<?php

/**
 * @file
 * FlickAPI integration module.
 *
 * The Flickr API module is as a helper module for other Drupal Flickr modules.
 * You don't need this module unless another module requires it or you want to
 * develop a new Flickr-based module.
 */

module_load_include('inc', 'flickapi', 'flickrapi.admin');

/**
 * Implements hook_menu().
 */
function flickrapi_menu() {
  $items = array();
  $items['admin/config/media/flickrapi'] = array(
    'title' => 'Flickr API Settings',
    'description' => 'Configure Flickr API credentials.',
    'access arguments' => array('configure flickr api'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('flickrapi_admin_settings'),
    'file' => 'flickrapi.admin.inc',
  );
  $items['admin/config/media/flickrapi/authenticate'] = array(
    'title' => 'Authenticate Flickr Credentials',
    'access arguments' => array('configure flickr api'),
    'page callback' => 'flickrapi_oauth_authenticate',
    'file' => 'flickrapi.admin.inc',
  );
  $items['admin/config/media/flickrapi/clear'] = array(
    'title' => 'Clear Flickr Credentials',
    'access arguments' => array('configure flickr api'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('flickrapi_oauth_clear_form'),
    'file' => 'flickrapi.admin.inc',
  );
  return $items;
}

/**
 * Implements hook_permission().
 */
function flickrapi_permission() {
  return array(
    'configure flickr api' => array(
      'title' => t('Configure Flickr API'),
      'description' => t('Set API keys and cache times for flickr queries'),
    ),
  );
}

/**
 * Implements hook_flush_caches().
 */
function flickrapi_flush_caches() {
  flickrapi_phpFlickr(TRUE);
}

/**
 * Returns the phpFlickr object.
 *
 * If we need to change anything, such as making the cache configuration,
 * then it'll all be done here.
 *
 * @return phpFlickr
 *   The phpFlickr object
 */
function flickrapi_phpFlickr($clear_cache = FALSE) {
  $api_key = variable_get('flickrapi_api_key', '');
  $api_secret = variable_get('flickrapi_api_secret', '');
  $cache = variable_get('flickrapi_cache', '');
  $cache_dir = variable_get('flickrapi_cache_path', '');

  if (empty($api_key) || empty($api_secret)) {
    drupal_set_message(t("Flickr API key not set"), 'error');
    if (user_access('configure flickr api')) {
      drupal_set_message(t('Please !configure', array('!configure' => l(t('configure the Flickr API settings'), 'admin/config/media/flickrapi'))));
    }
  }
  $flickr = new phpFlickr($api_key, $api_secret);

  // Override the default post function to enable OAuth.
  $flickr->setCustomPost('_flickrapi_post');

  // Enable caching.
  if ($cache == TRUE) {
    if ($clear_cache == TRUE) {
      $flickr->enableCache('fs', $cache_dir, 0);
    }
    else {
      $flickr->enableCache('fs', $cache_dir);
    }
  }

  return $flickr;
}

/**
 * Custom post function to enable OAuth requests.
 *
 * @param String $url
 *   the callback url for the API
 *
 * @param Array $data
 *   associative array with all Flickr paramters
 *
 * @return String
 *   serialized PHP response format
 *   see: http://www.flickr.com/services/api/response.php.html
 */
function _flickrapi_post($url, $data) {
  $consumer = DrupalOAuthConsumer::load(variable_get('flickrapi_api_key', ''), FALSE);
  $sig_method = FlickrApiOAuthClient::signatureMethod();
  $client = new FlickrApiOAuthClient($consumer, NULL, $sig_method);
  $response = $client->get($url, array('token' => TRUE, 'params' => $data));

  return $response;
}

/**
 * Override DrupalOAuthClient to use its protected get() function
 */
class FlickrApiOAuthClient extends DrupalOAuthClient {
  /**
   * Make an OAuth request.
   */
  function get($path, $options = array()) {
    return parent::get($path, $options);
  }
}

/**
 * Tries to match an 'identifier' onto a flickr nsid
 *
 * This function will first see whether $identifier is already
 * a nsid (format check only, no api call).  If it is not and the
 * identifier has the format of an email, an api call will be made to
 * check whether there is an nsid for that email.  If this is not the
 * case, the $identifier is treated as a username and an api call is
 * made to find the nsid for that username.
 *
 * If none of these succees, the result will be false
 *
 * @param Array $identifier
 *   identifier to find an nsid for
 *
 * @return String
 *   valid nsid or false if none can be found
 */
function flickrapi_get_user_nsid($identifier) {
  if (flickrapi_is_nsid($identifier)) {
    // Identifier is an NSID.
    return $identifier;
  }
  $f = flickrapi_phpFlickr();
  if (valid_email_address($identifier) && ($user = $f->people_findByEmail($identifier))) {
    return $user['nsid'];
  }
  if ($user = $f->people_findByUsername($identifier)) {
    return $user['nsid'];
  }

  return FALSE;
}

/**
 * Do a preg_match to check if the given ID is a valid Flickr user ID.
 *
 * @param String $id
 *   identifier to find an nsid for
 *
 * @return Boolean
 *   TRUE/FALSE
 */
function flickrapi_is_nsid($id) {
  return preg_match('/^\d+@N\d+$/', $id) ? TRUE : FALSE;
}

/**
 * Checks if a Flickr account has been already authenticated
 *
 * @return Boolean
 *   TRUE if the consumer key and consumer secret tokens were found
 */
function _flickrapi_is_authenticated() {
  return variable_get('flickrapi_api_key', '') && variable_get('flickrapi_api_secret', '');
}

/**
 * Clears OAuth token and keys
 *
 * @return Boolean
 *   TRUE if keys and oauth token were found
 */
function _flickrapi_oauth_clear() {
  $consumer_key = variable_get('flickrapi_api_key');
  $secret = variable_get('flickrapi_api_secret');
  // TODO get rid of this query and use an oauth_common API method when available
  $csid = db_query("SELECT csid FROM {oauth_common_consumer} WHERE consumer_key = :consumer_key AND secret = :secret", array(
    ':consumer_key' => $consumer_key,
    ':secret' => $secret,
    )
  )->fetchField();
  if ($csid) {
    DrupalOAuthConsumer::deleteConsumer($csid);
    variable_del('flickrapi_api_key');
    variable_del('flickrapi_api_secret');
    return TRUE;
  } else {
    return FALSE;
  }
}