package org.apache.maven.plugin.checkstyle;

 /*

  * 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.maven.plugin.MojoExecutionException;

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

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

 import org.apache.velocity.context.Context;

 import org.apache.velocity.exception.ResourceNotFoundException;

 import org.apache.velocity.exception.VelocityException;

 import org.codehaus.plexus.velocity.VelocityComponent;

 import java.io.File;

 import java.io.FileWriter;

 import java.io.IOException;

 import java.io.Writer;

 /**

  * <p>

  * A component to work with VelocityTemplates from within plugins.

  * </p>

  *

  * <p/>

  * You will need to reference the velocity component as a parameter

  * in your plugin.  Like this:

  * </p>

  * <pre>

  * /**

  *  * Velocity Component

  *  * @parameter expression="${component.org.codehaus.plexus.velocity.VelocityComponent}"

  *  * @readonly

  *  */

  *  private VelocityComponent velocity;

  * </pre>

  *

  * @author <a href="mailto:joakim@erdfelt.net">Joakim Erdfelt</a>

  */

 public class VelocityTemplate

 {

     private String templateDirectory;

     private Log log;

     private VelocityComponent velocity;

     public VelocityTemplate( VelocityComponent velocityComponent, String templateBaseDirectory )

     {

         this.velocity = velocityComponent;

         this.templateDirectory = templateBaseDirectory;

     }

     public String getTemplateDirectory()

     {

         return templateDirectory;

     }

     public VelocityComponent getVelocity()

     {

         return velocity;

     }

     /**

      * Using a specified Velocity Template and provided context, create the outputFilename.

      *

      * @param outputFilename the file to be generated.

      * @param template       the velocity template to use.

      * @param context        the velocity context map.

      * @throws VelocityException if the template was not found or any other Velocity exception.

      * @throws MojoExecutionException

      * @throws IOException

      */

     public void generate( String outputFilename, String template, Context context )

         throws VelocityException, MojoExecutionException, IOException

     {

         File f;

         try

         {

             f = new File( outputFilename );

             if ( !f.getParentFile().exists() )

             {

                 f.getParentFile().mkdirs();

             }

             Writer writer = new FileWriter( f );

             getVelocity().getEngine().mergeTemplate( templateDirectory + "/" + template, context, writer );

             writer.flush();

             writer.close();

             getLog().debug( "File " + outputFilename + " created..." );

         }

         catch ( ResourceNotFoundException e )

         {

             throw new ResourceNotFoundException( "Template not found: " + templateDirectory + "/" + template );

         }

         catch ( VelocityException e )

         {

             throw e; // to get past generic catch for Exception.

         }

         catch ( IOException e )

         {

             throw e; // to get past generic catch for Exception.

         }

         catch ( Exception e )

         {

             throw new MojoExecutionException( e.getMessage(), e );

         }

     }

     public void setTemplateDirectory( String templateDirectory )

     {

         this.templateDirectory = templateDirectory;

     }

     public void setVelocity( VelocityComponent velocity )

     {

         this.velocity = velocity;

     }

     public Log getLog()

     {

         if ( this.log == null )

         {

             this.log = new SystemStreamLog();

         }

         return log;

     }

     public void setLog( Log log )

     {

         this.log = log;

     }

 }