package org.apache.maven.scm.plugin;

/*
 * Copyright 2001-2005 The Apache Software Foundation.
 *
 * Licensed 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.maven.plugin.MojoExecutionException;
import org.apache.maven.scm.ScmException;
import org.apache.maven.scm.command.diff.DiffScmResult;
import org.apache.maven.scm.repository.ScmRepository;
import org.codehaus.plexus.util.FileUtils;

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

/**
 * @goal diff
 * @description Create a diff
 *
 * @author <a href="evenisse@apache.org">Emmanuel Venisse</a>
 * @version $Id$
 */
public class DiffMojo
    extends AbstractScmMojo
{
    /**
     * Start revision id
     *
     * @parameter expression="${startRevision}
     */
    private String startRevision;

    /**
     * End revision id
     *
     * @parameter expression="${endRevision}
     */
    private String endRevision;

    /**
     * Output file name
     *
     * @parameter expression="${outputFile}
     */
    private File outputFile;

    public void execute()
        throws MojoExecutionException
    {
        try
        {
            ScmRepository repository = getScmRepository();

            DiffScmResult result = getScmManager().getProviderByRepository( repository ).diff( repository,
                                                                                               getFileSet(),
                                                                                               startRevision,
                                                                                               endRevision );

            checkResult( result );

            getLog().info( 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 e )
        {
            throw new MojoExecutionException( "Cannot run checkout command : ", e );
        }
        catch ( ScmException e )
        {
            throw new MojoExecutionException( "Cannot run diff command : ", e );
        }
    }
}