<?php

/**
 * @task  routing URI Routing
 */
abstract class AphrontApplicationConfiguration {

  private $request;
  private $host;
  private $path;
  private $console;

  abstract public function getApplicationName();
  abstract public function getURIMap();
  abstract public function buildRequest();
  abstract public function build404Controller();
  abstract public function buildRedirectController($uri, $external);

  final public function setRequest(AphrontRequest $request) {
    $this->request = $request;
    return $this;
  }

  final public function getRequest() {
    return $this->request;
  }

  final public function getConsole() {
    return $this->console;
  }

  final public function setConsole($console) {
    $this->console = $console;
    return $this;
  }

  final public function setHost($host) {
    $this->host = $host;
    return $this;
  }

  final public function getHost() {
    return $this->host;
  }

  final public function setPath($path) {
    $this->path = $path;
    return $this;
  }

  final public function getPath() {
    return $this->path;
  }

  public function willBuildRequest() {}


/* -(  URI Routing  )-------------------------------------------------------- */


  /**
   * Using builtin and application routes, build the appropriate
   * @{class:AphrontController} class for the request. To route a request, we
   * first test if the HTTP_HOST is configured as a valid Phabricator URI. If
   * it isn't, we do a special check to see if it's a custom domain for a blog
   * in the Phame application and if that fails we error. Otherwise, we test
   * the URI against all builtin routes from @{method:getURIMap}, then against
   * all application routes from installed @{class:PhabricatorApplication}s.
   *
   * If we match a route, we construct the controller it points at, build it,
   * and return it.
   *
   * If we fail to match a route, but the current path is missing a trailing
   * "/", we try routing the same path with a trailing "/" and do a redirect
   * if that has a valid route. The idea is to canoncalize URIs for consistency,
   * but avoid breaking noncanonical URIs that we can easily salvage.
   *
   * NOTE: We only redirect on GET. On POST, we'd drop parameters and most
   * likely mutate the request implicitly, and a bad POST usually indicates a
   * programming error rather than a sloppy typist.
   *
   * If the failing path already has a trailing "/", or we can't route the
   * version with a "/", we call @{method:build404Controller}, which build a
   * fallback @{class:AphrontController}.
   *
   * @return pair<AphrontController,dict> Controller and dictionary of request
   *                                      parameters.
   * @task routing
   */
  final public function buildController() {
    $request = $this->getRequest();

    if (PhabricatorEnv::getEnvConfig('security.require-https')) {
      if (!$request->isHTTPS()) {
        $https_uri = $request->getRequestURI();
        $https_uri->setDomain($request->getHost());
        $https_uri->setProtocol('https');

        // In this scenario, we'll be redirecting to HTTPS using an absolute
        // URI, so we need to permit an external redirect.
        return $this->buildRedirectController($https_uri, true);
      }
    }

    $path         = $request->getPath();
    $host         = $request->getHost();
    $base_uri     = PhabricatorEnv::getEnvConfig('phabricator.base-uri');
    $prod_uri     = PhabricatorEnv::getEnvConfig('phabricator.production-uri');
    $file_uri     = PhabricatorEnv::getEnvConfig(
      'security.alternate-file-domain');
    $conduit_uris = PhabricatorEnv::getEnvConfig('conduit.servers');
    $allowed_uris = PhabricatorEnv::getEnvConfig('phabricator.allowed-uris');

    $uris = array_merge(
      array(
        $base_uri,
        $prod_uri,
      ),
      $conduit_uris,
      $allowed_uris);

    $cdn_routes = array(
      '/res/',
      '/file/data/',
      '/file/xform/',
      '/phame/r/',
      );

    $host_match = false;
    foreach ($uris as $uri) {
      if ($host === id(new PhutilURI($uri))->getDomain()) {
        $host_match = true;
        break;
      }
    }

    if (!$host_match) {
      if ($host === id(new PhutilURI($file_uri))->getDomain()) {
        foreach ($cdn_routes as $route) {
          if (strncmp($path, $route, strlen($route)) == 0) {
            $host_match = true;
            break;
          }
        }
      }
    }

    // NOTE: If the base URI isn't defined yet, don't activate alternate
    // domains.
    if ($base_uri && !$host_match) {

      try {
        $blog = id(new PhameBlogQuery())
          ->setViewer(new PhabricatorUser())
          ->withDomain($host)
          ->executeOne();
      } catch (PhabricatorPolicyException $ex) {
        throw new Exception(
          'This blog is not visible to logged out users, so it can not be '.
          'visited from a custom domain.');
      }

      if (!$blog) {
        if ($prod_uri && $prod_uri != $base_uri) {
          $prod_str = ' or '.$prod_uri;
        } else {
          $prod_str = '';
        }
        throw new Exception(
          'Specified domain '.$host.' is not configured for Phabricator '.
          'requests. Please use '.$base_uri.$prod_str.' to visit this instance.'
        );
      }

      // TODO: Make this more flexible and modular so any application can
      // do crazy stuff here if it wants.

      $path = '/phame/live/'.$blog->getID().'/'.$path;
    }

    list($controller, $uri_data) = $this->buildControllerForPath($path);
    if (!$controller) {
      if (!preg_match('@/$@', $path)) {
        // If we failed to match anything but don't have a trailing slash, try
        // to add a trailing slash and issue a redirect if that resolves.
        list($controller, $uri_data) = $this->buildControllerForPath($path.'/');

        // NOTE: For POST, just 404 instead of redirecting, since the redirect
        // will be a GET without parameters.

        if ($controller && !$request->isHTTPPost()) {
          $slash_uri = $request->getRequestURI()->setPath($path.'/');

          $external = strlen($request->getRequestURI()->getDomain());
          return $this->buildRedirectController($slash_uri, $external);
        }
      }
      return $this->build404Controller();
    }

    return array($controller, $uri_data);
  }


  /**
   * Map a specific path to the corresponding controller. For a description
   * of routing, see @{method:buildController}.
   *
   * @return pair<AphrontController,dict> Controller and dictionary of request
   *                                      parameters.
   * @task routing
   */
  final public function buildControllerForPath($path) {
    $maps = array();
    $maps[] = array(null, $this->getURIMap());

    $applications = PhabricatorApplication::getAllInstalledApplications();
    foreach ($applications as $application) {
      $maps[] = array($application, $application->getRoutes());
    }

    $current_application = null;
    $controller_class = null;
    foreach ($maps as $map_info) {
      list($application, $map) = $map_info;

      $mapper = new AphrontURIMapper($map);
      list($controller_class, $uri_data) = $mapper->mapPath($path);

      if ($controller_class) {
        if ($application) {
          $current_application = $application;
        }
        break;
      }
    }

    if (!$controller_class) {
      return array(null, null);
    }

    $request = $this->getRequest();

    $controller = newv($controller_class, array($request));
    if ($current_application) {
      $controller->setCurrentApplication($current_application);
    }

    return array($controller, $uri_data);
  }

}