package org.apache.maven.plugin.patch;
   
   /*
    * 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.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.codehaus.plexus.util.FileUtils;
  import org.codehaus.plexus.util.IOUtil;
  import org.codehaus.plexus.util.cli.CommandLineException;
  import org.codehaus.plexus.util.cli.CommandLineUtils;
  import org.codehaus.plexus.util.cli.Commandline;
  import org.codehaus.plexus.util.cli.StreamConsumer;
  
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.io.StringWriter;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  
  /**
   * Apply one or more patches to project sources.
   * 
   * @goal apply
   * @phase process-sources
   */
  public class ApplyMojo
      extends AbstractMojo
  {
  
      public static final List PATCH_FAILURE_WATCH_PHRASES;
  
      public static final List DEFAULT_IGNORED_PATCHES;
  
      public static final List DEFAULT_IGNORED_PATCH_PATTERNS;
  
      static
      {
          List watches = new ArrayList();
  
          watches.add( "fail" );
          watches.add( "skip" );
          watches.add( "reject" );
  
          PATCH_FAILURE_WATCH_PHRASES = watches;
  
          List ignored = new ArrayList();
  
          ignored.add( ".svn" );
          ignored.add( "CVS" );
  
          DEFAULT_IGNORED_PATCHES = ignored;
  
          List ignoredPatterns = new ArrayList();
  
          ignoredPatterns.add( ".svn/**" );
          ignoredPatterns.add( "CVS/**" );
  
          DEFAULT_IGNORED_PATCH_PATTERNS = ignoredPatterns;
      }
  
      /**
       * Whether to exclude default ignored patch items, such as <code>.svn</code> or <code>CVS</code> directories.
       * 
       * @parameter default-value="true"
       */
      private boolean useDefaultIgnores;
  
      /**
       * The list of patch file names, supplying the order in which patches should be applied. The path names in this list
       * must be relative to the base directory specified by the parameter <code>patchDirectory</code>. This parameter
       * is mutually exclusive with the <code>patchfile</code> parameter.
       * 
       * @parameter
       */
     protected List patches;
 
     /**
      * Whether to skip this goal's execution.
      * 
      * @parameter default-value="false" alias="patch.apply.skip"
      */
     private boolean skipApplication;
 
     /**
      * Flag to enable/disable optimization file from being written. This file tracks the patches that were applied the
      * last time this goal actually executed. It is required for cases where project-sources optimizations are enabled,
      * since project-sources will not be re-unpacked if they are at least as fresh as the source archive. If we avoid
      * re-unpacking project sources, we need to make sure we don't reapply patches.<br/> <strong>Note:</strong> If the
      * list of patches changes and this flag is enabled, a "<code>mvn clean</code>" must be executed before the next
      * build, to remove the tracking file.
      * 
      * @parameter default-value="true"
      */
     private boolean optimizations;
 
     /**
      * This is the tracking file used to maintain a list of the patches applied to the unpacked project sources which
      * are currently in the target directory. If this file is present, and project-source unpacking is optimized
      * (meaning it won't re-unpack unless the project-sources archive is newer), this goal will not execute and no
      * patches will be applied in the current build.
      * 
      * @parameter default-value="${project.build.directory}/optimization-files/patches-applied.txt"
      */
     private File patchTrackingFile;
 
     /**
      * The target directory for applying patches. Files in this directory will be modified.
      * 
      * @parameter alias="patchTargetDir" default-value="${project.build.sourceDirectory}"
      */
     private File targetDirectory;
 
     /**
      * Flag being <code>true</code> if the desired behavior is to fail the build on the first failed patch detected.
      * 
      * @parameter default-value="true"
      */
     private boolean failFast;
 
     /**
      * Setting natural order processing to <code>true</code> will cause all patches in a directory to be processed in
      * a natural order alleviating the need to declare patches directly in the project file.
      * 
      * @parameter default-value="false"
      */
     private boolean naturalOrderProcessing;
 
     /**
      * When the <code>strictPatching</code> flag is set, this parameter is useful to mark certain contents of the
      * patch-source directory that should be ignored without causing the build to fail.
      * 
      * @parameter
      */
     private List ignoredPatches;
 
