#!/usr/bin/perl

##
##  Program Name:        tsr (Tcrofut Search and Replace)
##  Author:                Timothy M. Crofut
##  Date:                Fri Apr 27 09:14:01 EDT 2001
##  File Type:                perl script
##
##  Purpose:                To replace a pattern with another pattern
##                      in the specified files of an entire
##                      subdirectory tree.


##
## set module-scoped variables and 'constants'.
##
$TRUE  = "true";
$FALSE = "false";
$HOME  = $ENV{"HOME"};
$USER  = $ENV{"USER"};
$USER =~ tr/a-z/A-Z/;
$USER_Length = length( $USER );
$DATE  = &getDate;
$ARGC  = @ARGV;

$CVS_LOG_DIR         = $HOME . "/.cvs_log";
$TEMP_FILE_EXTENTION = ".TSR";
$SEARCH_PATTERN      = "";
$REPLACE_PATTERN     = "";
$FILES_PATTERN       = "*";
$TSR_METAFILE        = "";
$TSR_METAFILE_EXT    = ".tsrm";
$ANNOTATE            = $FALSE;
$PRINT_FILE_NAMES    = $TRUE;
$PRINT_LINE_NUMBERS  = $FALSE;

##
## set some default values.
##
$cmd_str       = "";
$previous_file = "";


##
## loop through the command line arguments screening for tsr flags.
##
for( $i=0; $i<$ARGC; $i++ )
{
  $_ = $ARGV[$i];

  if( /^-s$/ )
  {
    $SEARCH_PATTERN = $ARGV[++$i];
    ##printf stdout "SEARCH_PATTERN: ->%s<-\n", $SEARCH_PATTERN;
  }
  elsif( /^-r$/ )
  {
    $REPLACE_PATTERN = $ARGV[++$i];
    ##printf stdout "REPLACE_PATTERN: ->%s<-\n", $REPLACE_PATTERN;
  }
  elsif( /^-f$/ )
  {
    $FILES_PATTERN = $ARGV[++$i];
    ##printf stdout "FILES_PATTERN: ->%s<-\n", $FILES_PATTERN;
  }
  elsif( /^-a$/ )
  {
    $ANNOTATE = $TRUE;
  }
  elsif( /^-fn$/ )
  {
    $PRINT_FILE_NAMES = $TRUE;
  }
  elsif( /^-ln$/ )
  {
    $PRINT_LINE_NUMBERS = $TRUE;
  }
  elsif( /^-MF$/ )
  {
    $TSR_METAFILE = $ARGV[++$i];
    ##printf stdout "TSR_METAFILE: ->%s<-\n", $TSR_METAFILE;

    if( $TSR_METAFILE eq "" )
    {
      &listTsrMetafiles;
      &cleanup;
    }
    else
    {
      if( ! (-f $CVS_LOG_DIR . "/" .
		$TSR_METAFILE . $TSR_METAFILE_EXT) )
      {
	$NEW_TSR_METAFILE = $TSR_METAFILE;
	$TSR_METAFILE = "";
	$_ = "";

	while( (! /^Y/) && (! /^N/) )
	{
	  printf stdout "!! Attention !!\n";
	  printf stdout "The tsr metafile you have specified ('" .
		        $NEW_TSR_METAFILE . "')\n";
          printf stdout "does NOT exist, would you like to" .
			" create it (Y/N) ? ";
	  $_ = <stdin>;
	  chop;
	  $_ =~ tr/[a-z]/[A-Z]/;
	}

	if( ! /^Y/ )
	{
	  &cleanup;
	}
      }
    }
  }
  elsif( /^-h$/ || /^-help$/ )
  {
    &showHelp;
  }
  else
  {
    @FILE_LIST = splice( @ARGV, $i );
    ##printf "FILE_LIST: ->%s<-\n", join( ' ', @FILE_LIST );
    $i = $ARGC;
  }
}

##
## if no search pattern specified, cleanup.
##
if( $SEARCH_PATTERN eq "" )
{
  printf "Error: tsr - No search pattern specified\n";
  &usage;
  &cleanup( 1 );
}


