#!/usr/local/bin/perl

use Getopt::Std;

$dir = "/data/ssf/1/obsred";
$suffix = ".fits";
$maxFile = 9999;

getopts('d:s:');
$dir = $opt_d if $opt_d ne "";
$suffix = $opt_s if $opt_s ne "";

$argc = @ARGV;
die "Usage: $0 [-d dir] [-s suffix] id date start end\n" if $argc != 4;

($id, $date, $start, $end) = @ARGV;
die "'start' must be less than or equal to 'end'\n" if $start > $end;

$listFile = "LIST$id";
if ( -f $listFile)
    {
    print "File '$listFile' exists. Do you want to overwrite it (y/n)? ";
    $overwrite = getc;
    die "File '$listFile' kept.\n" if $overwrite ne "y"; 
    }

open(LIST, ">$listFile");

for ($i = $start; $i <= $end; $i++)
    {
    $name = sprintf("%s/%s%04d%s", $dir, $date, $i, $suffix);
    if (-r $name)
        {
        print LIST "$name\n";
        }
    else
        {
        print "File '$name' not found.\n";
        }
    }

close(LIST);

# ok, this next bit is a real kludge, but I couldn't think of a nice
# way to do it on short notice.

for ($i = $end + 1; $i <= $maxFile; $i++)
    {
    $name = sprintf("%s/%s%04d%s", $dir, $date, $i, $suffix);
    if (-f $name)
        {
        $endName = sprintf("%s/%s%04d%s", $dir, $date, $end, $suffix);
        print stderr "Files more recent than '$endName' exist.\n";
        last;
        }
    }

print "File '$listFile' written.\n";
print "Now type:\n";
print "    imstack \@LIST$id cube$id\n";
print "    blkavg cube$id\[31:60,*,*\] spec$id 30 30 1\n";
print "    splot spec$id\n";