content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you under the Apache License, Version 2.0 (the
   *  "License"); you may not use this file except in compliance
   *  with the License.  You may obtain a copy of the License at
   *
   *        http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing,
   *  software distributed under the License is distributed on an
   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   *  KIND, either express or implied.  See the License for the
   *  specific language governing permissions and limitations
   *  under the License.
   */
  package org.apache.causeway.viewer.wicket.ui.components.table.nav.pagesize;
  
  import java.util.Optional;
  
  import org.apache.wicket.markup.html.form.Button;
  import org.apache.wicket.markup.html.list.ListItem;
  import org.apache.wicket.markup.html.panel.Panel;
  import org.apache.wicket.model.Model;
  
  import org.apache.causeway.applib.services.i18n.TranslationContext;
  import org.apache.causeway.core.metamodel.context.MetaModelContext;
  import org.apache.causeway.viewer.wicket.model.tableoption.PagesizeChoice;
  import org.apache.causeway.viewer.wicket.ui.components.table.DataTableWithPagesAndFilter;
  import org.apache.causeway.viewer.wicket.ui.components.widgets.links.AjaxLinkNoPropagate;
  import org.apache.causeway.viewer.wicket.ui.util.Wkt;
  import org.apache.causeway.viewer.wicket.ui.util.WktLinks;
  import org.apache.causeway.viewer.wicket.ui.util.WktTooltips;
  
  import lombok.Getter;
  import org.jspecify.annotations.NonNull;
  
  public class PagesizeChooser extends Panel {
      private static final long serialVersionUID = 1L;
  
      private static final String ID_PAGESIZE_BUTTON = "pagesizeButton";
      private static final String ID_PAGESIZE_LABEL = "pagesizeLabel";
      private static final String ID_PAGESIZE_CHOICE = "pagesizeChoice";
      private static final String ID_PAGESIZE_CHOICES = "pagesizeChoices";
  
      private static final String ID_VIEW_ITEM_TITLE = "viewItemTitle";
      private static final String ID_VIEW_ITEM_ICON = "viewItemIcon";
      private static final String ID_VIEW_ITEM_CHECKMARK = "viewItemCheckmark"; // indicator for the selected item
  
      @Getter final DataTableWithPagesAndFilter<?, ?> table;
  
      public PagesizeChooser(final String id, final DataTableWithPagesAndFilter<?, ?> table) {
          super(id);
          this.table = table;
      }
  
      @Override
      protected void onInitialize() {
          super.onInitialize();
          buildGui();
      }
  
      // -- HELPER
  
      private void buildGui() {
  
          var button = Wkt.add(this, new Button(ID_PAGESIZE_BUTTON));
  
          Wkt.labelAdd(button, ID_PAGESIZE_LABEL, table.getEntriesPerPageAsLiteral());
  
          Wkt.listViewAdd(this, ID_PAGESIZE_CHOICES, table.getPagesizeChoices(), item->{
              var link = Wkt.linkAdd(item, ID_PAGESIZE_CHOICE, target->{
                  var pagesizeChoice = item.getModelObject();
                  table.setItemsPerPage(pagesizeChoice.itemsPerPage());
                  table.setPageSizeHintAndBroadcast(target);
                  target.add(table);
              });
              // add title and icon to the link
              addIconAndTitle(item, link);
              // add checkmark to the link
              addCheckmark(item, link, table.getCurrentPagesizeChoice());
  
              Wkt.ajaxEnable(link);
          });
  
          WktTooltips.addTooltip(button, translate("How many rows to display per page"));
  
      }
  
      private String translate(final String text) {
          return MetaModelContext.translationServiceOrFallback()
                  .translate(TranslationContext.named("Table"), text);
      }
  
      private static void addIconAndTitle(
              final @NonNull ListItem<PagesizeChoice> item,
              final @NonNull AjaxLinkNoPropagate link) {
          WktLinks.listItemAsDropdownLink(item, link,
                  ID_VIEW_ITEM_TITLE, pagesizeChoice->Model.of(pagesizeChoice.translatedTitle()),
                  ID_VIEW_ITEM_ICON, null,
                  null);
      }
  
      private static void addCheckmark(
              final @NonNull ListItem<PagesizeChoice> item,
              final @NonNull AjaxLinkNoPropagate link,
              final @NonNull Optional<PagesizeChoice> currentPagesizeChoice) {
          var checkmarkForChoice = Wkt.labelAdd(link, ID_VIEW_ITEM_CHECKMARK, "");
  
          // whether the item in this loop is also the currently selected one (is to receive the checkmark)
          var isSelected = currentPagesizeChoice
                  .map(currentChoice->
                      currentChoice.equals(item.getModelObject()))
                  .orElse(false);
          checkmarkForChoice.setVisible(isSelected);
  
          // disable the link when selected
          if(isSelected) {
              link.setEnabled(false);
          }
      }
  
  }
  