<?php
/**
 * @file
 * Contains the core functions used by the OneAll Social Login Module.
 */


/**
 * Implements hook_menu().
 */
function oneall_social_login_core_menu() {
  // Setup callback handler.
  $items['oneall_social_login/callback'] = array(
    'title' => 'OneAll Social Login Callback',
    'page callback' => 'oneall_social_login_core_callback_handler',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
    'file' => 'oneall_social_login_core.module',
  );
  return $items;
}


/**
 * Returns a list of disabled functions.
 */
function oneall_social_get_disabled_functions() {
  $disabled_functions = trim(ini_get('disable_functions'));
  if (drupal_strlen($disabled_functions) == 0) {
    $disabled_functions = array();
  }
  else {
    $disabled_functions = explode(',', $disabled_functions);
    $disabled_functions = array_map('trim', $disabled_functions);
  }
  return $disabled_functions;
}


/**
 * Checks if CURL can be used.
 */
function oneall_social_login_core_check_curl($protocol = 'https') {
  if (in_array('curl', get_loaded_extensions()) && function_exists('curl_exec') && !in_array('curl_exec', oneall_social_get_disabled_functions())) {
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, ((drupal_strtolower($protocol) == 'http' ? 'http' : 'https') . '://www.oneall.com/ping.html'));
    curl_setopt($curl, CURLOPT_HEADER, 0);
    curl_setopt($curl, CURLOPT_TIMEOUT, 30);
    curl_setopt($curl, CURLOPT_VERBOSE, 0);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
    if (($http_data = curl_exec($curl)) !== FALSE) {
      $http_code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
      curl_close($curl);
      if ($http_code == 200 && drupal_strtolower($http_data) == 'ok') {
        return TRUE;
      }
    }
  }
  return FALSE;
}


/**
 * Checks if fsockopen can be used.
 */
function oneall_social_login_core_check_fsockopen($protocol = 'https') {
  if (function_exists('drupal_http_request') && !in_array('drupal_http_request', oneall_social_get_disabled_functions())) {
    $result = drupal_http_request((drupal_strtolower($protocol) == 'http' ? 'http' : 'https') . '://www.oneall.com/ping.html');
    if (is_object($result) && property_exists($result, 'code') && $result->code == 200) {
      if (property_exists($result, 'data')) {
        if (drupal_strtolower($result->data) == 'ok') {
          return TRUE;
        }
      }
    }
  }
  return FALSE;
}


/**
 * Sends an API request by using the given handler.
 */
function oneall_social_login_core_do_api_request($handler, $url, $options = array(), $timeout = 30) {
  // FSOCKOPEN?
  if (drupal_strtolower($handler) == 'fsockopen') {
    // BASIC AUTH?
    if (is_array($options) && isset($options['api_key']) && isset($options['api_secret'])) {
      if (preg_match('/^(http(s)?:\/\/)(.+)$/i', $url, $matches)) {
        $url = $matches[1] . $options['api_key'] . ':' . $options['api_secret'] . '@' . $matches[3];
      }
    }
    $result = drupal_http_request($url, array('timeout' => $timeout));
    if (is_object($result)) {
      // Done.
      return array(
        'http_code' => $result->code,
        'http_data' => $result->data,
      );
    }
  }
  // CURL?
  else {
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_HEADER, 0);

    // BASIC AUTH?
    if (is_array($options) && isset($options['api_key']) && isset($options['api_secret'])) {
      curl_setopt($curl, CURLOPT_USERPWD, $options['api_key'] . ":" . $options['api_secret']);
    }

    // Setup CURL options.
    curl_setopt($curl, CURLOPT_TIMEOUT, $timeout);
    curl_setopt($curl, CURLOPT_VERBOSE, 0);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($curl, CURLOPT_FAILONERROR, 0);

    $http_data = curl_exec($curl);
    $http_code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
    curl_close($curl);

    // Done.
    return array(
      'http_code' => $http_code,
      'http_data' => $http_data,
    );
  }
  return NULL;
}


/**
 * This is the callback handler.
 */
function oneall_social_login_core_callback_handler() {

  // Read Settings.
  $settings = oneall_social_login_core_get_settings();

  // No need to do anything if we haven't received these arguments.
  if (isset($_POST) && !empty($_POST['connection_token']) && !empty($_POST['oa_action']) && in_array($_POST['oa_action'], array('social_login', 'social_link'))) {

