/*

  * $Id: AbstractTemplateSuiteGenerator.java 1656976 2015-02-04 02:27:40Z nlebas $

  *

  * 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.apache.tiles.autotag.generate;

 import java.io.File;

 import java.io.IOException;

 import java.io.OutputStreamWriter;

 import java.io.Writer;

 import java.util.Map;

 import org.apache.tiles.autotag.core.AutotagRuntimeException;

 import org.apache.tiles.autotag.core.OutputLocator;

 import org.apache.tiles.autotag.model.TemplateSuite;

 import org.apache.tiles.autotag.tool.StringTool;

 import org.apache.velocity.Template;

 import org.apache.velocity.VelocityContext;

 import org.apache.velocity.app.VelocityEngine;

 import org.apache.velocity.exception.ParseErrorException;

 import org.apache.velocity.exception.ResourceNotFoundException;

 /**

  * A base template suite generator.

  *

  * @version $Rev: 1656976 $ $Date: 2015-02-04 03:27:40 +0100 (Wed, 04 Feb 2015) $

  */

 public abstract class AbstractTemplateSuiteGenerator implements TemplateSuiteGenerator {

     /**

      * The velocity engine.

      */

     private VelocityEngine velocityEngine;

     /**

      * Constructor.

      *

      * @param velocityEngine The Velocity engine.

      */

     public AbstractTemplateSuiteGenerator(VelocityEngine velocityEngine) {

         this.velocityEngine = velocityEngine;

     }

     @Override

     public void generate(OutputLocator outputLocator, String packageName, TemplateSuite suite, Map<String, String> parameters) {

         String filePath = 

                         getDirectoryName(packageName, suite, parameters)

                 + File.separator

                 + getFilename(packageName, suite, parameters);

                 if (!outputLocator.isUptodate(filePath)) {

                 VelocityContext context = new VelocityContext();

                 context.put("packageName", packageName);

                 context.put("suite", suite);

                 context.put("stringTool", new StringTool());

                 context.put("parameters", parameters);

                 try {

                     Template template = velocityEngine.getTemplate(getTemplatePath(

                             packageName, suite, parameters));

                     Writer writer = new OutputStreamWriter(outputLocator.getOutputStream(filePath));

                     try {

                         template.merge(context, writer);

                     } finally {

                         writer.close();

                     }

                 } catch (ResourceNotFoundException e) {

                     throw new AutotagRuntimeException("Cannot find template resource", e);

                 } catch (ParseErrorException e) {

                     throw new AutotagRuntimeException("The template resource is not parseable", e);

                 } catch (IOException e) {

                     throw new AutotagRuntimeException(

                             "I/O Exception when generating file", e);

                 } catch (RuntimeException e) {

                     throw e;

                 } catch (Exception e) {

                     throw new AutotagRuntimeException(

                             "Another generic exception while parsing the template resource",

                             e);

                 }

         }

     }

     /**

      * Calculates and returns the template path.

      *

      * @param packageName The name of the package.

      * @param suite The template suite.

      * @param parameters The map of parameters.

      * @return The template path.

      */

     protected abstract String getTemplatePath(

             String packageName, TemplateSuite suite,

             Map<String, String> parameters);

     /**

      * Calculates and returns the filename of the generated file.

      *

      * @param packageName The name of the package.

      * @param suite The template suite.

      * @param parameters The map of parameters.

      * @return The template path.

      */

     protected abstract String getFilename(String packageName,

             TemplateSuite suite, Map<String, String> parameters);

     /**

      * Calculates and returns the directory where the file will be written..

      *

      * @param packageName The name of the package.

      * @param suite The template suite.

      * @param parameters The map of parameters.

      * @return The template path.

      */

     protected abstract String getDirectoryName(

             String packageName, TemplateSuite suite,

             Map<String, String> parameters);

 }