#!/usr/bin/perl

use Time::Local;

# Routine to make PDS labels and proper FITS files for the NNSN data.
#
# Format: % makelbl nnsn.hdr
#
# Output is to nnsn.lbl, nnsn.fit; nnsn.hdr and nnsn.img are removed
#
# 16 May 2006, A.C.Raugh
#=======================================================================

if (@ARGV==0)
  { die "Usage: makelbl nnsn.hdr\n"; }

foreach $file (@ARGV)
  { if ($file !~ /\.hdr/)
      { printf STDERR "$file is not a FITS header, is it?\n";
        next;
      }

    # Find and open files:

    $name = $file;
    $name =~ s/\.hdr//;

    $lblfile = "$name.lbl";
    $imgfile = "$name.img";
    $hdrfile = "$name.hdr";
    $fitfile = "$name.fit";

    $FILE = $fitfile;
    $FILE =~ tr/a-z/A-Z/;

    open(FIT,$file) || die "Could not open $file for reading ($!)";
    open(LBL,"| ppodl -p >new/$lblfile") || 
        die "Could not open $lblfile for writing ($!)";

    # We'll completely parse the FITS header first, then write the label.

    $target = "1P/HALLEY 1 (1682 Q1)";
    $cc = 0;
    read FIT, $line, 80;
    $lc = 1;
    while ($line !~ /^END /)
      { if ($line =~ /^NAXIS1/)
          { $samples = substr($line,27,3); }
        elsif ($line =~ /^NAXIS2/)
          { $lines   = substr($line,27,3); }
        elsif ($line =~ /^BITPIX/)
          { $sample_bits = substr($line,28,2); }
        elsif ($line =~ /^FILE-NUM/)
          { $filenum = substr($line,24,6); }
        elsif ($line =~ /^DATE-OBS/)
          { $dd = substr($line,11,2);
            $mm = substr($line,14,2);
            $yy = substr($line,17,2);
            $date = "19$yy-$mm-${dd}T";
          }
        elsif ($line =~ /^TIME-OBS/)
          { $d = substr($line,20,10);
            $d = $d * 24.0;
            $hh = int($d);
            $d = ($d - $hh) * 60.0;
            $mm = int($d);
            $d = ($d - $mm) * 60.0;
            $ss = int($d + 0.5);
            if ($ss == 60)
              { $ss = 0;
                $mm++;
              }
            if ($mm == 60)
              { $mm = 0;
                $hh++;
              }
            $time = sprintf "%02d:%02d:%02d",$hh, $mm, $ss;
          }
        elsif ($line =~ /^LONG-OBS/)
          { $dd = substr($line,11,3);
            $mm = substr($line,15,2);
            $ss = substr($line,18,2);
            $val = ($dd * 1.0) + ($mm / 60.0) + ($ss / 3600.0);
            $obs_long = sprintf "%8.4f",$val;
          }
        elsif ($line =~ /^LAT--OBS/)
          { $s  = substr($line,11,1);
            $dd = substr($line,12,2);
            $mm = substr($line,15,2);
            $ss = substr($line,18,2);
            $val = ($dd * 1.0) + ($mm / 60.0) + ($ss / 3600.0);
            $obs_lat = sprintf "%s%07.4f",$s,$val;
          }
        elsif ($line =~ /^SYSTEM/)
          { $system = substr($line,11,8); }
        elsif ($line =~ /^OBSERVER= '([^']+)' \//)
          { $observer = $1;
            $observer =~ s/\s+$//;
          }
        elsif ($line =~ /^INSTRUME/)
          { $instrument = substr($line,11,60);
            $instrument =~ s/'\s+$//;
          }
        elsif ($line =~ /^OBSVTORY/)
          { $line =~ /'([^']+)'/;
            $observatory = $1;
            $observatory =~ s/\s+$//;
          }
        elsif ($line =~ /^ELEV-OBS/)
          { $elevation = substr($line,25,5); 
            $elevation =~ s/\s+//;
          }
        elsif ($line =~ /^TELESCOP/)
          { $line =~ /'([^']+)'/;
            $telescope = $1;
            $telescope =~ s/'\s+//;
          }
        elsif ($line =~ /^APERTURE/)
          { $aperture = substr($line,25,5); 
            $aperture =~ s/\s+//g;
          }
        elsif ($line =~ /^TELEFL/)
          { $focal_len = substr($line,21,10);
            $focal_len =~ s/\s+//g;
          }
        elsif ($line =~ /^PLTSCALE/)
          { $plate_scale = substr($line,21,10);
            $plate_scale =~ s/\s+//g;
          }
        elsif ($line =~ /^CROTA1/)
          { $pa = substr($line,21,10);
            $pa =~ s/\s+//g;
            $pa = $pa * 1.0;
          }
        elsif ($line =~ /^SENSE/)
          { $pa = (substr($line,29,1) eq "T")? $pa : 360.0 - $pa; }
        elsif ($line =~ /^DETECTOR/)
          { $detector = substr($line,11,40);
            $detector =~ s/\s*'.*//;
          }
        elsif ($line =~ /^DIGITIZE/)
          { $digitize = substr($line,11,40);
            if ($digitize !~ /^\s+'/)
              { $digitize =~ s/\s*'.*$//; }
            else
              { undef $digitize; }
          }
        elsif ($line =~ /^APSIZE/)
          { $apsize = substr($line,24,6);
            $apsize =~ s/\s+//g;
          }
        elsif ($line =~ /^FILTER\s+= '([^']+)' /)
          { $filter_name = $1; 
            $filter_name =~ s/\s+$//; $filter_name =~ s/\s+/_/g;
          }
        elsif ($line =~ /^EXPOSURE/)
          { $exposure = substr($line,23,7); }
        elsif ($line =~ /^AIRM-MID/)
          { $airmass = substr($line,25,5); }
        elsif ($line =~ /^QUALITY/)
          { $line =~ /'([^']+)'/;
            $quality = $1;
            $quality =~ s/\s+$//;
          }
        elsif ($line =~ /^BUNIT/)
          { $unit = substr($line,11,20);
            $unit =~ s/\s*'\s+//;
          }

