/*******************************************************************************
 * 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.db.impl.query;

import org.simantics.db.common.exception.DebugException;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.impl.graph.ReadGraphImpl;
import org.simantics.db.procedure.ListenerBase;
import org.simantics.db.request.RequestFlags;

final public class DirectObjects extends CollectionBinaryQuery<IntProcedure> {

	DirectObjects(final int r1, final int r2) {
		super(r1, r2);
	}

	@Override
	public int type() {
		return RequestFlags.INVALIDATE;
	}
	
//    @Override
//    public void clearResult(QuerySupport support) {
//    	setResult(INVALID_RESULT);
//    }

//	final public static void queryEach(ReadGraphImpl graph, final int r1, final int r2, final QueryProcessor provider, final CacheEntry parent, final ListenerBase listener, final IntProcedure procedure) throws DatabaseException {
//
//        assert(r1 != 0);
//        assert(r2 != 0);
//        
//        if(parent == null && listener == null) {
//        	DirectObjects.computeForEach(graph, r1, r2, null, procedure);
//        } else {
//        	QueryCache.runnerDirectObjects(graph, r1, r2, parent, listener, procedure);
//        }
//
//	}

	@Override
	final public void removeEntry(QueryProcessor provider) {
		provider.cache.remove(this);
	}

	//@Override
	public Object compute(ReadGraphImpl graph, final IntProcedure procedure) throws DatabaseException {
		computeForEach(graph, r1(), r2(), this, procedure);
		return getResult();
	}

	static public void computeForEach(ReadGraphImpl graph, int r1, int r2, final DirectObjects entry, final IntProcedure procedure) throws DatabaseException {

		QueryProcessor processor = graph.processor;
		
		processor.querySupport.ensureLoaded(graph, r1, r2);

		processor.querySupport.getObjects(graph, r1, r2, new IntProcedure() {

			@Override
			public void execute(ReadGraphImpl graph, int i) throws DatabaseException {
				procedure.execute(graph, i);
				if(entry != null) entry.add(i);
			}

			@Override
			public void finished(ReadGraphImpl graph) {
			}

			@Override
			public void exception(ReadGraphImpl graph, Throwable t) {
				if(DebugException.DEBUG) new DebugException(t).printStackTrace();
			}

		});

		if(entry != null) entry.finish(graph, processor);
		procedure.finished(graph);

	}

	@Override
	public String toString() {
		return "DirectObjects[" + r1() + " - " + r2() + "]";
	}

	@Override
	public void setReady() {
		statusOrException = READY;
	}
	
	final public void add(int add) {

		assert(isPending());

		IntArray value = (IntArray)getResult();
		value.add(add);

	}

	final private void finish(ReadGraphImpl graph, QueryProcessor provider) {
		setReady();
	}

	@Override
	public Object performFromCache(ReadGraphImpl graph, IntProcedure procedure) throws DatabaseException {

		assert(isReady());

		if(handleException(graph, procedure)) return getResult();

		final IntArray value = (IntArray)getResult();
		if(value.data == null) {
			if(value.sizeOrData != IntArray.NO_DATA) procedure.execute(graph, value.sizeOrData);
		} else {
			for(int i = 0;i < value.sizeOrData ; i++) procedure.execute(graph, value.data[i]);
		}

		procedure.finished(graph);
		
		return value;

	}

	@Override
	public void recompute(ReadGraphImpl graph) throws DatabaseException {
		
		compute(graph, new IntProcedure() {

			@Override
			public void finished(ReadGraphImpl graph) {
			}

			@Override
			public void exception(ReadGraphImpl graph, Throwable t) {
				throw new Error("Error in recompute.", t);
			}

			@Override
			public void execute(ReadGraphImpl graphd, int i) {
			}

		});

	}

    @Override
    boolean isImmutable(ReadGraphImpl graph) {
    	return graph.processor.isImmutable(r1());
    }
	
}