/**
    * This file Copyright (c) 2014-2016 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.transformer.item;
  
  import info.magnolia.cms.beans.runtime.FileProperties;
  import info.magnolia.cms.core.Path;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.objectfactory.Components;
  import info.magnolia.ui.form.field.definition.BasicUploadFieldDefinition;
  import info.magnolia.ui.form.field.transformer.Transformer;
  import info.magnolia.ui.form.field.upload.UploadReceiver;
  import info.magnolia.ui.vaadin.integration.jcr.AbstractJcrNodeAdapter;
  import info.magnolia.ui.vaadin.integration.jcr.DefaultProperty;
  import info.magnolia.ui.vaadin.integration.jcr.JcrNewNodeAdapter;
  import info.magnolia.ui.vaadin.integration.jcr.JcrNodeAdapter;
  
  import java.io.FileInputStream;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.List;
  import java.util.Locale;
  
  import javax.inject.Inject;
  import javax.jcr.Binary;
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.jackrabbit.JcrConstants;
  import org.apache.jackrabbit.value.BinaryImpl;
  import org.apache.jackrabbit.value.ValueFactoryImpl;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.vaadin.data.Item;
  import com.vaadin.data.Property;
  
  /**
   * Implementation of a {@link Transformer} that handle a Binary Item instead of a simple property.<br>
   * 
   * @param <T> property type used by the related field.
   */
  public class FileTransformer<T extends UploadReceiver> implements Transformer<T> {
  
      private static final Logger log = LoggerFactory.getLogger(FileTransformer.class);
  
      protected Item relatedFormItem;
      protected final BasicUploadFieldDefinition definition;
      protected final Class<T> type;
      private Locale locale;
      // item name
      protected String basePropertyName;
      // i18n item name
      protected String i18NPropertyName;
  
      @Inject
      public FileTransformer(Item relatedFormItem, BasicUploadFieldDefinition definition, Class<T> type) {
          this.definition = definition;
          this.relatedFormItem = relatedFormItem;
          this.type = type;
          this.basePropertyName = getBasePropertyName();
          if (hasI18NSupport()) {
              this.i18NPropertyName = this.basePropertyName;
          }
      }
 
     /**
      * Base on the validity of the received property, populate or not the property to the related Item.<br>
      * Call {@link FileTransformer#populateItem(Object, Item)} in case {@link FileTransformer#isValid(Object, Item)} return true. <br>
      * Otherwise call {@link FileTransformer#handleInvalid(Object, Item)}.
      */
     @Override
     public void writeToItem(T newValue) {
         Item item = getOrCreateFileItem();
         if (isValid(newValue, item)) {
             populateItem(newValue, item);
             getRootItem().addChild((AbstractJcrNodeAdapter) item);
         } else {
             handleInvalid(newValue, item);
         }
     }
 
     /**
      * Get the stored Item, and based of this Item, return {@link FileTransformer#createPropertyFromItem(Item)} .
      */
     @Override
     public T readFromItem() {
         // Initialize the child node list
         JcrNodeAdapter rootItem = getRootItem();
         // The root Item was never populated, add relevant child Item based on the stored nodes.
         if (!rootItem.hasChildItemChanges()) {
             populateStoredChildItems(rootItem);
         }
         // Get or create the file item.
         Item item = getOrCreateFileItem();
         return createPropertyFromItem(item);
     }
 
     /**
      * @return the existing Item otherwise create an empty new Item.
      */
     protected Item getOrCreateFileItem() {
         String itemName = getItemName();
         Item child = getRootItem().getChild(itemName);
         if (child != null) {
             return child;
         }
         Node node = null;
         try {
             node = getRootItem().getJcrItem();
             if (node.hasNode(itemName) && !(getRootItem() instanceof JcrNewNodeAdapter)) {
                 child = new JcrNodeAdapter(node.getNode(itemName));
             } else {
                 child = new JcrNewNodeAdapter(node, NodeTypes.Resource.NAME, itemName);
             }
         } catch (RepositoryException e) {
             log.error("Could get or create a child Item for {} ", NodeUtil.getPathIfPossible(node), e);
         }
         return child;
     }
 
     /**
      * Based on the i18n information, define the item name to use.
      */
     protected String getItemName() {
         if (hasI18NSupport()) {
             return this.i18NPropertyName;
         }
         return this.basePropertyName;
     }
 
     /**
      * @return related property initialized based on the Item.
      */
     public T createPropertyFromItem(Item item) {
         T uploadReceiver = initializeUploadReceiver();
 
         // Set File if the binary Item has data
         if (item.getItemProperty(JcrConstants.JCR_DATA) != null && item.getItemProperty(JcrConstants.JCR_DATA).getValue() != null) {
             String fileName = item.getItemProperty(FileProperties.PROPERTY_FILENAME) != null ? (String) item.getItemProperty(FileProperties.PROPERTY_FILENAME).getValue() : "";
             String MIMEType = item.getItemProperty(FileProperties.PROPERTY_CONTENTTYPE) != null ? String.valueOf(item.getItemProperty(FileProperties.PROPERTY_CONTENTTYPE).getValue()) : "";
             OutputStream out = uploadReceiver.receiveUpload(fileName, MIMEType);
             InputStream in;
             try {
                 in = ((BinaryImpl) item.getItemProperty(JcrConstants.JCR_DATA).getValue()).getStream();
                 IOUtils.copy(in, out);
                 IOUtils.closeQuietly(in);
                 IOUtils.closeQuietly(out);
             } catch (Exception e) {
                 e.printStackTrace();
             }
 
