<?php

/**
 * Controller handles HTTP requests, selects and executes appropriate resource. Afterwards sends out output generated by the View to the browser, and the execution halts: application waits for another request.
 * Implemented as a frontal controller: it is the only point of entry to the application.
 * It is an abstract class for sub-classing. An application Controller should extend the framework Controller and call the parent::process() to handle requests.
 * @package		diy-framework
 * @subpackage	controller
 * @author		Martynas Jusevicius <hide@address.com>
 * @link		http://www.xml.lt
 */

abstract class Controller implements Singleton
{
	protected $resource = null;
	protected $view = null;

/**
 * Constructs a new Controller.
 * Is private because of the Singleton pattern.
 */

	private function __construct() {}
	private function __clone() {}

/**
 * Extracts and returns the full URI (including both host and resource URIs) of the current Request, by striping the query string.
 * @param Request $request Request to extract the URI from
 * @return string URI
 */

	private static function getFullURI(Request $request)
	{
		$host = $request->getHeader("HTTP_HOST");
		//if ($request->getHeader("HTTP_X_FORWARDED_HOST") != null) $host = $request->getHeader("HTTP_X_FORWARDED_HOST");
		$URI = "http://".$host."/".self::getPath($request);
		return $URI;
	}

/**
 * Extracts and returns the path of the current Request, by striping the query string.
 * @param Request $request Request to extract the path from
 * @return string path
 */

	private static function getPath(Request $request)
	{
		$path = $request->getRequestURI();
		//$path = $request->getPathInfo(); // wrong URL encoding
		if ($pos = strpos($path, "?")) $path = substr($path, 0, $pos); // strip the query string
		$path = substr($path, 1); // strip the leading slash
		return $path;
	}

/**
 * Sets HTTP response headers and writes out the buffer.
 * @param Response $response Response to write out and to send to the client
 */

	protected static function output(Response $response)
	{
		header("HTTP/1.1 ".$response->getStatus());
		if ($response->getContentType() != null && $response->getCharacterEncoding() != null) header("Content-Type: ".$response->getContentType()."; charset=".$response->getCharacterEncoding());

		if ($response->getBuffer() != null) print $response->getBuffer();
		// exit
	}

/**
 * Processes the HTTP Request. Finds an appropriate Resource, passes the control to it, and displays the resulting View.
 * @param Request $request Request to process
 * @param Response $response Response to process
 */

	protected function process(Request $request, Response $response, ResourceMapping $mapping)
	{
		$uri = $this->getFullURI($request);
		$path = substr($uri, strlen($mapping->getHost()));
		$request->setAttribute("URI", $path);
		$this->resource = $mapping->findByURI($path);
		$this->view = null;

		if ($this->resource != null)
			switch ($request->getMethod())
			{
				case "GET":
					$this->view = $this->resource->doGet($request, $response);
				break;
				case "POST":
					$this->view = $this->resource->doPost($request, $response);
				break;
				case "PUT":
					$this->view = $this->resource->doPut($request, $response);
				break;
				case "DELETE":
					$this->view = $this->resource->doDelete($request, $response);
				break;
				default:
					$response->setStatus(Response::SC_METHOD_NOT_ALLOWED);
				break;
			}
	}

}

?>