#!/usr/bin/perl -Tw

use strict;
# to process query string paramters and print the proper HTTP header.
use CGI ":cgi";
use XML::LibXML;

my $q = new CGI;
# For test for test
#my $q = new CGI('request=GetObservation&offering=http://marinemetadata.org/cf#sea_water_salinity&SensorId=urn:gomoos:org:platform#A0116');

#######################################
# Determine the REQUEST type and make it upper case.
#######################################
my $request = '';
$request = uc( $q->param('request') ) if ( $q->param('request') );
$request = uc( $q->param('REQUEST') ) if ( $q->param('REQUEST') );

error("Missing REQUEST") if ! $request;

#######################################
# set the proper template and local data files based on $request
#######################################
my ($template_file, $data_file, $data_field_count) = ('', '', 0);
my @input_data = ();
my @input_field_names = ();
my @input_field_data = ();


if( $request eq 'GETCAPABILITIES' ){
	$template_file = 'GetCapabilities.tpl';
	$data_file = 'GetCapabilities.txt';
#	$data_field_count = 23;
	$data_field_count = 15; # drf5n
}

if( $request eq 'GETOBSERVATION' ){
	# GetObservation passes these
	my ($SensorId, $offering, $time, $urn) = ('','','', '');
	$template_file = 'GetObservation.tpl';
	$data_field_count = 2;

	$SensorId = uc( $q->param('SensorId') ) if $q->param('SensorId');
	error("SensorId required. Try SensorId=%23A011") if (!$SensorId);

	($urn, $SensorId) = split(/#/, $SensorId);
	# The Observation data text file is named: GetObservation_<SensorId>.txt
	# At GoMOOS the buoy id is the SensorId.

	$data_file = "GetObservation_$SensorId.txt";

	$offering = uc( $q->param('offering') ) if $q->param('offering');
	error("offering parameter required, try offering=URN:#23SEA_WATER_SALINITY") if (!$offering);

	# We don't care about the uri part.
	($urn, $offering) = split(/#/, $offering);

	error("Unknown offering parameter: $offering") if ($offering ne 'SEA_WATER_SALINITY');
	# We are not using time yet. We assume observation files contain the latest salinity readings.
	$time = $q->param('time') if $q->param('time');
}

########  Assert a good request
error("No template file -- request=$request not understood\n") 
   if ( ! ($template_file =~ /.+/) );


#######################################
# open the template
######################
# this allow us to open the template file and read it as one big string.

my $parser = XML::LibXML->new();
my $doc = $parser->parse_file( $template_file ) or 
    error("Could not open: $template_file $!");
			      
#my $sos_xml = $doc->serialize;  # drf get the template back from the DOM

#######################################
# open the local data file.
#######################################

open(DATA, "< $data_file") or error("Could not open: $data_file");

@input_data = <DATA>;

close(DATA);

chomp($input_data[0]);
chomp($input_data[1]);

# line 1 contains the field names
@input_field_names = split(/\|/, $input_data[0]);

# line 2 contains the local data
@input_field_data = split(/\|/, $input_data[1]);

if( @input_field_names != @input_field_data){
	error("Input field name count does not match input data count.");
}

if( @input_field_data != $data_field_count )
{
   error("$request data field count must be $data_field_count not $#input_field_data +1");
}




#######################################
# substitute our values in the template
#######################################
for (my $j = 0; $j <= $#input_field_names; $j++) { 
	my $fld = $input_field_names[$j];
	my $val = $input_field_data[$j];
#	print "#$fld:$val:looping replacement\n";

#	$sos_xml =~ s/\$$fld/$val/;  # don't do the text subs
        my @nodelist = ($doc->findnodes("//ows:$fld/child::text()"));
#        print "\nTrying //$fld", @nodelist;
        if (@nodelist) {
#	    print "--:",$nodelist[0]->data,"\n";
            $nodelist[0]->setData($val);
        };

}

#print "\n--------\n";
if($request eq 'GETCAPABILITES') {

	# skip the first two lines, each record afterward is an OMResult tuple, separated by ' ';
	for (my $j = 2; $j <= $#input_data; $j++){

	}

}

my $sos_xml = $doc->serialize;  # drf get the template back from the DOM


#######################################
# GETOBSERVATION OMResult
#######################################
if($request eq 'GETOBSERVATION') {
	my $tuple_separator = ' ';
	my $om_results = '';
	# skip the first two lines, each record afterward is an OMResult tuple, separated by ' ';
	for (my $j = 2; $j <= $#input_data; $j++){
		# skip comments
		next if( $input_data[$j] =~ /^#/);
		# Remove newlines and make sure no blanks. blank is our tuple separator.
		chomp($input_data[$j]);
		$input_data[$j] =~ s/$tuple_separator//g;
		$om_results .= $input_data[$j] . $tuple_separator;
	}

	$sos_xml =~ s/\$OMResult/$om_results/;
}

#######################################
# print the template
#######################################
print header(
		-type => 'text/xml',
);

print $sos_xml;

exit;

#######################################
sub error
{
	my $msg = shift;

	print header(
		-type => 'text/html',
	);
	print "<h3 style=\"color: red;\">$msg</h3>\n";
	warn $msg;
	exit;
}