/**
    * 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.dialog.formdialog;
  
  import static java.util.stream.Collectors.toList;
  import static java.util.stream.StreamSupport.stream;
  
  import info.magnolia.context.Context;
  import info.magnolia.i18nsystem.SimpleTranslator;
  import info.magnolia.ui.dialog.ResurfaceDialogViewImpl;
  import info.magnolia.ui.vaadin.extension.FocusFieldCaption;
  import info.magnolia.ui.vaadin.form.FormSection;
  import info.magnolia.ui.vaadin.form.FormViewReduced;
  import info.magnolia.ui.vaadin.form.field.FieldLayout;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Locale;
  import java.util.Optional;
  import java.util.function.Supplier;
  import java.util.stream.Stream;
  
  import javax.inject.Inject;
  
  import com.vaadin.server.ErrorMessage;
  import com.vaadin.server.Sizeable;
  import com.vaadin.shared.ui.ContentMode;
  import com.vaadin.ui.AbstractComponent;
  import com.vaadin.ui.ComboBox;
  import com.vaadin.ui.Component;
  import com.vaadin.ui.ComponentContainer;
  import com.vaadin.ui.FormLayout;
  import com.vaadin.ui.TabSheet;
  import com.vaadin.ui.themes.ValoTheme;
  import com.vaadin.v7.data.Item;
  import com.vaadin.v7.data.Validatable;
  import com.vaadin.v7.ui.AbstractField;
  import com.vaadin.v7.ui.Field;
  
  /**
   * Resurface, GWT-free form that'll be passed to the DialogBuilder.
   */
  public class ResurfaceFormViewImpl extends ResurfaceDialogViewImpl implements FormView {
  
      private final SimpleTranslator i18n;
      private final Supplier<Locale> userLanguage;
  
      private Item itemDatasource;
  
      private String title;
      private TabSheet tabSheet = new TabSheet();
      private ComboBox<Locale> languageSelector;
      private FormViewReduced.Listener listener;
      private boolean invalidFieldFocused;
  
      @Inject
      public ResurfaceFormViewImpl(SimpleTranslator i18n, Context context) {
          this.i18n = i18n;
          this.userLanguage = context::getLocale;
  
          // TabSheet height must be left undefined or dialogs won't showing their content when dialog's height is auto
          tabSheet.addStyleName("content");
          tabSheet.addStyleName(ValoTheme.TABSHEET_FRAMED);
  
          createLocaleSelector();
          this.setContent(() -> tabSheet);
     }
 
     @Override
     public void setCurrentLocale(Locale locale) {
         this.languageSelector.setValue(locale);
     }
 
     @Override
     public void setAvailableLocales(List<Locale> locales) {
         if (locales != null && !locales.isEmpty()) {
             languageSelector.clear();
             languageSelector.setItems(locales);
             getActionAreaView().setToolbarComponent(languageSelector);
         }
     }
 
     @Override
     public void setItemDataSource(Item newDataSource) {
         this.itemDatasource = newDataSource;
     }
 
     @Override
     public Item getItemDataSource() {
         return this.itemDatasource;
     }
 
     @Override
     public void setCaption(String caption) {
         this.title = caption;
     }
 
     @Override
     public String getTitle() {
         return this.title;
     }
 
     @Override
     public void addField(Field<?> field) {
         // NOOP
     }
 
     @Override
     public void addFormSection(String tabName, FormSection inputFields) {
         final FormLayout formLayout = new FormLayout(new ArrayList<>(inputFields.getComponents())
                 .stream()
                 .map(component -> createFieldLayout(component, inputFields.getComponentHelpDescription(component)))
                 .toArray(Component[]::new)
         );
         formLayout.setMargin(true);
         final TabSheet.Tab tab = this.tabSheet.addTab(formLayout, tabName);
         tab.setId(inputFields.getName());
         FocusFieldCaption.focusCaptionOf(formLayout);
     }
 
     private Component createFieldLayout(Component field, String componentHelpDescription) {
         FieldLayout fieldLayout = FieldLayout.of(field, componentHelpDescription, ((AbstractField) field).isRequired());
         fieldLayout.setCaption(field.getCaption());
         return fieldLayout;
     }
 
