/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.maven.plugins.antrun;
  
  import java.io.BufferedOutputStream;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.Set;
  
  import org.codehaus.plexus.configuration.PlexusConfiguration;
  import org.codehaus.plexus.util.xml.Xpp3DomUtils;
  import org.codehaus.plexus.util.xml.pull.MXSerializer;
  import org.codehaus.plexus.util.xml.pull.XmlSerializer;
  
  /**
   * Write the Ant target Plexus configuration to an XML file.
   */
  class AntrunXmlPlexusConfigurationWriter {
  
      private static final Set<String> EXCLUDED_ATTRIBUTES = new HashSet<>(Arrays.asList(
              Xpp3DomUtils.CHILDREN_COMBINATION_MODE_ATTRIBUTE, Xpp3DomUtils.SELF_COMBINATION_MODE_ATTRIBUTE));
  
      /**
       * @param configuration {@link PlexusConfiguration}
       * @param file File to write the Plexus configuration to.
       * @param customTaskPrefix Prefix to use for the custom Ant tasks. Empty if no prefix should be used.
       * @param antTargetName Name of the default Ant target.
       * @throws IOException In case of problems.
       */
      public void write(PlexusConfiguration configuration, File file, String customTaskPrefix, String antTargetName)
              throws IOException {
          MXSerializer serializer = new MXSerializer();
          serializer.setProperty(
                  "http://xmlpull.org/v1/doc/properties.html#serializer-line-separator",
                  System.getProperty("line.separator"));
          serializer.setProperty("http://xmlpull.org/v1/doc/properties.html#serializer-indentation", "  ");
          try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file))) {
              serializer.setOutput(bos, AntRunMojo.UTF_8);
              serializer.startDocument(AntRunMojo.UTF_8, null);
              if (!customTaskPrefix.isEmpty()) {
                  serializer.setPrefix(customTaskPrefix, AntRunMojo.TASK_URI);
              }
              serializer.startTag(null, "project");
              serializer.attribute(null, "name", "maven-antrun-");
              serializer.attribute(null, "default", antTargetName);
              write(configuration, serializer);
              serializer.endTag(null, "project");
              serializer.endDocument();
          }
      }
  
      private void write(PlexusConfiguration c, XmlSerializer serializer) throws IOException {
          serializer.startTag(null, c.getName());
          writeAttributes(c, serializer);
  
          int count = c.getChildCount();
          if (count == 0) {
              String value = c.getValue();
              if (value != null) {
                  serializer.text(value);
              }
          } else {
              for (int i = 0; i < count; i++) {
                  PlexusConfiguration child = c.getChild(i);
                  write(child, serializer);
              }
          }
  
          serializer.endTag(null, c.getName());
      }
  
      private void writeAttributes(PlexusConfiguration c, XmlSerializer serializer) throws IOException {
          String[] names = c.getAttributeNames();
  
          for (String name : names) {
              if (!EXCLUDED_ATTRIBUTES.contains(name)) {
                  serializer.attribute(null, name, c.getAttribute(name));
              }
          }
      }
 }