<?php defined("SYSPATH") or die("No direct script access.");
/**
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2009 Bharat Mediratta
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
 */

/**
 * Provides a driver-based interface for managing users and groups.
 */
class IdentityProvider_Core {
  protected static $instance;

  // Configuration
  protected $config;

  // Driver object
  protected $driver;

  /**
   * Returns a singleton instance of Identity.
   * There can only be one Identity driver configured at a given point
   *
   * @param   string  configuration
   * @return  Identity_Core
   */
  static function & instance() {
   if (!isset(self::$instance)) {
      // Create a new instance
      self::$instance = new IdentityProvider();
    }

    return self::$instance;
  }

  /**
   * Returns a singleton instance of Identity.
   * There can only be one Identity driver configured at a given point
   *
   * @param   string  configuration
   * @return  Identity_Core
   */
  static function reset() {
    self::$instance = new IdentityProvider();
  }

  /**
   * Loads the configured driver and validates it.
   *
   * @return  void
   */
  public function __construct() {
    $config = module::get_var("gallery", "identity_provider", "user");

    // Test the config group name
    if (($this->config = Kohana::config("identity.".$config)) === NULL) {
      throw new Exception("@todo NO USER LIBRARY CONFIGURATION FOR: $config");
    }

    // Set driver name
    $driver = "IdentityProvider_".ucfirst($this->config["driver"])."_Driver";

    // Load the driver
    if ( ! Kohana::auto_load($driver)) {
      throw new Kohana_Exception("core.driver_not_found", $this->config["driver"],
                                 get_class($this));
    }

    // Initialize the driver
    $this->driver = new $driver($this->config["params"]);

    // Validate the driver
    if ( !($this->driver instanceof IdentityProvider_Driver)) {
      throw new Kohana_Exception("core.driver_implements", $this->config["driver"],
                                 get_class($this), "IdentityProvider_Driver");
    }

    Kohana::log("debug", "Identity Library initialized");
  }

  /**
   * Determine if if the current driver supports updates.
   *
   * @return boolean true if the driver supports updates; false if read only
   */
  public function is_writable() {
    return !empty($this->config["allow_updates"]);
  }

  /**
   * @see IdentityProvider_Driver::activate.
   */
  public function activate() {
    $this->driver->activate();
  }

  /**
   * @see IdentityProvider_Driver::deactivate.
   */
  public function deactivate() {
    $this->driver->deactivate();
  }

  /**
   * @see IdentityProvider_Driver::guest.
   */
  public function guest() {
    return $this->driver->guest();
  }

  /**
   * @see IdentityProvider_Driver::create_user.
   */
  public function create_user($name, $full_name, $password) {
    return $this->driver->create_user($name, $full_name, $password);
  }

  /**
   * @see IdentityProvider_Driver::is_correct_password.
   */
  public function is_correct_password($user, $password) {
    return $this->driver->is_correct_password($user, $password);
  }

  /**
   * @see IdentityProvider_Driver::lookup_user.
   */
  public function lookup_user($id) {
    return $this->driver->lookup_user($id);
  }

  /**
   * @see IdentityProvider_Driver::lookup_user_by_name.
   */
  public function lookup_user_by_name($name) {
    return $this->driver->lookup_user_by_name($name);
  }

  /**
   * @see IdentityProvider_Driver::create_group.
   */
  public function create_group($name) {
    return $this->driver->create_group($name);
  }

  /**
   * @see IdentityProvider_Driver::everybody.
   */
  public function everybody() {
    return $this->driver->everybody();
  }

  /**
   * @see IdentityProvider_Driver::registered_users.
   */
  public function registered_users() {
    return $this->driver->everybody();
  }

  /**
   * @see IdentityProvider_Driver::lookup_group.
   */
  public function lookup_group($id) {
    return $this->driver->lookup_group($id);
  }

  /**
   * @see IdentityProvider_Driver::lookup_group_by_name.
   */
  public function lookup_group_by_name($name) {
    return $this->driver->lookup_group_by_name($name);
  }

  /**
   * @see IdentityProvider_Driver::get_user_list.
   */
  public function get_user_list($ids) {
    return $this->driver->get_user_list($ids);
  }

  /**
   * @see IdentityProvider_Driver::groups.
   */
  public function groups() {
    return $this->driver->groups();
  }
} // End Identity