#!/usr/local/bin/perl

require "../../cgi-lib.pl";

&ReadParse(*in);
print "Content-type: text/html\n\n";


OPEN(/WWW/httpd/cgi-bin/cab/goesbrowse/whirl);

#-------------------------------------------------
# Variable input from web page
#-------------------------------------------------

$sat=$in{'sat'};
$chan=$in{'chan'};
$year=$in{'year'};
$month=$in{'month'};
$dom=$in{'dom'};
$time=$in{'time'};

#-------------------------------------------------
# Set variables for satellite and channel
#-------------------------------------------------

if ($sat eq "GOES-8") {
	$sat2 = "g8";
} else {
	$sat2 = "g9";
}
if ($chan eq "Infrared") {
	$chan = "ir";
} else {
	$chan = "vis";
}

#-------------------------------------------------
# Build .gif file name for browse image based on input from user
#-------------------------------------------------

$gif=$sat2 . $chan . $dom . $month . $year . $time;

#-------------------------------------------------
# Set variables for earliest valid GOES-8 and GOES-9 dates 
#-------------------------------------------------

$g8begdate=961214;
$g9begdate=970107;
$skip=1;

#-------------------------------------------------
# Get current date (GMT) and set year, month, day and time variables
#-------------------------------------------------

$sdate = `date -u`;
$syear = substr($sdate,26,2);
$smon = substr($sdate,4,3);
$sdom = substr($sdate,8,2);
$stime = substr($sdate,11,2);

#-------------------------------------------------
# Convert current month from character to integer value
#-------------------------------------------------

if ($smon eq "Jan") {
	$snmon=1;
}
elsif ($smon eq "Feb") {
	$snmon=2;
}
elsif ($mon eq "Mar") {
	$snmon=3;
}
elsif ($mon eq "Apr") {
	$snmon=4;
}
elsif ($month eq "May") {
	$snmon=5;
}
elsif ($mon eq "Jun") {
	$snmon=6;
}
elsif ($mon eq "Jul") {
	$snmon=7;
}
elsif ($mon eq "Aug") {
	$snmon=8;
}
elsif ($month eq "Sep") {
	$snmon=9;
}
elsif ($month eq "Oct") {
	$snmon=10;
}
elsif ($mon eq "Nov") {
	$snmon=11;
}
elsif ($mon eq "Dec") {
	$snmon=12;
}

#-------------------------------------------------
# Concatenate current date/time variables 
#-------------------------------------------------

$syearmodati=($syear*1000000)+($snmon*10000)+($sdom*100)+($stime);

#-------------------------------------------------
# Convert user requested month from character to integer value
#-------------------------------------------------

if ($month eq "JAN") {
	$imon=1;
}
elsif ($month eq "FEB") {
	$imon=2;
}
elsif ($month eq "MAR") {
	$imon=3;
}
elsif ($month eq "APR") {
	$imon=4;
}
elsif ($month eq "MAY") {
	$imon=5;
}
elsif ($month eq "JUN") {
	$imon=6;
}
elsif ($month eq "JUL") {
	$imon=7;
}
elsif ($month eq "AUG") {
	$imon=8;
}
elsif ($month eq "SEP") {
	$imon=9;
}
elsif ($month eq "OCT") {
	$imon=10;
}
elsif ($month eq "NOV") {
	$imon=11;
}
elsif ($month eq "DEC") {
	$imon=12;
}

#-------------------------------------------------
# Concatenate user inputted date/time values 
#-------------------------------------------------

$iyearmoda=($year*10000)+($imon*100)+($dom);
$iyearmodati=($year*1000000)+($imon*10000)+($dom*100)+($time);

#-------------------------------------------------
# If future date requested, send error message
#-------------------------------------------------

if ($iyearmodati > $syearmodati) { 
print <<OUTPUT;
<CENTER>
<H3>
<P>
Browse images for future dates and times are not yet available!<BR>
<P>
</H3>
</CENTER>
OUTPUT
$skip=2;
}

#-------------------------------------------------
# IF GOES-8 date requested is prior to earliest 
# available date, send error message
#-------------------------------------------------

if (($sat eq "GOES-8") and ($iyearmoda < $g8begdate)) { 
print <<OUTPUT;
<CENTER>
<H3>
<P>
GOES-8 images prior to December 14, 1996 are not yet available!<BR>
<P>
</H3>
</CENTER>
OUTPUT
$skip=2;
}

#-------------------------------------------------
# IF GOES-9 date requested is prior to earliest 
# available date, send error message
#-------------------------------------------------

if (($sat eq "GOES-9") and ($iyearmoda < $g9begdate)){  
print <<OUTPUT;
<CENTER>
<H3>
<P>
GOES-9 images prior to January 07, 1997 are not yet available!<BR>
<P>
</H3>
</CENTER>
OUTPUT
$skip=2;
}

#-------------------------------------------------
# If .gif image is found, provide user with image information
# and thumbnail link to full size image
#-------------------------------------------------

print <<OUTPUT if -e "/ftp/pub/data/goesbrowse/$gif.gif";
<H2>
<P>
Image Information:<BR><BR>
</H2>
<H3>
Date:  $dom $month $year<BR>
Approximate Time:  $time UTC<BR>
Satellite:  $sat<BR>
Channel:  Infrared Channel 4<BR><BR>
Please click on the thumbnail image below for full size image.....<BR>
</H3>
</P>
<HR>
<A HREF="http://www.ncdc.noaa.gov/pub/data/goesbrowse/$gif.gif"><IMG SRC="http://www.ncdc.noaa.gov/pub/data/goesbrowse/$gif.gif" HIEGHT=200 WIDTH=267></a><BR><BR>
OUTPUT

#-------------------------------------------------
# If image requested is within range of data holdings but is missing,
# provide user with a list of possible reasons 
#-------------------------------------------------

if ($skip eq 1) {
print <<OUTPUT if not -e "/ftp/pub/data/goesbrowse/$gif.gif";
<H3>
<P>
The browse image you have requested in not available.  This could be due to several reasons, including:<BR><BR>
- An operational problem with the GOES satellite on your requested date and time.<BR>
- Problems with NCDC's GOES Browse image production system.<BR><BR>
Please contact the NCDC Satellite Services Group for more specific information.
</P>
</H3>
OUTPUT
}