<?php
/*
 +--------------------------------------------------------------------+
 | Copyright CiviCRM LLC. All rights reserved.                        |
 |                                                                    |
 | This work is published under the GNU AGPLv3 license with some      |
 | permitted exceptions and without any warranty. For full license    |
 | and copyright information, see https://civicrm.org/licensing       |
 +--------------------------------------------------------------------+
 */

/**
 *
 * @package CRM
 * @copyright CiviCRM LLC https://civicrm.org/licensing
 */
class CRM_Mailing_BAO_TrackableURL extends CRM_Mailing_DAO_TrackableURL {

  /**
   * Given a url, mailing id and queue event id, find or construct a
   * trackable url and redirect url.
   *
   * @param string $url
   *   The target url to track.
   * @param int $mailing_id
   *   The id of the mailing.
   * @param int $queue_id
   *   The queue event id (contact clicking through).
   *
   * @return string
   *   The redirect/tracking url
   */
  public static function getTrackerURL($url, $mailing_id, $queue_id) {
    if (strpos($url, '{') !== FALSE) {
      return self::getTrackerURLForUrlWithTokens($url, $mailing_id, $queue_id);
    }
    else {
      return self::getBasicTrackerURL($url, $mailing_id, $queue_id);
    }
  }

  private static function getBasicTrackerURL($url, $mailing_id, $queue_id) {
    static $urlCache = [];

    if (array_key_exists($mailing_id . $url, $urlCache)) {
      return $urlCache[$mailing_id . $url] . "&qid=$queue_id";
    }

    // hack for basic CRM-1014 and CRM-1151 and CRM-3492 compliance:
    // let's not replace possible image URLs, CiviMail URLs or internal anchor URLs
    if (preg_match('/\.(png|jpg|jpeg|gif|css)[\'"]?$/i', $url)
      or substr_count($url, 'civicrm/extern/')
      or substr_count($url, 'civicrm/mailing/')
      or ($url[0] === '#')
    ) {
      // let's not cache these, so they don't get &qid= appended to them
      return $url;
    }
    else {

      $hrefExists = FALSE;

      $tracker = new CRM_Mailing_BAO_TrackableURL();
      if (preg_match('/^href/i', $url)) {
        $url = preg_replace('/^href[ ]*=[ ]*[\'"](.*?)[\'"]$/i', '$1', $url);
        $hrefExists = TRUE;
      }

      $tracker->url = $url;
      $tracker->mailing_id = $mailing_id;

      if (!$tracker->find(TRUE)) {
        $tracker->save();
      }
      $id = $tracker->id;

      $redirect = CRM_Utils_System::externUrl('extern/url', "u=$id");
      $urlCache[$mailing_id . $url] = $redirect;
    }

    // This looks silly - calling the hook twice. This smells like an accident. Restoring old cache-based lookup.
    // $returnUrl = CRM_Utils_System::externUrl('extern/url', "u=$id&qid=$queue_id");
    $returnUrl = "{$urlCache[$mailing_id . $url]}&qid={$queue_id}";

    if ($hrefExists) {
      $returnUrl = "href='{$returnUrl}' rel='nofollow'";
    }

    return $returnUrl;
  }

  /**
   * Create a trackable URL for a URL with tokens.
   *
   * @param string $url
   * @param int $mailing_id
   * @param int|string $queue_id
   *
   * @return string
   */
  private static function getTrackerURLForUrlWithTokens($url, $mailing_id, $queue_id) {

    // Parse the URL.
    // (not using parse_url because it's messy to reassemble)
    if (!preg_match('/^([^?#]+)([?][^#]*)?(#.*)?$/', $url, $parsed)) {
      // Failed to parse it, give up and don't track it.
      return $url;
    }

    // If we have a token in the URL + path section, we can't tokenise.
    if (strpos($parsed[1], '{') !== FALSE) {
      return $url;
    }

    $trackable_url = $parsed[1];

    // Process the query parameters, if there are any.
    $tokenised_params = [];
    $static_params = [];
    if (!empty($parsed[2])) {
      $query_key_value_pairs = explode('&', substr($parsed[2], 1));

      // Separate the tokenised from the static parts.
      foreach ($query_key_value_pairs as $_) {
        if (strpos($_, '{') === FALSE) {
          $static_params[] = $_;
        }
        else {
          $tokenised_params[] = $_;
        }
      }
      // Add the static params to the trackable part.
      if ($static_params) {
        $trackable_url .= '?' . implode('&', $static_params);
      }
    }

    // Get trackable URL.
    $data = self::getBasicTrackerURL($trackable_url, $mailing_id, $queue_id);

    // Append the tokenised bits and the fragment.
    if ($tokenised_params) {
      // We know the URL will already have the '?'
      $data .= '&' . implode('&', $tokenised_params);
    }
    if (!empty($parsed[3])) {
      $data .= $parsed[3];
    }
    return $data;
  }

  /**
   * @param $url
   * @param $mailing_id
   *
   * @return int
   *   Url id of the given url and mail
   */
  public static function getTrackerURLId($url, $mailing_id) {
    $tracker = new CRM_Mailing_BAO_TrackableURL();
    $tracker->url = $url;
    $tracker->mailing_id = $mailing_id;
    if ($tracker->find(TRUE)) {
      return $tracker->id;
    }

    return NULL;
  }

}
