/**
 * 
 */
package org.gcube.informationsystem.resourceregistry.client.proxy;

import java.io.StringWriter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;

import javax.xml.ws.EndpointReference;

import org.gcube.common.clients.delegates.AsyncProxyDelegate;
import org.gcube.common.clients.delegates.ProxyDelegate;
import org.gcube.common.clients.exceptions.ServiceException;
import org.gcube.informationsystem.impl.utils.ISMapper;
import org.gcube.informationsystem.model.ER;
import org.gcube.informationsystem.model.ISManageable;
import org.gcube.informationsystem.model.entity.Entity;
import org.gcube.informationsystem.model.entity.Resource;
import org.gcube.informationsystem.resourceregistry.api.exceptions.ResourceRegistryException;
import org.gcube.informationsystem.resourceregistry.api.exceptions.er.ERNotFoundException;
import org.gcube.informationsystem.resourceregistry.api.exceptions.query.InvalidQueryException;
import org.gcube.informationsystem.resourceregistry.api.exceptions.schema.SchemaNotFoundException;
import org.gcube.informationsystem.resourceregistry.api.rest.AccessPath;
import org.gcube.informationsystem.resourceregistry.api.rest.httputils.HTTPCall;
import org.gcube.informationsystem.resourceregistry.api.rest.httputils.HTTPCall.HTTPMETHOD;
import org.gcube.informationsystem.types.TypeBinder;
import org.gcube.informationsystem.types.TypeBinder.TypeDefinition;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Luca Frosini (ISTI - CNR)
 */
public class ResourceRegistryClientImpl implements ResourceRegistryClient {

	private static final Logger logger = LoggerFactory
			.getLogger(ResourceRegistryClientImpl.class);

	private final AsyncProxyDelegate<EndpointReference> delegate;

	public static final String PATH_SEPARATOR = "/";

	public ResourceRegistryClientImpl(ProxyDelegate<EndpointReference> config) {
		this.delegate = new AsyncProxyDelegate<EndpointReference>(config);
	}

	
	@Override
	public <ERType extends ER> void exists(Class<ERType> clazz, UUID uuid)
			throws ERNotFoundException, ResourceRegistryException {
		String type = clazz.getSimpleName();
		try {
			logger.info("Going to check if {} with UUID {} exists", type, uuid);
			StringWriter stringWriter = new StringWriter();
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.ACCESS_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.INSTANCE_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(type);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(uuid.toString());

			HTTPCall<ERType> httpCall = new HTTPCall<>(stringWriter.toString(),
					HTTPMETHOD.HEAD, null);

			ResourceRegistryClientCall<ERType> call = new ResourceRegistryClientCall<>(
					clazz, httpCall);

			delegate.make(call);
			logger.info("{} with UUID {} exists", type, uuid);
		} catch (ResourceRegistryException e) {
			throw e;
		} catch (Exception e) {
			throw new ServiceException(e);
		}
	}
	
	@Override
	public <ERType extends ER> ERType getInstance(Class<ERType> clazz, UUID uuid)
			throws ERNotFoundException, ResourceRegistryException {
		String type = clazz.getSimpleName();
		try {
			logger.info("Going to get {} with UUID {}", type, uuid);
			StringWriter stringWriter = new StringWriter();
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.ACCESS_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.INSTANCE_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(type);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(uuid.toString());

			HTTPCall<ERType> httpCall = new HTTPCall<>(stringWriter.toString(),
					HTTPMETHOD.GET, null);

			ResourceRegistryClientCall<ERType> call = new ResourceRegistryClientCall<>(
					clazz, httpCall);

			ERType erType = delegate.make(call);
			logger.info("Got {} with UUID {} is {}", type, uuid, erType);
			return erType;
		} catch (ResourceRegistryException e) {
			logger.error("Error while getting {} with UUID {}", type, uuid, e);
			throw e;
		} catch (Exception e) {
			logger.error("Error while getting {} with UUID {}", type, uuid, e);
			throw new ServiceException(e);
		}
	}

