/*
    * 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.provider.git.gitexe.command.diff;
  
  import java.io.File;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.maven.scm.ScmException;
  import org.apache.maven.scm.ScmFileSet;
  import org.apache.maven.scm.ScmVersion;
  import org.apache.maven.scm.command.diff.AbstractDiffCommand;
  import org.apache.maven.scm.command.diff.DiffScmResult;
  import org.apache.maven.scm.provider.ScmProviderRepository;
  import org.apache.maven.scm.provider.git.command.GitCommand;
  import org.apache.maven.scm.provider.git.command.diff.GitDiffConsumer;
  import org.apache.maven.scm.provider.git.gitexe.command.GitCommandLineUtils;
  import org.codehaus.plexus.util.cli.CommandLineUtils;
  import org.codehaus.plexus.util.cli.Commandline;
  
  /**
   * @author <a href="mailto:struberg@yahoo.de">Mark Struberg</a>
   */
  public class GitDiffCommand extends AbstractDiffCommand implements GitCommand {
      /**
       * {@inheritDoc}
       */
      protected DiffScmResult executeDiffCommand(
              ScmProviderRepository repo, ScmFileSet fileSet, ScmVersion startVersion, ScmVersion endVersion)
              throws ScmException {
          GitDiffConsumer consumer = new GitDiffConsumer(fileSet.getBasedir());
          CommandLineUtils.StringStreamConsumer stderr = new CommandLineUtils.StringStreamConsumer();
          int exitCode;
  
          Commandline clDiff2Index = createCommandLine(fileSet.getBasedir(), startVersion, endVersion, false);
  
          exitCode = GitCommandLineUtils.execute(clDiff2Index, consumer, stderr);
          if (exitCode != 0) {
              return new DiffScmResult(
                      clDiff2Index.toString(), "The git-diff command failed.", stderr.getOutput(), false);
          }
  
          Commandline clDiff2Head = createCommandLine(fileSet.getBasedir(), startVersion, endVersion, true);
  
          exitCode = GitCommandLineUtils.execute(clDiff2Head, consumer, stderr);
          if (exitCode != 0) {
              return new DiffScmResult(clDiff2Head.toString(), "The git-diff command failed.", stderr.getOutput(), false);
          }
  
          return new DiffScmResult(
                  clDiff2Index.toString(), consumer.getChangedFiles(), consumer.getDifferences(), consumer.getPatch());
      }
  
      // ----------------------------------------------------------------------
      //
      // ----------------------------------------------------------------------
  
      /**
       * @param cached if <code>true</code> diff the index to the head, else diff the tree to the index
       */
      public static Commandline createCommandLine(
              File workingDirectory, ScmVersion startVersion, ScmVersion endVersion, boolean cached) {
          Commandline cl = GitCommandLineUtils.getBaseGitCommandLine(workingDirectory, "diff");
  
          if (cached) {
              cl.createArg().setValue("--cached");
          }
  
          if (startVersion != null && StringUtils.isNotEmpty(startVersion.getName())) {
              cl.createArg().setValue(startVersion.getName());
          }
          if (endVersion != null && StringUtils.isNotEmpty(endVersion.getName())) {
              cl.createArg().setValue(endVersion.getName());
          }
  
          return cl;
      }
  
      /**
       * Create a CommandLine for executing a git diff --raw command.
       * This will output all affected files affected since the given commit and
       * the current version.
       *
       * @param workingDirectory
      */
     public static Commandline createDiffRawCommandLine(File workingDirectory, String sha1) {
         Commandline cl = GitCommandLineUtils.getBaseGitCommandLine(workingDirectory, "diff");
 
         cl.createArg().setValue("--raw");
         cl.createArg().setValue(sha1);
 
         return cl;
     }
 }