/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.db.tests.api.request.exception;

import org.junit.Test;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.Session;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.procedure.adapter.ListenerAdapter;
import org.simantics.db.common.procedure.adapter.TransientCacheListener;
import org.simantics.db.common.request.WriteRequest;
import org.simantics.db.common.request.WriteResultRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.exception.ResourceNotFoundException;
import org.simantics.db.request.Read;
import org.simantics.db.testing.base.ExistingDatabaseTest;
import org.simantics.layer0.Layer0;

public class RecoveryFromExceptedState extends ExistingDatabaseTest {
	
	@Test
	public void test() throws Exception {
		
		Session session = getSession();
		
		final Layer0 L0 = Layer0.getInstance(session);

		final Resource A = session.syncRequest(new WriteResultRequest<Resource>() {

			@Override
			public Resource perform(WriteGraph graph) throws DatabaseException {

				Resource root = graph.getRootLibrary();
				Resource part = graph.newResource();
				graph.claim(part, L0.InstanceOf, null, L0.Entity);
				graph.claim(part, L0.PartOf, root);
				graph.claimLiteral(part, L0.HasName, "A");
				return part;

			}

		});

		try {

			/*
			 * Create the request. Listening is needed to enforce update of the query in subsequent write 
			 */
			session.syncRequest(new Read<Resource>() {

				@Override
				public Resource perform(ReadGraph graph) throws DatabaseException {
					return graph.getResource("http://A");
				}
				
			}, new ListenerAdapter<Resource>() {
				@Override
				public boolean isDisposed() {
					return false;
				}
			});

			/*
			 * Invalidates the request. Request is updated (is has a listener) and enters 'Excepted' state. 
			 */
			session.syncRequest(new WriteRequest() {

				@Override
				public void perform(WriteGraph graph) throws DatabaseException {

					graph.deny(A);
					graph.deny(graph.getRootLibrary(), L0.ConsistsOf, A);

				}

			});

			/*
			 * After this write the result is again valid. The request should be updated to 'Ready' state. 
			 */
			session.syncRequest(new WriteRequest() {

				@Override
				public void perform(WriteGraph graph) throws DatabaseException {

					Resource root = graph.getRootLibrary();
					Resource part = graph.newResource();
					graph.claim(part, L0.InstanceOf, null, L0.Entity);
					graph.claim(part, L0.PartOf, root);
					graph.claimLiteral(part, L0.HasName, "A");

				}

			});
			
			/*
			 * Validate the situation. 
			 */
			session.syncRequest(new Read<Resource>() {

				@Override
				public Resource perform(ReadGraph graph) throws DatabaseException {
					return graph.getResource("http://A");
				}
				
			}, TransientCacheListener.<Resource>instance());

		} catch(ResourceNotFoundException e) {

	        fail("getResource threw ResourceNotFoundException");

		}
		
	}

}