#!/usr/local/bin/perl
#  Script to take arguments from FilterDB.html, and return 
# an HTML page to the client.
#
#  The script can be considered in as consisting of the following parts:
#
#	(1) Read in arguments passed to script.
#	(2) Verification of arguments.
#	(3) Make Calculations.
#	(4) Generate return HTML page
#
# J.Brewer, August 1998.
##############################################################################


##############################################################################
#       (1) Read in arguments passed to script.
##############################################################################
# Below is from Gundavaram (Nutshell book)
$webmaster = "jbrewer\@eso\.org";
&parse_form_data (*ip);

# For compactness, assign array elements to variables...
$ccd   = $ip{'ccd'};
$lbls  = $ip{'lbls'};
$lo_x  = $ip{'lo_x'};
$hi_x  = $ip{'hi_x'};
$lo_y  = $ip{'lo_y'};
$hi_y  = $ip{'hi_y'};
$filt1 = $ip{'filt1'};
$filt2 = $ip{'filt2'};
$filt3 = $ip{'filt3'};
$filt4 = $ip{'filt4'};
##############################################################################


##############################################################################
#	(2) Verification of arguments.
##############################################################################

#  Set the error flag 
$error = 0;

#  Only check graph limits; other values submitted via
# pull down menus

#  Check validity of lo wavelength limit...
if ($lo_x <= 0){
  if (! $error){&first_error;}
  print "ERROR: Unphysical low-wavelength value...\n";
}

#  Check validity of hi wavelength limit...
if ($hi_x > 1100){
  if (! $error){&first_error;}
  print "ERROR: High wavelength limit beyond silicon band-gap\n";
}

# Check that hi_x > lo_x...
if ($lo_x > $hi_x){
  if (! $error){&first_error;}
  print "ERROR: Low wavelength must be smaller than large wave\n";
}

#  Check validity of lo transmission %age limit...
if ($lo_y < -10){
  if (! $error){&first_error;}
  print "ERROR: Low TX value...\n";
}

#  Check validity of lo transmission %age limit...
if ($lo_y > 110){
  if (! $error){&first_error;}
  print "ERROR: High TX value...\n";
}

# Check that hi_y is > lo_y...
if ($lo_x > $hi_x){
  if (! $error){&first_error;}
  print "ERROR: Low tx %age must be smaller than large tx %age\n";
}

# Bail out if an error occured...
if ($error){exit(1);}
##############################################################################


##############################################################################
#	(3) Read, increment and write id number. Delete old files.
##############################################################################
#  To avoid problems with netscape caching old GIF and PS files, I
# allocate an ID number to each file that is generated. This ID number is
# also used as a strike counter

#  Open file and read in current id value...
open (FILE, "<" . strikes) || die "Cannot open strikes for reading";
$hits = <FILE>;
close (FILE);
#  Incremented id value, open file a save new id...
$hits++;
open (FILE, ">" . strikes) || die "Cannot open strikes for writing";
print FILE $hits;
close (FILE);

#  To avoid disk space problems, delete the (n-4)th files...
$old = $hits - 4;
if(-e "G$old.gif"){unlink "G$old.gif";}
if(-e "G$old.ps"){unlink "G$old.ps";}
##############################################################################

##############################################################################
#       (4) Make plot: use c-shell script calling sm...
##############################################################################

#  Force a known path (external user has no path to inherit!). This is
# needed as the sm program uses ppmtogif.
$ENV{"PATH"} = ".:/usr/local/bin/:/bin/:/usr/local/netpbm/";

open (FILE, ">" . ip4sm) || die "Cannot open ip4sm for reading";
print FILE "$ccd $lbls $lo_x $hi_x $lo_y $hi_y $filt1 $filt2 $filt3 $filt4\n";
close (FILE);

system("sm < DrawTX.sm");
rename("TEMP.gif","G$hits.gif");
rename("TEMP.ps","G$hits.ps");


##############################################################################
#	(4) Generate return HTML page
##############################################################################
 
$dateX = `date`;

print <<end_of_print1;
Content-type: text/html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
        "http://www.w3.org/TR/REC-html40/loose.dtd">


