<?php

namespace OAuth2;

/**
 * Redirect the end-user's user agent with error message.
 *
 * @see http://tools.ietf.org/html/draft-ietf-oauth-v2-20#section-4.1
 *
 * @ingroup oauth2_error
 */
class OAuth2RedirectException extends OAuth2ServerException {
  
  protected $redirectUri;
  
  /**
   * @param $redirect_uri
   *   An absolute URI to which the authorization server will redirect the
   *   user-agent to when the end-user authorization step is completed.
   * @param $error
   *   A single error code as described in Section 4.1.2.1
   * @param $error_description
   *   (optional) A human-readable text providing additional information,
   *   used to assist in the understanding and resolution of the error
   *   occurred.
   * @param $state
   *   (optional) REQUIRED if the "state" parameter was present in the client
   *   authorization request. Set to the exact value received from the client.
   *
   * @see http://tools.ietf.org/html/draft-ietf-oauth-v2-20#section-4.1.2.1
   *
   * @ingroup oauth2_error
   */
  public function __construct($redirect_uri, $error, $error_description = NULL, $state = NULL) {
    parent::__construct(OAuth2::HTTP_FOUND, $error, $error_description);
    
    $this->redirectUri = $redirect_uri;
    if ($state) {
      $this->errorData['state'] = $state;
    }
    
  }
  
  /**
   * Redirect the user agent.
   *
   * @ingroup oauth2_section_4
   */
  public function getResponseHeaders() {
    $params = array('query' => $this->errorData);
    return array(
        'Location' => $this->buildUri($this->redirectUri, $params),
    );
  }

  /**
   * Build the absolute URI based on supplied URI and parameters.
   *
   * @param $uri
   *   An absolute URI.
   * @param $params
   *   Parameters to be append as GET.
   *
   * @return
   *   An absolute URI with supplied parameters.
   *
   * @ingroup oauth2_section_4
   */
  protected function buildUri($uri, $params) {
    $parse_url = parse_url($uri);

    // Add our params to the parsed uri
    foreach ($params as $k => $v) {
      if (isset($parse_url[$k]))
        $parse_url[$k] .= "&" . http_build_query($v);
      else
        $parse_url[$k] = http_build_query($v);
    }

    // Put humpty dumpty back together
    return
      ((isset($parse_url["scheme"])) ? $parse_url["scheme"] . "://" : "")
      . ((isset($parse_url["user"])) ? $parse_url["user"] . ((isset($parse_url["pass"])) ? ":" . $parse_url["pass"] : "") . "@" : "")
      . ((isset($parse_url["host"])) ? $parse_url["host"] : "")
      . ((isset($parse_url["port"])) ? ":" . $parse_url["port"] : "")
      . ((isset($parse_url["path"])) ? $parse_url["path"] : "")
      . ((isset($parse_url["query"])) ? "?" . $parse_url["query"] : "")
      . ((isset($parse_url["fragment"])) ? "#" . $parse_url["fragment"] : "");
  }
}