/*
    * 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.help;
  
  import javax.xml.XMLConstants;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.StringReader;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Properties;
  import java.util.Set;
  
  import org.codehaus.plexus.util.WriterFactory;
  import org.codehaus.plexus.util.xml.XMLWriter;
  import org.codehaus.plexus.util.xml.XmlWriterUtil;
  import org.jdom2.Document;
  import org.jdom2.JDOMException;
  import org.jdom2.input.SAXBuilder;
  import org.jdom2.output.Format;
  import org.jdom2.output.XMLOutputter;
  
  /**
   * Base class with common utilities to write effective Pom/settings.
   *
   * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
   * @since 2.1
   */
  public abstract class AbstractEffectiveMojo extends AbstractHelpMojo {
      /**
       * Utility method to write an XML content in a given file.
       *
       * @param output is the wanted output file.
       * @param content contains the XML content to be written to the file.
       * @throws IOException if any
       * @see AbstractHelpMojo#writeFile(File, String) if encoding is null.
       */
      protected static void writeXmlFile(File output, String content) throws IOException {
          if (output == null) {
              return;
          }
  
          output.getParentFile().mkdirs();
          try (Writer out = WriterFactory.newXmlWriter(output)) {
              out.write(content);
          }
      }
  
      /**
       * Write comments in the Effective POM/settings header.
       *
       * @param writer not null
       */
      protected static void writeHeader(XMLWriter writer) {
          XmlWriterUtil.writeCommentLineBreak(writer);
          XmlWriterUtil.writeComment(writer, " ");
          XmlWriterUtil.writeComment(writer, "Generated by Maven Help Plugin");
          XmlWriterUtil.writeComment(writer, "See: https://maven.apache.org/plugins/maven-help-plugin/");
          XmlWriterUtil.writeComment(writer, " ");
          XmlWriterUtil.writeCommentLineBreak(writer);
      }
  
      /**
       * Write comments in a normalize way.
       *
       * @param writer not null
       * @param comment not null
       */
      protected static void writeComment(XMLWriter writer, String comment) {
          XmlWriterUtil.writeCommentLineBreak(writer);
          XmlWriterUtil.writeComment(writer, " ");
          XmlWriterUtil.writeComment(writer, comment);
          XmlWriterUtil.writeComment(writer, " ");
          XmlWriterUtil.writeCommentLineBreak(writer);
      }
  
      /**
       * @param effectiveModel not null
      * @param encoding not null
      * @param omitDeclaration whether the XML declaration should be omitted from the effective pom
      * @return pretty format of the xml or the original {@code effectiveModel} if an error occurred.
      */
     protected static String prettyFormat(String effectiveModel, String encoding, boolean omitDeclaration) {
         SAXBuilder builder = new SAXBuilder();
         builder.setProperty(XMLConstants.ACCESS_EXTERNAL_DTD, "");
         builder.setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "");
         try {
             Document effectiveDocument = builder.build(new StringReader(effectiveModel));
 
             StringWriter w = new StringWriter();
             Format format = Format.getPrettyFormat();
             if (encoding != null) {
                 // This is a design flaw in JDOM, no NPE on null arguments, but null is not prohibited
                 format.setEncoding(encoding);
             }
             format.setLineSeparator(System.lineSeparator());
             format.setOmitDeclaration(omitDeclaration);
             XMLOutputter out = new XMLOutputter(format);
             out.output(effectiveDocument, w);
 
             return w.toString();
         } catch (JDOMException | IOException e) {
             return effectiveModel;
         }
     }
 
     /**
      * Properties which provides a sorted keySet().
      */
     protected static class SortedProperties extends Properties {
         /** serialVersionUID */
         static final long serialVersionUID = -8985316072702233744L;
 
         /** {@inheritDoc} */
         @SuppressWarnings({"rawtypes", "unchecked"})
         @Override
         public Set<Object> keySet() {
             Set<Object> keynames = super.keySet();
             List list = new ArrayList(keynames);
             Collections.sort(list);
 
             return new LinkedHashSet<>(list);
         }
     }
 }