<HTML>
<HEAD>
  <TITLE>WFI Filter Transmission Plot</TITLE>
</HEAD>

<BODY BACKGROUND="gifs/eso.gif">

<HR>
<CENTER>
<TABLE WIDTH="100%">
<TR>
  <TD ALIGN=LEFT>   <IMG SRC="gifs/eso-logo.gif" ALT="[eso logo]">
  <TD ALIGN=CENTER> <H1> WFI Filter Transmission Plot</H1>
  <TD ALIGN=RIGHT>  <IMG SRC="gifs/logo.jpg" ALT="[2p2 Logo]">
</TABLE>
</CENTER>
<HR>

<BR><BR>
<H2> <FONT COLOR="RED"><U> Entered Parameters </U></FONT></H2>

<TABLE>
<TR>
  <TD> Plot CCD: <TD><B>$ccd </B>
  <TD> Labels:   <TD><B>$lbls </B>
<TR>
  <TD> Low X:    <TD><B>$lo_x </B>
  <TD> High X:   <TD><B>$hi_x </B>
<TR>
  <TD> Low Y:    <TD><B>$lo_y </B>
  <TD> High Y:   <TD><B>$hi_y </B>
<TR>
  <TD> Filter 1: <TD><B>$filt1 </B>
  <TD> Filter 2: <TD><B>$filt2 </B>
<TR>
  <TD> Filter 3: <TD><B>$filt3 </B>
  <TD> Filter 4: <TD><B>$filt4 </B>
</TABLE>

<BR>
<CENTER>
  <H2> (Click on graph to download PostScript)</H2>
  <A HREF="G$hits.ps"><IMG SRC=G$hits.gif ALT="Click to download PostScript"></A>
</CENTER>

<BR><BR>

<CENTER>
<TABLE BORDER=3>
<TR>
  <TH> This Page Created: <BR> $dateX
  <TH> Strikes since Sept.99: <BR> $hits
  <TH> Comments: <BR> <A HREF="mailto:jbrewer\@eso.org"> jbrewer\@eso.org </A>
</TABLE>
</CENTER>

</BODY>
</HTML>
end_of_print1
##############################################################################


##############################################################################
#	sub first error: executed the first time an error occurs...
##############################################################################
sub first_error{
  print"Content-type: text/plain","\n\n";
  print"You have entered invalid data, please return to the form and \n"; 
  print"check your input using the below diagnostics \n\n\n"; 
  $error = 1;
}


##############################################################################
#	sub parse_form_data: decode arguments...
##############################################################################
sub parse_form_data
{
	local (*FORM_DATA) = @_;

	local ( $request_method, $query_string, @key_value_pairs,
		$key_value, $key, $value);

	$request_method = $ENV{'REQUEST_METHOD'};

	if ($request_method eq "GET") {
		$query_string = $ENV{'QUERY_STRING'};
	} elsif ($request_method eq "POST") {
		read (STDIN, $query_string, $ENV{'CONTENT_LENGTH'});
	} else {
		&return_error (500, "Server Error",
				    "Server uses unsupported method");
	}

	@key_value_pairs = split (/&/, $query_string);

	foreach $key_value (@key_value_pairs) {
		($key, $value) = split (/=/, $key_value);
		$value =~ tr/+/ /;
		$value =~ s/%([\dA-Fa-f][\dA-Fa-f])/pack ("C", hex ($1))/eg;

		if (defined($FORM_DATA{key})) {
			$FORM_DATA{$key} = join ("\0", $FORM_DATA{$key}, $value);
		} else {
			$FORM_DATA{$key} = $value;
		}
	}
}


##############################################################################
#	sub return_error: Error routine for form decoding....
##############################################################################
sub return_error
{
	local($status, $keyword, $message) = @_;

	
	print "Content-type: text/html", "\n";
	print "Status: ", $status, " ", $keyword, "\n\n";

	print <<End_of_Error;

	<title>CGI Program -- Unexpected Error</title>
	<H1>$keyword</H1>
	<HR>$message<HR>
	Please contact $webmaster for more information.

End_of_Error

	exit(1);
}