/*
 * 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.maven.scm.plugin;

import javax.inject.Inject;

import java.io.File;
import java.io.IOException;

import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.scm.ScmException;
import org.apache.maven.scm.command.diff.DiffScmResult;
import org.apache.maven.scm.manager.ScmManager;
import org.apache.maven.scm.repository.ScmRepository;
import org.apache.maven.settings.crypto.SettingsDecrypter;
import org.codehaus.plexus.util.FileUtils;

/**
 * Display the difference of the working copy with the latest copy in the configured scm url.
 *
 * @author <a href="evenisse@apache.org">Emmanuel Venisse</a>
 */
@Mojo(name = "diff", aggregator = true)
public class DiffMojo extends AbstractScmMojo {
    /**
     * The version type (branch/tag/revision) of scmVersion.
     */
    @Parameter(property = "startScmVersionType")
    private String startScmVersionType;

    /**
     * The version (revision number/branch name/tag name).
     */
    @Parameter(property = "startScmVersion")
    private String startScmVersion;

    /**
     * The version type (branch/tag/revision) of scmVersion.
     */
    @Parameter(property = "endScmVersionType")
    private String endScmVersionType;

    /**
     * The version (revision number/branch name/tag name).
     */
    @Parameter(property = "endScmVersion")
    private String endScmVersion;

    /**
     * Output file name.
     */
    @Parameter(property = "outputFile", defaultValue = "${project.artifactId}.diff")
    private File outputFile;

    @Inject
    public DiffMojo(ScmManager manager, SettingsDecrypter settingsDecrypter) {
        super(manager, settingsDecrypter);
    }

    /**
     * {@inheritDoc}
     */
    public void execute() throws MojoExecutionException {
        super.execute();

        try {
            ScmRepository repository = getScmRepository();

            DiffScmResult result = getScmManager()
                    .diff(
                            repository,
                            getFileSet(),
                            getScmVersion(startScmVersionType, startScmVersion),
                            getScmVersion(endScmVersionType, endScmVersion));

            checkResult(result);

            getLog().debug(result.getPatch());

            try {
                if (outputFile != null) {
                    FileUtils.fileWrite(outputFile.getAbsolutePath(), result.getPatch());
                }
            } catch (IOException e) {
                throw new MojoExecutionException("Can't write patch file.", e);
            }
        } catch (IOException | ScmException e) {
            throw new MojoExecutionException("Cannot run diff command : ", e);
        }
    }
}
