001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.maven.plugin.plugin;
020
021import javax.lang.model.SourceVersion;
022
023import java.io.File;
024import java.util.Arrays;
025import java.util.stream.Collectors;
026
027import org.apache.maven.plugin.MojoExecutionException;
028import org.apache.maven.plugins.annotations.Component;
029import org.apache.maven.plugins.annotations.LifecyclePhase;
030import org.apache.maven.plugins.annotations.Mojo;
031import org.apache.maven.plugins.annotations.Parameter;
032import org.apache.maven.plugins.annotations.ResolutionScope;
033import org.apache.maven.tools.plugin.generator.GeneratorException;
034import org.apache.maven.tools.plugin.generator.PluginHelpGenerator;
035import org.codehaus.plexus.util.StringUtils;
036import org.codehaus.plexus.velocity.VelocityComponent;
037
038/**
039 * Generates a <code>HelpMojo</code> class.
040 * Relies at runtime on one output file from {@link DescriptorGeneratorMojo}.
041 *
042 * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
043 * @since 2.4
044 */
045@Mojo(
046        name = "helpmojo",
047        defaultPhase = LifecyclePhase.GENERATE_SOURCES,
048        threadSafe = true,
049        requiresDependencyResolution = ResolutionScope.COMPILE)
050public class HelpGeneratorMojo extends AbstractGeneratorMojo {
051    /**
052     * The directory where the generated <code>HelpMojo</code> file will be put.
053     */
054    @Parameter(defaultValue = "${project.build.directory}/generated-sources/plugin")
055    protected File outputDirectory;
056
057    /**
058     * The name of the package for the generated <code>HelpMojo</code>.
059     * <p>
060     * By default, the package name will be calculated as <code>groupId + "." + artifactId</code> with additional
061     * <ul>
062     * <li><code>-</code> (dashes) will be replaced by <code>_</code> (underscores)</li>
063     * <li><code>_</code> (underscore) will be added before each number or Java keyword at the beginning of name</li>
064     * </ul>
065     *
066     * @since 2.6
067     */
068    @Parameter
069    private String helpPackageName;
070
071    /**
072     * Velocity component.
073     */
074    @Component
075    private VelocityComponent velocity;
076
077    String getHelpPackageName() {
078        String packageName = null;
079        if (StringUtils.isNotBlank(helpPackageName)) {
080            packageName = helpPackageName;
081        }
082
083        if (packageName == null) {
084            packageName = project.getGroupId() + "." + project.getArtifactId();
085            packageName = packageName.replace("-", "_");
086
087            String[] packageItems = packageName.split("\\.");
088            packageName =
089                    Arrays.stream(packageItems).map(this::prefixSpecialCase).collect(Collectors.joining("."));
090        }
091
092        return packageName;
093    }
094
095    private String prefixSpecialCase(String name) {
096        if (SourceVersion.isKeyword(name) || !Character.isJavaIdentifierStart(name.charAt(0))) {
097            name = "_" + name;
098        }
099        return name;
100    }
101
102    @Override
103    protected void generate() throws MojoExecutionException {
104        PluginHelpGenerator pluginHelpGenerator = new PluginHelpGenerator()
105                .setMavenProject(project)
106                .setHelpPackageName(getHelpPackageName())
107                .setGoalPrefix(goalPrefix)
108                .setVelocityComponent(velocity);
109
110        try {
111            pluginHelpGenerator.execute(outputDirectory);
112        } catch (GeneratorException e) {
113            throw new MojoExecutionException(e.getMessage(), e);
114        }
115
116        if (!project.getCompileSourceRoots().contains(outputDirectory.getAbsolutePath())) {
117            project.addCompileSourceRoot(outputDirectory.getAbsolutePath());
118        }
119    }
120}