/**
    * This file Copyright (c) 2012-2016 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.templating.jsp.taglib;
  
  import info.magnolia.cms.core.Content;
  import info.magnolia.cms.core.HierarchyManager;
  import info.magnolia.cms.core.ItemType;
  import info.magnolia.cms.util.NodeDataUtil;
  import info.magnolia.context.MgnlContext;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.repository.RepositoryConstants;
  
  import java.awt.Graphics2D;
  import java.awt.Image;
  import java.awt.image.BufferedImage;
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Calendar;
  
  import javax.imageio.ImageIO;
  import javax.jcr.AccessDeniedException;
  import javax.jcr.PathNotFoundException;
  import javax.jcr.RepositoryException;
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.JspWriter;
  
  import org.slf4j.LoggerFactory;
  import org.slf4j.Logger;
  
  import org.tldgen.annotations.BodyContent;
  import org.tldgen.annotations.Tag;
  
  /**
   * Creates a scaled copy of an image. The maximum width and height of the images can be specified via the
   * attributes. <br />
   * <br />
   * If the scaled image with the specified name does not exist in the repository, then this tag will create it and save
   * it. If the scaled image already exists, then it will not be recreated. <br />
   * <br />
   * The name of the node that contains the original image is set by the attribute 'parentContentNode', and the name of
   * the nodeData for the image is set by the attribute 'parentNodeDataName'. If 'parentContentNode' is null, the local
   * content node is used. <br />
   * <br />
   * The name of the content node that contains the new scaled image is set by the attribute 'imageContentNodeName'. This
   * node is created under the original image node. This ensures that, if the original images is deleted, so are all the
   * scaled versions. <br />
   * <br />
   * This tag writes out the handle of the content node that contains the image. <br />
   * <br />
   *
   * @jsp.tag name="scaleImage" body-content="empty"
   */
  @Tag(name="scaleImage", bodyContent=BodyContent.EMPTY)
  
  public class ScaleImageTag extends BaseImageTag {
      private static final Logger log = LoggerFactory.getLogger(ScaleImageTag.class);
  
      /**
       * Location for folder for temporary image creation.
       */
      private static final String TEMP_IMAGE_NAME = "tmp-img";
  
      /**
       * The value of the extension nodeData in the properties node.
       */
      private static final String PROPERTIES_EXTENSION_VALUE = "PNG";
 
     /**
      * Attribute: Image maximum height.
      */
     private int maxHeight = 0;
 
     /**
      * Attribute: Image maximum width.
      */
     private int maxWidth = 0;
 
     /**
      * Attribute: Allow resizing images beyond their original dimensions.
      * Enabled by default for backwards compatibility but keep in mind this can
      * result in images of very poor quality.
      */
     private boolean allowOversize = true;
 
     /**
      * Attribute: The name of the new content node to create.
      */
     private String imageContentNodeName;
 
     /**
      * Attribute: The name of the data node that contains the existing image.
      */
     private String parentNodeDataName;
 
     /**
      * The maximum height of the image in pixels.
      * @jsp.attribute required="false" rtexprvalue="true" type="int"
      */
     public void setMaxHeight(int maxHeight) {
         this.maxHeight = maxHeight;
     }
 
     /**
      * The maximum width of the image in pixels.
      * @jsp.attribute required="false" rtexprvalue="true" type="int"
      */
     public void setMaxWidth(int maxWidth) {
         this.maxWidth = maxWidth;
     }
 
     /**
      * Allow resizing images beyond their original dimensions?
      * @jsp.attribute required="false" rtexprvalue="true" type="boolean"
      */
     public void setAllowOversize(boolean allowOversize) {
         this.allowOversize = allowOversize;
     }
 
     /**
      * The name of the content node that contains the image to be copied and scaled.
      * @jsp.attribute required="false" rtexprvalue="true"
      */
     @Override
     public void setParentContentNodeName(String parentContentNodeName) {
         this.parentContentNodeName = parentContentNodeName;
     }
 
