/**
    * 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.creadur.whisker.plugin.maven;
  
  import java.io.File;
  
  import org.apache.creadur.whisker.app.Act;
  import org.apache.creadur.whisker.app.Whisker;
  import org.apache.creadur.whisker.app.load.StreamableResourceFactory;
  import org.apache.creadur.whisker.app.out.WriteResultsIntoDirectoryFactory;
  import org.apache.creadur.whisker.out.velocity.LoggingVelocityEngine;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.annotations.*;
  
  /**
   * Generates licensing related materials such as LICENSE and NOTICE documents
   * for assembled applications. The plugin is not bound to a specific lifecycle phase.
   */
  @Mojo(name = "generate", requiresProject = false)
  public class GenerateMojo extends AbstractMojo {
  
      /**
       * Destination for generated materials
       */
  	@Parameter(defaultValue = "${project.build.directory}")
      private File outputDirectory;
  
      /**
       * The licensing materials will be encoding thus.
       */
  	@Parameter(property = "outputEncoding", defaultValue = "${project.build.sourceEncoding}")
      private String outputEncoding;
  
      /**
       * This file contains a description of the licensing qualities of
       * the expected contents of the assembled application.
       */
  	@Parameter(property = "apacheWhiskerDescriptor", required = true)
      private File descriptor;
  
      /**
       * Generate licensing related materials such as LICENSE and NOTICE documents.
       * @throws MojoExecutionException when Whisker fails,
       * or when configured cannot be executed
       * @see org.apache.maven.plugin.Mojo#execute()
       */
      public void execute() throws MojoExecutionException {
          if (descriptor.exists()) {
              getLog().info("Reading descriptor from " + descriptor);
              if (descriptor.canRead()) {
                   try {
                      new Whisker().setLicenseDescriptor(new StreamableResourceFactory().streamFromFileResource(descriptor))
                          .setEngine(new LoggingVelocityEngine())
                          .setWriterFactory(new WriteResultsIntoDirectoryFactory(outputDirectory, outputEncoding))
                          .setAct(Act.GENERATE).act();
                  } catch (Exception e) {
                      throw new MojoExecutionException("Whisker failed to generate materials: " + e.getMessage(), e);
                  }
              } else {
                  throw new MojoExecutionException("Read permission required on Whisker descriptor file: " + descriptor);
              }
          } else {
              getLog().error("No descriptor found " + descriptor);
              throw new MojoExecutionException("Whisker descriptor file is missing: " + descriptor);
          }
      }
  
  }