<?php

/**
 * ownCloud - App Framework
 *
 * @author Bernhard Posselt, Thomas Tanghus, Bart Visscher
 * @copyright 2012 Bernhard Posselt nukeawhale@gmail.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/>.
 *
 */


namespace OC\AppFramework\Http;

use \OC\AppFramework\Controller\Controller;
use \OC\AppFramework\Middleware\MiddlewareDispatcher;


/**
 * Class to dispatch the request to the middleware dispatcher
 */
class Dispatcher {

	private $middlewareDispatcher;
	private $protocol;


	/**
	 * @param Http $protocol the http protocol with contains all status headers
	 * @param MiddlewareDispatcher $middlewareDispatcher the dispatcher which
	 * runs the middleware
	 */
	public function __construct(Http $protocol,
	                            MiddlewareDispatcher $middlewareDispatcher) {
		$this->protocol = $protocol;
		$this->middlewareDispatcher = $middlewareDispatcher;
	}


	/**
	 * Handles a request and calls the dispatcher on the controller
	 * @param Controller $controller the controller which will be called
	 * @param string $methodName the method name which will be called on
	 * the controller
	 * @return array $array[0] contains a string with the http main header,
	 * $array[1] contains headers in the form: $key => value, $array[2] contains
	 * the response output
	 */
	public function dispatch(Controller $controller, $methodName) {
		$out = array(null, array(), null);

		try {

			$this->middlewareDispatcher->beforeController($controller,
				$methodName);
			$response = $controller->$methodName();

			// if an exception appears, the middleware checks if it can handle the
			// exception and creates a response. If no response is created, it is
			// assumed that theres no middleware who can handle it and the error is
			// thrown again
		} catch(\Exception $exception){
			$response = $this->middlewareDispatcher->afterException(
				$controller, $methodName, $exception);
			if (is_null($response)) {
				throw $exception;
			}
		}

		$response = $this->middlewareDispatcher->afterController(
			$controller, $methodName, $response);

		// get the output which should be printed and run the after output
		// middleware to modify the response
		$output = $response->render();
		$out[2] = $this->middlewareDispatcher->beforeOutput(
			$controller, $methodName, $output);

		// depending on the cache object the headers need to be changed
		$out[0] = $this->protocol->getStatusHeader($response->getStatus(),
			$response->getLastModified(), $response->getETag());
		$out[1] = $response->getHeaders();

		return $out;
	}


}