         }
         return uploadReceiver;
     }
 
     protected T initializeUploadReceiver() {
         return (T) Components.newInstance(UploadReceiver.class, Path.getTempDirectory());
     }
 
     /**
      * @return true it the 'newValue' property is valid for being populated to the Item {@link FileTransformer#populateItem(Object, Item)}.
      */
     protected boolean isValid(T newValue, Item item) {
         return newValue != null && !newValue.isEmpty();
     }
 
     /**
      * Populate the related Item with the values of 'newItem' in case {@link FileTransformer#isValid(Object, Item)} return true.<br>
      * 
      * @see {@link FileTransformer#writeToItem(Object)}.
      */
     public Item populateItem(T newValue, Item item) {
         // Populate Data
         Property<Binary> data = getOrCreateProperty(item, JcrConstants.JCR_DATA, Binary.class);
         if (newValue != null) {
             try {
                 data.setValue(ValueFactoryImpl.getInstance().createBinary(new FileInputStream(newValue.getFile())));
             } catch (Exception re) {
                 log.error("Could not get Binary. Upload will not be performed", re);
                 getRootItem().removeChild((AbstractJcrNodeAdapter) item);
                 return null;
             }
         }
         getOrCreateProperty(item, FileProperties.PROPERTY_FILENAME, String.class).setValue(newValue.getFileName());
         getOrCreateProperty(item, FileProperties.PROPERTY_CONTENTTYPE, String.class).setValue(newValue.getMimeType());
         getOrCreateProperty(item, FileProperties.PROPERTY_LASTMODIFIED, Date.class).setValue(new Date());
         getOrCreateProperty(item, FileProperties.PROPERTY_SIZE, Long.class).setValue(newValue.getFileSize());
         getOrCreateProperty(item, FileProperties.PROPERTY_EXTENSION, String.class).setValue(newValue.getExtension());
         return item;
     }
 
     /**
      * Handle the related Item in case {@link FileTransformer#isValid(Object, Item)} return false.<br>
      * 
      * @see {@link FileTransformer#writeToItem(Object)}.
      */
     protected void handleInvalid(T newValue, Item item) {
         if (((AbstractJcrNodeAdapter) item).getParent() != null) {
             ((AbstractJcrNodeAdapter) item).getParent().removeChild((AbstractJcrNodeAdapter) item);
         }
     }
 
     /**
      * Get the required property from the Item, or create it if it does not exist.
      */
     protected Property getOrCreateProperty(Item item, String propertyName, Class<?> type) {
         if (item.getItemProperty(propertyName) == null) {
             item.addItemProperty(propertyName, new DefaultProperty(type, null));
         }
         return item.getItemProperty(propertyName);
     }
 
     /**
      * Defines the root item used to retrieve and create child items.
      */
     protected JcrNodeAdapter getRootItem() {
         return (JcrNodeAdapter) relatedFormItem;
     }
 
     /**
      * Populates the given root item with its child items.
      */
     protected void populateStoredChildItems(JcrNodeAdapter rootItem) {
         List<Node> childNodes = getStoredChildNodes(rootItem);
         for (Node child : childNodes) {
             JcrNodeAdapter item = new JcrNodeAdapter(child);
             item.setParent(rootItem);
             item.getParent().addChild(item);
         }
     }
 
     /**
      * Fetches child nodes of the given parent from JCR, filtered using the {@link NodeUtil#MAGNOLIA_FILTER} predicate.
      */
     protected List<Node> getStoredChildNodes(JcrNodeAdapter parent) {
         try {
             if (!(parent instanceof JcrNewNodeAdapter) && parent.getJcrItem().hasNodes()) {
                 return NodeUtil.asList(NodeUtil.getNodes(parent.getJcrItem(), NodeUtil.MAGNOLIA_FILTER));
             }
         } catch (RepositoryException re) {
             log.warn("Not able to access the Child Nodes of the following Node Identifier {}", parent.getItemId(), re);
         }
         return new ArrayList<Node>();
     }
 
     @Override
     public String getBasePropertyName() {
         return this.definition.getBinaryNodeName();
     }
 
     @Override
     public Class<T> getType() {
         return this.type;
     }
 
 
     /* I18nAwareHandler impl */
 
     @Override
     public boolean hasI18NSupport() {
         return definition.isI18n();
     }
 
     @Override
     public void setLocale(Locale locale) {
         this.locale = locale;
     }
 
     @Override
     public void setI18NPropertyName(String i18nPropertyName) {
         this.i18NPropertyName = i18nPropertyName;
     }
 
     @Override
     public Locale getLocale() {
         return this.locale;
     }
 
 }