/*
    * 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.devacfr.maven.skins.reflow.snippet;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.charset.Charset;
  
  import com.google.common.base.Charsets;
  import com.google.common.base.Strings;
  import com.google.common.io.CharSource;
  import com.google.common.io.Files;
  import org.apache.maven.doxia.macro.AbstractMacro;
  import org.apache.maven.doxia.macro.Macro;
  import org.apache.maven.doxia.macro.MacroExecutionException;
  import org.apache.maven.doxia.macro.MacroRequest;
  import org.apache.maven.doxia.sink.Sink;
  import org.codehaus.plexus.PlexusConstants;
  import org.codehaus.plexus.PlexusContainer;
  import org.codehaus.plexus.component.annotations.Component;
  import org.codehaus.plexus.context.Context;
  import org.codehaus.plexus.context.ContextException;
  import org.codehaus.plexus.personality.plexus.lifecycle.phase.Contextualizable;
  import org.jsoup.Jsoup;
  import org.jsoup.nodes.Document;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * @author Christophe Friederich
   * @since 2.4
   */
  @Component(role = Macro.class, hint = "partial")
  public class PartialTemplateMacro extends AbstractMacro implements Contextualizable {
  
      /** */
      @SuppressWarnings("unused")
      private static final Logger LOGGER = LoggerFactory.getLogger(PartialTemplateMacro.class);
  
      /** */
      @SuppressWarnings("unused")
      private PlexusContainer container;
  
      /**
       * in case of Exception during snippet download error will ignored and empty content returned.
       */
      private final boolean ignoreDownloadError = true;
  
      @Override
      public void contextualize(final Context context) throws ContextException {
          container = (PlexusContainer) context.get(PlexusConstants.PLEXUS_KEY);
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void execute(final Sink sink, final MacroRequest request) throws MacroExecutionException {
          final String filePath = (String) request.getParameter("file");
          String encoding = (String) request.getParameter("encoding");
  
          File file;
  
          if (Strings.isNullOrEmpty(encoding)) {
              encoding = Charsets.UTF_8.name();
          }
  
          if (!Strings.isNullOrEmpty(filePath)) {
              file = new File(filePath);
  
              if (!file.isAbsolute()) {
                  file = new File(request.getBasedir(), filePath);
              }
          } else {
              throw new IllegalArgumentException("The 'file' param has to be given.");
          }
  
          try {
              sink.rawText(getSnippet(file, encoding));
          } catch (final IOException e) {
              throw new MacroExecutionException("Error reading snippet", e);
          }
      }
 
     private String getSnippet(final File file, final String encoding) throws IOException {
         try {
             return convertSnippet(Files.asByteSource(file).asCharSource(Charset.forName(encoding)));
 
         } catch (final IOException e) {
             if (ignoreDownloadError) {
                 if (LOGGER.isDebugEnabled()) {
                     LOGGER.debug("IOException which reading " + file + ": " + e);
                 }
                 return "Error during retrieving content skip as ignoreDownloadError activated.";
             } else {
                 throw e;
             }
         }
     }
 
     String convertSnippet(final CharSource source) throws IOException {
         final String src = source.read();
         final Document doc = Jsoup.parse(src);
         return new ComponentResolver().normalize(doc).html();
     }
 }