/**
    * This file Copyright (c) 2013-2015 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.form.field.factory;
  
  import static com.google.common.base.Enums.getIfPresent;
  import static org.apache.commons.io.FilenameUtils.getExtension;
  import static org.apache.commons.lang3.StringUtils.isNotBlank;
  import static org.vaadin.aceeditor.AceMode.forFileEnding;
  
  import info.magnolia.context.MgnlContext;
  import info.magnolia.ui.form.field.definition.CodeFieldDefinition;
  
  import org.vaadin.aceeditor.AceEditor;
  import org.vaadin.aceeditor.AceMode;
  
  import com.google.common.base.Optional;
  import com.vaadin.data.Item;
  import com.vaadin.data.Property;
  import com.vaadin.event.FieldEvents.TextChangeEvent;
  import com.vaadin.event.FieldEvents.TextChangeListener;
  import com.vaadin.server.Sizeable.Unit;
  import com.vaadin.ui.Field;
  
  /**
   * Creates and initializes a code field, based on the {@link AceEditor} add-on for Vaadin.
   */
  public class CodeFieldFactory extends AbstractFieldFactory<CodeFieldDefinition, String> {
  
      private static final String FREEMARKER_LANGUAGE = "freemarker";
      private static final String ACE_EDITOR_FTL_ID = "ftl";
      private static final String ACE_EDITOR_RESOURCES = "/.resources/ace/";
  
      private AceEditor field;
  
      public CodeFieldFactory(CodeFieldDefinition definition, Item relatedFieldItem) {
          super(definition, relatedFieldItem);
      }
  
      @Override
      protected Field<String> createFieldComponent() {
          field = newAceEditor();
          // Add a TextChange Listener. This is needed as the current AceEditor implementation do not update the
          // linked datasource in case of text change.
          field.addTextChangeListener(createTextChangeListener(field));
          // Set style
          field.setStyleName("textcodefield");
          field.setUseWorker(false);
  
          return field;
      }
  
      /**
       * @return newly constructed {@link AceEditor}.
       */
      protected AceEditor newAceEditor() {
          AceEditor aceEditor = new AceEditor();
          if (MgnlContext.isWebContext()) {
              String aceEditorResourcePath = MgnlContext.getContextPath() + ACE_EDITOR_RESOURCES;
              aceEditor.setModePath(aceEditorResourcePath);
              aceEditor.setWorkerPath(aceEditorResourcePath);
              aceEditor.setThemePath(aceEditorResourcePath);
          }
          // If language is set, then we don't want to conflict with it.
          if (isNotBlank(definition.getLanguage())) {
              aceEditor.setMode(getModeType(definition.getLanguage()));
          } else if (isNotBlank(definition.getFileNameProperty())) {
              Property<?> fileNameProperty = item.getItemProperty(definition.getFileNameProperty());
              if (fileNameProperty != null) {
                 String fileName = String.valueOf(fileNameProperty.getValue());
                 String extension = getExtension(fileName);
                 AceMode mode = getAceModeByFileExtension(extension);
                 if (mode != null) {
                     aceEditor.setMode(mode);
                 }
             }
         }
         if (definition.getHeight() > 0) {
             aceEditor.setHeight(definition.getHeight(), Unit.PIXELS);
         }
         return aceEditor;
     }
 
     /**
      * Create a {@link TextChangeListener} in order to populate the typed text in the
      * related property datasource.
      */
     private TextChangeListener createTextChangeListener(final AceEditor field) {
         return new TextChangeListener() {
 
             @SuppressWarnings("unchecked")
             @Override
             public void textChange(TextChangeEvent event) {
                 field.getPropertyDataSource().setValue(event.getText());
             }
         };
     }
 
     /**
      * Get Ace-editor compliant mode type name for a language.
      *
      * TODO: currently only 'freemarker' -> 'ftl' case is handled, otherwise the method returns the string from definition.
      * If needed we could craft our own mapping from human-readable language names into the Ace editor mode identifiers.
      */
     private String getModeType(String language) {
         return FREEMARKER_LANGUAGE.equals(language) ? ACE_EDITOR_FTL_ID : language;
     }
 
     /**
      * Get the {@link AceMode} by file extension.
      * <p>
      * First tries to match the given extension against an AceMode value, otherwise looks into AceMode's additional mappings (<code>endingModeMap</code>).
      */
     private AceMode getAceModeByFileExtension(String extension) {
         // Trying the get AceMode from the Enum
         Optional<AceMode> aceModeValue = getIfPresent(AceMode.class, extension);
         if (aceModeValue.isPresent()) {
             return aceModeValue.get();
         } else {
             // Trying to get AceMode from the AceMode.endingModeMap
             AceMode aceMode = forFileEnding(extension);
             return aceMode != null ? aceMode : null;
         }
     }
 
 }