, TransportException::INTERRUPTED);
	}

	function __destruct()
	{
		$this->terminate();
	}

	public function terminate()
	{
		if ($this->socket) {
			fclose($this->socket);
			$this->socket = null;
		}
	}

	/**
	 * Change timeouts
	 * @param int $read read timeout (in ms), 0 to leave unchanged
	 * @param int $write write timeout (in ms), 0 to leave unchanged
	 */
	public function setTimeouts($read = 0, $write = 0)
	{
		if ($read) {
			$this->readTimeout['sec'] = (int)($read / 1000);
			$this->readTimeout['usec'] = ($read % 1000) * 1000;
		}
		if ($write) {
			$this->writeTimeout['sec'] = (int)($write / 1000);
			$this->writeTimeout['usec'] = ($write % 1000) * 1000;
		}
	}

	/**
	 * @return int Network idle time in seconds
	 */
	function getIdleTime()
	{
		$this->assertConnected();
		return time() - $this->lastNetworkActivity;
	}

	/**
	 * @throws TransportException
	 */
	private function assertConnected()
	{
		if (!$this->socket) {
			throw new TransportException('Connection not initialized', TransportException::NOT_INITIALIZED);
		}
	}

	/**
	 * @param string $method
	 * @param mixed[] $args
	 */
	function addCall($method, $args)
	{
		$this->multicallBuffer[] = [
			'methodName' => $method,
			'params' => $args
		];
	}

	/**
	 * @return mixed
	 */
	function multiquery()
	{
		switch (count($this->multicallBuffer)) {
			case 0:
				return [];
			case 1:
				$call = array_shift($this->multicallBuffer);
				return [$this->query($call['methodName'], $call['params'])];
			default:
				$result = $this->query('system.multicall', [$this->multicallBuffer]);
				foreach ($result as &$value) {
					if (isset($value['faultCode'])) {
						$value = FaultException::create($value['faultString'], $value['faultCode']);
					} else {
						$value = $value[0];
					}
				}
				$this->multicallBuffer = [];
				return $result;
		}
	}

	/**
	 * @param string $method
	 * @param mixed[] $args
	 * @return mixed
	 * @throws MessageException
	 */
	function query($method, $args = [])
	{
		$this->assertConnected();
		$xml = Request::encode($method, $args);

		if (strlen($xml) > self::MAX_REQUEST_SIZE - 8) {
			if ($method != 'system.multicall' || count($args[0]) < 2) {
				throw new MessageException('Request too large', MessageException::REQUEST_TOO_LARGE);
			}

			$mid = count($args[0]) >> 1;
			$res1 = $this->query('system.multicall', [array_slice($args[0], 0, $mid)]);
			$res2 = $this->query('system.multicall', [array_slice($args[0], $mid)]);
			return array_merge($res1, $res2);
		}

		$this->writeMessage($xml);
		return $this->flush(true);
	}

	/**
	 * @param string $xml
	 * @throws TransportException
	 */
	private function writeMessage($xml)
	{
		if ($this->requestHandle == (int)0xffffffff) {
			$this->requestHandle = (int)0x80000000;
		}
		$data = pack('V2', strlen($xml), ++$this->requestHandle) . $xml;
		if (!$this->write($data)) {
			$this->onIoFailure('while writing');
		}
		$this->lastNetworkActivity = time();
	}

	/**
	 * @param string $data
	 * @return boolean
	 */
	private function write($data)
	{
		@stream_set_timeout($this->socket, $this->writeTimeout['sec'], $this->writeTimeout['usec']);
		self::$sent += strlen($data);

		while (strlen($data) > 0) {
			$written = @fwrite($this->socket, $data);
			if ($written === 0 || $written === false) {
				return false;
			}

			$data = substr($data, $written);
		}

		return true;
	}

	/**
	 * @param bool $waitResponse
	 * @return mixed
	 * @throws FaultException
	 */
	private function flush($waitResponse = false)
	{
		$r = [$this->socket];
		while ($waitResponse || @stream_select($r, $w, $e, 0) > 0) {
			list($handle, $xml) = $this->readMessage();
			list($type, $value) = Request::decode($xml);
			switch ($type) {
				case 'fault':
					throw FaultException::create($value['faultString'], $value['faultCode']);
				case 'response':
					if ($handle == $this->requestHandle) {
						return $value;
					}
					break;
				case 'call':
					$this->callbacksBuffer[] = $value;
			}
		}
	}

	/**
	 * @return mixed[]
	 * @throws TransportException
	 * @throws MessageException
	 */
	private function readMessage()
	{
		$header = $this->read(8);
		if ($header === false) {
			$this->onIoFailure('while reading header');
		}

		extract(unpack('Vsize/Vhandle', $header));
		/** @var $size int */
		/** @var $handle int */
		if ($size == 0 || $handle == 0) {
			throw new TransportException('Incorrect header', TransportException::PROTOCOL_ERROR);
		}

		if ($size > self::MAX_RESPONSE_SIZE) {
			throw new MessageException('Response too large', MessageException::RESPONSE_TOO_LARGE);
		}

		$data = $this->read($size);
		if ($data === false) {
			$this->onIoFailure('while reading data');
		}

		$this->lastNetworkActivity = time();
		return [$handle, $data];
	}

	/**
	 * @return mixed[]
	 */
	function getCallbacks()
	{
		$this->assertConnected();
		$this->flush();
		$cb = $this->callbacksBuffer;
		$this->callbacksBuffer = [];
		return $cb;
	}
}

class TransportException extends Exception
{
	const NOT_INITIALIZED = 1;
	const INTERRUPTED = 2;
	const TIMED_OUT = 3;
	const WRONG_PROTOCOL = 4;
	const PROTOCOL_ERROR = 5;
}

class MessageException extends Exception
{
	const REQUEST_TOO_LARGE = 1;
	const RESPONSE_TOO_LARGE = 2;
}