<?php
/**
 * @author Bart Visscher <bartv@thisnet.nl>
 * @author Bernhard Posselt <dev@bernhard-posselt.com>
 * @author Frank Karlitschek <frank@owncloud.org>
 * @author Joas Schilling <nickvergessen@owncloud.com>
 * @author Jörn Friedrich Dreyer <jfd@butonic.de>
 * @author Lukas Reschke <lukas@owncloud.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Robin McCorkell <rmccorkell@karoshi.org.uk>
 * @author Scrutinizer Auto-Fixer <auto-fixer@scrutinizer-ci.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @copyright Copyright (c) 2015, ownCloud, Inc.
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

/**
 * Class to handle open collaboration services API requests
 *
 */
class OC_OCS {

	/**
	* reads input data from get/post and converts the date to a special data-type
	*
	* @param string $method HTTP method to read the key from
	* @param string $key Parameter to read
	* @param string $type Variable type to format data
	* @param string $default Default value to return if the key is not found
	* @return string Data or if the key is not found and no default is set it will exit with a 400 Bad request
	*/
	public static function readData($method, $key, $type = 'raw', $default = null) {
		$data = false;
		if ($method == 'get') {
			if (isset($_GET[$key])) {
				$data = $_GET[$key];
			} else if (isset($default)) {
				return $default;
			} else {
				$data = false;
			}
		} else if ($method == 'post') {
			if (isset($_POST[$key])) {
				$data = $_POST[$key];
			} else if (isset($default)) {
				return $default;
			} else {
				$data = false;
			}
		}
		if ($data === false) {
			echo self::generateXml('', 'fail', 400, 'Bad request. Please provide a valid '.$key);
			exit();
		} else {
			// NOTE: Is the raw type necessary? It might be a little risky without sanitization
			if ($type == 'raw') return $data;
			elseif ($type == 'text') return OC_Util::sanitizeHTML($data);
			elseif ($type == 'int')  return (int) $data;
			elseif ($type == 'float') return (float) $data;
			elseif ($type == 'array') return OC_Util::sanitizeHTML($data);
			else return OC_Util::sanitizeHTML($data);
		}
	}

	public static function notFound() {
		if($_SERVER['REQUEST_METHOD'] == 'GET') {
			$method='get';
		}elseif($_SERVER['REQUEST_METHOD'] == 'PUT') {
			$method='put';
		}elseif($_SERVER['REQUEST_METHOD'] == 'POST') {
			$method='post';
		}else{
			echo('internal server error: method not supported');
			exit();
		}

		$format = self::readData($method, 'format', 'text', '');
		$txt='Invalid query, please check the syntax. API specifications are here:'
		.' http://www.freedesktop.org/wiki/Specifications/open-collaboration-services. DEBUG OUTPUT:'."\n";
		$txt.=OC_OCS::getDebugOutput();
		echo(OC_OCS::generateXml($format, 'failed', 999, $txt));

	}

	/**
	* generated some debug information to make it easier to find failed API calls
	* @return string data
	*/
	private static function getDebugOutput() {
		$txt='';
		$txt.="debug output:\n";
		if(isset($_SERVER['REQUEST_METHOD'])) $txt.='http request method: '.$_SERVER['REQUEST_METHOD']."\n";
		if(isset($_SERVER['REQUEST_URI'])) $txt.='http request uri: '.$_SERVER['REQUEST_URI']."\n";
		if(isset($_GET)) foreach($_GET as $key=>$value) $txt.='get parameter: '.$key.'->'.$value."\n";
		if(isset($_POST)) foreach($_POST as $key=>$value) $txt.='post parameter: '.$key.'->'.$value."\n";
		return($txt);
	}