    // Clear session.
    oneall_social_login_core_clear_session();

    // API Connection Credentials.
    $api_subdomain = (!empty($settings['api_subdomain']) ? $settings['api_subdomain'] : '');
    $api_key = (!empty($settings['api_key']) ? $settings['api_key'] : '');
    $api_secret = (!empty($settings['api_secret']) ? $settings['api_secret'] : '');

    // API Connection Handler.
    $handler = (!empty($settings['http_handler']) ? $settings['http_handler'] : 'curl');
    $handler = ($handler == 'fsockopen' ? 'fsockopen' : 'curl');

    // API Connection Protocol.
    $protocol = (!empty($settings['http_protocol']) ? $settings['http_protocol'] : 'https');
    $protocol = ($protocol == 'http' ? 'http' : 'https');

    // Automatic or manual registration?
    $registration_method = (!empty($settings['registration_method']) ? $settings['registration_method'] : '');
    $registration_method = (in_array($registration_method, array(
      'manual',
      'auto_random_email',
      'auto_manual_email',
    )) ? $registration_method : 'manual');

    // Require approval?
    $registration_approval = (!empty($settings['registration_approval']) ? $settings['registration_approval'] : '');
    $registration_approval = (in_array($registration_approval, array(
      'inherit',
      'disable',
      'enable',
    )) ? $registration_approval : 'inherit');

    // Retrieved connection_token.
    $token = trim($_POST['connection_token']);

    // Settings missing.
    if (empty($api_subdomain) || empty($api_key) || empty($api_secret)) {
      drupal_set_message(t('OneAll Social Login is not setup correctly, please request the administrator to verify the API Settings'), 'error');
      watchdog('oneall_social_login_core', 'The API Settings are not filled out correctly', WATCHDOG_ERROR);
    }
    // Settings filled out.
    else {

      // Request identity details API.
      $data = oneall_social_login_core_do_api_request($handler, $protocol . '://' . $api_subdomain . '.api.oneall.com/connections/' . $token . '.json', array(
        'api_key' => $api_key,
        'api_secret' => $api_secret,
      ));

      if (is_array($data) && !empty($data['http_data'])) {
        $social_data = @drupal_json_decode($data['http_data']);

        // Everything seems to be ok.
        if (is_array($social_data) && isset($social_data['response']) && isset($social_data['response']['request']['status']['code']) && $social_data['response']['request']['status']['code'] == 200) {

          // The plugin that has been uses social_login/social_link.
          $data = $social_data['response']['result']['data'];

          // Save the social network data in a session.
          $_SESSION['oneall_social_login_session_open'] = 1;
          $_SESSION['oneall_social_login_session_time'] = time();
          $_SESSION['oneall_social_login_social_data'] = serialize($social_data);
          $_SESSION['oneall_social_login_origin'] = (!empty($_GET['origin']) ? $_GET['origin'] : '');

          // Unique user_token.
          $user_token = $data['user']['user_token'];

          // Extract identity.
          $identity = $data['user']['identity'];

          // Unique identity_token.
          $identity_token = $identity['identity_token'];

          // Social Network that has been used to connect.
          $provider_name = (!empty($identity['source']['name']) ? $identity['source']['name'] : t('Unkown'));

          // Try restoring the user for the token.
          $user_for_token = oneall_social_login_core_get_user_for_user_token($user_token);

          // Existing user.
          if (is_object($user_for_token) && !empty($user_for_token->uid)) {

            // Social Login Plugin used?
            if ($data['plugin']['key'] == 'social_login') {

              // Make sure that the user has not been blocked.
              $state['values']['name'] = $user_for_token->name;
              user_login_name_validate(array(), $state);
              if (!form_get_errors()) {
                // Login user.
                $form_state['uid'] = $user_for_token->uid;
                user_login_submit(array(), $form_state);
              }
            }
            // Social Link Plugin used?
            elseif ($data['plugin']['key'] == 'social_link') {

              // The user should be logged in.
              global $user;

              // User is logged in.
              if (is_object($user) && !empty($user->uid)) {

