#!/usr/bin/perl
use strict; 
use LWP::Simple;
use XML::LibXML;
#use XML::LibXML::XPathContext;
use CGI ":cgi";

print '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
# should be wqx_programs?
print "<odp_programs>\n";

my %state_codes = (
	'23' => 'ME',
	'33' => 'NH',
	'25' => 'MA',
	'90' => 'NB',
	'44' => 'RI',
	'09' => 'CT',
);

my $parser = XML::LibXML->new();

my $base_xml_url = 'http://qwwebservices.usgs.gov/Station/search?mimeType=xml&siteType=Estuary&statecode=';
while ( my ($st_code,$state) = each %state_codes)
{
	my $xml_url = $base_xml_url . $st_code;
	my $the_xml = LWP::Simple::get($xml_url);
	if( not $the_xml){
		warn "No response $st_code\n";
		next;
	}
	

	if($the_xml =~ /ExceptionReport/i )
	{
		warn "Exception: " .  $the_xml;
		next;
	}

	my $pxml = $parser->parse_string($the_xml);

	if(not $pxml)
	{
		warn "Could not parse $xml_url\n";
	}

	my $xc = XML::LibXML::XPathContext->new($pxml);

	# get namespaces from the root element and register them
	my $root = $pxml->documentElement();
	my @attributes = $root->attributes();
	foreach my $a (@attributes)
	{
		# we only care about the xmlns
		next unless $a->getName =~ /xmlns/; ;
		# xmlns:sos e.g.
		my @tmp = split( ":", $a->getName);
		my $url = $a->getData;
		# this maps the xmlns prefix to the value which should be a URL
		if( not $tmp[1]){
			$xc->registerNs( 'my' => $url);
		}else{
			$xc->registerNs( $tmp[1] => $url);
		}
	} # end foreach root attributes

	# get all MonitoringLocations
	my $org_cnt = 1;
	foreach my $node ( $xc->findnodes('//my:WQX/my:Organization') )
	{
		my $ml_cnt = 1;
		my $org_id = $xc->find('my:OrganizationDescription/my:OrganizationIdentifier', $node)->string_value;
		my $org_name = $xc->find('my:OrganizationDescription/my:OrganizationFormalName', $node)->string_value;
		foreach my $node2 ( $xc->findnodes('my:MonitoringLocation', $node) )
		{
			my $xml = '';
			my $ml_name = $xc->find('my:MonitoringLocationIdentity/my:MonitoringLocationName', $node2)->string_value;
			my $ml_id = $xc->find('my:MonitoringLocationIdentity/my:MonitoringLocationIdentifier', $node2)->string_value;
			my $ml_type = $xc->find('my:MonitoringLocationIdentity/my:MonitoringLocationTypeName', $node2)->string_value;
			my $ml_lat = $xc->find('my:MonitoringLocationGeospatial/my:LatitudeMeasure', $node2)->string_value;
			my $ml_lon = $xc->find('my:MonitoringLocationGeospatial/my:LongitudeMeasure', $node2)->string_value;
			my $ml_st_code = $xc->find('my:MonitoringLocationGeospatial/my:StateCode', $node2)->string_value;
			my $st = $state_codes{$ml_st_code};
			my $ml_cty_code = $xc->find('my:MonitoringLocationGeospatial/my:CountyCode', $node2)->string_value;
			my $title = "$ml_name $st";
			$xml .= '<odp_entry ';
			$xml .= ' entry_id="' . $ml_id . '" ';
			$xml .= ' full_entry_id="' . $ml_id. '" ';
			$xml .= ' entry_title="' . $ml_name . '" ';
			$xml .= ' data_center="' . $org_id . '" ';
			$xml .= ' data_center_name="' . $org_name . '" ';
			$xml .= ' min_lat="' . $ml_lat . '" ';
			$xml .= ' max_lat="' . $ml_lat . '" ';
			$xml .= ' min_lon="' . $ml_lon . '" ';
			$xml .= ' max_lon="' . $ml_lon . '" ';
			$xml .= ' center_lat="' . $ml_lat . '" ';
			$xml .= ' center_lon="' . $ml_lon . '" ';
			$xml .= " />\n";

			$ml_cnt++;
			print $xml;
		} # end foreach MonitoringLocation
		$org_cnt++;
	} # end foreach Organization

} # end while each state_codes

print "</odp_programs>\n";

exit;