<?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.
 */
class item_Core {
  static function move($source, $target) {
    access::required("view", $source);
    access::required("view", $target);
    access::required("edit", $source);
    access::required("edit", $target);

    $parent = $source->parent();
    if ($parent->album_cover_item_id == $source->id) {
      if ($parent->children_count() > 1) {
        foreach ($parent->children(2) as $child) {
          if ($child->id != $source->id) {
            $new_cover_item = $child;
            break;
          }
        }
        item::make_album_cover($new_cover_item);
      } else {
        item::remove_album_cover($parent);
      }
    }

    $source->move_to($target);

    // If the target has no cover item, make this it.
    if ($target->album_cover_item_id == null)  {
      item::make_album_cover($source);
    }
  }

  static function make_album_cover($item) {
    $parent = $item->parent();
    access::required("view", $item);
    access::required("view", $parent);
    access::required("edit", $parent);

    model_cache::clear();
    $parent->album_cover_item_id = $item->is_album() ? $item->album_cover_item_id : $item->id;
    $parent->thumb_dirty = 1;
    $parent->save();
    graphics::generate($parent);
    $grand_parent = $parent->parent();
    if ($grand_parent && $grand_parent->album_cover_item_id == null)  {
      item::make_album_cover($parent);
    }
  }

  static function remove_album_cover($album) {
    access::required("view", $album);
    access::required("edit", $album);
    @unlink($album->thumb_path());

    model_cache::clear();
    $album->album_cover_item_id = null;
    $album->thumb_width = 0;
    $album->thumb_height = 0;
    $album->thumb_dirty = 1;
    $album->save();
    graphics::generate($album);
  }

  static function validate_no_slashes($input) {
    if (strpos($input->value, "/") !== false) {
      $input->add_error("no_slashes", 1);
    }
  }

  static function validate_no_trailing_period($input) {
    if (rtrim($input->value, ".") !== $input->value) {
      $input->add_error("no_trailing_period", 1);
    }
  }

  static function validate_url_safe($input) {
    if (preg_match("/[^A-Za-z0-9-_]/", $input->value)) {
      $input->add_error("not_url_safe", 1);
    }
  }

  /**
   * Sanitize a filename into something presentable as an item title
   * @param string $filename
   * @return string title
   */
  static function convert_filename_to_title($filename) {
    $title = strtr($filename, "_", " ");
    $title = preg_replace("/\..*?$/", "", $title);
    $title = preg_replace("/ +/", " ", $title);
    return $title;
  }

  /**
   * Convert a filename into something we can use as a url component.
   * @param string $filename
   */
  static function convert_filename_to_slug($filename) {
    $result = pathinfo($filename, PATHINFO_FILENAME);
    $result = preg_replace("/[^A-Za-z0-9-_]+/", "-", $result);
    return trim($result, "-");
  }

  /**
   * Display delete confirmation message and form
   * @param object $item
   * @return string form
   */
  static function get_delete_form($item) {
    if (Input::instance()->get("page_type") == "album") {
      $page_type = "album";
    } else {
      $page_type = "photo";
    }
    $form = new Forge(
      "quick/delete/$item->id?page_type=$page_type", "", "post", array("id" => "g-confirm-delete"));
    $form->hidden("_method")->value("put");
    $group = $form->group("confirm_delete")->label(t("Confirm Deletion"));
    $group->submit("")->value(t("Delete"));
    return $form;
  }

  /**
   * Get the next weight value
   */
  static function get_max_weight() {
    // Guard against an empty result when we create the first item.  It's unfortunate that we
    // have to check this every time.
    // @todo: figure out a better way to bootstrap the weight.
    $result = Database::instance()
      ->select("weight")->from("items")
      ->orderby("weight", "desc")->limit(1)
      ->get()->current();
    return ($result ? $result->weight : 0) + 1;
  }

  /**
   * Add a set of restrictions to any following queries to restrict access only to items
   * viewable by the active user.
   * @chainable
   */
  static function viewable($model) {
    $view_restrictions = array();
    if (!identity::active_user()->admin) {
      foreach (identity::group_ids_for_active_user() as $id) {
        // Separate the first restriction from the rest to make it easier for us to formulate
        // our where clause below
        if (empty($view_restrictions)) {
          $view_restrictions[0] = "items.view_$id";
        } else {
          $view_restrictions[1]["items.view_$id"] = access::ALLOW;
        }
      }
    }
    switch (count($view_restrictions)) {
    case 0:
      break;

    case 1:
      $model->where($view_restrictions[0], access::ALLOW);
      break;

    default:
      $model->open_paren();
      $model->where($view_restrictions[0], access::ALLOW);
      $model->orwhere($view_restrictions[1]);
      $model->close_paren();
      break;
    }

    return $model;
  }

  /**
   * Return the root Item_Model
   * @return Item_Model
   */
  static function root() {
    return model_cache::get("item", 1);
  }
}