        elsif ($line =~ /^COMMENT/)
          { $val = substr($line,8,72);
            $val =~ s/^\s+//;
            $val =~ s/\s+$//;
            $val =~ s/"/''/g;
            $comment[$cc] = "  $val";
            $cc++;
          }
        elsif ($line =~ /^HISTORY/)
          { $val = substr($line,8,72);
            $val =~ s/^\s+//;
            $val =~ s/\s+$//;
            $comment[$cc] = "  $val";
            $cc++;
          }

        # Next line:

        read FIT,$line,80;
        $lc++;
      }

    # Done with the FITS file.

    close(FIT);
    $sample_bytes = $sample_bits / 8;
    $lc = $lc / 36.0;
    $header_records = ($lc == int($lc))? $lc : (int($lc)+1);
    $lc = ($lines * $samples * $sample_bytes) / 2880;
    $data_records   = ($lc == int($lc))? $lc : (int($lc)+1);
    $file_records = $header_records + $data_records;

    $pas = $plate_scale * $apsize;

    # We calculate the start time by taking the observation time and 
    # substracting half the exposure time:

    $obstime = $date . $time;
    $year = substr($date,0,4);
    $mon  = substr($date,5,2)-1;
    $day  = substr($date,8,2);
    $hour = substr($time,0,2);
    $min  = substr($time,3,2);
    $sec  = substr($time,6,2);
    $timeobs = timelocal($sec,$min,$hour,$day,$mon,$year);
    $time = $timeobs - ($exposure / 2.0);
    ($sec,$min,$hour,$day,$mon,$year) = localtime($time);
    $year += 1900;
    $mon++;
    $start_time = sprintf "%4d-%02d-%02dT%02d:%02d:%02d", 
                          $year, $mon, $day, $hour, $min, $sec;
    $time = $timeobs + ($exposure / 2.0);
    ($sec,$min,$hour,$day,$mon,$year) = localtime($time);
    $year += 1900;
    $mon++;
    $stop_time = sprintf "%4d-%02d-%02dT%02d:%02d:%02d", 
                          $year, $mon, $day, $hour, $min, $sec;

