apache-rat-plugin/src/main/java/org/apache/rat/mp/AbstractRatMojo.java

package org.apache.rat.mp;

/*
 * 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.commons.io.IOUtils;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.project.MavenProject;
import org.apache.rat.Defaults;
import org.apache.rat.Report;
import org.apache.rat.ReportConfiguration;
import org.apache.rat.analysis.IHeaderMatcher;
import org.apache.rat.analysis.util.HeaderMatcherMultiplexer;
import org.apache.rat.api.RatException;
import org.apache.rat.config.SourceCodeManagementSystems;
import org.apache.rat.license.ILicenseFamily;
import org.apache.rat.mp.util.ScmIgnoreParser;
import org.apache.rat.report.IReportable;
import org.apache.rat.report.claim.ClaimStatistic;
import org.codehaus.plexus.util.DirectoryScanner;

import javax.xml.transform.TransformerConfigurationException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.UndeclaredThrowableException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import static org.apache.rat.mp.util.ExclusionHelper.addEclipseDefaults;
import static org.apache.rat.mp.util.ExclusionHelper.addIdeaDefaults;
import static org.apache.rat.mp.util.ExclusionHelper.addMavenDefaults;
import static org.apache.rat.mp.util.ExclusionHelper.addPlexusAndScmDefaults;

/**
 * Abstract base class for Mojos, which are running Rat.
 */
public abstract class AbstractRatMojo extends AbstractMojo {

    /**
     * The base directory, in which to search for files.
     */
    @Parameter(property = "rat.basedir", defaultValue = "${basedir}", required = true)
    private File basedir;

    /**
     * Specifies the licenses to accept. Deprecated, use {@link #licenses}
     * instead.
     *
     * @deprecated Use {@link #licenses} instead.
     */
    @Deprecated
    @Parameter
    private HeaderMatcherSpecification[] licenseMatchers;

    /**
     * Specifies the licenses to accept. By default, these are added to the
     * default licenses, unless you set {@link #addDefaultLicenseMatchers} to
     * false.
     *
     * @since 0.8
     */
    @Parameter
    private IHeaderMatcher[] licenses;

    /**
     * The set of approved license family names.
     *
     * @deprecated Use {@link #licenseFamilies} instead.
     */
    @Deprecated
    private LicenseFamilySpecification[] licenseFamilyNames;

    /**
     * Specifies the license families to accept.
     *
     * @since 0.8
     */
    @Parameter
    private ILicenseFamily[] licenseFamilies;

    /**
     * Whether to add the default list of license matchers.
     */
    @Parameter(property = "rat.addDefaultLicenseMatchers", defaultValue = "true")
    private boolean addDefaultLicenseMatchers;

    /**
     * Specifies files, which are included in the report. By default, all files
     * are included.
     */
    @Parameter
    private String[] includes;

    /**
     * Specifies files, which are excluded in the report. By default, no files
     * are excluded.
     */
    @Parameter
    private String[] excludes;

    /**
     * Whether to use the default excludes when scanning for files. The default
     * excludes are:
     * <ul>
     * <li>meta data files for source code management / revision control systems,
     * see {@link SourceCodeManagementSystems}</li>
     * <li>temporary files used by Maven, see <a
     * href="#useMavenDefaultExcludes">useMavenDefaultExcludes</a></li>
     * <li>configuration files for Eclipse, see <a
     * href="#useEclipseDefaultExcludes">useEclipseDefaultExcludes</a></li>
     * <li>configuration files for IDEA, see <a
     * href="#useIdeaDefaultExcludes">useIdeaDefaultExcludes</a></li>
     * </ul>
     */
    @Parameter(property = "rat.useDefaultExcludes", defaultValue = "true")
    private boolean useDefaultExcludes;

    /**
     * Whether to use the Maven specific default excludes when scanning for
     * files. Maven specific default excludes are given by the constant
     * MAVEN_DEFAULT_EXCLUDES: The <code>target</code> directory, the
     * <code>cobertura.ser</code> file, and so on.
     */
    @Parameter(property = "rat.useMavenDefaultExcludes", defaultValue = "true")
    private boolean useMavenDefaultExcludes;

    /**
     * Whether to parse source code management system (SCM) ignore files and use their contents as excludes.
     * At the moment this works for the following SCMs:
     *
     * @see org.apache.rat.config.SourceCodeManagementSystems
     */
    @Parameter(property = "rat.parseSCMIgnoresAsExcludes", defaultValue = "true")
    private boolean parseSCMIgnoresAsExcludes;

    /**
     * Whether to use the Eclipse specific default excludes when scanning for
     * files. Eclipse specific default excludes are given by the constant
     * ECLIPSE_DEFAULT_EXCLUDES: The <code>.classpath</code> and
     * <code>.project</code> files, the <code>.settings</code> directory, and so
     * on.
     */
    @Parameter(property = "rat.useEclipseDefaultExcludes", defaultValue = "true")
    private boolean useEclipseDefaultExcludes;