     /**
      * Flag that, when set to <code>true</code>, will make sure that all patches included in the <code>patches</code>
      * list must be present and describe the full contents of the patch directory. If <code>strictPatching</code> is
      * set to <code>true</code>, and the <code>patches</code> list has a value that does not correspond to a file
      * in the patch directory, the build will fail. If <code>strictPatching</code> is set to <code>true</code>, and
      * the patch directory contains files not listed in the <code>patches</code> parameter, the build will fail. If
      * set to <code>false</code>, only the patches listed in the <code>patches</code> parameter that have
      * corresponding files will be applied; the rest will be ignored.
      * 
      * @parameter default-value="false"
      */
     private boolean strictPatching;
 
     /**
      * The number of directories to be stripped from patch file paths, before applying, starting from the leftmost, or
      * root-est.
      * 
      * @parameter default-value="0"
      */
     private int strip;
 
     /**
      * Whether to ignore whitespaces when applying the patches.
      * 
      * @parameter default-value="true"
      */
     private boolean ignoreWhitespace;
 
     /**
      * Whether to treat these patches as having reversed source and dest in the patch syntax.
      * 
      * @parameter default-value="false"
      */
     private boolean reverse;
 
     /**
      * Whether to make backups of the original files before modding them.
      * 
      * @parameter default-value="false"
      */
     private boolean backups;
 
     /**
      * List of phrases to watch for in the command output from the patch tool. If one is found, it will cause the build
      * to fail. All phrases should be lower-case <em>only</em>. By default, the phrases <code>fail</code>,
      * <code>skip</code> and <code>reject</code> are used.
      * 
      * @parameter
      */
     private List failurePhrases = PATCH_FAILURE_WATCH_PHRASES;
 
     /**
      * The original file which will be modified by the patch. By default, the patch tool will automatically derive the
      * original file from the header of the patch file.
      * 
      * @parameter
      */
     private File originalFile;
 
     /**
      * The output file which is the original file, plus modifications from the patch. By default, the file(s) will be
      * patched inplace.
      * 
      * @parameter
      */
     private File destFile;
 
     /**
      * The single patch file to apply. This parameter is mutually exclusive with the <code>patches</code> parameter.
      * 
      * @parameter
      */
     private File patchFile;
 
     /**
      * The base directory for the file names specified by the parameter <code>patches</code>.
      * 
      * @parameter default-value="src/main/patches"
      */
     private File patchDirectory;
 
     /**
      * When set to <code>true</code>, the empty files resulting from the patching process are removed. Empty ancestor
      * directories are removed as well.
      * 
      * @parameter default-value="false"
      * @since 1.1
      */
     private boolean removeEmptyFiles;
 
     /**
      * Apply the patches. Give preference to patchFile over patchSourceDir/patches, and preference to originalFile over
      * workDir.
      */
     public void execute()
         throws MojoExecutionException, MojoFailureException
     {
         boolean patchDirEnabled = ( ( patches != null ) && !patches.isEmpty() ) || naturalOrderProcessing;
         boolean patchFileEnabled = patchFile != null;
 
         // if patches is null or empty, and naturalOrderProcessing is not true then disable patching
         if ( !patchFileEnabled && !patchDirEnabled )
         {
             getLog().info( "Patching is disabled for this project." );
             return;
         }
 
         if ( skipApplication )
         {
             getLog().info( "Skipping patch file application (per configuration)." );
             return;
         }
 
         patchTrackingFile.getParentFile().mkdirs();
 
         Map patchesToApply = null;
 
         try
         {
             if ( patchFileEnabled )
             {
                 patchesToApply = Collections.singletonMap( patchFile.getName(), createPatchCommand( patchFile ) );
             }
             else
             {
                 if ( !patchDirectory.isDirectory() )
                 {
                     throw new FileNotFoundException( "The base directory for patch files does not exist: "
                         + patchDirectory );
                 }
 