##
## if a tsr metafile was specified on the command line,
## use its contents as the list of source files.
##
if( $TSR_METAFILE ne "" )
{
  $cmd_str = $CVS_LOG_DIR . "/" . $TSR_METAFILE .  $TSR_METAFILE_EXT;
}
elsif( $NEW_TSR_METAFILE ne "" )
{
  $cmd_str = "find . -name \"" . $FILES_PATTERN . "\" |";
}
##
## if files were specified on the command line,
## search through the specified files, otherwise
## maintain default of searching through ALL files.
##
elsif( $FILES_PATTERN ne "" )
{
  $cmd_str = "find . -name \"" . $FILES_PATTERN . "\" |";
}


if( $cmd_str ne "" )
{
  ##
  ## open pipe to the command.
  ##
  open( pCmd, $cmd_str ) ||
      die "Error: tsr - Unable to open '" . $cmd_str . "' command";

  $file_count = 0;
  while( <pCmd> )
  {
    chop;
    ( @FILE_LIST[$file_count++], @junk ) = split( ':' );
  }
  close( pCmd );
}

if( @FILE_LIST )
{
  if( $NEW_TSR_METAFILE ne "" )
  {
    $NEW_TSR_METAFILE_PATH = $CVS_LOG_DIR . "/" . $NEW_TSR_METAFILE .
			     $TSR_METAFILE_EXT;
    printf stdout "NEW_TSR_METAFILE_PATH: ->%s<-\n",
                  $NEW_TSR_METAFILE_PATH;
    open( pNewTsrMetafile, "> $NEW_TSR_METAFILE_PATH" ) ||
      die "Error: tsr - Unable to create tsr metafile '" .
          $NEW_TSR_METAFILE . "'";
  }

  foreach $input_file ( @FILE_LIST )
  {
    if( pNewTsrMetafile )
    {
      printf pNewTsrMetafile "%s\n", $input_file;
    }

    if( $input_file eq $previous_file )
    {
      next;
    }
    $previous_file = $input_file;
    $_ = $input_file;
  
    ##
    ## do not process the current and parent directory entries.
    ##
    if( /^\.$/ || /^\.\.$/ )
    {
      next;
    }
  
    if( $ANNOTATE eq $TRUE )
    {
      @ANNOTATION = &getAnnotation( $input_file );
    }
  
    ##
    ## open the input file for read.
    ##
    if( ! open( pInputFile, $input_file ) )
    {
      printf stderr "Error: tsr - Unable to open file '" .
                    $_ . "' for read\n";
      next;
    }
    ##
    ## open the temp output file for write.
    ##
    if( $REPLACE_PATTERN ne "" )
    {
      $temp_file = $input_file . $TEMP_FILE_EXTENTION;
      open( pOutputFile, "> $temp_file" ) ||
          die "Error: tsr - Unable to open temp output file '" .
              $temp_file . "' for write";
    }
  
    $line_count = 0;
    while( <pInputFile> )
    {
      ++$line_count;
      chop;
      if( /$SEARCH_PATTERN/ )
      {
  
        if( $REPLACE_PATTERN ne "" )
        {
          printf stdout "MATCH FOUND in '%s' ...", $input_file;
  
          if( @ANNOTATION[0] ne "" )
          {
            printf pOutputFile "%s\n", $ANNOTATION[0];
            printf pOutputFile "%s\n", $_;
            printf pOutputFile "%s\n", $ANNOTATION[1];
  
            s/$SEARCH_PATTERN/$REPLACE_PATTERN/g;
            printf pOutputFile "%s\n", $_;
            printf pOutputFile "%s\n", $ANNOTATION[2];
          }
          else
          {
            s/$SEARCH_PATTERN/$REPLACE_PATTERN/g;
            printf pOutputFile "%s\n", $_;
          }
          printf stdout "REPLACED.", $input_file;
          printf stdout "\n";
        }
        else
        {
          if( $PRINT_FILE_NAMES eq $TRUE )
          {
            printf stdout "%s:", $input_file;
          }
          if( $PRINT_LINE_NUMBERS eq $TRUE )
          {
            printf stdout "%d:", $line_count;
          }
          printf stdout "%s\n", $_;
        }
      }
      else
      {
        print pOutputFile $_, "\n";
      }
    }
    if( pInputFile )
    {
      close( pInputFile );
    }
    if( $REPLACE_PATTERN )
    {
      close( pOutputFile );
  
