// Reverse a context diff.
// Bruno Haible 26.1.1999

/*
 * Copyright (C) 1996, 1997, 1999, 2000, 2002 Bruno Haible
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

import java.io.*;

class IntRef {
	int _i;
	public IntRef (int i) { _i = i; }
	public int getValue () { return _i; }
	public void setValue (int i) { _i = i; }
}

class DiffParse {
	public static Long parseInteger (String str, IntRef index) {
		int i = index.getValue();
		boolean negative = false;
		if (str.charAt(i) == '-') {
			i++;
			negative = true;
		}
		int after_sign = i;
		long val = 0;
		for (;;) {
			char c = str.charAt(i);
			if (!(c >= '0' && c <= '9'))
				break;
			val = val*10 + (c-'0');
			i++;
		}
		if (after_sign < i) {
			index.setValue(i);
			return new Long(negative ? -val : val);
		} else
			return null; // was: throw new NumberFormatException();
	}
}

class ContextIn {
	DataInput _in_stream;
	int _linenum;		// Number of last read line.
	String _line;		// Last read line, or null.
	public ContextIn (DataInput stream) {
		_in_stream = stream;
		_linenum = 0;
		_line = null;
	}
	// Read the next line.
	public void nextLine () throws IOException {
		String line = _in_stream.readLine();
		_linenum++;
		_line = line;
	}
	// Read the next line, if the last line has already been digested.
	public void prepareLine () throws IOException {
		if (_line == null)
			nextLine();
	}
}

class ContextOut {
	DataOutput _out_stream;
	public ContextOut (DataOutput stream) {
		_out_stream = stream;
	}
}

class ContextdiffHalfhunkParams {
	// A contextdiff half hunk...
	int start_line;
	int end_line;
}
// ... is introduced by a line of the form "*** %d,%d ****" or "*** %d ****".
class ContextdiffHalfhunkParse {
	public static ContextdiffHalfhunkParams parseContextdiffHalfhunkLine (String line, char fillchar) {
	  IntRef index;
	  int i;
	  if (line.length() >= 10) {
	    if (   line.charAt(0) == fillchar
	        && line.charAt(1) == fillchar
	        && line.charAt(2) == fillchar
	        && line.charAt(3) == ' ') {
	      index = new IntRef(4);
	      Long start_line = DiffParse.parseInteger(line,index);
	      i = index.getValue();
	      Long end_line;
	      if (start_line != null
	          && i+1 <= line.length()
	          && line.charAt(i) == ',') {
	        index = new IntRef(i+1);
	        end_line = DiffParse.parseInteger(line,index);
	        i = index.getValue();
	      } else {
	        end_line = new Long(start_line.longValue() > 0 ? start_line.longValue() : start_line.longValue() - 1);
	      }
	      if (i+5 == line.length()
	          && line.charAt(i) == ' '
	          && line.charAt(i+1) == fillchar
	          && line.charAt(i+2) == fillchar
	          && line.charAt(i+3) == fillchar
	          && line.charAt(i+4) == fillchar) {
	        ContextdiffHalfhunkParams result = new ContextdiffHalfhunkParams();
	        result.start_line = start_line.intValue();
	        result.end_line = end_line.intValue();
	        return result;
	  } } }
	  return null;
	}
}

class ContextdiffHalfhunk extends ContextdiffHalfhunkParams {
	StringVector lines;
	int changes;
	ContextdiffHalfhunk () {
		lines = new StringVector();
		changes = 0;
	}
	ContextdiffHalfhunk (ContextdiffHalfhunkParams params) {
		start_line = params.start_line;
		end_line = params.end_line;
		lines = new StringVector();
		changes = 0;
	}
}

class cdiffreverse {

	/* Should have multiple inheritance, really!
	static class ContextInOut {
		ContextIn _cin;
		ContextOut _cout;
		ContextInOut (DataInput istream, DataOutput ostream) {
			_cin = new ContextIn(istream);
			_cout = new ContextOut(ostream);
		}
	}
	*/

