package org.apache.maven.scm.provider.jazz.command.diff;
   
   /*
    * 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 java.io.File;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.maven.scm.ScmException;
  import org.apache.maven.scm.ScmFile;
  import org.apache.maven.scm.ScmFileSet;
  import org.apache.maven.scm.ScmFileStatus;
  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.command.status.StatusScmResult;
  import org.apache.maven.scm.provider.ScmProviderRepository;
  import org.apache.maven.scm.provider.jazz.command.JazzConstants;
  import org.apache.maven.scm.provider.jazz.command.JazzScmCommand;
  import org.apache.maven.scm.provider.jazz.command.consumer.DebugLoggerConsumer;
  import org.apache.maven.scm.provider.jazz.command.consumer.ErrorConsumer;
  import org.apache.maven.scm.provider.jazz.command.status.JazzStatusCommand;
  
  // The Maven SCM plugin "diff" goal may have different interpretations in RTC depending on how
  // the user is using RTC. In one instance, the user may expect the diff to report back on the differences between
  // the local 'sandbox' and their connected repository workspace (ie. What files are 'unresolved'). 
  // Other users may want the diff the report back the differences between their connected repository workspace
  // and the stream that it flows with (ie. What files are 'outgoing' / 'incoming').
  // As a first step, we would have to figure out how to distinguish between these two use cases when using this goal.
  
  // Whilst, the above is true, based upon the SVN implementation, its diff does a difference
  // between the local working copy (sandbox) vs's repository (workspace repository).
  //
  // So this implementation will compare the sandbox with the workspace repository (even if there is
  // a valid flow target). As the "scm diff" command does not support this direct comparison (I have
  // had an Enhancement Work Item opened to do so), we will call the "scm status" command to get all
  // of the change files, and then iterate through all of them to get a diff of all of them. The combined
  // output of all of the various diffs will then be returned as a single output operation.
  // -Chris 24/02/12
  
  // The following RTC commands may be useful however it retrieving the required information. 
  //
  // 1. RTC "compare" command:  Compare two workspaces/streams/baselines/snapshots, showing differing baselines and
  // change sets. 
  // See the following links for additional information on the RTC "compare" command:
  // RTC 2.0.0.2:
  // http://publib.boulder.ibm.com/infocenter/rtc/v2r0m0/topic/com.ibm.team.scm.doc/topics/r_scm_cli_compare.html
  // RTC 3.0:
  // http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0/topic/com.ibm.team.scm.doc/topics/r_scm_cli_compare.html
  // RTC 3.0.1:
  // http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0m1/topic/com.ibm.team.scm.doc/topics/r_scm_cli_compare.html
  //
  // 2. RTC "diff" command:  Compare two states of a file. 
  // See the following links for additional information on the RTC "diff" command:
  // RTC 2.0.0.2:
  // http://publib.boulder.ibm.com/infocenter/rtc/v2r0m0/topic/com.ibm.team.scm.doc/topics/r_scm_cli_diff.html
  // RTC 3.0:
  // http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0/topic/com.ibm.team.scm.doc/topics/r_scm_cli_diff.html
  // RTC 3.0.1:
  // http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0m1/topic/com.ibm.team.scm.doc/topics/r_scm_cli_diff.html
  //
  // 3. RTC "status" command:  Show modification status of items in a workspace. 
  // See the following links for additional information on the RTC "status" command:
  // RTC 2.0.0.2:
  // http://publib.boulder.ibm.com/infocenter/rtc/v2r0m0/topic/com.ibm.team.scm.doc/topics/r_scm_cli_status.html
  // RTC 3.0:
  // http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0/topic/com.ibm.team.scm.doc/topics/r_scm_cli_status.html
  // RTC 3.0.1:
  // http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0m1/topic/com.ibm.team.scm.doc/topics/r_scm_cli_status.html
  //
  
  /**
   * @author <a href="mailto:ChrisGWarp@gmail.com">Chris Graham</a>
   */
  public class JazzDiffCommand
      extends AbstractDiffCommand
  {
      /**
       * {@inheritDoc}
       */
      protected DiffScmResult executeDiffCommand( ScmProviderRepository repo, ScmFileSet fileSet,
                                                 ScmVersion startRevision, ScmVersion endRevision )
         throws ScmException
     {
         if ( getLogger().isDebugEnabled() )
         {
             getLogger().debug( "Executing diff command..." );
         }
 
         File baseDir = fileSet.getBasedir();
         File parentFolder = ( baseDir.getParentFile() != null ) ? baseDir.getParentFile() : baseDir;
 
         // First execute the status command to get the list of changed files.
         JazzStatusCommand statusCmd = new JazzStatusCommand();
         statusCmd.setLogger( getLogger() );
         StatusScmResult statusCmdResult = statusCmd.executeStatusCommand( repo, fileSet );
         List<ScmFile> statusScmFiles = statusCmdResult.getChangedFiles();
 
         // In this case, we also use it across multiple calls to "scm diff" so that we
         // sum all output into on.
         JazzScmCommand diffCmd = null;
         StringBuilder patch = new StringBuilder();
         Map<String, CharSequence> differences = new HashMap<String, CharSequence>();
 
         // Now lets iterate through them
         for ( ScmFile file : statusScmFiles )
         {
             if ( file.getStatus() == ScmFileStatus.MODIFIED )
             {
                 // The "scm status" command returns files relative to the sandbox root.
                 // Whereas the "scm diff" command needs them relative to the working directory.
                 File fullPath = new File( parentFolder, file.getPath() );
                 String relativePath = fullPath.toString().substring( baseDir.toString().length() );
                 getLogger().debug( "Full Path     : '" + fullPath + "'" );
                 getLogger().debug( "Relative Path : '" + relativePath + "'" );
 
                 // Now call "scm diff on it"
                 // In this case, we use the DebugLoggerConsumer's ability to store captured output
                 DebugLoggerConsumer diffConsumer = new DebugLoggerConsumer( getLogger() );
                 ErrorConsumer errConsumer = new ErrorConsumer( getLogger() );
                 diffCmd = createDiffCommand( repo, fileSet, relativePath );
                 int status = diffCmd.execute( diffConsumer, errConsumer );
                 if ( status != 0 )
                 {
                     // Return a false result (not the usual SCMResult)
                     return new DiffScmResult( diffCmd.toString(), "The scm diff command failed.",
                                               errConsumer.getOutput(), false );
                 }
                 // Append to patch (all combined)
                 patch.append( diffConsumer.getOutput() );
                 // Set the differences map <File, <CharSequence>
                 differences.put( relativePath, diffConsumer.getOutput() );
             }
         }
 
         return new DiffScmResult( diffCmd.toString(), statusCmdResult.getChangedFiles(), differences,
                                   patch.toString() );
     }
 
     public JazzScmCommand createDiffCommand( ScmProviderRepository repo, ScmFileSet fileSet, String relativePath )
     {
         JazzScmCommand command = new JazzScmCommand( JazzConstants.CMD_DIFF, repo, fileSet, getLogger() );
         command.addArgument( JazzConstants.ARG_FILE );
         command.addArgument( relativePath );
         return command;
     }
 }