package org.apache.maven.plugin.resource.loader;

 /*

  * 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.

  */

 import java.io.BufferedInputStream;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileNotFoundException;

 import java.io.InputStream;

 import java.util.Hashtable;

 import java.util.Vector;

 import org.apache.commons.collections.ExtendedProperties;

 import org.apache.velocity.exception.ResourceNotFoundException;

 import org.apache.velocity.runtime.resource.Resource;

 import org.apache.velocity.runtime.resource.loader.ResourceLoader;

 import org.apache.velocity.util.StringUtils;

 /**

  * Resource Loader for external projects.

  * 

  * @version $Id: org.apache.maven.plugin.resource.loader.ProjectResourceLoader.html 816584 2012-05-08 12:33:35Z hboutemy $

  */

 public class ProjectResourceLoader

     extends ResourceLoader

 {

     /**

      * The paths to search for templates.

      */

     private Vector paths = null;

     /**

      * Used to map the path that a template was found on

      * so that we can properly check the modification

      * times of the files.

      */

     private Hashtable templatePaths = new Hashtable();

     public void init( ExtendedProperties configuration )

     {

         rsvc.info( "ProjectResourceLoader : initialization starting." );

         String separator = System.getProperty( "file.separator" );

         String path = System.getProperty( "user.dir" ) + separator + "src" + separator + "main" + separator

             + "resources" + separator;

         rsvc.info( "path :" + path );

         paths = new Vector();

         paths.add( path );

         int sz = paths.size();

         for ( int i = 0; i < sz; i++ )

         {

             rsvc.info( "ProjectResourceLoader : adding path '" + (String) paths.get( i ) + "'" );

         }

         rsvc.info( "ProjectResourceLoader : initialization complete." );

     }

     /**

      * Get an InputStream so that the Runtime can build a

      * template with it.

      *

      * @param templateName name of template to get

      * @return InputStream containing the template

      * @throws ResourceNotFoundException if template not found

      *         in the file template path.

      */

     public synchronized InputStream getResourceStream( String templateName )

         throws ResourceNotFoundException

     {

         /*

          * Make sure we have a valid templateName.

          */

         if ( templateName == null || templateName.length() == 0 )

         {

             /*

              * If we don't get a properly formed templateName then

              * there's not much we can do. So we'll forget about

              * trying to search any more paths for the template.

              */

             throw new ResourceNotFoundException( "Need to specify a file name or file path!" );

         }

         String template = StringUtils.normalizePath( templateName );

         if ( template == null || template.length() == 0 )

         {

             String msg = "Project Resource loader error : argument " + template

                 + " contains .. and may be trying to access " + "content outside of template root.  Rejected.";

             rsvc.error( "ProjectResourceLoader : " + msg );

             throw new ResourceNotFoundException( msg );

         }

         /*

          *  if a / leads off, then just nip that :)

          */

         if ( template.startsWith( "/" ) )

         {

             template = template.substring( 1 );

         }

         int size = paths.size();

         for ( int i = 0; i < size; i++ )

         {

             String path = (String) paths.get( i );

             InputStream inputStream = findTemplate( path, template );

             if ( inputStream != null )

             {

                 /*

                  * Store the path that this template came

                  * from so that we can check its modification

                  * time.

                  */

                 templatePaths.put( templateName, path );

                 return inputStream;

             }

         }

         /*

          * We have now searched all the paths for

          * templates and we didn't find anything so

          * throw an exception.

          */

         String msg = "ProjectResourceLoader Error: cannot find resource " + template;

         throw new ResourceNotFoundException( msg );

     }

     /**

      * Try to find a template given a normalized path.

      * 

      * @param path a normalized path

      * @return InputStream input stream that will be parsed

      *

      */

     private InputStream findTemplate( String path, String template )

     {

         try

         {

             File file = new File( path, template );

             if ( file.canRead() )

             {

                 return new BufferedInputStream( new FileInputStream( file.getAbsolutePath() ) );

             }

             else

             {

                 return null;

             }

         }

         catch ( FileNotFoundException fnfe )

         {

             /*

              *  log and convert to a general Velocity ResourceNotFoundException

              */

             return null;

         }

     }

     /**

      * How to keep track of all the modified times

      * across the paths.  Note that a file might have

      * appeared in a directory which is earlier in the

      * path; so we should search the path and see if

      * the file we find that way is the same as the one

      * that we have cached.

      */

     public boolean isSourceModified( Resource resource )

     {

         /*

          * we assume that the file needs to be reloaded; 

          * if we find the original file and it's unchanged,

          * then we'll flip this.

          */

         boolean modified = true;

         String fileName = resource.getName();

         String path = (String) templatePaths.get( fileName );

         File currentFile = null;

         for ( int i = 0; currentFile == null && i < paths.size(); i++ )

         {

             String testPath = (String) paths.get( i );

             File testFile = new File( testPath, fileName );

             if ( testFile.canRead() )

             {

                 currentFile = testFile;

             }

         }

         File file = new File( path, fileName );

         if ( currentFile == null || !file.exists() )

         {

             /*

              * noop: if the file is missing now (either the cached

              * file is gone, or the file can no longer be found)

              * then we leave modified alone (it's set to true); a 

              * reload attempt will be done, which will either use

              * a new template or fail with an appropriate message

              * about how the file couldn't be found.

              */

         }

         else if ( currentFile.equals( file ) && file.canRead() )

         {

             /*

              * if only if currentFile is the same as file and

              * file.lastModified() is the same as

              * resource.getLastModified(), then we should use the

              * cached version.

              */

             modified = ( file.lastModified() != resource.getLastModified() );

         }

         /*

          * rsvc.debug("isSourceModified for " + fileName + ": " + modified);

          */

         return modified;

     }

     public long getLastModified( Resource resource )

     {

         String path = (String) templatePaths.get( resource.getName() );

         File file = new File( path, resource.getName() );

         if ( file.canRead() )

         {

             return file.lastModified();

         }

         else

         {

             return 0;

         }

     }

 }