/**
    * 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.security.app.dialog.field;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import com.vaadin.ui.Button;
  import com.vaadin.ui.Component;
  import com.vaadin.v7.data.Property;
  import com.vaadin.v7.data.Validator;
  import com.vaadin.v7.data.util.ObjectProperty;
  import com.vaadin.v7.ui.AbstractField;
  import com.vaadin.v7.ui.CustomField;
  import com.vaadin.v7.ui.Field;
  import com.vaadin.v7.ui.HorizontalLayout;
  import com.vaadin.v7.ui.Label;
  import com.vaadin.v7.ui.VerticalLayout;
  
  /**
   * A field implementation dedicated to access control lists. In effect, this is a multi-value field
   * for {@link AccessControlField AccessControlFields}, supporting addition and removal of entries.
   *
   * <p>New entries are created through the </p>
   */
  public class AccessControlListField extends CustomField<AccessControlList> {
      private final Map<Long, String> permissions;
      private final NewEntryHandler newEntryHandler;
  
      private VerticalLayout layout;
      private List<Field<AccessControlList.Entry>> entryFields = new ArrayList<>();
      private ValueChangeListener valueChangeListener;
  
      private String addButtonCaption = "Add";
      private String removeButtonCaption = "Remove";
      private String emptyPlaceholderCaption = "No access";
      private EntryFieldFactory entryFieldFactory;
  
      /**
       * Creates an AccessControlListField with the given set of permissions.
       *
       * @param permissions a map whose keys are permission values, and whose values are the corresponding captions to display in the permission select.
       * @param newEntryHandler the handler creating actual entries with default values, to append to this field.
       */
      public AccessControlListField(Map<Long, String> permissions, NewEntryHandler newEntryHandler) {
          this.permissions = permissions;
          this.newEntryHandler = newEntryHandler;
      }
  
      @Override
      protected Component initContent() {
          layout = new VerticalLayout();
          layout.setSpacing(false);
  
          AccessControlList<AccessControlList.Entry> acl = getValue();
          List<Component> entryRows = buildEntryRows(acl);
          layout.addComponents(entryRows.toArray(new Component[0]));
  
          if (acl.getEntries().isEmpty()) {
              layout.addComponent(new Label(emptyPlaceholderCaption));
          }
  
          if (newEntryHandler != null) {
              final Button addButton = new Button(addButtonCaption);
              addButton.addClickListener(new Button.ClickListener() {
                  @Override
                  public void buttonClick(Button.ClickEvent event) {
                     AccessControlList.Entry entry = newEntryHandler.createEntry();
                     AccessControlList<AccessControlList.Entry> value = getValue();
                     if (value == null) {
                         value = new AccessControlList<>();
                         setValue(value);
                     }
                     value.addEntry(entry);
 
                     Field<AccessControlList.Entry> entryField = getEntryFieldFactory().createField(entry);
                     // set validation visibility from parent field
                     if (entryField instanceof AbstractField) {
                         ((AbstractField) entryField).setValidationVisible(isValidationVisible());
                     }
 
                     // update layout
                     entryFields.add(entryField);
                     layout.addComponent(buildEntryRow(entryField), layout.getComponentCount() - 1);
                     if (layout.getComponent(0) instanceof Label) {
                         layout.removeComponent(layout.getComponent(0));
                     }
                 }
             });
             layout.addComponent(addButton);
         }
         return layout;
     }
 
     protected List<Component> buildEntryRows(AccessControlList<AccessControlList.Entry> acl) {
         List<Component> entryRows = new ArrayList<>();
         if (acl != null) {
             for (final AccessControlList.Entry entry : acl.getEntries()) {
                 Field<AccessControlList.Entry> entryField = getEntryFieldFactory().createField(entry);
                 // set validation visibility from parent field
                 if (entryField instanceof AbstractField) {
                     ((AbstractField) entryField).setValidationVisible(isValidationVisible());
                 }
 
                 entryFields.add(entryField);
                 entryRows.add(buildEntryRow(entryField));
             }
         }
         return entryRows;
     }
 
     protected Component buildEntryRow(final Field<AccessControlList.Entry> entryField) {
         final HorizontalLayout entryRow = new HorizontalLayout();
         entryRow.setSpacing(true);
         entryRow.setWidth("100%");
 
         Button deleteButton = new Button();
         deleteButton.setHtmlContentAllowed(true);
         deleteButton.setCaption("<span class=\"" + "icon-trash" + "\"></span>");
         deleteButton.addStyleName("inline");
         deleteButton.setDescription(removeButtonCaption);
         deleteButton.addClickListener(new Button.ClickListener() {
 