    /**
     * Whether to use the IDEA specific default excludes when scanning for
     * files. IDEA specific default excludes are given by the constant
     * IDEA_DEFAULT_EXCLUDES: The <code>*.iml</code>, <code>*.ipr</code> and
     * <code>*.iws</code> files and the <code>.idea</code> directory.
     */
    @Parameter(property = "rat.useIdeaDefaultExcludes", defaultValue = "true")
    private boolean useIdeaDefaultExcludes;

    /**
     * Whether to exclude subprojects. This is recommended, if you want a
     * separate apache-rat-plugin report for each subproject.
     */
    @Parameter(property = "rat.excludeSubprojects", defaultValue = "true")
    private boolean excludeSubProjects;

    /**
     * Will skip the plugin execution, e.g. for technical builds that do not take licence compliance into account.
     *
     * @since 0.11
     */
    @Parameter(property = "rat.skip", defaultValue = "false")
    protected boolean skip;

    /**
     * Holds the maven-internal project to allow resolution of artifact properties during mojo runs.
     */
    @Parameter(defaultValue = "${project}", required = true, readonly = true)
    private MavenProject project;

    /**
     * @return Returns the Maven project.
     */
    protected MavenProject getProject() {
        return project;
    }

    /**
     * Returns the set of {@link IHeaderMatcher header matchers} to use.
     *
     * @return list of license matchers to use
     * @throws MojoFailureException   An error in the plugin configuration was detected.
     * @throws MojoExecutionException An error occurred while calculating the result.
     */
    protected List<IHeaderMatcher> getLicenseMatchers()
            throws MojoFailureException, MojoExecutionException {
        final List<IHeaderMatcher> matchers = new ArrayList<IHeaderMatcher>();
        if (licenses != null) {
            matchers.addAll(Arrays.asList(licenses));
        }

        if (licenseMatchers != null) {
            for (final HeaderMatcherSpecification spec : licenseMatchers) {
                final String className = spec.getClassName();
                final IHeaderMatcher headerMatcher = newInstance(
                        IHeaderMatcher.class, className);
                matchers.add(headerMatcher);
            }
        }

        if (addDefaultLicenseMatchers) {
            matchers.addAll(Defaults.DEFAULT_MATCHERS);
        }
        return matchers;
    }

    private <T> T newInstance(final Class<T> clazz, final String className)
            throws MojoExecutionException, MojoFailureException {
        try {
            final ClassLoader cl = Thread.currentThread()
                    .getContextClassLoader();
            @SuppressWarnings("unchecked") // incorrect cast will be caught below
            final T o = (T) cl.loadClass(className).newInstance();

            if (!clazz.isAssignableFrom(o.getClass())) {
                throw new MojoFailureException("The class "
                        + o.getClass().getName() + " does not implement "
                        + clazz.getName());
            }
            return o;
        } catch (final InstantiationException e) {
            throw new MojoExecutionException("Failed to instantiate class "
                    + className + ": " + e.getMessage(), e);
        } catch (final ClassCastException e) {
            throw new MojoExecutionException("The class " + className
                    + " is not implementing " + clazz.getName() + ": "
                    + e.getMessage(), e);
        } catch (final IllegalAccessException e) {
            throw new MojoExecutionException("Illegal access to class "
                    + className + ": " + e.getMessage(), e);
        } catch (final ClassNotFoundException e) {
            throw new MojoExecutionException("Class " + className
                    + " not found: " + e.getMessage(), e);
        }
    }

    /**
     * Adds the given string array to the list.
     *
     * @param pList  The list to which the array elements are being added.
     * @param pArray The strings to add to the list.
     */
    private static void add(List<String> pList, String[] pArray) {
        if (pArray != null) {
            Collections.addAll(pList, pArray);
        }
    }

    /**
     * Creates an iterator over the files to check.
     *
     * @return A container of files, which are being checked.
     */
    protected IReportable getResources() {
        final DirectoryScanner ds = new DirectoryScanner();
        ds.setBasedir(basedir);
        setExcludes(ds);
        setIncludes(ds);
        ds.scan();
        whenDebuggingLogExcludedFiles(ds);
        final String[] files = ds.getIncludedFiles();
        logAboutIncludedFiles(files);
        try {
            return new FilesReportable(basedir, files);
        } catch (final IOException e) {
            throw new UndeclaredThrowableException(e);
        }
    }

    private void logAboutIncludedFiles(final String[] files) {
        if (files.length == 0) {
            getLog().warn("No resources included.");
        } else {
            getLog().info(
                    files.length
                            + " resources included (use -debug for more details)");
            if (getLog().isDebugEnabled()) {
                for (final String resource : files) {
                    getLog().debug(" - included " + resource);
                }
            }
        }
    }

    private void whenDebuggingLogExcludedFiles(final DirectoryScanner ds) {
        if (getLog().isDebugEnabled()) {
            final String[] excludedFiles = ds.getExcludedFiles();
            if (excludedFiles.length == 0) {
                getLog().debug("No excluded resources.");
            } else {
                getLog().debug(
                        "Excluded " + excludedFiles.length + " resources:");
                for (final String resource : excludedFiles) {
                    getLog().debug(" - excluded " + resource);
                }
            }
        }
    }

