/*******************************************************************************
 * Copyright (c) 2007, 2018 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.impl.query;

import org.simantics.db.RelationInfo;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.impl.graph.ReadGraphImpl;
import org.simantics.db.impl.procedure.InternalProcedure;
import org.simantics.db.request.RequestFlags;

public final class RelationInfoQuery extends UnaryQueryP<RelationInfo> {

	RelationInfoQuery(int resource) {
		super(resource);
	}

	@Override
	public final void removeEntry(QueryProcessor provider) {
		provider.cache.remove(this);
	}

	private static void computeAssertions(ReadGraphImpl graph, int r, final boolean isFinal, final boolean isFunctional, RelationInfoQuery parent, final InternalProcedure<RelationInfo> procedure) throws DatabaseException {

		QueryProcessor processor = graph.processor;

		final int isUsedInAssertion = processor.getHasPredicateInverse();
		assert(isUsedInAssertion != 0);

		QueryCache.runnerDirectObjects(graph, r, isUsedInAssertion, parent, null, new IntProcedure() {

			boolean done = false;

			@Override
			public void execute(ReadGraphImpl graph, int i) throws DatabaseException {
				if(done) return;
				done = true;
				RelationInfo result = new RelationInfo(r, isFunctional, isFinal, true);
				procedure.execute(graph, result);
			}

			@Override
			public void finished(ReadGraphImpl graph) throws DatabaseException {
				if(done) return;
				done = true;
				RelationInfo result = new RelationInfo(r, isFunctional, isFinal, false);
				procedure.execute(graph, result);
			}

			@Override
			public void exception(ReadGraphImpl graph, Throwable throwable) throws DatabaseException {
				if(done) return;
				done = true;
				DatabaseException e = new DatabaseException("Internal error in RelationInfoQuery");
				procedure.exception(graph, e);
			}

		});

	}

	public static void computeForEach(ReadGraphImpl graph, int r, RelationInfoQuery entry, InternalProcedure<RelationInfo> procedure_) throws DatabaseException {

		InternalProcedure<RelationInfo> procedure = entry != null ? entry : procedure_;

		QueryProcessor provider = graph.processor;

		final int superRelationOf = provider.getSuperrelationOf();
		assert(superRelationOf != 0);

		IntSet direct = QueryCache.resultDirectPredicates(graph, r, entry, null);
		IntSet types = QueryCache.resultTypes(graph, r, entry, null);

		computeAssertions(graph, r, !direct.contains(superRelationOf), types.contains(graph.processor.getFunctionalRelation()), entry, procedure);

		if(entry != null) entry.performFromCache(graph, procedure_);

	}

	@Override
	public void compute(ReadGraphImpl graph, final InternalProcedure<RelationInfo> procedure) throws DatabaseException {
		computeForEach(graph, id, this, procedure);
	}

	@Override
	public String toString() {
		return "RelationInfoQuery[" + id + "]";
	}

	@Override
	public int type() {
		return RequestFlags.IMMEDIATE_UPDATE;
	}

    @Override
    public void serializeValue(QuerySerializer serializer) {
        RelationInfo ri = getResult();
        serializer.addResource(ri.predicate);
        serializer.add(ri.isFunctional ? (byte)1 : 0);
        serializer.add(ri.isFinal ? (byte)1 : 0);
        serializer.add(ri.isAsserted ? (byte)1 : 0);
    }

}