/*******************************************************************************
 * Copyright (c) 2004-2010 Gabor Bergmann 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:
 *    Gabor Bergmann - initial API and implementation
 *******************************************************************************/

package org.eclipse.viatra2.gtasm.patternmatcher.incremental.hardwired;

import org.eclipse.emf.common.util.EList;
import org.eclipse.viatra2.gtasm.patternmatcher.incremental.adapters.GTASMBuildable;
import org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.RetePatternBuildException;
import org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.Stub;
import org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.matcher.IPatternMatcherContext;
import org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.tuple.FlatTuple;
import org.eclipse.viatra2.gtasmmodel.gtasm.metamodel.gt.GTPattern;
import org.eclipse.viatra2.gtasmmodel.gtasm.metamodel.gt.PatternVariable;

/**
 * Hardwired pattern matcher for direct instantiation.
 * Enumerates type-instance pairs for direct instanceOf relationships, i.e. subtyping is ignored.
 * 
 * Usage:
 * @Incremental('reinterpret'='directInstantiation')
 * pattern immediateInstanceOf(Type, Instance) = {}
 * 
 * @author Bergmann Gábor
 *
 */
public class HardwiredDirectInstantiation<StubHandle, Collector> {
	protected GTASMBuildable<StubHandle, Collector> buildable;
	protected IPatternMatcherContext<GTPattern> context;
	protected GTPattern gtPattern;
	protected Collector prodNode;
	/**
	 * @param buildable
	 * @param context
	 * @param gtPattern
	 * @param prodNode
	 */
	public HardwiredDirectInstantiation(
			GTASMBuildable<StubHandle, Collector> buildable,
			IPatternMatcherContext<GTPattern> context,
			GTPattern gtPattern, Collector prodNode) {
		super();
		this.buildable = buildable.getNextContainer().putOnTab(gtPattern);
		this.context = context;
		this.gtPattern = gtPattern;
		this.prodNode = prodNode;
	}
	/**
	 * @return
	 */
	public Collector run() throws RetePatternBuildException {
		EList<PatternVariable> symParameters = gtPattern.getSymParameters();
		if (symParameters.size() != 2) {
			throw new RetePatternBuildException(
					"Pattern {1} is annotated as directInstatiation, should have two arguments", 
					new String[]{gtPattern.getFqn()}, gtPattern);
		}
		// TODO nicer Variable name
		Stub<StubHandle> instantiationDirect = 
			buildable.instantiationDirectStub(new FlatTuple(symParameters.toArray()));
		buildable.buildConnection(instantiationDirect, prodNode);
		return prodNode;
	}
	
	

}