    private void setIncludes(DirectoryScanner ds) {
        if (includes != null) {
            ds.setIncludes(includes);
        }
    }

    private void setExcludes(DirectoryScanner ds) {
        final List<String> excludeList = buildDefaultExclusions();
        if (excludes == null || excludes.length == 0) {
            getLog().info("No excludes explicitly specified.");
        } else {
            for (final String exclude : excludes) {
                getLog().info("Exclude: " + exclude);
            }
        }
        add(excludeList, excludes);
        if (!excludeList.isEmpty()) {
            final String[] allExcludes = excludeList.toArray(new String[excludeList
                    .size()]);
            ds.setExcludes(allExcludes);
        }
    }

    private List<String> buildDefaultExclusions() {
        final Set<String> results = new HashSet<String>();

        addPlexusAndScmDefaults(getLog(), useDefaultExcludes, results);
        addMavenDefaults(getLog(), useMavenDefaultExcludes, results);
        addEclipseDefaults(getLog(), useEclipseDefaultExcludes, results);
        addIdeaDefaults(getLog(), useIdeaDefaultExcludes, results);

        if(parseSCMIgnoresAsExcludes) {
            getLog().info("Will parse SCM ignores for exclusions...");
            results.addAll(ScmIgnoreParser.getExclusionsFromSCM(getLog(), project.getBasedir()));
            getLog().info("Finished adding exclusions from SCM ignore files.");
        }

        if (excludeSubProjects && project != null
                && project.getModules() != null) {
            for (final Object o : project.getModules()) {
                final String moduleSubPath = (String) o;
                results.add(moduleSubPath + "/**/*");
            }
        }

        getLog().debug("Finished creating list of implicit excludes.");
        if (results.isEmpty()) {
            getLog().info("No excludes implicitly specified.");
        } else {
            getLog().info(
                    results.size()
                            + " implicit excludes (use -debug for more details).");
            for (final String exclude : results) {
                getLog().debug("Implicit exclude: " + exclude);
            }
        }

        return new ArrayList<String>(results);
    }

    /**
     * Creates the report as a string.
     *
     * @param styleSheet The style sheet to use when formatting the report
     * @return Report contents
     * @throws MojoFailureException   An error in the plugin configuration was detected.
     * @throws MojoExecutionException An error occurred while creating the report.
     */
    protected String createReport(InputStream styleSheet)
            throws MojoExecutionException, MojoFailureException {
        StringWriter sw = new StringWriter();
        PrintWriter pw = null;
        try {
            pw = new PrintWriter(sw);
            createReport(new PrintWriter(sw), styleSheet);
            final String result = sw.toString();
            pw.close();
            pw = null;
            sw.close();
            sw = null;
            return result;
        } catch (IOException e) {
            throw new MojoExecutionException(e.getMessage(), e);
        } finally {
            IOUtils.closeQuietly(pw);
            IOUtils.closeQuietly(sw);
        }
    }

    /**
     * Writes the report to the given stream.
     *
     * @param out   The target writer, to which the report is being written.
     * @param style The stylesheet to use, or <code>null</code> for raw XML
     * @return the current statistic.
     * @throws MojoFailureException   An error in the plugin configuration was detected.
     * @throws MojoExecutionException Another error occurred while creating the report.
     */
    protected ClaimStatistic createReport(Writer out, InputStream style)
            throws MojoExecutionException, MojoFailureException {
        final ReportConfiguration configuration = getConfiguration();
        try {
            if (style != null) {
                return Report.report(out, getResources(), style, configuration);
            } else {
                return Report.report(getResources(), out, configuration);
            }
        } catch (final TransformerConfigurationException e) {
            throw new MojoExecutionException(e.getMessage(), e);
        } catch (final IOException e) {
            throw new MojoExecutionException(e.getMessage(), e);
        } catch (final InterruptedException e) {
            throw new MojoExecutionException(e.getMessage(), e);
        } catch (final RatException e) {
            throw new MojoExecutionException(e.getMessage(), e);
        }
    }

    protected ReportConfiguration getConfiguration()
            throws MojoFailureException, MojoExecutionException {
        final ReportConfiguration configuration = new ReportConfiguration();
        configuration.setHeaderMatcher(new HeaderMatcherMultiplexer(
                getLicenseMatchers()));
        configuration.setApprovedLicenseNames(getApprovedLicenseNames());
        return configuration;
    }

    private ILicenseFamily[] getApprovedLicenseNames()
            throws MojoExecutionException, MojoFailureException {
        final List<ILicenseFamily> list = new ArrayList<ILicenseFamily>();
        if (licenseFamilies != null) {
            list.addAll(Arrays.asList(licenseFamilies));
        }
        if (licenseFamilyNames != null) {
            for (final LicenseFamilySpecification spec : licenseFamilyNames) {
                list.add(newInstance(ILicenseFamily.class, spec.getClassName()));
            }
        }

        if (list.isEmpty()) {
            return null;
        }
        return list.toArray(new ILicenseFamily[list.size()]);
    }
}