#!/usr/bin/perl

# Routine to adjust the comments in the *centers.lbl files to indicate that 
# given coordinates are 1-based.  To do this, we'll just be rewriting the
# label DESCRIPTION field and the DESCRIPTION of two of the columns.
#
# Descends recursively through directories starting with cwd.
#
#=============================================================================

use File::Find;

# Run:

find({wanted=>\&fixit},".");

# That's it for the main routine.

#----------------------------------------------------------------------------

sub fixit
  # Routine to fix the "*_centers.lbl" files DESCRIPTION fields for the TABLE
  # object and two of the COLUMN objects.  All other files are ignored.  We 
  # are CDed to the local directory when this routine is called.

{ my ($filename, $line);
  my $TMPFILE = "zzzTMP";

  $filename = $_;

  return if ($filename !~ /_centers\.lbl$/);

  # Open files:

  open (OLD, "varlen -rmcr $filename |") ||
    die "Could not open $File::Find::name pipe for reading ($!).";

  open (NEW, "| fixlen -c > $TMPFILE") ||
    die "Could not open $file::Find::dir/$TMPFILE pipe for writing ($!).";

  
  # First we loop through the label looking for the first DESCRIPTION, which
  # will be the TABLE description:

  $line =<OLD>;
  while ($line !~ /\s*DESCRIPTION\s*=/)
    { printf NEW $line;
      $line = <OLD>;
    }

  # Now we want to read past all of the DESCRIPTION.  Regardless of file type,
  # it takes at least one more line.  We'll loop until we find a closing quote,
  # assuming that the file is syntactically correct, of course:

  $line = <OLD>;
  while ($line !~ /\"/)
    { $line = <OLD>; }

  # We now output the new DESCRIPTION, which depends on the file name:

  if ($filename =~ /^comet/)
    { printf NEW 
  " DESCRIPTION                       = \"(x,y) position of the center\n";
      printf NEW
  "        of comet 9P/Tempel 1 on the archived reduced CCD images.\n";
      printf NEW
  "        The first pixel is (1,1).\"\n";
    }

  else
    { printf NEW 
  " DESCRIPTION                       = \"(x,y) positions of the centers\n";
      printf NEW
  "        of standard stars in the Landolt star field on the archived\n";  
      printf NEW
  "        reduced CCD images.  The first pixel is (1,1).\"\n";
    }

  # That takes care of the TABLE description.  Now we need to find the two
  # columns that need their descriptions updated.  We'll look for them by 
  # name, stopping when we find the name "X_CENTER":

  $line = <OLD>;

  while ($line !~ /^\s*NAME\s*=\s*"X_CENTER"/)
    { printf NEW $line;
      $line=<OLD>;
    }
  printf NEW $line;

  # Now we want the next DESCRIPTION field:

  $line = <OLD>;
  while ($line !~ /^\s*DESCRIPTION\s*=/)
    { printf NEW $line;
      $line = <OLD>;
    }

  # As before, we want to delete this DESCRIPTION and replace it with a new
  # one. It may run one or two lines:

  if ($line !~ /^\s*DESCRIPTION\s*=\s*".*"\s*$/)
    { $line = <OLD>; 
      if ($line !~ /^\s*[^"=]*"\s*$/)
        { printf STDERR "Couldn't find end of X_CENTER.DESCRIPTION in";
          printf STDERR "$File::Find::name.\n";
          close(OLD);
          close(NEW);
          return;
        }
    }

  # Now we add our new DESCRIPTION:

  $line = "  DESCRIPTION                      = \"x-coordinate of the center\n";
  printf NEW $line;
  if ($filename =~ /^comet/)
    { $line = "        of the comet.  First pixel is (1,1).\"\n"; }
  else
    { $line = "        of the star.  First pixel is (1,1).\"\n"; }
  printf NEW $line;

  # And we repeat the entire process for the Y_CENTER column:

  $line = <OLD>;

  while ($line !~ /^\s*NAME\s*=\s*"Y_CENTER"/)
    { printf NEW $line;
      $line=<OLD>;
    }
  printf NEW $line;

  # Now we want the next DESCRIPTION field:

  $line = <OLD>;
  while ($line !~ /^\s*DESCRIPTION\s*=/)
    { printf NEW $line;
      $line = <OLD>;
    }

  # As before, we want to delete this DESCRIPTION and replace it with a new
  # one. It may run one or two lines:

  if ($line !~ /^\s*DESCRIPTION\s*=\s*".*"\s*$/)
    { $line = <OLD>; 
      if ($line !~ /^\s*[^"=]*"\s*$/)
        { printf STDERR "Couldn't find end of Y_CENTER.DESCRIPTION in";
          printf STDERR "$File::Find::name.\n";
          close(OLD);
          close(NEW);
          return;
        }
    }

  # Now we add our new DESCRIPTION:

  $line = "  DESCRIPTION                      = \"y-coordinate of the center\n";
  printf NEW $line;
  if ($filename =~ /^comet/)
    { $line = "        of the comet.  First pixel is (1,1).\"\n"; }
  else
    { $line = "        of the star.  First pixel is (1,1).\"\n"; }
  printf NEW $line;

  # And now we loop to the end of the label:

  while ($line=<OLD>)
    { printf NEW $line; }

  # And we're done:

  close(OLD);
  close(NEW);
  rename $TMPFILE, $filename;

  return;
}