	static class ContextInOut extends ContextIn {
		DataOutput _out_stream;
		String _program_name;
		ContextInOut (DataInput istream, DataOutput ostream) {
			super (istream);
			_out_stream = ostream;
			_program_name = "cdiffreverse";
		}
		ContextdiffHalfhunk getHalfhunk (char fillchar, char insertchar) throws IOException {
			prepareLine();
			if (_line == null)
				return null;
			ContextdiffHalfhunkParams halfhunk_params =
			  ContextdiffHalfhunkParse.parseContextdiffHalfhunkLine(_line,fillchar);
			if (halfhunk_params == null)
				return null;
			ContextdiffHalfhunk halfhunk = new ContextdiffHalfhunk(halfhunk_params);
			boolean in_change = false;
			for (;;) {
				nextLine();
				if (_line == null)
					break;
				if (!(_line.length() >= 2))
					break;
				char indicator = _line.charAt(0);
				if (!(   indicator == ' '
				      || indicator == '!'
				      || indicator == insertchar))
					break;
				if (!(_line.charAt(1) == ' '))
					break;
				if (indicator == '!') {
					if (!in_change)
						halfhunk.changes++;
					in_change = true;
				} else
					in_change = false;
				halfhunk.lines.addElement(_line);
			}
			return halfhunk;
		}
		// Compare two half-hunks for consistency.
		String compareHalfhunks (ContextdiffHalfhunk old_half, ContextdiffHalfhunk new_half) {
			StringVector old_lines = old_half.lines;
			StringVector new_lines = new_half.lines;
			if (!(old_half.changes == new_half.changes))
				return "changes count";
			int old_i = 0;
			int new_i = 0;
			for (;;) {
				while (old_i < old_lines.size()) {
					char indicator = old_lines.elementAt(old_i).charAt(0);
					if (indicator == ' ' || indicator == '!')
						break;
					old_i++;
				}
				while (new_i < new_lines.size()) {
					char indicator = new_lines.elementAt(new_i).charAt(0);
					if (indicator == ' ' || indicator == '!')
						break;
					new_i++;
				}
				if (old_i == old_lines.size() && new_i == new_lines.size())
					break;
				if (old_i == old_lines.size())
					return "too few old lines";
				if (new_i == new_lines.size())
					return "too few new lines";
				String next_old_line = old_lines.elementAt(old_i);
				String next_new_line = new_lines.elementAt(new_i);
				char old_indicator = next_old_line.charAt(0);
				char new_indicator = next_new_line.charAt(0);
				if (old_indicator == ' ' && new_indicator == ' ') {
					if (!next_old_line.equals(next_new_line))
						return "different indicators";
					old_i++;
					new_i++;
				} else if (old_indicator == '!' && new_indicator == '!') {
					do { old_i++; }
					  while (old_i < old_lines.size()
					         && old_lines.elementAt(old_i).charAt(0) == '!');
					do { new_i++; }
					  while (new_i < new_lines.size()
					         && new_lines.elementAt(new_i).charAt(0) == '!');
				} else {
					return "bad indicator";
				}
			}
			return null;
		}
		static String two_lines_string (int start_line, int end_line) {
			if (start_line <= end_line)
				return String.valueOf(start_line)
				       .concat(",")
				       .concat(String.valueOf(end_line));
			else
				return String.valueOf(start_line);
		}
		void doHunks () throws IOException {
			for (;;) {
				prepareLine();
				if (_line == null)
					break;
				if (!(_line.length()>=15 && _line.startsWith("***************")))
					break;
				nextLine();
				ContextdiffHalfhunk old_half = getHalfhunk('*','-');
				if (old_half == null)
					break;
				ContextdiffHalfhunk new_half = getHalfhunk('-','+');
				if (new_half == null)
					break;
				int old_start_line = old_half.start_line;
				int old_end_line   = old_half.end_line;
				int old_lines_count = old_end_line - old_start_line + 1;
				int new_start_line = new_half.start_line;
				int new_end_line   = new_half.end_line;
				int new_lines_count = new_end_line - new_start_line + 1;
				StringVector old_lines = old_half.lines;
				StringVector new_lines = new_half.lines;
				// Consistency checks.
				if (!(old_lines.size()==0 || old_lines.size() == old_lines_count)) {
					System.err.print(_program_name);
					System.err.print(": Warning: Hunk ending at line ");
					System.err.print(_linenum - (_line != null ? 1 : 0));
					System.err.print(" has wrong old line numbers");
					System.err.println();
					break;
				}
				if (!(new_lines.size()==0 || new_lines.size() == new_lines_count)) {
					System.err.print(_program_name);
					System.err.print(": Warning: Hunk ending at line ");
					System.err.print(_linenum - (_line != null ? 1 : 0));
					System.err.print(" has wrong new line numbers");
					System.err.println();
					break;
				}
				if (old_lines.size()==0 && new_lines.size()==0) {
					System.err.print(_program_name);
					System.err.print(": Warning: Empty hunk ending at line ");
