Allow to impersonate as an user account based on information from a content type.

Drupal impersonate

/**
 * Allow Masquerade role users to impersonate Role1 or Role2 accounts.
 * Note that these users will never see their own account for editing or otherwise.
 * As soon as they log in they will act on behalf of the account
 * that we specify they can masquerade as.
 *
 * Only administrators should be able to control the list of users
 * allowed to masquerade.
 *
 * @param $edit
 * @param $account
 */
function yourmodule_user_login(&$edit, $account){
  global $user;
  $managed_uid = null;

  if (!isset($_POST['form_id']) || $_POST['form_id'] != 'user_pass_reset') {

    /**
     * Select from masquerading Content Type the user that has same id with logged in user
     */
    $query = new EntityFieldQuery();
    $result = $query->entityCondition("entity_type", 'node')
      ->entityCondition('bundle', 'masquerading')
      ->fieldCondition('field_user_who_can_masquerade', 'target_id', $user->uid, '=')
      ->range(0,1)
      ->execute();

    /**
     * If found, get the user that is to be impersonated and login as them
     * [no session needs saving as we never need it]
     */
    if(count($result) >0 ) {
      $node = reset($result['node']);
      $node_loaded = node_load($node->nid);
      $wrapper = entity_metadata_wrapper('node', $node_loaded);
      $managed_uid = $wrapper->field_impersonated_account->raw();

      /**
       * Just an extra caution to make sure we never impersonate an admin
       * and that the user we impersonate is of the roles we actually allow.
       */
      if($managed_uid != null) {
        $managed_user =  user_load($managed_uid);
        if(isset($managed_user)) {
          if(!array_intersect($managed_user->roles, array('Art Organisation', 'Gallery'))) {
            return;
          }
  
          if($managed_uid > 1) {
            $user = user_load($managed_uid);
            $edit['redirect'] = 'node/486';
          }
        }
      }
    }
  }
}