/**
    * This file Copyright (c) 2013-2018 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.detail;
  
  import static java.util.Comparator.comparing;
  import static java.util.stream.Collectors.toList;
  
  import info.magnolia.ui.api.i18n.I18NAuthoringSupport;
  import info.magnolia.ui.api.app.SubAppContext;
  import info.magnolia.ui.api.app.SubAppDescriptor;
  import info.magnolia.ui.api.location.DefaultLocation;
  import info.magnolia.ui.api.location.Location;
  import info.magnolia.ui.contentapp.browser.ActionExecutionService;
  import info.magnolia.ui.framework.ContextProperty;
  import info.magnolia.ui.framework.UiFrameworkView;
  import info.magnolia.ui.framework.ViewContext;
  import info.magnolia.ui.framework.app.BaseSubApp;
  import info.magnolia.ui.framework.databinding.ItemProviderStrategy;
  import info.magnolia.ui.framework.databinding.view.EditorView;
  import info.magnolia.ui.framework.databinding.view.FormView;
  
  import java.util.Collections;
  import java.util.List;
  import java.util.Locale;
  
  import javax.inject.Inject;
  
  import org.apache.commons.lang3.StringUtils;
  
  import com.vaadin.ui.Button;
  import com.vaadin.ui.ComboBox;
  import com.vaadin.ui.Component;
  import com.vaadin.ui.CssLayout;
  
  /**
   * Generic form detail subapp.
   *
   * @param <T> item type.
   */
  public class ContentDetailSubApp<T> extends BaseSubApp<ContentDetailSubApp.DetailSubAppView> {
  
      private final DetailDescriptor<T, ?> subAppDescriptor;
      private final I18NAuthoringSupport i18NAuthoringSupport;
      private final ActionExecutionService actionExecutionService;
      private LocationContext locationContext;
      private ItemProviderStrategy<T> itemProviderStrategy;
  
      @Inject
      protected ContentDetailSubApp(SubAppContext subAppContext, I18NAuthoringSupport i18NAuthoringSupport, ActionExecutionService actionExecutionService) {
          super(subAppContext, new DetailSubAppView());
          this.actionExecutionService = actionExecutionService;
          this.subAppDescriptor = (DetailDescriptor<T, ?>) getSubAppContext().getSubAppDescriptor();
          this.i18NAuthoringSupport = i18NAuthoringSupport;
      }
  
      @Override
      public DetailSubAppView start(Location location) {
          super.start(location);
  
          final DetailSubAppView view = getView();
  
          view.bindDatasourceDefinition(subAppDescriptor.getDatasource());
  
          final LocaleContext localeContext = view.bindContext(LocaleContext.class);
          final Locale currentLocale = getSubAppContext().getAuthoringLocale() != null ?
                  getSubAppContext().getAuthoringLocale() :
                  i18NAuthoringSupport.getDefaultLocale();
          localeContext.current().set(currentLocale);
 
         this.locationContext = view.bindContext(LocationContext.class);
         this.locationContext.location().set(DetailLocation.wrap(location));
         //TODO: passed dataSource in order to fetch the RestDataProvider from it.
         this.itemProviderStrategy = view.create(subAppDescriptor.getItemProvider(), subAppDescriptor.getDatasource());
 
         view.bindInstance(SubAppDescriptor.class, this.subAppDescriptor);
         view.bindInstance(ItemProviderStrategy.class, itemProviderStrategy);
 
         final FormView<T> form = (FormView<T>) view.getViewProvider().create(subAppDescriptor.getForm(), subAppDescriptor.getDatasource());
 
         view.bindInstance(EditorView.class, form);
 
         // Wrap it to a layout to support i18n bellow
         final CssLayout content = new CssLayout();
         content.setSizeFull();
         content.addComponent(form.asVaadinComponent());
 
         view.setForm(content);
 
         locationContext.location().observeNullable(l -> itemProviderStrategy.read().ifPresent(form::populate));
         localeContext.current().observeNullable(locale -> {
             content.removeAllComponents();
             content.addComponent(form.getLayout(locale));
         });
 
         // TODO - restore action functionality
 
         return view;
     }
 
     private List<Component> createPrimaryActions() {
         return subAppDescriptor.getActions().entrySet().stream()
                 .map((action) -> {
                     Button button = new Button(action.getKey(), e -> actionExecutionService.executeAction(action.getKey(), action.getValue()));
                     button.addStyleName(action.getKey());
                     return button;
                 })
                 // move commit button to the top
                 .sorted(comparing(button -> button.getStyleName().contains("commit")))
                 .collect(toList());
     }
 
     private Component createLocateSelector(LocaleContext localeContext) {
 
         final ComboBox<Locale> locales = new ComboBox<>();
 
