/*******************************************************************************
 * 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.support.undoRedoSupport;

import java.util.Map;

import org.junit.Test;
import org.simantics.databoard.Bindings;
import org.simantics.db.ChangeSetIdentifier;
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.request.ReadRequest;
import org.simantics.db.common.request.WriteRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.service.UndoRedoSupport;
import org.simantics.db.testing.base.ExistingDatabaseTest;
import org.simantics.layer0.Layer0;
import org.simantics.utils.DataContainer;

/**
 * Tests undo of add statement.
 */
public class UndoTest01 extends ExistingDatabaseTest {

	@Test
    public void testUndo1() throws Exception {

    	Session session = getSession();
        final UndoRedoSupport support = session.getService(UndoRedoSupport.class);
        final DataContainer<Resource> subject = new DataContainer<Resource>();
        
        try {
            session.syncRequest(new WriteRequest() {
                @Override
                public void perform(WriteGraph graph) throws DatabaseException {
                    // Use any non-functional relation
                    Layer0 b = Layer0.getInstance(graph);
                    Resource s = graph.newResource();
                    graph.claim(s, b.InstanceOf, b.Entity);
                    subject.set(s);
                }
            });
        } catch (Throwable e) {
            fail("Write transaction threw an unknown exception ", e);
        }

        try {
            session.syncRequest(new ReadRequest() {
                @Override
                public void run(ReadGraph graph) throws DatabaseException {
                    assert(graph.hasStatement(subject.get()));
                }
            });
        } catch (Throwable e) {
            fail("Read transaction threw an unexpected exception ", e);
        }
        try {
            support.undo(session, 1);
        } catch (Throwable e) {
            fail("Undo operation threw an unexpected exception.", e);
        }
        
        try {
            session.syncRequest(new ReadRequest() {
                @Override
                public void run(ReadGraph graph) throws DatabaseException {
                	assert(!graph.hasStatement(subject.get()));
                }
            });
        } catch (Throwable e) {
            e.printStackTrace();
            fail("Read transaction threw an unexpected exception ", e);
        }
        
    }

}

class Context {
    private final Session session;
    private final UndoRedoSupport support;
    Resource r;
    Integer value = 0;
    Integer oldValue = 0;
    Context(Session session, UndoRedoSupport support) {
        this.session = session;
        this.support = support;
    }
    void create() throws DatabaseException {
        session.syncRequest(new WriteRequest() {
            @Override
            public void perform(WriteGraph graph) throws DatabaseException {
                graph.markUndoPoint();
                Layer0 b = Layer0.getInstance(graph);
                r = graph.newResource();
                graph.claim(r, b.InstanceOf, b.Entity);
            }
        });
    }
    void createAndSet() throws DatabaseException {
        session.syncRequest(new WriteRequest() {
            @Override
            public void perform(WriteGraph graph) throws DatabaseException {
                graph.markUndoPoint();
                Layer0 b = Layer0.getInstance(graph);
                r = graph.newResource();
                graph.claim(r, b.InstanceOf, b.Entity);
                graph.claimValue(r, ++value, Bindings.INTEGER);
                oldValue = value;
            }
        });
    }
    void add() throws DatabaseException {
        try {
            session.syncRequest(new WriteRequest() {
                @Override
                public void perform(WriteGraph graph) throws DatabaseException {
                    graph.markUndoPoint();
                    graph.claimValue(r, ++value, Bindings.INTEGER);
                    oldValue = value;
                }
            });
        } catch (Throwable e) {
            throw new DatabaseException("Write transaction threw an unknown exception:", e);
        }
    }
    void check() throws DatabaseException {
        session.syncRequest(new ReadRequest() {
            @Override
            public void run(ReadGraph graph) throws DatabaseException {
                Integer i = graph.getPossibleValue(r, Bindings.INTEGER);
                if (null == i) {
                    if (0 != value)
                        throw new DatabaseException("Failed to verify value.");
                } else if (value != i)
                    throw new DatabaseException("Failed to verify value. Expected " + value + " got " + i + ".");
            }
        });
    }
    void checkStatements() throws DatabaseException {
        session.syncRequest(new ReadRequest() {
            @Override
            public void run(ReadGraph graph) throws DatabaseException {
               if (!graph.hasStatement(r))
                   throw new DatabaseException("Failed to verify statments. Expected statements.");
            }
        });
    }
    void checkNoStatements() throws DatabaseException {
        session.syncRequest(new ReadRequest() {
            @Override
            public void run(ReadGraph graph) throws DatabaseException {
               if (graph.hasStatement(r))
                   throw new DatabaseException("Failed to verify statments. Expected no statements.");
            }
        });
    }
    void addAppend() throws DatabaseException {
        try {
            session.syncRequest(new WriteRequest() {
                @Override
                public void perform(WriteGraph graph) throws DatabaseException {
                    graph.markUndoPoint();
                    graph.claimValue(r, ++value, Bindings.INTEGER);
                }
            });
        } catch (Throwable e) {
            throw new DatabaseException("Write transaction threw an unknown exception:", e);
        }
    }
    class ChangeSetIdentifierImpl implements ChangeSetIdentifier {
        private final long id;
        ChangeSetIdentifierImpl(long id) {
            this.id = id;
        }
        @Override
        public long getId() {
            return id;
        }

        @Override
        public Map<String, byte[]> getMetadata() {
            return null;
        }
        
    }
    void undo() throws DatabaseException {
        support.undo(session, 1);
        value -= 1;
    }
}