     /**
      * The name of the data node that contains the image data to be copied and scaled.
      * @jsp.attribute required="true" rtexprvalue="true"
      */
     public void setParentNodeDataName(String parentNodeDataName) {
         this.parentNodeDataName = parentNodeDataName;
     }
 
     /**
      * The name of the new contentNode that will contain the scaled version of the image.
      * @jsp.attribute required="true" rtexprvalue="true"
      */
     @Override
     public void setImageContentNodeName(String imageContentNodeName) {
         this.imageContentNodeName = imageContentNodeName;
     }
 
     @Override
     public void doTag() throws JspException {
         // initialize everything
         Content parentContentNode;
         Content imageContentNode;
         JspWriter out = this.getJspContext().getOut();
 
         try {
 
             // set the parent node that contains the original image
             if ((this.parentContentNodeName == null) || (this.parentContentNodeName.equals(""))) {
                 parentContentNode = MgnlContext.getAggregationState().getCurrentContent();
             }
             else {
                 HierarchyManager hm = MgnlContext.getHierarchyManager(RepositoryConstants.WEBSITE);
                 // if this name starts with a '/', then assume it is a node handle
                 // otherwise assume that its is a path relative to the local content node
                 if (this.parentContentNodeName.startsWith("/")) {
                     parentContentNode = hm.getContent(this.parentContentNodeName);
                 }
                 else {
                     String handle = MgnlContext.getAggregationState().getCurrentContentNode().getPath();
                     parentContentNode = hm.getContent(handle + "/" + this.parentContentNodeName);
                 }
             }
 
             // check if the new image node exists, if not then create it
             if (parentContentNode.hasContent(this.imageContentNodeName)) {
                 imageContentNode = parentContentNode.getContent(this.imageContentNodeName);
             }
             else {
                 // create the node
                 imageContentNode = parentContentNode.createContent(this.imageContentNodeName, ItemType.CONTENTNODE);
                 parentContentNode.save();
             }
             // if the node does not have the image data or should be rescaled (i.e., something has c
             // then create the image data
             if (!imageContentNode.hasNodeData(this.parentNodeDataName) || rescale(parentContentNode, imageContentNode)) {
                 this.createImageNodeData(parentContentNode, imageContentNode);
             }
             // write out the handle for the new image and exit
             StringBuffer handle = new StringBuffer(imageContentNode.getHandle());
             handle.append("/");
             handle.append(getFilename());
             out.write(handle.toString());
         }
         catch (PathNotFoundException e) {
             log.error("PathNotFoundException occured in ScaleImage tag: {}", e.getMessage(), e);
         }
         catch (AccessDeniedException e) {
             log.error("AccessDeniedException occured in ScaleImage tag: {}", e.getMessage(), e);
         }
         catch (RepositoryException e) {
             log.error("RepositoryException occured in ScaleImage tag: {}", e.getMessage(), e);
         }
         catch (FileNotFoundException e) {
             log.error("FileNotFoundException occured in ScaleImage tag: {}", e.getMessage(), e);
         }
         catch (IOException e) {
             log.error("IOException occured in ScaleImage tag: {}", e.getMessage(), e);
         }
         this.cleanUp();
     }
 
     /**
      * Checks to see if the previously scaled image needs to be rescaled. This is true when the parent content node has
      * been updated or the height or width parameters have changed.
      * @param parentContentNode The node containing the scaled image node
      * @param imageContentNode The scaled image node
      * @return
      */
     protected boolean rescale(Content parentContentNode, Content imageContentNode) {
 
         try {
             Calendar parentModified = NodeTypes.LastModified.getLastModified(parentContentNode.getJCRNode());
             Calendar imageModified = NodeTypes.LastModified.getLastModified(imageContentNode.getJCRNode());
 
             if (parentModified.after(imageModified)) {
                 return true;
             }
         } catch (RepositoryException e) {
             // if we can't determine last modification of the nodes then do the safe thing and go for rescaling
             return true;
         }
 
         int originalHeight = (int) imageContentNode.getNodeData("maxHeight").getLong();
         int originalWidth = (int) imageContentNode.getNodeData("maxWidth").getLong();
 
         return originalHeight != maxHeight || originalWidth != maxWidth;
     }
 
     /**
      * Set objects to null.
      */
     public void cleanUp() {
         this.parentNodeDataName = null;
         this.imageContentNodeName = null;
         this.maxWidth = 0;
         this.maxHeight = 0;
     }
 