                // The existing token does not match the current user!
                if ($user_for_token->uid <> $user->uid) {
                  drupal_set_message(t('This @social_network account is already linked to another user.', array(
                    '@social_network' => $provider_name,
                  )), 'error');
                }
                // The existing token matches the current user!
                else {
                  // Link identity.
                  if ($data['plugin']['data']['action'] == 'link_identity') {
                    oneall_social_login_core_map_identity_token_to_user_token($user, $identity_token, $user_token, $provider_name);
                    drupal_set_message(t('The @social_network account has been linked to your account.', array(
                      '@social_network' => $provider_name,
                    )), 'status');
                  }
                  // Unlink identity.
                  else {
                    oneall_social_login_core_unmap_identity_token($identity_token);
                    drupal_set_message(t('The social network account has been unlinked from your account.'), 'status');
                  }

                  // Clear session.
                  oneall_social_login_core_clear_session();

                  // Redirect to profile.
                  drupal_goto('user/' . $user->uid . '/edit');
                }
              }
              // User is not logged in.
              else {
                drupal_set_message(t('You must be logged in to perform this action.'), 'error');

                // Clear session.
                oneall_social_login_core_clear_session();

                // Redirect to home.
                drupal_goto();
              }
            }
          }
          // New user.
          else {
            // New users may register.
            if (variable_get('user_register', 1)) {

              // Extract the user's email address.
              $user_email = '';
              $user_email_is_verified = NULL;
              $user_email_is_random = NULL;

              if (isset($identity['emails']) && is_array($identity['emails'])) {
                while (!$user_email_is_verified && (list(, $email) = each($identity['emails']))) {
                  $user_email = $email['value'];
                  $user_email_is_verified = (!empty($email['is_verified']));
                }
              }

              // The admin has chosen the automatic registration.
              if ($registration_method <> 'manual') {

                // No email address / Email address already exists.
                if (empty($user_email) || oneall_social_login_core_get_uid_for_email($user_email) !== FALSE) {

                  // The admin wants users to fill out their email manually.
                  if ($registration_method == 'auto_manual_email') {

                    // We have to fall back to the default registration.
                    $registration_method = 'manual';
                  }
                  // The admin has enabled the usage of random email addresses.
                  else {

                    // Create a bogus email.
                    $user_email = oneall_social_login_core_create_random_email();

                    // Flag - is used further down.
                    $user_email_is_random = TRUE;
                  }
                }
              }

              // Automatic registration is still enabled.
              if ($registration_method <> 'manual') {

                // If something goes wrong fall back to manual registration.
                $registration_method = 'manual';

                // Extract User Firstname.
                $user_first_name = (!empty($identity['name']['givenName']) ? $identity['name']['givenName'] : '');

                // Extract User Lastname.
                $user_last_name = (!empty($identity['name']['familyName']) ? $identity['name']['familyName'] : '');

                // Forge User Login.
                $user_login = '';
                if (!empty($identity['preferredUsername'])) {
                  $user_login = $identity['preferredUsername'];
                }
                elseif (!empty($identity['displayName'])) {
                  $user_login = $identity['displayName'];
                }
                elseif (!empty($identity['name']['formatted'])) {
                  $user_login = $identity['name']['formatted'];
                }
                else {
                  $user_login = trim($user_first_name . ' ' . $user_last_name);
                }

                // We absolutely need a unique username.
                if (drupal_strlen(trim($user_login)) == 0 || oneall_social_login_core_get_uid_for_name(trim($user_login)) !== FALSE) {
                  $i = 1;
                  $user_login = $provider_name . t('User');
                  while (oneall_social_login_core_get_uid_for_name($user_login) !== FALSE) {
                    $user_login = $provider_name . t('User') . $i++;
                  }
                }

                // We also need a password.
                $user_password = user_password(8);

                // Check the approval setting.
                switch ($registration_approval) {
                  // No approval required.
                  case 'disable':
                    $user_status = 1;
                    break;

                  // Manual approval required.
                  case 'enable':
                    $user_status = 0;
                    break;

                  // Use the system-wide setting.
                  default:
                    $user_status = (variable_get('user_register') == 2 ? 0 : 1);
                    break;
                }

                // Setup the default users roles.
                $user_roles = array(
                  DRUPAL_AUTHENTICATED_RID => 'authenticated user',
                );

                // Make sure at least one module implements our hook.
                if (count(module_implements('oneall_social_login_core_default_user_roles')) > 0) {
                  // Call modules that implements the hook.
                  $user_roles = module_invoke_all('oneall_social_login_core_default_user_roles', $user_roles);
                }

