<?php

namespace SilverStripe\Dev;

use SilverStripe\Control\Cookie_Backend;
use SilverStripe\Control\Session;
use SilverStripe\Control\Controller;
use SilverStripe\Control\Director;
use SilverStripe\Control\HTTPResponse;
use SilverStripe\Core\Injector\Injector;
use SimpleByName;
use Exception;
use SimplePage;
use SimplePageBuilder;

/**
 * Represents a test usage session of a web-app
 * It will maintain session-state from request to request
 */
class TestSession {

	/**
	 * @var Session
	 */
	private $session;

	/**
	 * @var Cookie_Backend
	 */
	private $cookies;

	/**
	 * @var HTTPResponse
	 */
	private $lastResponse;

	/**
	 * Necessary to use the mock session
	 * created in {@link session} in the normal controller stack,
	 * e.g. to overwrite Member::currentUser() with custom login data.
	 *
	 * @var Controller
	 */
	protected $controller;

	/**
	 * Fake HTTP Referer Tracking, set in {@link get()} and {@link post()}.
	 *
	 * @var string
	 */
	private $lastUrl;

	public function __construct() {
		$this->session = Injector::inst()->create('SilverStripe\\Control\\Session', array());
		$this->cookies = Injector::inst()->create('SilverStripe\\Control\\Cookie_Backend');
		$this->controller = new Controller();
		$this->controller->setSession($this->session);
		$this->controller->pushCurrent();
	}

	public function __destruct() {
		// Shift off anything else that's on the stack.  This can happen if something throws
		// an exception that causes a premature TestSession::__destruct() call
		while(Controller::has_curr() && Controller::curr() !== $this->controller) Controller::curr()->popCurrent();

		if(Controller::has_curr()) $this->controller->popCurrent();
	}

	/**
	 * Submit a get request
	 *
	 * @uses Director::test()
	 * @param string $url
	 * @param Session $session
	 * @param array $headers
	 * @param array $cookies
	 * @return HTTPResponse
	 */
	public function get($url, $session = null, $headers = null, $cookies = null) {
		$headers = (array) $headers;
		if($this->lastUrl && !isset($headers['Referer'])) $headers['Referer'] = $this->lastUrl;
		$this->lastResponse = Director::test(
			$url,
			null,
			$session ?: $this->session,
			null,
			null,
			$headers,
			$cookies ?: $this->cookies
		);
		$this->lastUrl = $url;
		if(!$this->lastResponse) user_error("Director::test($url) returned null", E_USER_WARNING);
		return $this->lastResponse;
	}

	/**
	 * Submit a post request
	 *
	 * @uses Director::test()
	 * @param string $url
	 * @param array $data
	 * @param array $headers
	 * @param Session $session
	 * @param string $body
	 * @param array $cookies
	 * @return HTTPResponse
	 */
	public function post($url, $data, $headers = null, $session = null, $body = null, $cookies = null) {
		$headers = (array) $headers;
		if($this->lastUrl && !isset($headers['Referer'])) $headers['Referer'] = $this->lastUrl;
		$this->lastResponse = Director::test(
			$url,
			$data,
			$session ?: $this->session,
			null,
			$body,
			$headers,
			$cookies ?: $this->cookies
		);
		$this->lastUrl = $url;
		if(!$this->lastResponse) user_error("Director::test($url) returned null", E_USER_WARNING);
		return $this->lastResponse;
	}

	/**
	 * Submit the form with the given HTML ID, filling it out with the given data.
	 * Acts on the most recent response.
	 *
	 * Any data parameters have to be present in the form, with exact form field name
	 * and values, otherwise they are removed from the submission.
	 *
	 * Caution: Parameter names have to be formatted
	 * as they are in the form submission, not as they are interpreted by PHP.
	 * Wrong: array('mycheckboxvalues' => array(1 => 'one', 2 => 'two'))
	 * Right: array('mycheckboxvalues[1]' => 'one', 'mycheckboxvalues[2]' => 'two')
	 *
	 * @see http://www.simpletest.org/en/form_testing_documentation.html
	 *
	 * @param string $formID HTML 'id' attribute of a form (loaded through a previous response)
	 * @param string $button HTML 'name' attribute of the button (NOT the 'id' attribute)
	 * @param array $data Map of GET/POST data.
	 * @return HTTPResponse
	 * @throws Exception
	 */
	public function submitForm($formID, $button = null, $data = array()) {
		$page = $this->lastPage();
		if($page) {
			$form = $page->getFormById($formID);
			if (!$form) {
				user_error("TestSession::submitForm failed to find the form {$formID}");
			}

			foreach($data as $k => $v) {
				$form->setField(new SimpleByName($k), $v);
			}

			if($button) {
				$submission = $form->submitButton(new SimpleByName($button));
				if(!$submission) throw new Exception("Can't find button '$button' to submit as part of test.");
			} else {
				$submission = $form->submit();
			}

			$url = Director::makeRelative($form->getAction()->asString());

			$postVars = array();
			parse_str($submission->_encode(), $postVars);
			return $this->post($url, $postVars);

		} else {
			user_error("TestSession::submitForm called when there is no form loaded."
				. " Visit the page with the form first", E_USER_WARNING);
		}
	}

	/**
	 * If the last request was a 3xx response, then follow the redirection
	 *
	 * @return HTTPResponse The response given, or null if no redirect occurred
	 */
	public function followRedirection() {
		if($this->lastResponse->getHeader('Location')) {
			$url = Director::makeRelative($this->lastResponse->getHeader('Location'));
			$url = strtok($url, '#');
			return $this->get($url);
		}
	}

	/**
	 * Returns true if the last response was a 3xx redirection
	 *
	 * @return bool
	 */
	public function wasRedirected() {
		$code = $this->lastResponse->getStatusCode();
		return $code >= 300 && $code < 400;
	}

	/**
	 * Get the most recent response
	 *
	 * @return HTTPResponse
	 */
	public function lastResponse() {
		return $this->lastResponse;
	}

	/**
	 * Return the fake HTTP_REFERER; set each time get() or post() is called.
	 *
	 * @return string
	 */
	public function lastUrl() {
		return $this->lastUrl;
	}

	/**
	 * Get the most recent response's content
	 *
	 * @return string
	 */
	public function lastContent() {
		if(is_string($this->lastResponse)) return $this->lastResponse;
		else return $this->lastResponse->getBody();
	}

	/**
	 * Return a CSSContentParser containing the most recent response
	 *
	 * @return CSSContentParser
	 */
	public function cssParser() {
		return new CSSContentParser($this->lastContent());
	}

	/**
	 * Get the last response as a SimplePage object
	 *
	 * @return SimplePage The response if available
	 */
	public function lastPage() {
		require_once("thirdparty/simpletest/http.php");
		require_once("thirdparty/simpletest/page.php");
		require_once("thirdparty/simpletest/form.php");

		$builder = new SimplePageBuilder();
		if($this->lastResponse) {
			$page = &$builder->parse(new TestSession_STResponseWrapper($this->lastResponse));
			$builder->free();
			unset($builder);

			return $page;
		}
	}

	/**
	 * Get the current session, as a Session object
	 *
	 * @return Session
	 */
	public function session() {
		return $this->session;
	}
}