// Convert a unidiff to a context diff.
// Bruno Haible 30.12.1995 (Common Lisp), 12.1.1996 (C++), 25.1.1997 (Java)

/*
 * Copyright (C) 1995, 1996, 1997, 1999, 2000 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 UnidiffHunkParams {
	// An unidiff hunk...
	int old_start_line;
	int old_line_count;
	int new_start_line;
	int new_line_count;
}
// ... is introduced by a line of the form "@@ -%d,%d +%d,%d @@%s".
class UnidiffHunkParse {
	public static UnidiffHunkParams parseUnidiffHunkLine (String line) {
	  IntRef index;
	  int i;
	  if (line.length() >= 11) {
	    if (   line.charAt(0) == '@'
	        && line.charAt(1) == '@'
	        && line.charAt(2) == ' '
	        && line.charAt(3) == '-') {
	      index = new IntRef(4);
	      Long old_start_line = DiffParse.parseInteger(line,index);
	      i = index.getValue();
	      if (old_start_line != null
	          && i+1 <= line.length()
	          && line.charAt(i) == ',') {
	        index = new IntRef(i+1);
	        Long old_line_count = DiffParse.parseInteger(line,index);
	        i = index.getValue();
	        if (old_line_count != null
	            && i+2 <= line.length()
	            && line.charAt(i) == ' '
	            && line.charAt(i+1) == '+') {
	          index = new IntRef(i+2);
	          Long new_start_line = DiffParse.parseInteger(line,index);
	          i = index.getValue();
	          if (new_start_line != null
	              && i+1 <= line.length()
	              && line.charAt(i) == ',') {
	            index = new IntRef(i+1);
	            Long new_line_count = DiffParse.parseInteger(line,index);
	            i = index.getValue();
	            if (new_line_count != null
	                && i+3 <= line.length()
	                && line.charAt(i) == ' '
	                && line.charAt(i+1) == '@'
	                && line.charAt(i+2) == '@') {
	              UnidiffHunkParams result = new UnidiffHunkParams();
	              result.old_start_line = old_start_line.intValue();
	              result.old_line_count = old_line_count.intValue();
	              result.new_start_line = new_start_line.intValue();
	              result.new_line_count = new_line_count.intValue();
	              return result;
	  } } } } } }
	  return null;
	}
}

class ud2cd {

	static class PieceBuffer {
		StringVector _destination;
		StringVector _buffer;
		PieceBuffer (StringVector dest) {
			_destination = dest;
			_buffer = new StringVector();
		}
	}

	static class TwoPieceBuffer {
		PieceBuffer _pb_old;
		PieceBuffer _pb_new;
		TwoPieceBuffer (StringVector olds, StringVector news) {
			_pb_old = new PieceBuffer(olds);
			_pb_new = new PieceBuffer(news);
		}
		void add_old_line (String line) {
			_pb_old._buffer.addElement(line);
		}
		void add_new_line (String line) {
			_pb_new._buffer.addElement(line);
		}
		// flush the buffers
		static String prep_exclam (String line) {
			return "! ".concat(line);
		}
		static String prep_plus (String line) {
			return "+ ".concat(line);
		}
		static String prep_minus (String line) {
			return "- ".concat(line);
		}
		void done () {
			StringEnumeration sloop;
			if (_pb_old._buffer.size() > 0)
				if (_pb_new._buffer.size() > 0) {
					// Prepend "! " to each line.
					for (sloop = new StringVectorEnumerator(_pb_old._buffer);
					     sloop.hasMoreElements(); )
						_pb_old._destination.addElement(prep_exclam(sloop.nextElement()));
					for (sloop = new StringVectorEnumerator(_pb_new._buffer);
					     sloop.hasMoreElements(); )
						_pb_new._destination.addElement(prep_exclam(sloop.nextElement()));
				} else {
					// Prepend "- " to each old line.
					for (sloop = new StringVectorEnumerator(_pb_old._buffer);
					     sloop.hasMoreElements(); )
						_pb_old._destination.addElement(prep_minus(sloop.nextElement()));
				}
			else
				if (_pb_new._buffer.size() > 0) {
					// Prepend "+ " to each new line.
					for (sloop = new StringVectorEnumerator(_pb_new._buffer);
					     sloop.hasMoreElements(); )
						_pb_new._destination.addElement(prep_plus(sloop.nextElement()));
				} else {
					// Nothing.
				}
			_pb_old._buffer.removeAllElements();
			_pb_new._buffer.removeAllElements();
		}
	}

