package org.codehaus.mojo.javascript.assembler;
   
   /*
    * Copyright 2001-2005 The Apache Software Foundation.
    *
    * Licensed 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.
   */
  
  import java.io.File;
  import java.util.Iterator;
  import java.util.List;
  
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.parsers.DocumentBuilderFactory;
  
  import org.apache.commons.jxpath.JXPathContext;
  import org.codehaus.plexus.logging.LogEnabled;
  import org.codehaus.plexus.logging.Logger;
  import org.w3c.dom.Document;
  import org.w3c.dom.Node;
  
  /**
   * @author <a href="mailto:nicolas@apache.org">Nicolas De Loof</a>
   */
  public class JsBuilderAssemblerReader
      implements AssemblerReader, LogEnabled
  {
      private Logger logger;
  
      /**
       * {@inheritDoc}
       * 
       * @see org.codehaus.plexus.logging.LogEnabled#enableLogging(org.codehaus.plexus.logging.Logger)
       */
      public void enableLogging( Logger logger )
      {
          this.logger = logger;
      }
  
      private static final String OUTPUT = "$output/";
  
      /**
       * {@inheritDoc}
       * 
       * @see org.codehaus.mojo.javascript.assembler.AssemblerReader#getAssembler(java.io.File)
       */
      public Assembler getAssembler( File file )
          throws Exception
      {
          logger.info( "Reading assembler descriptor " + file.getAbsolutePath() );
          DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
          Document dom = builder.parse( file );
  
          Assembler assembler = new Assembler();
          JXPathContext xpath = JXPathContext.newContext( dom );
          xpath.setLenient( true );
          String src = (String) xpath.getValue( "//directory/@name" );
          List nodes = xpath.selectNodes( "//target" );
          for ( Iterator iterator = nodes.iterator(); iterator.hasNext(); )
          {
              Node node = (Node) iterator.next();
              Script script = new Script();
              assembler.addScript( script );
              JXPathContext nodeContext = JXPathContext.newContext( node );
              String fileName = (String) nodeContext.getValue( "@file" );
              fileName = fileName.replace( '\\', '/' );
              if ( fileName.startsWith( OUTPUT ) )
              {
                  fileName = fileName.substring( OUTPUT.length() );
              }
              script.setFileName( fileName );
  
              for ( Iterator iter = nodeContext.iterate( "//include/@name" ); iter.hasNext(); )
              {
                  String include = ( (String) iter.next() ).replace( '\\', '/' );
                  if ( src != null && src.length() > 0 )
                  {
                      include = include.substring( src.length() + 1 );
                  }
                  script.addInclude( include );
              }
          }
          return assembler;
      }
  }