/*

  * $Id: AbstractGenerateMojo.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.plugin;

 import java.io.File;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.OutputStream;

 import java.net.URL;

 import java.net.URLClassLoader;

 import java.net.URLConnection;

 import java.util.List;

 import java.util.Map;

 import java.util.Properties;

 import org.apache.maven.model.Resource;

 import org.apache.maven.plugin.AbstractMojo;

 import org.apache.maven.plugin.MojoExecutionException;

 import org.apache.maven.plugins.annotations.Component;

 import org.apache.maven.plugins.annotations.Parameter;

 import org.apache.maven.project.MavenProject;

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

 import org.apache.tiles.autotag.generate.TemplateGenerator;

 import org.apache.tiles.autotag.generate.TemplateGeneratorFactory;

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

 import org.apache.velocity.app.VelocityEngine;

 import org.sonatype.plexus.build.incremental.BuildContext;

 import com.thoughtworks.xstream.XStream;

 import com.thoughtworks.xstream.converters.reflection.Sun14ReflectionProvider;

 /**

  * Abstract class to generate boilerplate code starting from template model classes.

  *

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

  */

 public abstract class AbstractGenerateMojo extends AbstractMojo {

         /**

      * The position of the template suite XML descriptor.

      */

     static final String META_INF_TEMPLATE_SUITE_XML = "META-INF/template-suite.xml";

     /**

      * The classpath elements.

      */

     @Parameter(property = "project.compileClasspathElements", required = true, readonly = true)

     List<String> classpathElements;

     /**

      * Location of the generated classes.

      */

         @Parameter(defaultValue = "${project.build.directory}/autotag-classes", required = true)

         File classesOutputDirectory;

     /**

      * Location of the generated resources.

      */

         @Parameter(defaultValue = "${project.build.directory}/autotag-resources", required = true)

     File resourcesOutputDirectory;

     /**

      * Name of the request class.

      */

         @Parameter(defaultValue = "org.apache.tiles.request.Request", required = true)

     String requestClass;

     /**

      * Name of the package.

      */

         @Parameter(required = true)

     String packageName;

         @Component

     MavenProject project;

         @Component

     BuildContext buildContext;

         OutputLocator classesOutputLocator;

         OutputLocator resourcesOutputLocator;

     /** {@inheritDoc} */

     public void execute() throws MojoExecutionException {

         try {

                 TemplateSuite suite;

                 URLConnection templateSuite = findTemplateSuiteDescriptor();

                 long lastModified = templateSuite.getLastModified();

                 InputStream stream = templateSuite.getInputStream();

             try {

                     XStream xstream = new XStream(new Sun14ReflectionProvider());

                     suite = (TemplateSuite) xstream.fromXML(stream);

             } finally {

                     stream.close();

             }

             classesOutputLocator = new MavenOutputLocator(classesOutputDirectory, lastModified);

             resourcesOutputLocator = new MavenOutputLocator(resourcesOutputDirectory, lastModified);

             Properties props = new Properties();

             InputStream propsStream = getClass().getResourceAsStream("/org/apache/tiles/autotag/velocity.properties");

             props.load(propsStream);

             propsStream.close();

             TemplateGenerator generator = createTemplateGeneratorFactory(

                     new VelocityEngine(props)).createTemplateGenerator();

             generator.generate(packageName, suite, getParameters(), getRuntimeClass(), requestClass);

             if (generator.isGeneratingResources()) {

                     buildContext.refresh(resourcesOutputDirectory);

                 addResourceDirectory(resourcesOutputDirectory.getAbsolutePath());

             }

             if (generator.isGeneratingClasses()) {

                     buildContext.refresh(classesOutputDirectory);

                 addCompileSourceRoot(classesOutputDirectory.getAbsolutePath());

             }

         } catch (IOException e) {

             throw new MojoExecutionException("error", e);

         } catch (RuntimeException e) {

             throw e;

         } catch (Exception e) {

             throw new MojoExecutionException("error", e);

         }

     }

         private void addResourceDirectory(String directory) {

                 boolean addResource = true;

                 @SuppressWarnings("unchecked")

                 List<Resource> resources = project.getResources();

                 for(Resource resource: resources) {

                         if(directory.equals(resource.getDirectory())) {

                                 addResource = false;

                         }

                 }

                 if(addResource) {

                     Resource resource = new Resource();

                     resource.setDirectory(directory);

                     project.addResource(resource);

                 }

         }

         private void addCompileSourceRoot(String directory) {

                 boolean addResource = true;

                 @SuppressWarnings("unchecked")

                 List<String> roots = project.getCompileSourceRoots();

                 for(String root: roots) {

                         if(directory.equals(root)) {

                                 addResource = false;

                         }

                 }

                 if(addResource) {

                     project.addCompileSourceRoot(directory);

                 }

         }

         /**

      * Creates a template generator factory.

      *

      * @param velocityEngine The Velocity engine.

      * @return The template generator factory.

      */

     protected abstract TemplateGeneratorFactory createTemplateGeneratorFactory(VelocityEngine velocityEngine);

     /**

      * Returns the map of parameters.

      *

      * @return The parameters.

      */

     protected abstract Map<String, String> getParameters();

     /**

      * Searches for the template suite descriptor in all dependencies and sources.

      *

      * @return The inputstream of the identified descriptor.

      * @throws IOException If something goes wrong.

      */

     private URLConnection findTemplateSuiteDescriptor() throws IOException {

         URL[] urls = new URL[classpathElements.size()];

         int i = 0;

         for ( String classpathElement: classpathElements )

         {

             urls[i++] = new File(classpathElement).toURI().toURL();

         }

         ClassLoader cl = new URLClassLoader( urls );

         return cl.getResource(META_INF_TEMPLATE_SUITE_XML).openConnection();

     }

     /**

      * Name of the Runtime class.

      * @return The name of the Runtime class.

      */

     protected abstract String getRuntimeClass();

     private final class MavenOutputLocator implements OutputLocator {

             private File outputDirectory;

             private long sourceLastModified;

             private MavenOutputLocator(File outputDirectory, long sourceLastModified) {

                     this.outputDirectory = outputDirectory;

                     this.sourceLastModified = sourceLastModified;

             }

                 @Override

                 public OutputStream getOutputStream(String resourcePath)

                                 throws IOException {

                         File target = new File(outputDirectory, resourcePath);

                         target.getParentFile().mkdirs();

                         return buildContext.newFileOutputStream(target);

                 }

                 @Override

                 public boolean isUptodate(String resourcePath) {

                         File target = new File(outputDirectory, resourcePath);

                         return target.exists() && target.lastModified() > sourceLastModified;

                 }

         }

 }