             @Override
             public void buttonClick(Button.ClickEvent event) {
                 AccessControlList<AccessControlList.Entry> acl = getValue();
                 acl.removeEntry(entryField.getValue());
                 entryFields.remove(entryField);
                 if (isValidationVisible()) {
                     // make sure to re-validate if problematic entry is removed
                     fireValueChange(false);
                 }
 
                 // update layout
                 layout.removeComponent(entryRow);
                 if (acl.getEntries().size() == 0) {
                     layout.addComponentAsFirst(new Label(emptyPlaceholderCaption));
                 }
             }
         });
 
         entryRow.addComponents(entryField, deleteButton);
         entryRow.setExpandRatio(entryField, 1f);
         return entryRow;
     }
 
     public String getAddButtonCaption() {
         return addButtonCaption;
     }
 
     public void setAddButtonCaption(String addButtonCaption) {
         this.addButtonCaption = addButtonCaption;
     }
 
     public String getRemoveButtonCaption() {
         return removeButtonCaption;
     }
 
     public void setRemoveButtonCaption(String removeButtonCaption) {
         this.removeButtonCaption = removeButtonCaption;
     }
 
     public String getEmptyPlaceholderCaption() {
         return emptyPlaceholderCaption;
     }
 
     public void setEmptyPlaceholderCaption(String emptyPlaceholderCaption) {
         this.emptyPlaceholderCaption = emptyPlaceholderCaption;
     }
 
     @Override
     public Class<AccessControlList> getType() {
         return AccessControlList.class;
     }
 
     @Override
     public AccessControlList<AccessControlList.Entry> getValue() {
         return super.getValue();
     }
 
     @Override
     protected void validate(AccessControlList fieldValue) throws Validator.InvalidValueException {
         List<Validator.InvalidValueException> causes = new ArrayList<>();
         // first invoke self-validation
         try {
             super.validate(fieldValue);
         } catch (Validator.InvalidValueException e) {
             causes.add(e);
         }
 
         // then validate individual entries
         for (Field<AccessControlList.Entry> entryField : entryFields) {
             try {
                 entryField.validate();
             } catch (Validator.InvalidValueException e) {
                 causes.add(e);
             }
         }
 
         if (!causes.isEmpty()) {
             // until we display errors on sub-fields, display causes' messages by passing null in first arg
             // see AbstractErrorMessage#getFormattedHtmlMessage
             throw new Validator.InvalidValueException(null, causes.toArray(new Validator.InvalidValueException[0]));
         }
     }
 
     /*
      * Make sure to propagate inner value changes when validation is visible (i.e. field is invalid);
      * so that corrected values are validated on the fly and eventually remove validation marks.
      */
     @Override
     public void setValidationVisible(boolean validateAutomatically) {
         super.setValidationVisible(validateAutomatically);
         for (Field<?> entryField : entryFields) {
             if (entryField instanceof AbstractField) {
                 ((AbstractField) entryField).setValidationVisible(isValidationVisible());
             }
         }
 
         if (validateAutomatically && valueChangeListener == null) {
             valueChangeListener = new ValueChangeListener() {
                 @Override
                 public void valueChange(Property.ValueChangeEvent event) {
                     fireValueChange(false);
                 }
             };
             for (Field<?> entryField : entryFields) {
                 entryField.addValueChangeListener(valueChangeListener);
             }
         } else if (!validateAutomatically && valueChangeListener != null) {
             for (Field<?> entryField : entryFields) {
                 entryField.removeValueChangeListener(valueChangeListener);
             }
             valueChangeListener = null;
         }
     }
 
     public EntryFieldFactory getEntryFieldFactory() {
         if (entryFieldFactory == null) {
             this.entryFieldFactory = new DefaultEntryFieldFactory();
         }
         return entryFieldFactory;
     }
 
     public void setEntryFieldFactory(EntryFieldFactory entryFieldFactory) {
         this.entryFieldFactory = entryFieldFactory;
     }
 
     /**
      * The handler used to create new ACL entries.
      */
     public interface NewEntryHandler {
         /**
          * Creates and returns a new {@link AccessControlList.Entry Entry} to feed into this field's {@linkplain AccessControlList acl} value.
          */
         AccessControlList.Entry createEntry();
     }
 
     /**
      * A factory creating individual fields for ACL entries.
      */
     public interface EntryFieldFactory {
         /**
          * Creates a {@link Field} and binds the given {@link AccessControlList.Entry Entry} to it.
          */
         Field<AccessControlList.Entry> createField(AccessControlList.Entry entry);
     }
 
     /**
      * Default implementation creates a standard AccessControlField with validator.
      */
     public class DefaultEntryFieldFactory implements EntryFieldFactory {
         @Override
         public Field<AccessControlList.Entry> createField(AccessControlList.Entry entry) {
             AccessControlField entryField = new AccessControlField(permissions);
             entryField.setPropertyDataSource(new ObjectProperty<>(entry));
             return entryField;
         }
     }
 }