#!/usr/bin/perl

## Copyright (C) 2010 - 2013 ICM, Warsaw University
## 
## Licensed under the Apache License, Version 2.0 (the "License");
## you may not use this file except in compliance with the License.
## You may obtain a copy of the License at
## 
##      http://www.apache.org/licenses/LICENSE-2.0
## 
## Unless required by applicable law or agreed to in writing, software
## distributed under the License is distributed on an "AS IS" BASIS,
## WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
## See the License for the specific language governing permissions and
## limitations under the License.

use REST::Client;
use Google::ProtocolBuffers;
use Config::Properties;

#loads properties file client.properties
sub loadPropfile() {
	my $confPath = "client.properties";
	open my $fh, '<', "$confPath" or die "unable to open configuration file $confPath";

	my $properties = Config::Properties->new();
	$properties->load($fh);
	return $properties; 
}

#ask service registry
sub findService() {
	my $registryUrl = shift;
	my $serviceId = shift;
	my $serviceVer = shift;
	my $client = REST::Client->new();

	#ask registry about:
	# ServiceId
	# Service Version
	# Client Name: some name to self introduce 
	# Protocol: rest
	$url = "$registryUrl/$serviceId/$serviceVer/perlClient/rest";

	#send request and expect result in Protocol Buffer format
	$client->GET($url,{Accept => 'application/x-protobuf;charset=UTF-8'});

	if( $client->responseCode() ne '200' ){
     		die "Server return code ", $client->responseCode(), "\nService url: $url\n";
 	}

	die "Service $serviceId not found in registry " if(!$client->responseContent());

	#parsing return service description
	my ServiceDescriptorProto $servDesc = ServiceDescriptorProto->decode($client->responseContent());

	#read about service location: url for service
	my ConnectionDescriptorProto $location = $servDesc->{locations}[0];

	print "$serviceId rest location: ",$location->{location},", protocol:", $location->{protocol}, "\n";

	return $location->{location};
}

1;