/*******************************************************************************
 * Copyright (c) 2007, 2013 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.objmap.graph.rules;

import org.simantics.db.ReadGraph;
import org.simantics.db.WriteGraph;
import org.simantics.objmap.backward.IBackwardMapping;
import org.simantics.objmap.bidirectional.IBidirectionalMappingRule;
import org.simantics.objmap.exceptions.MappingException;
import org.simantics.objmap.forward.IForwardMapping;
import org.simantics.objmap.graph.rules.domain.IDomainAccessor;
import org.simantics.objmap.graph.rules.range.IRangeAccessor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A rule that synchronizes collection of elements between
 * domain and range accessors. Elements are mapped from
 * between domain and range during the synchronization.
 * @author Hannu Niemistö
 */
public class MappedElementRule<Domain, Range> implements IBidirectionalMappingRule<Domain, Range> {
    
    static final Logger LOGGER = LoggerFactory.getLogger(MappedElementRule.class);
    
	IDomainAccessor<Domain,Domain> domainAccessor;
	IRangeAccessor<Range,Range> rangeAccessor;
	
	public MappedElementRule(IDomainAccessor<Domain,Domain> domainAccessor,
            IRangeAccessor<Range,Range> rangeAccessor) {
        this.domainAccessor = domainAccessor;
        this.rangeAccessor = rangeAccessor;
    }

    @Override
	public boolean updateDomain(WriteGraph g, IBackwardMapping<Domain, Range> map,
			Domain domainElement, Range rangeElement)
			throws MappingException {
        LOGGER.trace("    MappedElementRule.updateDomain");
	    Range value = rangeAccessor.get(rangeElement);
	    Domain mappedValue = value == null ? null : map.inverseMap(g, value);//map.inverseGet(value);
		return domainAccessor.set(g, domainElement, mappedValue);
	}

	@Override
	public boolean updateRange(ReadGraph g, IForwardMapping<Domain, Range> map,
			Domain domainElement, Range rangeElement)
			throws MappingException {
        LOGGER.trace("    MappedElementRule.updateRange");   
	    Domain value = domainAccessor.get(g, domainElement);
        Range mappedValue = value == null ? null : map.map(g, value);////map.get(value);
        return rangeAccessor.set(rangeElement, mappedValue);
	}	
	
	public void createDomain(WriteGraph g, IBackwardMapping<Domain,Range> map, Domain domainElement, Range rangeElement) throws MappingException {
		updateDomain(g, map, domainElement, rangeElement);
	};
	
	public void createRange(ReadGraph g, IForwardMapping<Domain,Range> map, Domain domainElement, Range rangeElement) throws MappingException {
		updateRange(g, map, domainElement, rangeElement);
	};
}