plugins/org.eclipse.emf.edapt.declaration/src/org/eclipse/emf/edapt/declaration/merge/PartitionReference.java

package org.eclipse.emf.edapt.declaration.merge;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.emf.ecore.EClass;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.edapt.declaration.EdaptConstraint;
import org.eclipse.emf.edapt.declaration.EdaptOperation;
import org.eclipse.emf.edapt.declaration.EdaptParameter;
import org.eclipse.emf.edapt.declaration.OperationImplementation;
import org.eclipse.emf.edapt.internal.common.MetamodelFactory;
import org.eclipse.emf.edapt.internal.common.MetamodelUtils;
import org.eclipse.emf.edapt.spi.migration.Instance;
import org.eclipse.emf.edapt.spi.migration.Metamodel;
import org.eclipse.emf.edapt.spi.migration.Model;

/**
 * {@description}
 *
 * @author herrmama
 * @author $Author$
 * @version $Rev$
 * @levd.rating YELLOW Hash: 68F716BB2693886FD361F0707D989606
 */
@EdaptOperation(identifier = "partitionReference", label = "Partition Reference", description = "In the metamodel, a reference is partitioned into a number of references according to its type. A sub reference is created for each subclass of the reference's type. Finally, the original reference is deleted. In the model, the value of the reference is partitioned accordingly.")
public class PartitionReference extends OperationImplementation {

	/** {@description} */
	@EdaptParameter(main = true, description = "The reference to be partitioned")
	public EReference reference;

	/** {@description} */
	@EdaptConstraint(restricts = "reference", description = "The reference must be multi-valued")
	public boolean checkReferenceMany(EReference reference) {
		return reference.isMany();
	}

	/** {@description} */
	@EdaptConstraint(restricts = "reference", description = "The type of the reference must be abstract")
	public boolean checkReferenceTypeAbstract(EReference reference) {
		final EClass type = reference.getEReferenceType();
		return !MetamodelUtils.isConcrete(type);
	}

	/** {@inheritDoc} */
	@SuppressWarnings("unchecked")
	@Override
	public void execute(Metamodel metamodel, Model model) {

		final EClass contextClass = reference.getEContainingClass();
		final EClass type = reference.getEReferenceType();

		// metamodel adaptation
		final List<EReference> subReferences = new ArrayList<EReference>();
		for (final EClass subClass : metamodel.getESubTypes(type)) {
			final String name = subClass.getName().substring(0, 1).toLowerCase()
				+ subClass.getName().substring(1);
			final EReference subReference = MetamodelFactory.newEReference(
				contextClass, name, subClass, 0, -1, reference
					.isContainment());
			subReferences.add(subReference);
		}

		metamodel.delete(reference);

		// model migration
		for (final Instance instance : model.getAllInstances(contextClass)) {
			final List<Instance> values = (List<Instance>) instance.unset(reference);
			for (final Instance value : values) {
				final EReference subReference = getReferenceForInstance(
					subReferences, value);
				instance.add(subReference, value);
			}
		}
	}

	/** Find the reference that can hold instances of a certain type. */
	private EReference getReferenceForInstance(List<EReference> references,
		Instance value) {
		for (final EReference reference : references) {
			if (value.instanceOf(reference.getEReferenceType())) {
				return reference;
			}
		}
		return null;
	}
}