/*
    *    Copyright 2009-2022 the original author or authors.
    *
    *    Licensed under the Apache License, Version 2.0 (the "License");
    *    you may not use this file except in compliance with the License.
    *    You may obtain a copy of the License at
    *
    *       http://www.apache.org/licenses/LICENSE-2.0
    *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   */
  package com.googlecode.htmlcompressor.velocity;
  
  import com.googlecode.htmlcompressor.compressor.XmlCompressor;
  
  import java.io.IOException;
  import java.io.StringWriter;
  import java.io.Writer;
  
  import org.apache.velocity.context.InternalContextAdapter;
  import org.apache.velocity.exception.MethodInvocationException;
  import org.apache.velocity.exception.TemplateInitException;
  import org.apache.velocity.runtime.RuntimeServices;
  import org.apache.velocity.runtime.directive.Directive;
  import org.apache.velocity.runtime.parser.node.Node;
  
  /**
   * Velocity directive that compresses an XML content within #compressXml ... #end block. Compression parameters are set
   * by default.
   *
   * @author <a href="mailto:serg472@gmail.com">Sergiy Kovalchuk</a>
   *
   * @see XmlCompressor
   */
  public class XmlCompressorDirective extends Directive {
  
      /** The Constant xmlCompressor. */
      private static final XmlCompressor xmlCompressor = new XmlCompressor();
  
      @Override
      public String getName() {
          return "compressXml";
      }
  
      @Override
      public int getType() {
          return BLOCK;
      }
  
      @Override
      public void init(RuntimeServices rs, InternalContextAdapter context, Node node) throws TemplateInitException {
          super.init(rs, context, node);
          log = rs.getLog();
  
          // set compressor properties
          xmlCompressor.setEnabled(rs.getBoolean("userdirective.compressXml.enabled", true));
          xmlCompressor.setRemoveComments(rs.getBoolean("userdirective.compressXml.removeComments", true));
          xmlCompressor.setRemoveIntertagSpaces(rs.getBoolean("userdirective.compressXml.removeIntertagSpaces", true));
      }
  
      @Override
      public boolean render(InternalContextAdapter context, Writer writer, Node node)
              throws IOException, MethodInvocationException {
  
          // render content
          StringWriter content = new StringWriter();
          node.jjtGetChild(0).render(context, content);
  
          // compress
          try {
              writer.write(xmlCompressor.compress(content.toString()));
          } catch (Exception e) {
              writer.write(content.toString());
              String msg = "Failed to compress content: " + content.toString();
              log.error(msg, e);
              throw new RuntimeException(msg, e);
  
          }
          return true;
  
      }
  
  }