/*******************************************************************************
 * Copyright (c) 2004-2008 Andras Schmidt, Andras Balogh, Istvan Rath and Daniel Varro
 * 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:
 *    Andras Schmidt, Andras Balogh, Istvan Rath - initial API and implementation
 *******************************************************************************/

package org.eclipse.viatra2.natives;

import org.eclipse.viatra2.core.EDeleteSemantics;
import org.eclipse.viatra2.core.IEntity;
import org.eclipse.viatra2.core.IModelSpace;
import org.eclipse.viatra2.errors.VPMCoreException;
import org.eclipse.viatra2.errors.VPMRuntimeException;
import org.eclipse.viatra2.natives.NativeFunctionParameter.ParameterType;

@VIATRANativeFunction(name = "clean", remark = "Deletes model elements faster than the \"delete()\" rule (recursive).", params = { @NativeFunctionParameter(name = "entities", type = { ParameterType.MODEL_ELEMENT }, isVarArg = true, description = "model element references to top-level entities to be deleted.") }, returns = { ParameterType.BOOLEAN })
public class CleanFunction implements ASMNativeFunction {

	private void recursive_delete(IEntity target) throws VPMCoreException {
		// delete all children recursively
		while (!target.getContents().isEmpty()) {
			try {
				recursive_delete((IEntity) target.getContents().iterator()
						.next());
			} catch (ClassCastException e) {
				System.out.println("Non-entity content detected at "
						+ target.getFullyQualifiedName());
			}
		}
		target.getModelSpace().getModelManager().deleteEntity(target,
				EDeleteSemantics.DELETE_SEMANTICS_FORCE);

	}

	public Object evaluate(IModelSpace msp, Object[] params)
			throws VPMRuntimeException {

		try {
			for (Object param : params) {
				if (param instanceof IEntity) {
					recursive_delete((IEntity) param);
				}
			}
		} catch (VPMCoreException cex) {
			return Boolean.FALSE;
		}

		return Boolean.TRUE;
	}

	public String getDescription() {
		return "Implements a fast, recursive model element delete algorithm.";
	}

	public String getID() {
		return this.getClass().getCanonicalName();
	}

	public String getName() {
		return "clean";
	}

}