#!/usr/bin/perl
#
# MAKE1DSPEC constructs an empty 1dspec file to hold 1d spectra extracted
#            from a 1dspec file using the write command in viewspectra
#
#  USAGE:  make1dspec filename
#
#  DATE:   01 Feb 06

use lib "$ENV{'COSMOS_HOME'}/lib/perl";
use lib "$ENV{'COSMOS_HOME'}/lib/perl/i386";
use PDL;
use PDL::AutoLoader;
use PDL::IO::Misc;
use PDL::ImageND;
use PDL::NiceSlice;
use Astro::FITS::CFITSIO;

########################### default parameters ################################

$file=shift;
$file=~s/_2spec//;
$twodfile=$file."_2spec.fits";
$onedfile=$file."_1spec.fits";

# open 2dspec file

if($fptr){$fptr->close_file($status);}
if(!(-e $twodfile)){
  die("file $twodfile cannot be found");}
$status=0;
$fptr=Astro::FITS::CFITSIO::open_file($twodfile,Astro::FITS::CFITSIO::READONLY
                                      (),$status);
if($status){
  die("Error $status opening file");}
$fptr->get_img_parm($bitpix,undef,$naxes,$status);
($size,$wid,$npln)=@$naxes;
$FOBJ=zeroes($size);
if($npln != 2){
  die("input file is not a 2dspec file");}
$sz=$size-1;
$status=0;
$fptr->read_key(Astro::FITS::CFITSIO::TFLOAT(),"CRVAL1",$lambda0,undef,
                $status);
if($status){
  die("Error reading file $file header CRVAL1");}
$fptr->read_key(Astro::FITS::CFITSIO::TFLOAT(),"CDELT1",$dlambda,undef,
                $status);
if($status){
  die("Error reading file $file header CDELT1");}
$fptr->read_key(Astro::FITS::CFITSIO::TFLOAT(),"EXPTIME",$exptime,undef,
                $status);
if($status){
  die("Error reading file $file header EXPTIME");}
$fptr->read_key(Astro::FITS::CFITSIO::TFLOAT(),"N_SLITS",$nspec,undef,
                $status);
if($status){
  die("Error reading file $file header N_SLITS");}
$status=0;

# create 1dspec filej

$status=0;
$optr=Astro::FITS::CFITSIO::create_file($onedfile,$status);
if($status){
  die("Error $status creating file $file");}

# write blank spectra

for($nobj=1;$nobj<=$nspec;$nobj++){
  
  #read spectrum parameters
  $status=0;
  $fptr->movabs_hdu($nobj,undef,$status);
  if($status){
    die("cannot find spectrum $nobj");}
  $fptr->get_img_parm($bitpix,undef,$naxes,$status);
  if($status){
    die("Error reading spectrum $nobj parameters");}
  ($size,$wid,$npln)=@$naxes;
  $fptr->read_key(Astro::FITS::CFITSIO::TSTRING(),"OBJECT",$objname,undef,
                  $status);
  $fptr->read_key(Astro::FITS::CFITSIO::TINT(),"SLITNUM",$slitnum,undef,
                  $status);
  if($status){
    die("Error reading spectrum $nobj parameters");}
  
  #write blank spectrum

  @naxes=[$size];
  $optr->create_img(Astro::FITS::CFITSIO::FLOAT_IMG(),1,@naxes,$status);
  if($status){
    die("Error $status creating image");}  
  $optr->write_key(Astro::FITS::CFITSIO::TFLOAT(),"CRVAL1",$lambda0,undef,
                   $status);
  $optr->write_key(Astro::FITS::CFITSIO::TFLOAT(),"CDELT1",$dlambda,undef,
                   $status);
  $optr->write_key(Astro::FITS::CFITSIO::TSTRING(),"OBJECT",$objname,undef,
                   $status);
  $optr->write_key(Astro::FITS::CFITSIO::TINT(),"SLITNUM",$slitnum,undef,
                   $status);
  if($status){printf("Error $status writing file\n");}
  if($nobj==1){
    $optr->write_key(Astro::FITS::CFITSIO::TINT(),"N_SLITS",$nspec,undef,
                   $status);
    if($status){printf("Error $status writing file\n");}
    $optr->write_key(Astro::FITS::CFITSIO::TFLOAT(),"EXPTIME",$exptime,undef,
                   $status);
  if($status){printf("Error $status writing file\n");}
  }
  $optr->write_pix(Astro::FITS::CFITSIO::TFLOAT(),[1,1],$size,
                   $FOBJ->get_dataref,$status);
  if($status)
  {die("Error $status writing file");}
}
$optr->close_file($status);