         List<Locale> availableLocales = i18NAuthoringSupport.getAvailableLocales();
         if (availableLocales.isEmpty()) {
             availableLocales = Collections.singletonList(i18NAuthoringSupport.getDefaultLocale());
         }
 
         locales.setItems(availableLocales);
         locales.setItemCaptionGenerator(Locale::getDisplayLanguage);
         locales.setEmptySelectionAllowed(false);
         locales.setSelectedItem(localeContext.current().value().orElse(i18NAuthoringSupport.getDefaultLocale()));
         locales.addValueChangeListener(locale -> localeContext.current().set(locale.getValue()));
 
         return locales;
     }
 
     @Override
     public void locationChanged(Location location) {
         super.locationChanged(location);
         this.locationContext.location().set(DetailLocation.wrap(location));
     }
 
     @Override
     public void stop() {
         getView().destroy();
     }
 
     /**
      * LocationContext.
      */
     public interface LocationContext extends ViewContext {
         //TODO: getLocation();
         ContextProperty<DetailLocation> location();
     }
 
     /**
      * LocaleContext.
      */
     public interface LocaleContext extends ViewContext {
         //TODO: getCurrentLocale();
         ContextProperty<Locale> current();
     }
 
     /**
      * Form view for detail subapp.
      */
     protected static class DetailSubAppView implements UiFrameworkView {
 
         private Component form;
 
         @Override
         public Component asVaadinComponent() {
             return form;
         }
 
         public void setForm(Component form) {
             this.form = form;
         }
     }
 
     /**
      * ItemLocation used by implementations of {@link ContentDetailSubApp}.
      * Extends the Default Location by adding fields for:
      * <ul>
      * <li>the nodePath (some/node/path)</li>
      * <li>the viewType</li>
      * <li>the node version (version)</li>
      * </ul>
      * <p>
      * {@code appType:appName:subAppId;some/node/path:viewType:version}
      */
     public static class DetailLocation extends DefaultLocation {
 
         private String viewType;
         private String nodePath;
         private String version;
         // Position of the parameter based on the ':' used as separator.
         private final static int NODE_PATH_PARAM_POSITION = 0;
         private final static int VIEW_TYPE_PARAM_POSITION = 1;
         private final static int VERSION_PARAM_POSITION = 2;
 
         public DetailLocation(String appName, String subAppId, String parameter) {
             super(LOCATION_TYPE_APP, appName, subAppId, parameter);
 
             setNodePath(extractNodePath(parameter));
             setViewType(extractViewType(parameter));
             setVersion(extractVersion(parameter));
         }
 
         public DetailLocation(String appName, String subAppId, String viewType, String nodePath, String version) {
             super(LOCATION_TYPE_APP, appName, subAppId);
 
             setNodePath(nodePath);
             setViewType(viewType);
             setVersion(version);
             updateParameter();
         }
 
         public String getNodePath() {
             return unescapeSpecialCharacters(nodePath);
         }
 
         /**
          * If the node path is empty, assume root path.
          */
         private void setNodePath(String nodePath) {
             this.nodePath = (nodePath == null || nodePath.isEmpty()) ? "/" : escapeSpecialCharacters(nodePath);
         }
 
         public String getViewType() {
             return viewType;
         }
 
         public void setViewType(String viewType) {
             this.viewType = viewType;
         }
 
         public String getVersion() {
             return unescapeSpecialCharacters(version);
         }
 
         public void setVersion(String version) {
             this.version = escapeSpecialCharacters(version);
         }
 
         public boolean hasVersion() {
             return StringUtils.isNotBlank(version);
         }
 
         /**
          * Extract the Node path from the parameter.
          *
          * @param parameter some/node/path:viewType:version
          * @return some/node/path
          */
         private String extractNodePath(String parameter) {
             return getParameter(parameter, NODE_PATH_PARAM_POSITION);
         }
 
         /**
          * Extract the viewType from the parameter.
          *
          * @param parameter some/node/path:viewType:version
          * @return viewType
          */
         private String extractViewType(String parameter) {
             String action = getParameter(parameter, VIEW_TYPE_PARAM_POSITION);
             return action;
         }
 
         /**
          * Extract the Node Version from the parameter.
          *
          * @param parameter some/node/path:viewType:version
          * @return version
          */
         private String extractVersion(String parameter) {
             return getParameter(parameter, VERSION_PARAM_POSITION);
         }
 
         protected String getParameter(String parameter, int position) {
             String arguments[] = StringUtils.split(parameter, ':');
             if (position <= arguments.length - 1) {
                 return arguments[position];
             }
             return "";
         }
 
         protected void updateParameter() {
             StringBuilder sb = new StringBuilder();
             sb.append(nodePath);
             sb.append(":");
             sb.append(viewType);
             if (StringUtils.isNotBlank(version)) {
                 sb.append(":");
                 sb.append(version);
             }
             super.setParameter(sb.toString());
         }
 
         public static DetailLocation wrap(Location location) {
             return new DetailLocation(location.getAppName(), location.getSubAppId(), location.getParameter());
         }
 
         public void updateNodePath(String newNodePath) {
             setNodePath(newNodePath);
             updateParameter();
         }
 
         public void updateViewtype(String newViewType) {
             setViewType(newViewType);
             updateParameter();
         }
 
         public void updateVersion(String newVersion) {
             setVersion(newVersion);
             updateParameter();
         }
     }
 }