/*
    * 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.pdf;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.Reader;
  import java.io.StringReader;
  import java.util.Locale;
  import java.util.Properties;
  
  import org.apache.maven.doxia.document.DocumentModel;
  import org.apache.maven.doxia.document.io.xpp3.DocumentXpp3Reader;
  import org.apache.maven.plugin.logging.Log;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.shared.utils.io.FileUtils;
  import org.codehaus.plexus.interpolation.EnvarBasedValueSource;
  import org.codehaus.plexus.interpolation.InterpolationException;
  import org.codehaus.plexus.interpolation.Interpolator;
  import org.codehaus.plexus.interpolation.MapBasedValueSource;
  import org.codehaus.plexus.interpolation.ObjectBasedValueSource;
  import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
  import org.codehaus.plexus.util.IOUtil;
  import org.codehaus.plexus.util.ReaderFactory;
  import org.codehaus.plexus.util.introspection.ReflectionValueExtractor;
  import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
  
  /**
   * Read and filter a DocumentModel from a document descriptor file.
   *
   * @author ltheussl
   */
  public class DocumentDescriptorReader {
      /** A MavenProject to extract additional info. */
      private final MavenProject project;
  
      /** Used to log the interpolated document descriptor. */
      private final Log log;
  
      private final Locale locale;
  
      /**
       * Constructor.
       */
      public DocumentDescriptorReader() {
          this(null, null, null);
      }
  
      /**
       * Constructor.
       *
       * @param project may be null.
       */
      public DocumentDescriptorReader(final MavenProject project) {
          this(project, null, null);
      }
  
      /**
       * Constructor.
       *
       * @param project may be null.
       * @param log may be null.
       */
      public DocumentDescriptorReader(final MavenProject project, final Log log, final Locale locale) {
          this.project = project;
          this.log = log;
          this.locale = locale;
      }
  
      /**
       * Read and filter the <code>docDescriptor</code> file.
       *
       * @param docDescriptor not null, corresponding to non-localized descriptor file.
       * @return a DocumentModel instance.
       * @throws XmlPullParserException if an error occurs during parsing.
       * @throws IOException if an error occurs during reading.
       */
      public DocumentModel readAndFilterDocumentDescriptor(File docDescriptor)
              throws XmlPullParserException, IOException {
          if (locale != null) {
              String descriptorFilename = docDescriptor.getName();
              String localized = FileUtils.removeExtension(descriptorFilename)
                      + '_'
                     + locale.getLanguage()
                     + '.'
                     + FileUtils.getExtension(descriptorFilename);
             File localizedDocDescriptor = new File(docDescriptor.getParentFile(), localized);
 
             if (localizedDocDescriptor.exists()) {
                 docDescriptor = localizedDocDescriptor;
             }
         }
 
         try {
             // System properties
             final Properties filterProperties = System.getProperties();
             // Project properties
             if (project != null && project.getProperties() != null) {
                 filterProperties.putAll(project.getProperties());
             }
 
             final Interpolator interpolator = new RegexBasedInterpolator();
             interpolator.addValueSource(new MapBasedValueSource(filterProperties));
             interpolator.addValueSource(new EnvarBasedValueSource());
             interpolator.addValueSource(new ObjectBasedValueSource(project) {
                 /** {@inheritDoc} */
                 public Object getValue(final String expression) {
                     try {
                         return ReflectionValueExtractor.evaluate(expression, project);
                     } catch (Exception e) {
                         addFeedback("Failed to extract '" + expression + "' from: " + project, e);
                     }
 
                     return null;
                 }
             });
 
             final DateBean bean = new DateBean();
             interpolator.addValueSource(new ObjectBasedValueSource(bean));
 
             try (Reader reader = ReaderFactory.newXmlReader(docDescriptor)) {
                 final String interpolatedDoc = interpolator.interpolate(IOUtil.toString(reader));
 
                 if (log != null && log.isDebugEnabled()) {
                     log.debug("Interpolated document descriptor (" + docDescriptor.getAbsolutePath() + ")\n"
                             + interpolatedDoc);
                 }
 
                 // No Strict
                 return new DocumentXpp3Reader().read(new StringReader(interpolatedDoc), false);
             }
         } catch (InterpolationException e) {
             throw new IOException("Error interpolating document descriptor", e);
         }
     }
 }