                 List foundPatchFiles = FileUtils.getFileNames( patchDirectory, "*", null, false );
 
                 patchesToApply = findPatchesToApply( foundPatchFiles, patchDirectory );
 
                 checkStrictPatchCompliance( foundPatchFiles );
             }
 
             String output = applyPatches( patchesToApply );
 
             checkForWatchPhrases( output );
 
             writeTrackingFile( patchesToApply );
         }
         catch ( IOException ioe )
         {
             throw new MojoExecutionException( "Unable to obtain list of patch files", ioe );
         }
     }
 
     private Map findPatchesToApply( List foundPatchFiles, File patchSourceDir )
         throws MojoFailureException
     {
         Map patchesApplied = new LinkedHashMap();
 
         if ( naturalOrderProcessing )
         {
             patches = new ArrayList( foundPatchFiles );
             Collections.sort( patches );
         }
 
         String alreadyAppliedPatches = "";
 
         try
         {
             if ( optimizations && patchTrackingFile.exists() )
             {
                 alreadyAppliedPatches = FileUtils.fileRead( patchTrackingFile );
             }
         }
         catch ( IOException ioe )
         {
             throw new MojoFailureException( "unable to read patch tracking file: " + ioe.getMessage() );
         }
 
         for ( Iterator it = patches.iterator(); it.hasNext(); )
         {
             String patch = (String) it.next();
 
             if ( alreadyAppliedPatches.indexOf( patch ) == -1 )
             {
                 File patchFile = new File( patchSourceDir, patch );
 
                 getLog().debug( "Looking for patch: " + patch + " in: " + patchFile );
 
                 if ( !patchFile.exists() )
                 {
                     if ( strictPatching )
                     {
                         throw new MojoFailureException( this, "Patch operation cannot proceed.",
                                                         "Cannot find specified patch: \'" + patch
                                                             + "\' in patch-source directory: \'" + patchSourceDir
                                                             + "\'.\n\nEither fix this error, "
                                                             + "or relax strictPatching." );
                     }
                     else
                     {
                         getLog().info(
                                        "Skipping patch: " + patch + " listed in the parameter \"patches\"; "
                                            + "it is missing." );
                     }
                 }
                 else
                 {
                     foundPatchFiles.remove( patch );
 
                     patchesApplied.put( patch, createPatchCommand( patchFile ) );
                 }
             }
         }
 
         return patchesApplied;
     }
 
     private void checkStrictPatchCompliance( List foundPatchFiles )
         throws MojoExecutionException
     {
         if ( strictPatching )
         {
             List ignored = new ArrayList();
 
             if ( ignoredPatches != null )
             {
                 ignored.addAll( ignoredPatches );
             }
 
             if ( useDefaultIgnores )
             {
                 ignored.addAll( DEFAULT_IGNORED_PATCHES );
             }
 
             List limbo = new ArrayList( foundPatchFiles );
 
             for ( Iterator it = ignored.iterator(); it.hasNext(); )
             {
                 String ignoredFile = (String) it.next();
 
                 limbo.remove( ignoredFile );
             }
 
             if ( !limbo.isEmpty() )
             {
                 StringBuffer extraFileBuffer = new StringBuffer();
 
                 extraFileBuffer.append( "Found " + limbo.size() + " unlisted patch files:" );
 
                 for ( Iterator it = foundPatchFiles.iterator(); it.hasNext(); )
                 {
                     String patch = (String) it.next();
 
                     extraFileBuffer.append( "\n  \'" ).append( patch ).append( '\'' );
                 }
 
                 extraFileBuffer.append( "\n\nEither remove these files, "
                     + "add them to the patches configuration list, " + "or relax strictPatching." );
 
                 throw new MojoExecutionException( extraFileBuffer.toString() );
             }
         }
     }
 
     private String applyPatches( Map patchesApplied )
         throws MojoExecutionException
     {
         final StringWriter outputWriter = new StringWriter();
 
         StreamConsumer consumer = new StreamConsumer()
         {
             public void consumeLine( String line )
             {
                 if ( getLog().isDebugEnabled() )
                 {
                     getLog().debug( line );
                 }
 
                 outputWriter.write( line + "\n" );
             }
         };
 