					System.err.print(_linenum - (_line != null ? 1 : 0));
					System.err.println();
					break;
				}
				if (old_lines.size()==0) {
					if (!(new_half.changes == 0)) {
						System.err.print(_program_name);
						System.err.print(": Warning: Old lines missing in hunk ending at line ");
						System.err.print(_linenum - (_line != null ? 1 : 0));
						System.err.println();
						break;
					}
				} else if (new_lines.size()==0) {
					if (!(old_half.changes == 0)) {
						System.err.print(_program_name);
						System.err.print(": Warning: New lines missing in hunk ending at line ");
						System.err.print(_linenum - (_line != null ? 1 : 0));
						System.err.println();
						break;
					}
				} else {
					String mismatchp = compareHalfhunks(old_half,new_half);
					if (mismatchp != null) {
						System.err.print(_program_name);
						System.err.print(": Warning: Mismatch (");
						System.err.print(mismatchp);
						System.err.print(") between old and new lines in hunk ending at line ");
						System.err.print(_linenum - (_line != null ? 1 : 0));
						System.err.println();
						break;
					}
				}
				// Output a reversed context diff hunk.
				_out_stream.writeBytes("***************\n");
				_out_stream.writeBytes("*** ");
				_out_stream.writeBytes(two_lines_string(new_start_line,new_end_line));
				_out_stream.writeBytes(" ****\n");
				for (StringEnumeration sloop = new StringVectorEnumerator(new_lines);
				     sloop.hasMoreElements(); ) {
					String line = sloop.nextElement();
					if (line.charAt(0) == '+') {
						_out_stream.writeBytes("-");
						_out_stream.writeBytes(line.substring(1));
					} else if (line.charAt(0) == '-') {
						_out_stream.writeBytes("+");
						_out_stream.writeBytes(line.substring(1));
					} else
						_out_stream.writeBytes(line);
					_out_stream.writeBytes("\n");
				}
				_out_stream.writeBytes("--- ");
				_out_stream.writeBytes(two_lines_string(old_start_line,old_end_line));
				_out_stream.writeBytes(" ----\n");
				for (StringEnumeration sloop = new StringVectorEnumerator(old_lines);
				     sloop.hasMoreElements(); ) {
					String line = sloop.nextElement();
					if (line.charAt(0) == '+') {
						_out_stream.writeBytes("-");
						_out_stream.writeBytes(line.substring(1));
					} else if (line.charAt(0) == '-') {
						_out_stream.writeBytes("+");
						_out_stream.writeBytes(line.substring(1));
					} else
						_out_stream.writeBytes(line);
					_out_stream.writeBytes("\n");
				}
			}
		}
		void doFiles () throws IOException {
			for (;;) {
				String headline = null;
				String oldfile = null;
				String newfile = null;
				for (;;) {
					prepareLine();
					if (_line == null)
						break;
					if (_line.length() >= 4
					    && _line.charAt(0) == 'd'
					    && _line.charAt(1) == 'i'
					    && _line.charAt(2) == 'f'
					    && _line.charAt(3) == 'f')
						headline = _line;
					else
					if (_line.length() >= 4
					    && _line.charAt(0) == '*'
					    && _line.charAt(1) == '*'
					    && _line.charAt(2) == '*'
					    && _line.charAt(3) == ' ')
						break;
					else {
						//	System.err.print(_program_name);
						//	System.err.print(": Warning: Junk at line ");
						//	System.err.print(linenum);
						//	System.err.print(".");
						//	System.err.println();
						_out_stream.writeBytes(_line);
						_out_stream.writeBytes("\n");
					}
					_line = null;
				}
				if (_line == null)
					break;
				if (_line.length() >= 4
				    && _line.charAt(0) == '*'
				    && _line.charAt(1) == '*'
				    && _line.charAt(2) == '*'
				    && _line.charAt(3) == ' ') {
					oldfile = _line.substring(4);
					nextLine();
				}
				if (_line == null)
					break;
				if (_line.length() >= 4
				    && _line.charAt(0) == '-'
				    && _line.charAt(1) == '-'
				    && _line.charAt(2) == '-'
				    && _line.charAt(3) == ' ') {
					newfile = _line.substring(4);
					nextLine();
				}
				if (_line == null)
					break;
				if (headline != null) {
					_out_stream.writeBytes(headline);
					_out_stream.writeBytes("\n");
				}
				if (oldfile != null && newfile != null) {
					_out_stream.writeBytes("*** ");
					_out_stream.writeBytes(newfile);
					_out_stream.writeBytes("\n");
					_out_stream.writeBytes("--- ");
					_out_stream.writeBytes(oldfile);
					_out_stream.writeBytes("\n");
				}
				doHunks();
			}
		}
	}

	// Main program!
	public static void main (String args[]) {
		ContextInOut context =
		  new ContextInOut(new DataInputStream(System.in), new DataOutputStream(System.out));
		try {
			context.doFiles();
		}
		catch (IOException e) {
			System.exit(1);
		}
		if (System.out.checkError())
			System.exit(1);
	}
}