                // Setup the user fields.
                $user_fields = array(
                  'name' => $user_login,
                  'mail' => $user_email,
                  'pass' => $user_password,
                  'status' => $user_status,
                  'init' => $user_email,
                  'roles' => $user_roles,
                );

                // Create a new user.
                $account = user_save('', $user_fields);

                // The new account has been created correctly.
                if ($account !== FALSE) {

                  // Disable Drupal legacy registration.
                  $registration_method = 'auto';

                  // Link the fresh account with OneAll.
                  oneall_social_login_core_map_identity_token_to_user_token($account, $identity_token, $user_token, $provider_name);

                  // If enabled: retrieve the picture and save it locally.
                  if (!isset($settings['registration_retrieve_avatars']) OR $settings['registration_retrieve_avatars'] <> 'disable') {
                    // Grab the social avatar and link it to the user account.
                    oneall_social_login_core_link_social_network_avatar($social_data, $account);
                  }

                  // Log the new user in.
                  if (($uid = user_authenticate($user_login, $user_password)) !== FALSE) {
                    global $user;

                    // Loads a user object.
                    $user = user_load($uid);

                    // Finalize the login process.
                    $login_array = array(
                      'name' => $user_login,
                    );
                    user_login_finalize($login_array);

                    // Send email if it's not a random email.
                    if ($user_email_is_random !== TRUE) {
                      // No approval required.
                      if ($user_status == 1) {
                        _user_mail_notify('register_no_approval_required', $user);
                        drupal_set_message(t('You have succesfully created an account and linked it with your @social_network account.', array(
                          '@social_network' => $provider_name,
                        )), 'status');
                      }
                      // Approval required.
                      else {
                        $a = _user_mail_notify('register_pending_approval', $user);
                        drupal_set_message(t('Thank you for applying for an account. Your account is currently pending approval by the site administrator.<br />You will receive an email once your account has been approved and you can then login with your @social_network account.', array(
                          '@social_network' => $provider_name,
                        )), 'status');
                      }
                    }
                    // Random email used.
                    else {
                      drupal_set_message(t('You have succesfully created an account and linked it with your @social_network account.', array(
                        '@social_network' => $provider_name,
                      )), 'status');
                    }
                  }
                  // For some reason we could not log the user in.
                  else {
                    // Redirect to login page (login manually).
                    drupal_set_message(t('Error while logging you in, please try to login manually.'), 'error');
                    drupal_goto('user/login');
                  }
                }
                // An error occured during user_save().
                else {
                  // Redirect to registration page (register manually).
                  drupal_set_message(t('Error while creating your user account, please try to register manually.'), 'error');
                  drupal_goto('user/register');
                }
              }

              // Use the legacy registration form?
              if ($registration_method == 'manual') {
                // Redirect to the registration page (+ prepopulate form).
                // See: oneall_social_login_core_form_user_register_form_alter.
                drupal_goto('user/register');
              }
            }
            // Registration disabled.
            else {
              drupal_set_message(t('Only site administrators can create new user accounts.'), 'error');
              drupal_goto();
            }
          }
        }
      }
      else {
        watchdog('oneall_social_login_core', 'Invalid JSON received from resource', WATCHDOG_ERROR);
      }
    }
  }

  // Return to the main page.
  drupal_goto();
}


/**
 * Implements hook_user_insert().
 */
function oneall_social_login_core_user_insert(&$edit, $account, $category) {
  // Check if we come from a valid session.
  if (isset($_SESSION) && !empty($_SESSION['oneall_social_login_session_open']) && !empty($_SESSION['oneall_social_login_social_data'])) {
    // Restore data.
    $social_data = @unserialize($_SESSION['oneall_social_login_social_data']);

    // Check format.
    if (is_array($social_data) && isset($social_data['response']) && isset($social_data['response']['request']['status']['code']) && $social_data['response']['request']['status']['code'] == 200) {

      // Retrieve required data.
      $user_data = $social_data['response']['result']['data']['user'];

      // Unique user_token.
      $user_token = $user_data['user_token'];

      // Unique identity_token.
      $identity_token = $user_data['identity']['identity_token'];

      // Social Network used to connect.
      $provider_name = $user_data['identity']['source']['name'];

