/**
    * This file Copyright (c) 2018 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.ui.contentapp.browser;
  
  import static java.util.stream.Collectors.toSet;
  
  import info.magnolia.ui.api.app.SubAppContext;
  import info.magnolia.ui.contentapp.ContentBrowserSubApp;
  import info.magnolia.ui.contentapp.browser.actions.ActionbarView;
  import info.magnolia.ui.contentapp.configuration.BrowserDescriptor;
  import info.magnolia.ui.contentapp.configuration.WorkbenchDefinition;
  import info.magnolia.ui.framework.ContextProperty;
  import info.magnolia.ui.UIComponent;
  import info.magnolia.ui.ValueContext;
  import info.magnolia.ui.ViewDefinition;
  import info.magnolia.ui.datasource.ItemResolver;
  import info.magnolia.ui.datasource.DatasourceDefinition;
  import info.magnolia.ui.observation.DatasourceObservation;
  
  import java.util.Collection;
  import java.util.Objects;
  import java.util.Optional;
  
  import javax.inject.Inject;
  
  import org.apache.commons.lang3.StringUtils;
  
  import com.vaadin.ui.Composite;
  import com.vaadin.ui.HorizontalLayout;
  import com.vaadin.ui.VerticalLayout;
  
  /**
   * View part of the new browser sub-app.
   *
   * @param <T> item type.
   * @param <DS> data source definition type.
   */
  public class Browser<T, DS extends DatasourceDefinition> extends Composite implements UIComponent {
  
      private final ContextProperty<ContentBrowserSubApp.BrowserLocation> location;
      private final SubAppContext subAppContext;
      private final ItemResolver<T> itemResolver;
  
      @Inject
      public Browser(
              ValueContext<T> valueContext,
              ContentBrowserSubApp.LocationContext locationContext,
              BrowserDescriptor<T, DS> descriptor,
              DatasourceObservation observation,
              ItemInteractionAvailability<T> interactionAvailability,
              SubAppContext subAppContext,
              ItemResolver<T> itemResolver) {
          this.subAppContext = subAppContext;
          this.itemResolver = itemResolver;
          this.location = locationContext.location();
  
          observation.register(() -> valueContext.current().update(currentValue -> {
              return currentValue.stream().filter(interactionAvailability::isItemAvailable).collect(toSet());
          }));
  
          valueContext.observe(selectedItems -> {
              if (!location.value().isPresent()) {
                  return;
              }
  
              location.update(location -> {
                  pushItemPathIntoLocation(selectedItems, location);
              });
         });
 
         location.observe(locationOptional -> locationOptional.ifPresent(location -> {
                     Optional<String> currentPath = valueContext.getSingle().map(itemResolver::getId);
                     String newPath = location.getNodePath();
                     if (currentPath.map(path -> !Objects.equals(path, newPath)).orElse(StringUtils.isNotBlank(newPath))) {
                         itemResolver.getItemById(newPath).ifPresent(valueContext::set);
                     }
                 })
         );
 
         layout(descriptor);
     }
 
     private void pushItemPathIntoLocation(Collection<T> selectedItems, ContentBrowserSubApp.BrowserLocation location) {
         location.updateNodePath(selectedItems.stream().findFirst().map(itemResolver::getId).orElse(""));
         updateLocation(location);
     }
 
     private void updateLocation(ContentBrowserSubApp.BrowserLocation location) {
         subAppContext.getAppContext().updateSubAppLocation(subAppContext, location);
     }
 
     void layout(BrowserDescriptor<T, DS> descriptor) {
         final HorizontalLayout workbenchWrapper = new HorizontalLayout();
         workbenchWrapper.setSizeFull();
 
         WorkbenchDefinition<T> workbenchDefinition = descriptor.getWorkbench();
         Workbench<T> workbench = create("workbench", workbenchDefinition);
 
         workbench.onContentViewTypeChange(viewId -> location.update(location -> {
             location.updateViewType(viewId);
         }));
 
         workbench.setTitle(descriptor.getLabel());
 
         workbenchWrapper.addComponentsAndExpand(workbench);
         workbenchWrapper.addComponents(create("actionbar", ActionbarView.class, descriptor.getActionbar()));
 
         StatusBar<T> statusBar = create(
                 ViewDefinition.<StatusBar<T>>builder()
                         .withName("statusbar")
                         .withImplementationClass(StatusBar.class)
                         .build());
 
         VerticalLayout browser = new VerticalLayout(workbenchWrapper, statusBar.asVaadinComponent());
         browser.setSizeFull();
         browser.setSpacing(false);
         browser.setMargin(false);
         browser.setExpandRatio(workbenchWrapper, 1f);
         browser.setExpandRatio(statusBar.asVaadinComponent(), 0);
         browser.addStyleName("browser");
 
         setCompositionRoot(browser);
         setSizeFull();
     }
 
     public void setLocation(ContentBrowserSubApp.BrowserLocation location) {
         this.location.set(location);
     }
 }