         // used if failFast is false
         List failedPatches = new ArrayList();
 
         for ( Iterator it = patchesApplied.entrySet().iterator(); it.hasNext(); )
         {
             Map.Entry entry = (Entry) it.next();
             String patchName = (String) entry.getKey();
             Commandline cli = (Commandline) entry.getValue();
 
             try
             {
                 getLog().info( "Applying patch: " + patchName );
 
                 int result = executeCommandLine( cli, consumer, consumer );
 
                 if ( result != 0 )
                 {
                     if ( failFast )
                     {
                         throw new MojoExecutionException( "Patch command failed with exit code " + result + " for "
                             + patchName + ". Please see console and debug output for more information." );
                     }
                     else
                     {
                         failedPatches.add( patchName );
                     }
                 }
             }
             catch ( CommandLineException e )
             {
                 throw new MojoExecutionException( "Failed to apply patch: " + patchName
                     + ". See debug output for more information.", e );
             }
         }
 
         if ( !failedPatches.isEmpty() )
         {
             getLog().error( "Failed applying one or more patches:" );
             for ( Iterator it = failedPatches.iterator(); it.hasNext(); )
             {
                 getLog().error( "* " + it.next() );
             }
             throw new MojoExecutionException( "Patch command failed for one or more patches."
                 + " Please see console and debug output for more information." );
         }
 
         return outputWriter.toString();
     }
 
     private int executeCommandLine( Commandline cli, StreamConsumer out, StreamConsumer err )
         throws CommandLineException
     {
         if ( getLog().isDebugEnabled() )
         {
             getLog().debug( "Executing: " + cli );
         }
 
         int result = CommandLineUtils.executeCommandLine( cli, out, err );
 
         if ( getLog().isDebugEnabled() )
         {
             getLog().debug( "Exit code: " + result );
         }
 
         return result;
     }
 
     private void writeTrackingFile( Map patchesApplied )
         throws MojoExecutionException
     {
         FileWriter writer = null;
         try
         {
             boolean appending = patchTrackingFile.exists();
 
             writer = new FileWriter( patchTrackingFile, appending );
 
             for ( Iterator it = patchesApplied.keySet().iterator(); it.hasNext(); )
             {
                 if ( appending )
                 {
                     writer.write( System.getProperty( "line.separator" ) );
                 }
 
                 String patch = (String) it.next();
                 writer.write( patch );
 
                 if ( it.hasNext() )
                 {
                     writer.write( System.getProperty( "line.separator" ) );
                 }
             }
 
             writer.flush();
         }
         catch ( IOException e )
         {
             throw new MojoExecutionException( "Failed to write patch-tracking file: " + patchTrackingFile, e );
         }
         finally
         {
             IOUtil.close( writer );
         }
     }
 
     private void checkForWatchPhrases( String output )
         throws MojoExecutionException
     {
         for ( Iterator it = failurePhrases.iterator(); it.hasNext(); )
         {
             String phrase = (String) it.next();
 
             if ( output.indexOf( phrase ) > -1 )
             {
                 throw new MojoExecutionException( "Failed to apply patches (detected watch-phrase: \'" + phrase
                     + "\' in output). " + "If this is in error, configure the patchFailureWatchPhrases parameter." );
             }
         }
     }
 
     /**
      * Add a new Patch task to the Ant calling mechanism. Give preference to originalFile/destFile, then workDir, and
      * finally ${basedir}.
      */
     private Commandline createPatchCommand( File patchFile )
     {
         Commandline cli = new Commandline();
 
         cli.setExecutable( "patch" );
 
         cli.setWorkingDirectory( targetDirectory.getAbsolutePath() );
 
         cli.createArg().setValue( "-p" + strip );
 
         if ( ignoreWhitespace )
         {
             cli.createArg().setValue( "-l" );
         }
 
         if ( reverse )
         {
             cli.createArg().setValue( "-R" );
         }
 
         if ( backups )
         {
             cli.createArg().setValue( "-b" );
         }
 
         if ( removeEmptyFiles )
         {
             cli.createArg().setValue( "-E" );
         }
 
         cli.createArg().setValue( "-i" );
         cli.createArg().setFile( patchFile );
 
         if ( destFile != null )
         {
             cli.createArg().setValue( "-o" );
             cli.createArg().setFile( destFile );
         }
 
         if ( originalFile != null )
         {
             cli.createArg().setFile( originalFile );
         }
 
         return cli;
     }
 
 }