      // Tie user to token.
      if (!empty($user_token) && !empty($identity_token) && !empty($provider_name)) {
        oneall_social_login_core_map_identity_token_to_user_token($account, $identity_token, $user_token, $provider_name);
      }

      // Read the OneAll Settings.
      $settings = oneall_social_login_core_get_settings();

      // Grabs the social network avatar and links it to a user account.
      if (!empty($settings['registration_retrieve_avatars']) AND $settings['registration_retrieve_avatars'] == 'enable') {
        oneall_social_login_core_link_social_network_avatar($social_data, $account);
      }

      // Forces the approval setting for Social Login users.
      if (!empty($settings['registration_approval']) AND $settings['registration_approval'] <> 'inherit') {
        switch ($settings['registration_approval']) {
          // Disable approval.
          case 'disable':
            db_update('users')->fields(array('status' => 1))->condition('uid', $account->uid)->execute();
            break;

          // Enable approval.
          case 'enable':
            db_update('users')->fields(array('status' => 0))->condition('uid', $account->uid)->execute();
            break;
        }
      }
    }

    // Clear the session.
    oneall_social_login_core_clear_session();
  }
}


/**
 * Implements hook_user_login().
 */
function oneall_social_login_core_user_login(&$edit, $account) {
  // Check if we come from a valid session.
  if (isset($_SESSION) && !empty($_SESSION['oneall_social_login_session_open']) && !empty($_SESSION['oneall_social_login_social_data'])) {
    // Restore data.
    $social_data = @unserialize($_SESSION['oneall_social_login_social_data']);

    // Check format.
    if (is_array($social_data) && isset($social_data['response']) && isset($social_data['response']['request']['status']['code']) && $social_data['response']['request']['status']['code'] == 200) {

      // Retrieve required data.
      $user_data = $social_data['response']['result']['data']['user'];

      // Unique user_token.
      $user_token = $user_data['user_token'];

      // Unique identity_token.
      $identity_token = $user_data['identity']['identity_token'];

      // Social Network used to connect.
      $provider_name = $user_data['identity']['source']['name'];

      // Check if token is already linked.
      $uid = oneall_social_login_core_get_uid_for_user_token($user_token);

      // Already linked.
      if (is_numeric($uid)) {
        // Linked to a different user?
        if ($account->uid <> $uid) {
          drupal_set_message(t('Sorry, but this @social_network account is already linked to another user on this website.', array(
            '@social_network' => $provider_name,
          )), 'error');
        }
      }
      // Not linked.
      else {
        // Link to this user.
        if (oneall_social_login_core_map_identity_token_to_user_token($account, $identity_token, $user_token, $provider_name)) {
          drupal_set_message(t('Your @social_network account has been linked to your account. You may now use @social_network to login.', array(
            '@social_network' => $provider_name,
          )), 'status');
        }
      }
    }
    else {
      watchdog('oneall_social_login_core', 'Invalid JSON received from resource', WATCHDOG_ERROR);
    }

    // Restore to origin.
    $origin = (isset($_SESSION['oneall_social_login_origin']) ? $_SESSION['oneall_social_login_origin'] : '');

    // Clear session.
    oneall_social_login_core_clear_session();

    // Redirect to origin.
    if (drupal_strlen(trim($origin)) > 0) {
      drupal_goto($origin);
    }
  }
}


/**
 * Grabs tge social network avatar and links it to a user account.
 */
function oneall_social_login_core_link_social_network_avatar($social_data, $account) {

  // Read Settings.
  $settings = oneall_social_login_core_get_settings();

  // Check social data format.
  if (is_array($social_data) && isset($social_data['response']) && isset($social_data['response']['request']['status']['code']) && $social_data['response']['request']['status']['code'] == 200) {

    // Retrieve required data.
    $user_data = $social_data['response']['result']['data']['user'];

    // Check if we have a picture in the social network data.
    if (!empty($user_data['identity']['pictureUrl']) AND is_object($account) AND !empty($account->uid)) {

      // Picture source and target.
      $picture_url = $user_data['identity']['pictureUrl'];
      $picture_directory = file_default_scheme() . '://' . variable_get('user_picture_path', 'pictures');

      // Prepare the picture directory.
      if (file_prepare_directory($picture_directory, FILE_CREATE_DIRECTORY)) {

        // Base name of the file.
        $file_base_name = $picture_directory . '/picture-' . $account->uid . '-' . REQUEST_TIME;