	@Override
	public List<? extends Entity> getInstances(String type,
			Boolean polymorphic) throws ResourceRegistryException {
		try {
			logger.info("Going to get all instances of {} ", type);
			StringWriter stringWriter = new StringWriter();
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.ACCESS_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.INSTANCES_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(type);

			Map<String, String> parameters = new HashMap<>();
			parameters.put(AccessPath.POLYMORPHIC_PARAM, polymorphic.toString());

			HTTPCall<String> httpCall = new HTTPCall<>(stringWriter.toString(),
					HTTPMETHOD.GET, parameters);

			ResourceRegistryClientCall<String> call = new ResourceRegistryClientCall<>(
					String.class, httpCall);

			String ret = delegate.make(call);
			logger.info("Got instances of {} are {}", type, ret);

			return ISMapper.unmarshalList(Entity.class, ret);
			
		} catch (ResourceRegistryException e) {
			logger.error("Error while getting {} instances", type, e);
			throw e;
		} catch (Exception e) {
			logger.error("Error while getting {} instances", type, e);
			throw new ServiceException(e);
		}
	}

	@Override
	public List<Resource> getInstancesFromEntity(
			String relationType, Boolean polymorphic, UUID reference,
			Direction direction) throws ResourceRegistryException {
		try {
			logger.info("Going to get all instances of {} from/to {}", relationType,
					reference.toString());
			StringWriter stringWriter = new StringWriter();
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.ACCESS_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.INSTANCES_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(relationType);

			Map<String, String> parameters = new HashMap<>();
			parameters.put(AccessPath.POLYMORPHIC_PARAM, polymorphic.toString());
			parameters.put(AccessPath.REFERENCE, reference.toString());
			parameters.put(AccessPath.DIRECTION, direction.toString());

			HTTPCall<String> httpCall = new HTTPCall<>(stringWriter.toString(),
					HTTPMETHOD.GET, parameters);

			ResourceRegistryClientCall<String> call = new ResourceRegistryClientCall<>(
					String.class, httpCall);

			String ret = delegate.make(call);
			logger.info("Got instances of {} from/to {} are {}", relationType,
					reference.toString(), ret);

			return ISMapper.unmarshalList(Resource.class, ret);
		
		} catch (ResourceRegistryException e) {
			logger.error("Error while getting instances of {} from/to {}", relationType, e);
			throw e;
		} catch (Exception e) {
			logger.error("Error while getting instances of {} from/to {}", relationType, e);
			throw new ServiceException(e);
		}
	}

	@Override
	public <ISM extends ISManageable> List<TypeDefinition> getSchema(
			Class<ISM> clazz, Boolean polymorphic)
			throws SchemaNotFoundException, ResourceRegistryException {

		String type = clazz.getSimpleName();
		try {
			logger.info("Going to get {} schema", type);
			StringWriter stringWriter = new StringWriter();
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.ACCESS_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(AccessPath.SCHEMA_PATH_PART);
			stringWriter.append(PATH_SEPARATOR);
			stringWriter.append(type);

			Map<String, String> parameters = new HashMap<>();
			parameters.put(AccessPath.POLYMORPHIC_PARAM, polymorphic.toString());

			HTTPCall<String> httpCall = new HTTPCall<>(stringWriter.toString(),
					HTTPMETHOD.GET, parameters);

			ResourceRegistryClientCall<String> call = new ResourceRegistryClientCall<>(
					String.class, httpCall);
			String schema = delegate.make(call);
			logger.info("Got schema for {} is {}", type, schema);

			return TypeBinder.deserializeTypeDefinitions(schema);
			
		} catch (ResourceRegistryException e) {
			logger.error("Error while getting {}schema for {}",
					polymorphic ? AccessPath.POLYMORPHIC_PARAM + " " : "",
					type, e);
			throw e;
		} catch (Exception e) {
			logger.error("Error while getting {}schema for {}",
					polymorphic ? AccessPath.POLYMORPHIC_PARAM + " " : "",
					type, e);
			throw new ServiceException(e);
		}
	}

	@Override
	public String query(String query, int limit, String fetchPlan)
			throws InvalidQueryException {
		ResourceRegistryQuery rrq = new ResourceRegistryQuery(delegate);
		return rrq.query(query, limit, fetchPlan);
	}

}