package org.apache.tomcat.maven.common.run;

 /*

  * 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 org.apache.catalina.loader.WebappLoader;

 import org.apache.maven.plugin.logging.Log;

 import java.io.File;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.Date;

 import java.util.HashMap;

 import java.util.Map;

 /**

  * A {@linkplain WebappLoader} implementation that allows scanning for changes to project classpath in support of

  * context reloads.

  *

  * @author Ryan Connolly

  * @since 2.0

  */

 public class ExternalRepositoriesReloadableWebappLoader

     extends WebappLoader

 {

     /**

      * Last modification times of all jar and class files.

      */

     private Map<String, Long> modificationTimeMap = new HashMap<String, Long>();

     private Log log;

     /**

      * Default Constructor.

      */

     public ExternalRepositoriesReloadableWebappLoader()

     {

         super();

     }

     /**

      * Convenience Constructor allows setting of a parent ClassLoader.

      *

      * @param parent the ClassLoader instance to set as this Loader's parent ClassLoader.

      */

     public ExternalRepositoriesReloadableWebappLoader( ClassLoader parent, Log log )

     {

         super( parent );

         this.log = log;

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public void addRepository( String repository )

     {

         super.addRepository( repository );

         try

         {

             File file = new File( new URL( repository ).getPath().replaceAll( "%20", " " ) );

             if ( file.isDirectory() )

             {

                 addClassDirectory( file );

             }

             else if ( file.isFile() && file.getName().endsWith( ".jar" ) )

             {

                 addFile( file );

             }

         }

         catch ( MalformedURLException muex )

         {

             throw new RuntimeException( muex );

         }

     }

     /**

      * Tracks modification times of files in the given class directory.

      *

      * @param directory the File directory to track modification times for.

      */

     private void addClassDirectory( File directory )

     {

         for ( File file : directory.listFiles() )

         {

             if ( file.isDirectory() )

             {

                 //remember also directory last modification time

                 addFile( file );

                 addClassDirectory( file );

             }

             else if ( file.isFile() )

             {

                 addFile( file );

             }

         }

     }

     /**

      * Tracks last modification time of the given File.

      *

      * @param file the File for which to track last modification time.

      */

     private void addFile( File file )

     {

         modificationTimeMap.put( file.getAbsolutePath(), file.lastModified() );

     }

     /**

      * Check if {@link WebappLoader} says modified(), if not then check files from added repositories.

      */

     @Override

     public boolean modified()

     {

         boolean modified = super.modified();

         if ( !modified )

         {

             if ( log != null )

             {

                 log.debug( "classPath scanning started at " + new Date().toString() );

             }

             for ( Map.Entry<String, Long> entry : modificationTimeMap.entrySet() )

             {

                 String key = entry.getKey();

                 File file = new File( key );

                 if ( file.exists() )

                 {

                     // file could be deleted.

                     Long savedLastModified = modificationTimeMap.get( key );

                     if ( file.lastModified() > savedLastModified )

                     {

                         modified = true;

                         modificationTimeMap.put( key, file.lastModified() );

                         // directory last modification time can change when some class,

                         // jar or subdirectory was added or deleted.

                         if ( file.isDirectory() )

                         {

                             addClassDirectory( file );

                         }

                     }

                 }

             }

         }

         if ( log != null )

         {

             log.debug( "context " + modified + " at " + new Date().toString() );

         }

         return modified;

     }

 }