        // Check which api connection handler should be used.
        $handler = (!empty($settings['http_handler']) ? $settings['http_handler'] : 'curl');
        $handler = ($handler == 'fsockopen' ? 'fsockopen' : 'curl');

        // Get the picture data by using the chosen handler.
        $http_result = oneall_social_login_core_do_api_request($handler, $picture_url);

        // Save the picture data locally.
        $tmp_name = $file_base_name . '.tmp';
        $tmp_path = file_stream_wrapper_uri_normalize($tmp_name);
        $tmp_file = file_save_data($http_result['http_data'], $tmp_path, FILE_EXISTS_REPLACE);

        // Get the picture details.
        if (($file_info = image_get_info($tmp_path)) !== FALSE) {

          // Rename the temporary file to the correct extension.
          $real_name = $file_base_name . '.' . strtolower($file_info['extension']);
          $real_path = file_stream_wrapper_uri_normalize($real_name);
          $real_file = file_move($tmp_file, $real_path, FILE_EXISTS_REPLACE);

          // Make sure that the picture isn't too large for the site settings.
          $max_dimensions = variable_get('user_picture_dimensions', '85x85');
          $errors = file_validate_image_resolution($real_file, $max_dimensions);

          // Update the database.
          if (count($errors) == 0) {

            // Link the managed file to this user.
            $real_file->uid = $account->uid;
            $real_file = file_save($real_file);

            // Link the file usage to user and file.
            file_usage_add($real_file, 'user', 'user', $account->uid);

            // Update user record.
            db_update('users')->fields(array('picture' => $real_file->fid))->condition('uid', $account->uid)->execute();
          }
        }
      }
    }
  }
}


/**
 * Unlinks an identity_token from an existing user account.
 */
function oneall_social_login_core_unmap_identity_token($identity_token) {
  db_delete('oneall_social_login_identities')->condition('identity_token', $identity_token)->execute();
}


/**
 * Links a user_token/identity_token to an existing user account.
 */
function oneall_social_login_core_map_identity_token_to_user_token($account, $identity_token, $user_token, $provider_name) {

  // Start transaction.
  $db_transaction = db_transaction();

  try {
    // Update authmaps.
    user_set_authmaps($account, array(
      'authname_oneall_social_login' => $user_token,
    ));

    // Get the new authmap identifier.
    $aid = db_select('authmap', 'a')->fields('a', array('aid'))->condition('module', 'oneall_social_login', '=')->condition('authname', $user_token, '=')->execute()->fetchField();

    if (is_numeric($aid)) {

      // Remove duplicate identities.
      db_delete('oneall_social_login_identities')->condition('aid', $aid)->condition('identity_token', $identity_token)->execute();

      // Add identity.
      db_insert('oneall_social_login_identities')->fields(array(
        'aid' => $aid,
        'identity_token' => $identity_token,
        'provider_name' => $provider_name,
      ))->execute();

      // Success.
      return TRUE;
    }
  }
  catch (Exception $e) {
    $db_transaction->rollback();
    watchdog_exception('oneall_social_login_core', $e);
  }

  // Error.
  return FALSE;
}


/**
 * Implements hook_form_alter().
 */
function oneall_social_login_core_form_alter(&$form, &$form_state) {
  // Hook into login page.
  if (is_array($form) && isset($form['#form_id']) && $form['#form_id'] == 'user_login') {
    // Check if we come from a valid session.
    if (isset($_SESSION) && !empty($_SESSION['oneall_social_login_session_open']) && !empty($_SESSION['oneall_social_login_social_data'])) {
      // Restore data.
      $social_data = @unserialize($_SESSION['oneall_social_login_social_data']);

      // Check format.
      if (is_array($social_data) && isset($social_data['response']) && isset($social_data['response']['request']['status']['code']) && $social_data['response']['request']['status']['code'] == 200) {
        // Read settings.
        $settings = oneall_social_login_core_get_settings();

        // Used Provider.
        $provider_name = $social_data['response']['result']['data']['user']['identity']['source']['name'];