    # Now we write the PDS label:

    printf LBL "PDS_VERSION_ID = PDS3\n\n";
    printf LBL "RECORD_TYPE = \"FIXED_LENGTH\"\n";
    printf LBL "RECORD_BYTES = 2880\n";
    printf LBL "FILE_RECORDS = $file_records\n\n";
    printf LBL "DATA_SET_ID = \"IHW-C-NNSN-3-EDR-HALLEY-V2.0\"\n";
    printf LBL "PRODUCT_ID = \"$name\"\n";
    printf LBL "PRODUCT_NAME = \"IHW NNSN IMAGE $filenum\"\n";
    printf LBL "PRODUCT_CREATION_TIME = 2006-05-16\n";
    printf LBL "\n";
    printf LBL "INSTRUMENT_HOST_NAME = \"IHW NEAR-NUCLEUS STUDIES NETWORK\"\n";
    printf LBL "INSTRUMENT_HOST_ID = \"NNSN\"\n";
    printf LBL "INSTRUMENT_NAME = \"IHW NEAR-NUCLEUS STUDIES NETWORK\"\n";
    printf LBL "INSTRUMENT_ID = \"NNSN\"\n";
    printf LBL "TARGET_NAME = \"$target\"\n";
    printf LBL "START_TIME = $start_time\n";
    printf LBL "STOP_TIME = $stop_time\n";
    printf LBL "\n";
    printf LBL "OBSERVATION_TIME = $obstime\n";
    printf LBL "OBSERVATION_ID = \"$filenum\"\n";
    printf LBL "OBSERVER_FULL_NAME = \"$observer\"\n";
    printf LBL "FILTER_NAME = $filter_name\n";
    printf LBL "EXPOSURE_DURATION = $exposure <SECOND>\n";
    printf LBL "AIRMASS = $airmass\n";
    printf LBL "DATA_QUALITY_DESC = \"$quality\"\n";
    printf LBL "\n";
    printf LBL "DESCRIPTION = \"\n";
    printf LBL "System code: $system\n";
    printf LBL "Observatory Info\n";
    printf LBL "            Name: $observatory\n";
    printf LBL "       Elevation: $elevation\n";
    printf LBL "  East Longitude: $obs_long\n";
    printf LBL "  North Latitude: $obs_lat\n";
    printf LBL "       Telescope: $telescope\n";
    printf LBL "                  aperture $aperture meters\n";
    printf LBL "                  effective focal length $focal_len meters\n";
    printf LBL "        Detector: $detector\n";
    printf LBL "       Digitizer: $digitize\n" if ($digitize);
    printf LBL "     Plate Scale: $plate_scale arsec/mm\n";
    printf LBL "\n";
    printf LBL "Comments from the FITS header:\n";
    printf LBL "\n";
    for ($i=0; $i<$cc; $i++)
      { printf LBL "$comment[$i]\n"; }
    printf LBL "\"\n";
    printf LBL "\n";
    printf LBL "^FITS_HEADER = (\"$file\",1)\n";
    printf LBL "^IMAGE       = (\"$file\",%d)\n",$header_records+1;
    printf LBL "\n";
    printf LBL "OBJECT = FITS_HEADER\n";
    printf LBL "HEADER_TYPE = \"FITS\"\n";
    printf LBL "RECORDS = %d\n",$header_records;
    printf LBL "BYTES = %d\n", $header_records * 2880;
    printf LBL "DESCRIPTION = \"FITS Standard NOST 100-2.0\"\n";
    printf LBL "END_OBJECT = FITS_HEADER\n";
    printf LBL "\n";
    printf LBL "OBJECT = IMAGE\n";
    printf LBL "LINES = $lines\n";
    printf LBL "LINE_SAMPLES = $samples\n";
    printf LBL "SAMPLE_BITS = $sample_bits\n";
    printf LBL "SAMPLE_TYPE = \"MSB_INTEGER\"\n";
    printf LBL "UNIT = \"$unit\"\n" if ($unit);
    printf LBL "AXIS_ORDER_TYPE = \"FIRST_INDEX_FASTEST\"\n";
    printf LBL "LINE_DISPLAY_DIRECTION = \"DOWN\"\n";
    printf LBL "SAMPLE_DISPLAY_DIRECTION = \"RIGHT\"\n";
    printf LBL "PIXEL_ANGULAR_SCALE = (%4.2f,%4.2f)\n",$pas,$pas;
    printf LBL "DESCRIPTION = \"\n";
    printf LBL "    Plate scale: $plate_scale arcsec/mm\n";
    printf LBL "     Pixel size: $apsize mm/pixel\n\n";
    printf LBL "Position angle of sample axis = $pa degrees,\n";
    printf LBL "measured counterclockwise from North to East.\n";
    printf LBL "\"\n";
    printf LBL "END_OBJECT = IMAGE\n";
    printf LBL "\n";
    printf LBL "END\n";

    # Done with the label:

    close(LBL);

    # Create the full FITS file:

    system "cat $hdrfile $imgfile > new/$fitfile";

    # Next file:

  }