     /**
      * Create an image file that is a scaled version of the original image.
      * @param imageContentNode node
      */
     private void createImageNodeData(Content parentContentNode, Content imageContentNode) throws PathNotFoundException,
         RepositoryException, IOException {
 
         // get the original image, as a buffered image
         InputStream oriImgStr = parentContentNode.getNodeData(this.parentNodeDataName).getStream();
         BufferedImage oriImgBuff = ImageIO.read(oriImgStr);
         oriImgStr.close();
         // create the new image file
         File newImgFile = this.scaleImage(oriImgBuff);
 
         NodeDataUtil.getOrCreate(imageContentNode, "maxHeight").setValue(maxHeight);
         NodeDataUtil.getOrCreate(imageContentNode, "maxWidth").setValue(maxWidth);
 
         createImageNode(newImgFile, imageContentNode);
 
         newImgFile.delete();
     }
 
     /**
      * Create an image file that is a scaled version of the original image.
      * @param oriImgBuff the original image file
      * @return the new image file
      */
     private File scaleImage(BufferedImage oriImgBuff) throws IOException {
         // get the dimesnions of the original image
         int oriWidth = oriImgBuff.getWidth();
         int oriHeight = oriImgBuff.getHeight();
         // get scale factor for the new image
         double scaleFactor = this.scaleFactor(oriWidth, oriHeight);
         // get the width and height of the new image
         int newWidth = new Double(oriWidth * scaleFactor).intValue();
         int newHeight = new Double(oriHeight * scaleFactor).intValue();
         // create the thumbnail as a buffered image
         Image newImg = oriImgBuff.getScaledInstance(newWidth, newHeight, Image.SCALE_AREA_AVERAGING);
         BufferedImage newImgBuff = new BufferedImage(
             newImg.getWidth(null),
             newImg.getHeight(null),
             BufferedImage.TYPE_INT_RGB);
         Graphics2D g = newImgBuff.createGraphics();
         g.drawImage(newImg, 0, 0, null);
         g.dispose();
         // create the new image file in the temporary dir
         File newImgFile = File.createTempFile(TEMP_IMAGE_NAME, PROPERTIES_EXTENSION_VALUE);
 
         ImageIO.write(newImgBuff, PROPERTIES_EXTENSION_VALUE, newImgFile);
         // return the file
         return newImgFile;
     }
 
     /**
      * Calculate the scale factor for the image.
      * @param originalWidth the image width
      * @param originalHeight the image height
      * @return the scale factor
      */
     private double scaleFactor(int originalWidth, int originalHeight) {
         double scaleFactor;
 
         int scaleWidth = this.maxWidth;
         int scaleHeight = this.maxHeight;
 
         if (!this.allowOversize) {
             scaleWidth = Math.min(this.maxWidth, originalWidth);
             scaleHeight = Math.min(this.maxHeight, originalHeight);
         }
 
         if (scaleWidth <= 0 && scaleHeight <= 0) {
             // may a copy at the same size
             scaleFactor = 1;
         }
         else if (scaleWidth <= 0) {
             // use height
             scaleFactor = (double) scaleHeight / (double) originalHeight;
         }
         else if (scaleHeight <= 0) {
             // use width
             scaleFactor = (double) scaleWidth / (double) originalWidth;
         }
         else {
             // create two scale factors, and see which is smaller
             double scaleFactorWidth = (double) scaleWidth / (double) originalWidth;
             double scaleFactorHeight = (double) scaleHeight / (double) originalHeight;
             scaleFactor = Math.min(scaleFactorWidth, scaleFactorHeight);
         }
         return scaleFactor;
     }
 
     @Override
     protected String getFilename() {
         return this.parentNodeDataName;
     }
 }