<?php
  /**
   * ownCloud - App Framework
   *
   * @author Bernhard Posselt, Thomas Tanghus, Bart Visscher

   * @copyright 2012 Bernhard Posselt <dev@bernhard-posselt.com>

   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or any later version.
   *
   * This library 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 along with this library.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  
  /**
   * Public interface of ownCloud for apps to use.
   * AppFramework\HTTP\Response class
   */
  
  namespace OCP\AppFramework\Http;
  
  use OCP\AppFramework\Http;
  
  /**
   * Base class for responses. Also used to just send headers.
   *
   * It handles headers, HTTP status code, last modified and ETag.
   */
  class Response {
  
  	/**
  	 * Headers - defaults to ['Cache-Control' => 'no-cache, must-revalidate']
  	 * @var array
  	 */
  	private $headers = array(
  		'Cache-Control' => 'no-cache, must-revalidate'
  	);
  
  
  	/**
  	 * HTTP status code - defaults to STATUS OK
  	 * @var string
  	 */
  	private $status = Http::STATUS_OK;
  
  
  	/**
  	 * Last modified date
  	 * @var \DateTime
  	 */
  	private $lastModified;
  
  
  	/**
  	 * ETag
  	 * @var string
  	 */
  	private $ETag;
  
  
  	/**
  	 * Caches the response
  	 * @param int $cacheSeconds the amount of seconds that should be cached
  	 * if 0 then caching will be disabled
  	 */
  	public function cacheFor($cacheSeconds) {
  
  		if($cacheSeconds > 0) {
  			$this->addHeader('Cache-Control', 'max-age=' . $cacheSeconds .
  				', must-revalidate');
  		} else {
  			$this->addHeader('Cache-Control', 'no-cache, must-revalidate');
  		}

  		return $this;

  	}
  
  
  	/**
  	 * Adds a new header to the response that will be called before the render
  	 * function
  	 * @param string $name The name of the HTTP header
  	 * @param string $value The value, null will delete it

  	 * @return Response Reference to this object

  	 */
  	public function addHeader($name, $value) {

  		$name = trim($name);  // always remove leading and trailing whitespace
  		                      // to be able to reliably check for security 
  		                      // headers

  		if(is_null($value)) {
  			unset($this->headers[$name]);
  		} else {
  			$this->headers[$name] = $value;
  		}

  
  		return $this;

  	}
  
  
  	/**
  	 * Returns the set headers
  	 * @return array the headers
  	 */
  	public function getHeaders() {
  		$mergeWith = array();
  
  		if($this->lastModified) {
  			$mergeWith['Last-Modified'] =
  				$this->lastModified->format(\DateTime::RFC2822);
  		}
  
  		if($this->ETag) {
  			$mergeWith['ETag'] = '"' . $this->ETag . '"';
  		}
  
  		return array_merge($mergeWith, $this->headers);
  	}
  
  
  	/**
  	 * By default renders no output
  	 * @return null
  	 */
  	public function render() {
  		return null;
  	}
  
  
  	/**
  	* Set response status
  	* @param int $status a HTTP status code, see also the STATUS constants

  	* @return Response Reference to this object

  	*/
  	public function setStatus($status) {
  		$this->status = $status;

  
  		return $this;

  	}
  
  
  	/**
  	 * Get response status
  	 */
  	public function getStatus() {
  		return $this->status;
  	}
  
  
  	/**
  	 * Get the ETag
  	 * @return string the etag
  	 */
  	public function getETag() {
  		return $this->ETag;
  	}
  
  
  	/**
  	 * Get "last modified" date

  	 * @return \DateTime RFC2822 formatted last modified date

  	 */
  	public function getLastModified() {
  		return $this->lastModified;
  	}
  
  
  	/**
  	 * Set the ETag
  	 * @param string $ETag

  	 * @return Response Reference to this object

  	 */
  	public function setETag($ETag) {
  		$this->ETag = $ETag;

  
  		return $this;

  	}
  
  
  	/**
  	 * Set "last modified" date
  	 * @param \DateTime $lastModified

  	 * @return Response Reference to this object

  	 */
  	public function setLastModified($lastModified) {
  		$this->lastModified = $lastModified;

  
  		return $this;

  	}
  
  
  }