/**
    * 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.admincentral;
  
  import info.magnolia.event.EventBus;
  import info.magnolia.icons.MagnoliaAppIcon;
  import info.magnolia.icons.MagnoliaIcons;
  import info.magnolia.ui.api.app.AppView;
  import info.magnolia.ui.api.event.AdmincentralEventBus;
  import info.magnolia.ui.api.shell.CloseAppEvent;
  import info.magnolia.ui.api.view.View;
  import info.magnolia.ui.vaadin.extension.CloseIcon;
  
  import javax.inject.Named;
  
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.inject.Inject;
  import com.vaadin.server.KeyMapper;
  import com.vaadin.server.Page;
  import com.vaadin.server.ThemeResource;
  import com.vaadin.shared.Registration;
  import com.vaadin.ui.Component;
  import com.vaadin.ui.Label;
  import com.vaadin.ui.TabSheet;
  import com.vaadin.ui.themes.ValoTheme;
  
  /**
   * The Admincentral app view consists of a plain Vaadin TabSheet component, where each sub-app turns into a new tab..
   *
   * @see info.magnolia.ui.api.app.AppView
   */
  public class AdmincentralAppView implements AppView {
      private static final Logger log = LoggerFactory.getLogger(AdmincentralAppView.class);
  
      // TODO candidate for extraction to ResurfaceTheme constants
      private static final String TABSHEET_APP = "app";
  
      private final TabSheet tabsheet;
  
      private Listener listener;
      private KeyMapper<TabSheet.Tab> mapper = new KeyMapper<>();
  
      @Inject
      public AdmincentralAppView(@Named(AdmincentralEventBus.NAME) EventBus eventBus) {
          TabSheet tabsheet = new TabSheet();
          tabsheet.setSizeFull();
          tabsheet.addStyleNames(ValoTheme.TABSHEET_FRAMED, TABSHEET_APP);
  
          Registration registration = tabsheet.addSelectedTabChangeListener(event -> {
              if (event.isUserOriginated()) {
                  Component selectedTabContent = event.getTabSheet().getSelectedTab();
                  String instanceId = mapper.key(tabsheet.getTab(selectedTabContent));
                  log.debug("FOCUS " + instanceId);
                  listener.onFocus(instanceId);
              }
          });
  
          tabsheet.setCloseHandler((ts, tabContent) -> {
              TabSheet.Tab tab = ts.getTab(tabContent);
              String instanceId = mapper.key(tab);
              log.debug("CLOSE " + instanceId);
  
              // Move to the main tab if active tab is about to be closed
              if (instanceId.equals(getActiveSubAppView())) {
                  tabsheet.setSelectedTab(tabsheet.getTab(0));
             }
 
             // if close handler was set, then tabsheet should remove its tab manually
             ts.removeTab(tab);
             listener.onClose(instanceId);
         });
 
         this.tabsheet = tabsheet;
         CloseIcon.extend(this.tabsheet, () -> {
             // remove listener when closing an app
             // to prevent multiple location change events to be fired by the corresponding sub apps
             // firing those events for each sub app does not make sense because we're closing whole app
             // it is enough to just destroy sub app views and call location changed event only for the parent app
             registration.remove();
             eventBus.fireEvent(new CloseAppEvent());
         });
     }
 
     @Override
     public String addSubAppView(View view, String caption, boolean closable) {
         return addSubAppView(view, caption, "", closable);
     }
 
     @Override
     public String addSubAppView(View view, String caption, String icon, boolean closable) {
         if (view == null) {
             view = () -> new Label("No sub-app view to display");
         }
 
         TabSheet.Tab tab = tabsheet.addTab(view.asVaadinComponent(), caption);
         MagnoliaIcons.forCssClass(icon).ifPresent(tab::setIcon);
 
         tab.setClosable(closable);
         tabsheet.setSelectedTab(tab);
 
         /* TODO check what for and evolve AppView contract */
         return mapper.key(tab);
     }
 
     @Override
     public void setActiveSubAppView(String instanceId) {
         tabsheet.setSelectedTab(mapper.get(instanceId));
     }
 
     @Override
     public String getActiveSubAppView() {
         Component selectedTabContent = tabsheet.getSelectedTab();
         return mapper.key(tabsheet.getTab(selectedTabContent));
     }
 
     @Override
     public void updateCaption(String instanceId, String caption) {
         TabSheet.Tab tab = mapper.get(instanceId);
         tab.setCaption(caption);
     }
 
     @Override
     public void setTheme(String themeName) {
         String stylename = String.format("app-%s", themeName);
         final String themeUrl = String.format("../%s/styles.css", themeName);
 
         final Component vaadinComponent = asVaadinComponent();
         vaadinComponent.addStyleName(stylename);
         final ThemeResource res = new ThemeResource(themeUrl);
 
         if (vaadinComponent.isAttached()) {
             Page.getCurrent().getStyles().add(res);
         } else {
             vaadinComponent.addAttachListener(event -> Page.getCurrent().getStyles().add(res));
         }
     }
 
     @Override
     public void setListener(Listener listener) {
         this.listener = listener;
     }
 
     @Override
     public View getSubAppViewContainer(String instanceId) {
         TabSheet.Tab tab = mapper.get(instanceId);
         return tab::getComponent;
     }
 
     @Override
     public void closeSubAppView(String instanceId) {
         TabSheet.Tab tab = mapper.get(instanceId);
         if (tab != null) {
             tabsheet.removeTab(tab);
         }
     }
 
     @Override
     public void setAppLogo(String logo) {
         TabSheet.Tab mainTab = tabsheet.getTab(0);
         MagnoliaAppIcon.forName(logo)
                 .or(MagnoliaIcons::forCssClass)
                 .or(MagnoliaIcons.APP)
                 .ifPresent(mainTab::setIcon);
     }
 
     @Override
     public void setAppLogo(String logo, String bgcolor) {
         setAppLogo(logo);
     }
 
     // TODO Deprecate?
     @Override
     public void setAppName(String appName) {
         TabSheet.Tab tab = tabsheet.getTab(0);
         if (tab != null && StringUtils.isEmpty(tab.getCaption())) {
             tab.setCaption(appName);
         }
     }
 
     @Override
     public void setTabCaptionsAsHtml() {
         tabsheet.setTabCaptionsAsHtml(true);
     }
 
     @Override
     public TabSheet asVaadinComponent() {
         return tabsheet;
     }
 }