      ##
      ## rename the temp file to replace the original file.
      ##
      system( "mv " . $temp_file . " " . $input_file );
    }
  }

  if( pNewTsrMetafile )
  {
    close( pNewTsrMetafile );
  }
}
else
{
  printf "Error: tsr - No files specified.\n";
  &usage;
  &cleanup;
}


##----- sub getAnnotation -----
sub getAnnotation
{
  local( $_ ) = @_;
  local( @annotation )      = null;
  local( $file_type_known ) = $FALSE;
  local( $open_comment )    = "";
  local( $hang_comment )    = "";
  local( $close_comment )   = "";

  if( /\.c$/ || /\.reg$/ || /\.h$/ )
  {
    $open_comment    = "/*";
    $hang_comment = "* /";
    $close_comment   = "*/";
    $file_type_known = $TRUE;
  }
  elsif( /\.html$/ )
  {
    $open_comment  = "<!-- ";
    $hang_comment  = "";
    $close_comment = " -->";
    $file_type_known = $TRUE;
  }

  if( $file_type_known eq $TRUE )
  {
    @annotation[0] = $open_comment . "tsr-annotation{ ===== " .
                     $USER . " " .  $DATE .  " =====" .
                     $hang_comment;
    @annotation[1] = $open_comment .
		     "-" x ( length(@annotation[0]) -4 ) .
		     $close_comment;
    @annotation[2] = $open_comment .
                     "tsr-annotation} " .
		     "=" x (length(@annotation[0]) -
			 length("tsr-annotation{ ") -4) .
		     $close_comment;
  }

  return @annotation;
}


##----- sub listTsrMetafiles -----
sub listTsrMetafiles
{
  local( $cmd_str ) = "cd " . $CVS_LOG_DIR . "; ls *" .
                      $TSR_METAFILE_EXT;

  open( pCmd, "$cmd_str |" ) ||
      die "Error: cvs - Unable to open '" . $cmd_str .
      "' command pipe";
  while( <pCmd> )
  {
    chop;
    @fields = split( /\./, $_ );
    printf stdout "%s\n", @fields[0];
  }
  close( pCmd );

}


##----- sub getDate -----
sub getDate
{
  local( $date ) = "";
  local( $cmd_str );

  $cmd_str = "date";
  open( pDateCmd, "$cmd_str |" ) ||
      die "Error: tsr - Unable to open '" . $cmd_str .
          "' command pipe";
  $date = <pDateCmd>;
  chop $date;
  close( pDateCmd );

  return $date;
}


##----- sub usage -----
sub usage
{
  printf stdout "Usage: tsr [-h[elp]] [-s] [-r] [-f] [-a] [-ln]" .
                " [-MF [tsr metafile]] [file specs]\n";
}


##----- sub showHelp -----
sub showHelp
{
  &usage;

  printf stdout "\n";
  printf stdout "  flags:\n";
  printf stdout "   -h,-help             display this help info.\n";
  printf stdout "   -s <search pattern>  pattern for which to" .
                " search\n";
  printf stdout "   -r <replace pattern> pattern with which to" .
                " replace 'search pattern'\n";
  printf stdout "   -f <file spec>       files in which to" .
                " perform search/replace\n";
  printf stdout "   -a                   create annotations" .
                " (comments) arround search and\n" .
                "                          replace patterns" .
                " in target files\n";
  printf stdout "   -ln                  print line numbers\n";
  printf stdout "   -MF [metafile]        'metafile' contains names of" .
                " modules (one per line)\n" . 
                "                          upon which to perform the" .
                " specified command.  If\n" .
                "                          'metafile' not specified" .
                ", returns list of available\n" .
                "                          metafiles\n";
  ##printf stdout "   -fn          print file names\n";
  &cleanup( 0 );
}


##----- sub cleanup -----
sub cleanup
{
  local( $exit_code ) = @_;

  exit $exit_code;
}