	/* 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 = "ud2cd";
		}
		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;
				UnidiffHunkParams hunk_params = UnidiffHunkParse.parseUnidiffHunkLine(_line);
				if (hunk_params == null)
					break;
				int old_start_line = hunk_params.old_start_line;
				int new_start_line = hunk_params.new_start_line;
				int old_end_line = hunk_params.old_start_line
				                   + hunk_params.old_line_count - 1;
				int new_end_line = hunk_params.new_start_line
				                   + hunk_params.new_line_count - 1;
				int old_line_count = hunk_params.old_line_count;
				int new_line_count = hunk_params.new_line_count;
				StringVector old_lines = new StringVector();
				StringVector new_lines = new StringVector();
				boolean no_old_lines = true;
				boolean no_new_lines = true;
				TwoPieceBuffer buffer = new TwoPieceBuffer(old_lines,new_lines);
				loop:
				for (;;) {
					_line = null;
					if (!((old_line_count > 0) || (new_line_count > 0)))
						break;
					prepareLine();
					if (_line == null)
						break;
					if (!(_line.length() >= 1))
						break;
					switch (_line.charAt(0)) {
						case ' ':
						{
							buffer.done();
							String sp_line = "  ".concat(_line.substring(1));
							old_lines.addElement(sp_line); old_line_count--;
							new_lines.addElement(sp_line); new_line_count--;
							break;
						}
						case '-':
						{
							buffer.add_old_line(_line.substring(1)); old_line_count--;
							no_old_lines = false;
							break;
						}
						case '+':
						{
							buffer.add_new_line(_line.substring(1)); new_line_count--;
							no_new_lines = false;
							break;
						}
						default:
							break loop;
					}
				}
				buffer.done();
				StringEnumeration sloop;
				_out_stream.writeBytes("***************\n");
				_out_stream.writeBytes("*** ");
				_out_stream.writeBytes(two_lines_string(old_start_line,old_end_line));
				_out_stream.writeBytes(" ****\n");
				if (!no_old_lines) {
					for (sloop = new StringVectorEnumerator(old_lines);
					     sloop.hasMoreElements(); ) {
						_out_stream.writeBytes(sloop.nextElement());
						_out_stream.writeBytes("\n");
					}
				}
				_out_stream.writeBytes("--- ");
				_out_stream.writeBytes(two_lines_string(new_start_line,new_end_line));
				_out_stream.writeBytes(" ----\n");
				if (!no_new_lines) {
					for (sloop = new StringVectorEnumerator(new_lines);
					     sloop.hasMoreElements(); ) {
						_out_stream.writeBytes(sloop.nextElement());
						_out_stream.writeBytes("\n");
					}
				}
				if ((old_line_count > 0) || (new_line_count > 0)) {
					System.err.print(_program_name);
					System.err.print(": Warning: Incomplete hunk ending at line ");
					System.err.print(_linenum - (_line != null ? 1 : 0));
					System.err.println();
				}
				else if ((old_line_count != 0) || (new_line_count != 0)) {
					System.err.print(_program_name);
					System.err.print(": Warning: Overly long hunk ending at line ");
					System.err.print(_linenum - (_line != null ? 1 : 0));
					System.err.println();
				}
			}
		}
		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(oldfile);
					_out_stream.writeBytes("\n");
					_out_stream.writeBytes("--- ");
					_out_stream.writeBytes(newfile);
					_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);
	}
}