/*******************************************************************************
 * Copyright (c) 2007, 2010 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.mapping.constraint.instructions;

import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.utils.NameUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.layer0.utils.predicates.IUnaryPredicate;
import org.simantics.layer0.utils.predicates.Type;
import org.simantics.mapping.IContextualModification;

public class UnaryPredicateInstruction extends Instruction1 {
	
	IUnaryPredicate predicate;

	public UnaryPredicateInstruction(int variable0, IUnaryPredicate predicate) {
		super(variable0);
		this.predicate = predicate;
	}
	
	@Override
	public Object query(ReadGraph g, Object[] bindings) throws DatabaseException {
//		ITask task = ThreadLogger.getInstance().begin("g");
		if(predicate.has(g, (Resource)bindings[variable0])) {
//			task.finish();
			return null;
		}
		else {
//			task.finish();
			return IInstruction.FAILURE;
		}
	}
	
	@Override
	public Object next(ReadGraph g, Object[] bindings, Object continuation) {
		return IInstruction.FAILURE;
	}
	
	@Override
	public IContextualModification claim(ReadGraph g, Object[] bindings) throws DatabaseException {
		Resource r = (Resource)bindings[variable0];
//		ITask task = ThreadLogger.getInstance().begin("g");
		if(!predicate.has(g, r)) {
//			task.finish();		
			return new IContextualModification() {

				@Override
				public void perform(WriteGraph g, Object[] bindings) throws DatabaseException {
//					ITask task = ThreadLogger.getInstance().begin("g");
			        if(DEBUG_MODI)
			            System.out.println("claim(" + predicate + ", " + 
			                    NameUtils.getSafeName(g, (Resource)bindings[variable0]));
			        if(!DISABLE_MODI)
			        	predicate.add(g, (Resource)bindings[variable0]);
//					task.finish();
				}
			
			};
		}
//		task.finish();
		return null;
	}

	@Override
	public void doClaim(WriteGraph g, Object[] bindings) throws DatabaseException {
		Resource r0 = (Resource)bindings[variable0];
//		ITask task = ThreadLogger.getInstance().begin("g");
		if(DEBUG) {
    		String predicateName = predicate.toString();
    		if(predicate instanceof Type)
    		    predicateName = ":: " + NameUtils.getSafeName(g, ((Type)predicate).getType());
    		System.out.println("@ claimUnary(" + NameUtils.getSafeName(g, r0) + ", " + predicateName + ")");
		}
        if(DEBUG_MODI)
            System.out.println("claim(" + predicate + ", " + 
                    NameUtils.getSafeName(g, (Resource)bindings[variable0]));
        if(!DISABLE_MODI)
        	predicate.add(g, r0);
//		task.finish();
	}
	
	@Override
	public IContextualModification deny(ReadGraph g, Object[] bindings) throws DatabaseException {
		Resource r = (Resource)bindings[variable0];
		if(predicate.has(g, r))
			return new IContextualModification() {

				@Override
				public void perform(WriteGraph g, Object[] bindings) throws DatabaseException {
				    if(DEBUG_MODI)
				        System.out.println("deny(" + predicate + ", " + 
				                NameUtils.getSafeName(g, (Resource)bindings[variable0]));
				    if(!DISABLE_MODI)
				    	predicate.remove(g, (Resource)bindings[variable0]);
				}
			
			};
		return null;
	}
	
	@Override
	public void doDeny(WriteGraph g, Object[] bindings) throws DatabaseException {
		Resource r0 = (Resource)bindings[variable0];
		if(predicate.has(g, r0)) {
            if(DEBUG_MODI)
                System.out.println("deny(" + predicate + ", " + 
                        NameUtils.getSafeName(g, (Resource)bindings[variable0]));
            if(!DISABLE_MODI)
            	predicate.remove(g, r0);
		}
	}

	@Override
	public void toString(StringBuilder b, int indent) {
		b.append('(');
		b.append(variable0);
		b.append(')');
	}
}