        // No message if the module is not shown on the registration page.
        if (empty($settings['registration_page_icons']) || $settings['registration_page_icons'] <> 'disable') {
          $form['oneall_social_login_core_create_account'] = array(
            '#type' => 'item',
            '#weight' => -110,
            '#title' => t('I would like to create a new account'),
            '#description' => t('If you do not have an account on this website yet, <a href="@link_register">create a new account</a> to link your @social_network account to this account.', array(
              '@social_network' => $provider_name,
              '@link_register' => url('user/register'),
            )),
          );
        }
        // Tell the user what is going on.
        $form['oneall_social_login_core_link_account'] = array(
          '#type' => 'item',
          '#weight' => -100,
          '#title' => t('I already have an account'),
          '#description' => t('If you have already an account on this website, login below to link your @social_network to this account.', array(
            '@social_network' => $provider_name,
          )),
        );
      }
    }
  }
}


/**
 * Implements hook_form_USER_REGISTER_alter().
 */
function oneall_social_login_core_form_user_register_form_alter(&$form, &$form_state) {

  // Check if we come from a valid session.
  if (isset($_SESSION) && !empty($_SESSION['oneall_social_login_session_open']) && !empty($_SESSION['oneall_social_login_social_data'])) {
    // Restore data.
    $social_data = @unserialize($_SESSION['oneall_social_login_social_data']);

    // Check format.
    if (is_array($social_data) && isset($social_data['response']) && isset($social_data['response']['request']['status']['code']) && $social_data['response']['request']['status']['code'] == 200) {

      // Read settings.
      $settings = oneall_social_login_core_get_settings();

      // Convenience variables.
      $data = $social_data['response']['result']['data'];
      $identity = $data['user']['identity'];
      $identity_id = $identity['id'];
      $provider_name = $identity['source']['name'];

      // Email.
      $user_email = '';
      $user_email_is_verified = FALSE;
      if (isset($identity['emails']) && is_array($identity['emails'])) {
        while (!$user_email_is_verified && (list(, $email) = each($identity['emails']))) {
          $user_email = $email['value'];
          $user_email_is_verified = (!empty($email['is_verified']));
        }
      }

      // Login.
      $user_login = '';
      if (!empty($identity['preferredUsername'])) {
        $user_login = $identity['preferredUsername'];
      }
      elseif (!empty($identity['displayName'])) {
        $user_login = $identity['displayName'];
      }
      elseif (!empty($identity['name']['formatted'])) {
        $user_login = $identity['name']['formatted'];
      }
      elseif (!empty($identity['name']['displayName'])) {
        $user_login = $identity['name']['displayName'];
      }

      // Prepopulate.
      $form['account']['name']['#default_value'] = $user_login;
      $form['account']['mail']['#default_value'] = $user_email;

      // Don't show message if the module is not on the registration page.
      if (empty($settings['login_page_icons']) || $settings['login_page_icons'] <> 'disable') {
        $form['oneall_social_login_core_link_account'] = array(
          '#type' => 'item',
          '#weight' => -100,
          '#title' => t('Do you already have an account?'),
          '#description' => t('If you have already an account on this website, <a href="@link_login">log in</a> to link @social_network to this account.', array(
            '@social_network' => $provider_name,
            '@link_login' => url('user'),
          )),
        );
      }

      // Tell the user what is going on.
      $form['oneall_social_login_core_create_account'] = array(
        '#type' => 'item',
        '#weight' => -100,
        '#title' => t('Would you like to create a new account?'),
        '#description' => t('Please complete the form to create your account. Once your account has been created, you can use @social_network to log in.', array(
          '@social_network' => $provider_name,
        )),
      );
    }
  }
}


/**
 * Remove the session data.
 */
function oneall_social_login_core_clear_session() {
  foreach (array(
    'session_open',
    'session_time',
    'social_data',
    'origin',
  ) as $key) {
    $key = 'oneall_social_login_' . $key;
    if (isset($_SESSION[$key])) {
      unset($_SESSION[$key]);
    }
  }
}


/**
 * Return the user for a user_token.
 */
function oneall_social_login_core_get_user_for_user_token($user_token) {
  $uid = oneall_social_login_core_get_uid_for_user_token($user_token);
  if (is_numeric($uid)) {
    if (($user = user_load($uid, FALSE)) !== FALSE) {
      return $user;
    }
  }
  return FALSE;
}