	/**
	 * generates the xml or json response for the API call from an multidimenional data array.
	 * @param string $format
	 * @param string $status
	 * @param string $statuscode
	 * @param string $message
	 * @param array $data
	 * @param string $tag
	 * @param string $tagattribute
	 * @param int $dimension
	 * @param int|string $itemscount
	 * @param int|string $itemsperpage
	 * @return string xml/json
	 */
	public static function generateXml($format, $status, $statuscode,
		$message, $data=array(), $tag='', $tagattribute='', $dimension=-1, $itemscount='', $itemsperpage='') {
		if($format=='json') {
			$json=array();
			$json['status']=$status;
			$json['statuscode']=$statuscode;
			$json['message']=$message;
			$json['totalitems']=$itemscount;
			$json['itemsperpage']=$itemsperpage;
			$json['data']=$data;
			return(json_encode($json));
		}else{
			$txt='';
			$writer = xmlwriter_open_memory();
			xmlwriter_set_indent( $writer, 2 );
			xmlwriter_start_document($writer );
			xmlwriter_start_element($writer, 'ocs');
			xmlwriter_start_element($writer, 'meta');
			xmlwriter_write_element($writer, 'status', $status);
			xmlwriter_write_element($writer, 'statuscode', $statuscode);
			xmlwriter_write_element($writer, 'message', $message);
			if($itemscount<>'') xmlwriter_write_element($writer, 'totalitems', $itemscount);
			if(!empty($itemsperpage)) xmlwriter_write_element($writer, 'itemsperpage', $itemsperpage);
			xmlwriter_end_element($writer);
			if($dimension=='0') {
				// 0 dimensions
				xmlwriter_write_element($writer, 'data', $data);

			}elseif($dimension=='1') {
				xmlwriter_start_element($writer, 'data');
				foreach($data as $key=>$entry) {
					xmlwriter_write_element($writer, $key, $entry);
				}
				xmlwriter_end_element($writer);

			}elseif($dimension=='2') {
				xmlwriter_start_element($writer, 'data');
				foreach($data as $entry) {
					xmlwriter_start_element($writer, $tag);
					if(!empty($tagattribute)) {
						xmlwriter_write_attribute($writer, 'details', $tagattribute);
					}
					foreach($entry as $key=>$value) {
						if(is_array($value)) {
							foreach($value as $k=>$v) {
								xmlwriter_write_element($writer, $k, $v);
							}
						} else {
							xmlwriter_write_element($writer, $key, $value);
						}
					}
					xmlwriter_end_element($writer);
				}
				xmlwriter_end_element($writer);

			}elseif($dimension=='3') {
				xmlwriter_start_element($writer, 'data');
				foreach($data as $entrykey=>$entry) {
					xmlwriter_start_element($writer, $tag);
					if(!empty($tagattribute)) {
						xmlwriter_write_attribute($writer, 'details', $tagattribute);
					}
					foreach($entry as $key=>$value) {
						if(is_array($value)) {
							xmlwriter_start_element($writer, $entrykey);
							foreach($value as $k=>$v) {
								xmlwriter_write_element($writer, $k, $v);
							}
							xmlwriter_end_element($writer);
						} else {
							xmlwriter_write_element($writer, $key, $value);
						}
					}
					xmlwriter_end_element($writer);
				}
				xmlwriter_end_element($writer);
			}elseif($dimension=='dynamic') {
				xmlwriter_start_element($writer, 'data');
				OC_OCS::toxml($writer, $data, 'comment');
				xmlwriter_end_element($writer);
			}

			xmlwriter_end_element($writer);

			xmlwriter_end_document( $writer );
			$txt.=xmlwriter_output_memory( $writer );
			unset($writer);
			return($txt);
		}
	}

	/**
	 * @param resource $writer
	 * @param array $data
	 * @param string $node
	 */
	public static function toXml($writer, $data, $node) {
		foreach($data as $key => $value) {
			if (is_numeric($key)) {
				$key = $node;
			}
			if (is_array($value)) {
				xmlwriter_start_element($writer, $key);
				OC_OCS::toxml($writer, $value, $node);
				xmlwriter_end_element($writer);
			}else{
				xmlwriter_write_element($writer, $key, $value);
			}
		}
	}
}