     @Override
     public void showValidation(boolean isVisible) {
         invalidFieldFocused = false;
         getComponents().forEach(field -> {
             FieldLayout fieldLayout = null;
             if (field instanceof FieldLayout) {
                 fieldLayout = (FieldLayout) field;
                 field = fieldLayout.getField();
             }
             if (field instanceof AbstractField) {
                 AbstractField abstractField = (AbstractField) field;
                 abstractField.setValidationVisible(isVisible);
                 if (fieldLayout != null) {
                     fieldLayout.getValidationStatusHandler().accept(
                             Optional.ofNullable(abstractField.getErrorMessage())
                                     .map(ErrorMessage::getFormattedHtmlMessage)
                                     .orElse("")
                     );
                     if (!invalidFieldFocused && !abstractField.isValid()) {
                         fieldLayout.focus();
                         invalidFieldFocused = true;
                     }
                 }
             }
         });
     }
 
     @Override
     public void setShowAllEnabled(boolean enabled) {
         // NOOP
     }
 
     @Override
     public void setDescriptionVisibility(boolean isVisible) {
         // NOOP
     }
 
     @Override
     public boolean isValid() {
         return getFields().stream().allMatch(Validatable::isValid);
     }
 
     @Override
     public List<FormSection> getFormSections() {
         return stream(tabSheet.spliterator(), false)
                 .map(component -> new FormSectionAdapter((ComponentContainer) component, tabSheet.getTab(component).getId()))
                 .collect(toList());
     }
 
     @Override
     @Deprecated
     public Collection<Field<?>> getFields() {
         return getComponents()
                 .map(component -> component instanceof FieldLayout ? ((FieldLayout) component).getField() : component)
                 .filter(component -> component instanceof Field)
                 .map(component -> (Field<?>) component)
                 .collect(toList());
     }
 
     private Stream<Component> getComponents() {
         return getFormSections().stream()
                 .flatMap(sections -> sections.getComponents().stream());
     }
 
     @Override
     public void setListener(FormViewReduced.Listener listener) {
         this.listener = listener;
     }
 
     @Override
     public AbstractComponent asVaadinComponent() {
 
         /*
          * When a {@code com.vaadin.ui.TabSheet} is provided, let's check how many
          * {@code com.vaadin.ui.TabSheet.Tab} elements it contains. If only one, only show that.
          */
         if (tabSheet.getComponentCount() == 1) {
             tabSheet.addStyleName("single-tab");
         } else {
             tabSheet.removeStyleName("single-tab");
         }
 
         return tabSheet;
     }
 
     private void createLocaleSelector() {
         languageSelector = new ComboBox<>();
         // Language selector must have width 125px (include padding right 10px)
         languageSelector.setWidth(150, Sizeable.Unit.PIXELS);
         languageSelector.setDescription(i18n.translate("languageSelector.description"), ContentMode.HTML);
         languageSelector.setItemCaptionGenerator(locale -> {
             // display languages in user's preferred locale, not system's
             Locale preferredLocale = userLanguage.get();
             String label = locale.getDisplayLanguage(preferredLocale);
             if (!locale.getDisplayCountry(preferredLocale).isEmpty()) {
                 label += " (" + locale.getDisplayCountry(preferredLocale) + ")";
             }
             return label;
         });
         languageSelector.setEmptySelectionAllowed(false);
         languageSelector.setTextInputAllowed(false);
         languageSelector.addValueChangeListener(event -> {
             if (this.listener != null) {
                 this.listener.localeChanged(event.getValue());
             }
         });
     }
 
     void updateFormView(List<FormSection> sections) {
         tabSheet.removeAllComponents();
         sections.forEach(section -> addFormSection(section.getName(), section));
     }
 
     private final class FormSectionAdapter extends FormSection {
 
         private final ComponentContainer layout;
 
         FormSectionAdapter(ComponentContainer layout, String name) {
             this.layout = layout;
             setName(name);
         }
 
         @Override
         public void setComponentHelpDescription(Component c, String description) {
             getState().helpDescriptions.put(c, description);
         }
 
         @Override
         public String getComponentHelpDescription(Component c) {
             return getState().helpDescriptions.get(c);
         }
 
         @Override
         public void addComponent(Component c) {
             accessTabLayout().addComponent(c);
         }
 
         ComponentContainer accessTabLayout() {
             return layout;
         }
 
         @Override
         public void removeAllComponents() {
             accessTabLayout().removeAllComponents();
         }
 
         @Override
         public void removeComponent(Component c) {
             accessTabLayout().removeComponent(c);
         }
 
         @Override
         public Iterator<Component> iterator() {
             return accessTabLayout().iterator();
         }
 
         @Override
         public int getComponentCount() {
             return accessTabLayout().getComponentCount();
         }
 
         @Override
         public List<Component> getComponents() {
             return stream(accessTabLayout().spliterator(), false).collect(toList());
         }
     }
 }