/**
 * Return the uid for a user_token.
 */
function oneall_social_login_core_get_uid_for_user_token($user_token) {
  $uid = db_query("SELECT uid FROM {authmap} WHERE module = :module AND authname = :authname", array(
    ':module' => 'oneall_social_login',
    ':authname' => $user_token,
  ))->fetchField();
  return (is_numeric($uid) ? $uid : FALSE);
}


/**
 * Return the user_token for a uid.
 */
function oneall_social_login_core_get_user_token_for_uid($uid) {
  $user_token = db_query("SELECT authname FROM {authmap} WHERE module = :module AND uid = :uid", array(
    ':module' => 'oneall_social_login',
    ':uid' => $uid,
  ))->fetchField();
  return (!empty($user_token) ? $user_token : FALSE);
}


/**
 * Get the uid for a name.
 */
function oneall_social_login_core_get_uid_for_name($name) {
  $uid = db_query("SELECT uid FROM {users} WHERE name = :name", array(
    ':name' => $name,
  ))->fetchField();
  return (!empty($uid) ? $uid : FALSE);
}


/**
 * Get the uid for an email address.
 */
function oneall_social_login_core_get_uid_for_email($mail) {
  $uid = db_query("SELECT uid FROM {users} WHERE mail = :mail", array(
    ':mail' => $mail,
  ))->fetchField();
  return (!empty($uid) ? $uid : FALSE);
}


/**
 * Create a random email address.
 */
function oneall_social_login_core_create_random_email() {
  do {
    $email = md5(uniqid(rand(10000, 99999))) . "@example.com";
  } while (oneall_social_login_core_get_uid_for_email($email) !== FALSE);
  return $email;
}

/**
 * Return the settings.
 */
function oneall_social_login_core_get_settings() {

  // Container.
  $settings = array();
  $settings['enabled_providers'] = array();

  // Read settings.
  $results = db_query("SELECT setting, value FROM {oneall_social_login_settings}");
  foreach ($results as $result) {
    $settings[$result->setting] = $result->value;
    if (drupal_substr($result->setting, 0, 8) == 'provider' && !empty($result->value)) {
      $settings['enabled_providers'][] = drupal_substr($result->setting, 9, drupal_strlen($result->setting));
    }
  }
  return $settings;
}


/**
 * Add a Link to the footer.
 */
function oneall_social_login_core_preprocess_page(&$vars, $hook) {
  if (is_array($vars['page']) && isset($vars['page']) && isset($vars['page']['footer'])) {
    if (isset($vars['page']['footer']['system_powered-by']) && isset($vars['page']['footer']['system_powered-by']['#markup'])) {
      $vars['page']['footer']['system_powered-by']['#markup'] .= '&nbsp; | &nbsp;' . l(t('Social Login'), 'http://www.oneall.com/services/') . ' ' . t('powered by') . ' ' . l(t('OneAll'), 'http://www.oneall.com/');
    }
  }
}

/**
 * Retur the list of available providers.
 */
function oneall_social_login_core_get_available_providers() {

  $available_providers = array(
    'facebook' => array(
      'name' => 'Facebook',
    ),
    'twitter' => array(
      'name' => 'Twitter',
    ),
    'google' => array(
      'name' => 'Google',
    ),
    'linkedin' => array(
      'name' => 'LinkedIn',
    ),
    'github' => array(
      'name' => 'Github.com',
    ),
    'skyrock' => array(
      'name' => 'Skyrock.com',
    ),
    'yahoo' => array(
      'name' => 'Yahoo',
    ),
    'foursquare' => array(
      'name' => 'Foursquare',
    ),
    'youtube' => array(
      'name' => 'YouTube',
    ),
    'openid' => array(
      'name' => 'OpenID',
    ),
    'wordpress' => array(
      'name' => 'Wordpress.com',
    ),
    'hyves' => array(
      'name' => 'Hyves',
    ),
    'paypal' => array(
      'name' => 'PayPal',
    ),
    'livejournal' => array(
      'name' => 'LiveJournal',
    ),
    'vkontakte' => array(
      'name' => 'VKontakte',
    ),
    'stackexchange' => array(
      'name' => 'StackExchange',
    ),
    'steam' => array(
      'name' => 'Steam Community',
    ),
    'mailru' => array(
      'name' => 'Mail.ru',
    ),
    'odnoklassniki' => array(
      'name' => 'Odnoklassniki',
    ),
    'windowslive' => array(
      'name' => 'Windows Live',
    ),
  );

  return $available_providers;
}