/*
    * The Kuali Financial System, a comprehensive financial management system for higher education.
    * 
    * Copyright 2005-2014 The Kuali Foundation
    * 
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Affero General Public License as
    * published by the Free Software Foundation, either version 3 of the
    * License, or (at your option) any later version.
   * 
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU Affero General Public License for more details.
   * 
   * You should have received a copy of the GNU Affero General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  import java.io.BufferedReader;
  import java.io.BufferedWriter;
  import java.io.File;
  import java.io.FileReader;
  import java.io.FileWriter;
  import java.util.HashSet;
  import java.util.regex.Pattern;
  
  public class PartialMergeHelper {
  
      static final Pattern fileBreakPattern = Pattern.compile("^Index: ");
  
      public static void main(String[] args) throws Exception {
          String partialMergeDiffFileName = args[0];
          String completeMergeDiffFileName = args[1];
          String mergeRemainderDiffFileName = args[2];
  
          HashSet<String> filesInPartialMerge = new HashSet<String>();
  
          // first, go through the partial merge file and extract all the updated file names
          // build a list of the file break patterns and save in a HashSet
          File partialMergeFile = new File( partialMergeDiffFileName );
          System.out.println( "Partial Merge file: " + partialMergeFile.getAbsolutePath() );
          BufferedReader r = new BufferedReader(new FileReader( partialMergeFile ) );
          String line;
          while ( (line = r.readLine()) != null ) {
              if ( fileBreakPattern.matcher(line).find() ) {
                  System.out.println( "Adding to partial merge file list: " + line );
                  filesInPartialMerge.add(line);
              }
          }
  
          // second, loop over the complete merge file, suppressing any entries which appear in the
          // first merge file
          File inputFile = new File( completeMergeDiffFileName );
          System.out.println( "Attemping to read from file: " + inputFile.getAbsolutePath() );
          File outputFile = new File ( mergeRemainderDiffFileName );
          System.out.println( "Output file: " + outputFile.getAbsolutePath() );
          r = new BufferedReader(new FileReader( inputFile ) );
          BufferedWriter w = new BufferedWriter( new FileWriter(outputFile) );
          boolean inFileSuppressionMode = false;
          int suppressionLineCount = 0;
          while ( (line = r.readLine()) != null ) {
              if ( fileBreakPattern.matcher(line).find() ) {
  //                if ( inFileSuppressionMode ) {
  //                    System.out.println( "Completing File Suppression.  Lines Removed: " + suppressionLineCount );
  //                }
                  inFileSuppressionMode = false;
                  System.out.println( "Found File Break: " + line );
                  if ( filesInPartialMerge.contains(line) ) {
                      System.out.println( "    HAS ALREADY BEEN MERGED - SUPPRESSING OUTPUT" );
                      inFileSuppressionMode = true;
                      suppressionLineCount = 0;
                  }
              }
              if ( !inFileSuppressionMode ) {
                  w.write(line);
                  w.newLine();
              } else {
                  suppressionLineCount++;
              }
          }
          if ( inFileSuppressionMode ) {
              System.out.println( "Completing File Suppression.  Lines Removed: " + suppressionLineCount );
          }
          r.close();
          w.close();
      }
  
  }