resource-registry-publisher/src/main/java/org/gcube/informationsystem/resourceregistry/publisher/proxy/ResourceRegistryPublisherImpl.java

package org.gcube.informationsystem.resourceregistry.publisher.proxy;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringWriter;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.xml.ws.EndpointReference;

import org.gcube.common.authorization.client.Constants;
import org.gcube.common.authorization.library.provider.SecurityTokenProvider;
import org.gcube.common.clients.Call;
import org.gcube.common.clients.delegates.AsyncProxyDelegate;
import org.gcube.common.clients.delegates.ProxyDelegate;
import org.gcube.common.clients.exceptions.ServiceException;
import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.informationsystem.impl.utils.Entities;
import org.gcube.informationsystem.model.embedded.Embedded;
import org.gcube.informationsystem.model.entity.Facet;
import org.gcube.informationsystem.model.entity.Resource;
import org.gcube.informationsystem.model.relation.ConsistsOf;
import org.gcube.informationsystem.model.relation.IsRelatedTo;
import org.gcube.informationsystem.resourceregistry.api.rest.EntityPath;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class ResourceRegistryPublisherImpl implements ResourceRegistryPublisher {

	private static final Logger logger = LoggerFactory.getLogger(ResourceRegistryPublisher.class);
	
	private final AsyncProxyDelegate<EndpointReference> delegate;

	public static final String PATH_SEPARATOR ="/";
	public static final String PARAM_STARTER ="?";
	public static final String PARAM_EQUALS = "=";
	public static final String PARAM_SEPARATOR ="&";
	
	public ResourceRegistryPublisherImpl(ProxyDelegate<EndpointReference> config) {
		this.delegate = new AsyncProxyDelegate<EndpointReference>(config);
	}
	
	class ResourceRegistryCall<C> implements Call<EndpointReference, C> {

		protected final Class<C> clazz;
		protected final StringWriter stringWriter;
		protected final String method;
		
		public ResourceRegistryCall(Class<C> clazz, StringWriter stringWriter, String method){
			this.clazz = clazz;
			this.stringWriter = stringWriter;
			this.method = method;
		}
		
		protected String getURLStringFromEndpointReference(EndpointReference endpoint) throws IOException {
			JaxRSEndpointReference jaxRSEndpointReference = new JaxRSEndpointReference(endpoint);
			return jaxRSEndpointReference.toString();
		}
		
		protected HttpURLConnection makeRequest(URL url, String method) throws Exception {
			HttpURLConnection connection = (HttpURLConnection) url.openConnection();
			if (SecurityTokenProvider.instance.get()==null) {
				if(ScopeProvider.instance.get()==null){
					throw new RuntimeException("Null Token and Scope. Please set your token first.");
				}
				connection.setRequestProperty("gcube-scope", ScopeProvider.instance.get());
			}else{
				connection.setRequestProperty(Constants.TOKEN_HEADER_ENTRY, SecurityTokenProvider.instance.get());
			}
			connection.setDoOutput(true);
			connection.setDoInput(true);
			connection.setRequestProperty("Content-type", "text/plain");
			connection.setRequestMethod(method);
			return connection;
		}
		
		@Override
		public C call(EndpointReference endpoint) throws Exception {
			String urlFromEndpointReference = getURLStringFromEndpointReference(endpoint);
			StringBuilder callUrl = new StringBuilder(urlFromEndpointReference);
			callUrl.append(stringWriter.toString());
			
			URL url = new URL(callUrl.toString());
			HttpURLConnection connection = makeRequest(url, method);
			
			logger.debug("Response code for {} is {} : {}",
					callUrl.toString(), connection.getResponseCode(),
					connection.getResponseMessage());

			if (connection.getResponseCode() != 200) {
				throw new Exception("Error Contacting Resource Registry Service");
			}

			StringBuilder result = new StringBuilder();
			try (BufferedReader reader = new BufferedReader(
					new InputStreamReader(
							(InputStream) connection.getContent()))) {
				String line;
				while ((line = reader.readLine()) != null) {
					result.append(line);
				}
			}
			
			return Entities.unmarshal(clazz, result.toString());
		}
		
	}
	
	
	@Override
	public <E extends Embedded> E createEmbedded(E embedded) {
		return null;
	}

	@Override
	public <E extends Embedded> E updateEmbedded(E embedded) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <E extends Embedded> E deleteEmbedded(E embedded) {
		// TODO Auto-generated method stub
		return null;
	}


	@Override
	public <F extends Facet> F createFacet(Class<F> facetClass, F facet) {
		
		try {
			StringWriter stringWriter = new StringWriter();
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(EntityPath.ENTITY_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(EntityPath.FACET_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(facetClass.getSimpleName());
			stringWriter.append(PARAM_STARTER);
			stringWriter.append(EntityPath.DEFINITION_PARAM);
			stringWriter.append(PARAM_EQUALS);
			
			Entities.marshal(facet, stringWriter);
			ResourceRegistryCall<F> call = new ResourceRegistryCall<>(facetClass, stringWriter, "PUT");
			return delegate.make(call);
		} catch (Exception e) {
			logger.error("Error Creating Facet", e);
			throw new ServiceException(e);
		}
	}

	@Override
	public <F extends Facet> F updateFacet(F facet) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <F extends Facet> F deleteFacet(F facet) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <R extends Resource> R createResource(R resource) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <R extends Resource> R deleteResource(R resource) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <C extends ConsistsOf<Resource, Facet>> C createConsistsOf(
			C consistsOf) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <C extends ConsistsOf<Resource, Facet>> C updateConsistsOf(
			C consistsOf) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <C extends ConsistsOf<Resource, Facet>> C deleteConsistsOf(
			C consistsOf) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <I extends IsRelatedTo<Resource, Resource>> I create(I isRelatedTo) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <I extends IsRelatedTo<Resource, Resource>> I update(I isRelatedTo) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public <I extends IsRelatedTo<Resource, Resource>> I delete(I isRelatedTo) {
		// TODO Auto-generated method stub
		return null;
	}

}