<?php
/**
 * A HTTP client class
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2014 Core Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.ship-simu.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
class HttpClient extends BaseClient implements Client {
	// Constants
	const HTTP_EOL = "\r\n";
	const HTTP_USER_AGENT = 'HttpClient-Core/1.0';

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Set default user agent string (to allow other classes to override this)
		$this->setUserAgent(self::HTTP_USER_AGENT);

		// Call parent constructor
		parent::__construct(__CLASS__);
	}

	/**
	 * Creates an instance of this Client class and prepares it for usage
	 *
	 * @param	$socketResource		Resource of a socket (optional)
	 * @return	$clientInstance		An instance of a Client class
	 */
	public final static function createHttpClient ($socketResouce = FALSE) {
		// Get a new instance
		$clientInstance = new HttpClient();

		// Set socket resource
		$clientInstance->setSocketResource($socketResource);

		// Return the prepared instance
		return $clientInstance;
	}

	/**
	 * Checks wether proxy configuration is used
	 *
	 * @return	$isUsed		Wether proxy is used
	 */
	protected function isProxyUsed () {
		// Do we have cache?
		if (!isset($GLOBALS[__METHOD__])) {
			// Determine it
			$GLOBALS[__METHOD__] = (($this->getConfigInstance()->getConfigEntry('proxy_host') != '') && ($this->getConfigInstance()->getConfigEntry('proxy_port') > 0));
		} // END - if

		// Return cache
		return $GLOBALS[__METHOD__];
	}

	/**
	 * Sets up a proxy tunnel for given hostname and through resource
	 *
	 * @param	$host		Host to connect to
	 * @param	$port		Port number to connect to
	 * @return	$response	Response array
	 */
	protected function setupProxyTunnel ($host, $port) {
		// Initialize array
		$response = array('', '', '');

		// Do the connect
		$respArray = $this->doConnectRequest($host, $port);

		// Analyze first header line
		if (((strtolower($respArray[0]) !== 'http/1.0') && (strtolower($respArray[0]) !== 'http/1.1')) || ($respArray[1] != '200')) {
			// Response code is not 200
			return $response;
		} // END - if

		// All fine!
		return $respArray;
	}

	/**
	 * Sends a raw HTTP request out to given host/port
	 *
	 * @param	$method			Request method (GET, POST, HEAD, CONNECT, ...)
	 * @param	$host			Host to connect to
	 * @param	$port			Port number to connect to
	 * @return	$responseArray	Array with raw response
	 */
	private function sendRawHttpRequest ($method, $host, $port, array $header = array()) {
		// Minimum raw HTTP/1.1 request
		$rawRequest  = $method . ' ' . $host . ':' . $port . ' HTTP/1.1' . self::HTTP_EOL;
		$rawRequest .= 'Host: ' . $host . ':' . $port . self::HTTP_EOL;

		// Use login data to proxy? (username at least)
		if ($this->getConfigInstance()->getConfigEntry('proxy_username') != '') {
			// Add it as well
			$encodedAuth = base64_encode($this->getConfigInstance()->getConfigEntry('proxy_username') . ':' . $this->getConfigInstance()->getConfigEntry('proxy_password'));
			$rawRequest .= 'Proxy-Authorization: Basic ' . $encodedAuth . self::HTTP_EOL;
		} // END - if

		// Add last new-line
		$rawRequest .= self::HTTP_EOL;
		//* DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('HTTP-CLIENT[' . __METHOD__ . ':' . __LINE__ . ']: rawRequest=' . $rawRequest);

		// Write request
		fwrite($this->getSocketResource(), $rawRequest);

		// Got response?
		if (feof($this->getSocketResource())) {
			// No response received
			return $response;
		} // END - if

		// Read the first line
		$resp = trim(fgets($this->getSocketResource(), 10240));

		// "Explode" the string to an array
		$responseArray = explode(' ', $resp);

		// And return it
		return $responseArray;
	}

	/**
	 * A HTTP/1.1 CONNECT request
	 *
	 * @param	$host	Host to connect to
	 * @param	$port	Port number to connect to
	 * @return	$responseArray	An array with the read response
	 */
	public function doConnectRequest ($host, $port) {
		// Prepare extra header(s)
		$headers = array(
			'Proxy-Connection' => 'Keep-Alive'
		);

		// Prepare raw request
		$responseArray = $this->sendRawHttpRequest('CONNECT', $host, $port, $headers);

		// Return response array
		return $responseArray;
	}
}

// [EOF]
?>