/*
    * 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.site.descriptor;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.StringWriter;
  import java.io.Writer;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.maven.doxia.site.SiteModel;
  import org.apache.maven.doxia.site.io.xpp3.SiteXpp3Writer;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.codehaus.plexus.util.xml.PrettyPrintXMLWriter;
  import org.codehaus.plexus.util.xml.XMLWriter;
  import org.codehaus.plexus.util.xml.XmlStreamWriter;
  import org.codehaus.plexus.util.xml.XmlWriterUtil;
  
  /**
   * Displays the effective site descriptor as an XML for this build, after inheritance and interpolation of
   * <code>site.xml</code>, for the first locale.
   *
   * @author <a href="mailto:hboutemy@apache.org">Hervé Boutemy</a>
   *
   * @since 2.2
   */
  @Mojo(name = "effective-site", requiresReports = true)
  public class EffectiveSiteMojo extends AbstractSiteDescriptorMojo {
      /**
       * Optional parameter to write the output of this help in a given file, instead of writing to the console.
       * <p>
       * <b>Note</b>: Could be a relative path.
       * </p>
       */
      @Parameter(property = "output")
      protected File output;
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void execute() throws MojoExecutionException, MojoFailureException {
          SiteModel siteModel = prepareSiteModel(getLocales().get(0));
  
          StringWriter w = new StringWriter();
          XMLWriter writer = new PrettyPrintXMLWriter(
                  w, StringUtils.repeat(" ", XmlWriterUtil.DEFAULT_INDENTATION_SIZE), siteModel.getModelEncoding(), null);
  
          writeHeader(writer);
  
          writeEffectiveSite(siteModel, writer);
  
          String effectiveSite = w.toString();
  
          if (output != null) {
              try {
                  writeXmlFile(output, effectiveSite);
              } catch (IOException e) {
                  throw new MojoExecutionException("Cannot write effective site descriptor to output: " + output, e);
              }
  
              if (getLog().isInfoEnabled()) {
                  getLog().info("Effective site descriptor written to: " + output);
              }
          } else {
              StringBuilder message = new StringBuilder();
  
              message.append("\nEffective site descriptor, after inheritance and interpolation:\n\n");
              message.append(effectiveSite);
              message.append("\n");
  
              if (getLog().isInfoEnabled()) {
                  getLog().info(message.toString());
              }
          }
      }
  
      /**
       * 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 Site Plugin");
         XmlWriterUtil.writeComment(writer, "See: https://maven.apache.org/plugins/maven-site-plugin/");
         XmlWriterUtil.writeComment(writer, " ");
         XmlWriterUtil.writeCommentLineBreak(writer);
 
         XmlWriterUtil.writeLineBreak(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);
 
         XmlWriterUtil.writeLineBreak(writer);
     }
 
     private void writeEffectiveSite(SiteModel siteModel, XMLWriter writer) throws MojoExecutionException {
         String effectiveSite;
 
         StringWriter sWriter = new StringWriter();
         SiteXpp3Writer siteWriter = new SiteXpp3Writer();
         try {
             siteWriter.write(sWriter, siteModel);
         } catch (IOException e) {
             throw new MojoExecutionException("Cannot serialize site descriptor to XML", e);
         }
 
         effectiveSite = sWriter.toString();
         // remove XML prolog
         int xmlPrologStart = effectiveSite.indexOf("<?xml");
         int xmlPrologEnd = effectiveSite.indexOf("?>", xmlPrologStart);
         effectiveSite = effectiveSite.substring(xmlPrologEnd + 2).trim();
 
         writeComment(writer, "Effective site descriptor for project \'" + project.getId() + "\'");
 
         writer.writeMarkup(effectiveSite);
     }
 
     protected static void writeXmlFile(File output, String content) throws IOException {
         try (Writer out = new XmlStreamWriter(output)) {
             output.getParentFile().mkdirs();
 
             out.write(content);
         }
     }
 }