/*******************************************************************************
 * 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.exception.DatabaseException;
import org.simantics.db.impl.graph.ReadGraphImpl;
import org.simantics.db.impl.procedure.InternalProcedure;
import org.simantics.db.procedure.ListenerBase;

import gnu.trove.procedure.TIntProcedure;

final public class TypeHierarchy extends UnaryQuery<InternalProcedure<IntSet>> {
    
    TypeHierarchy(final int resource) {
        super(resource);
    }
    
    final public static void queryEach(ReadGraphImpl graph, final int r, final QueryProcessor provider, final CacheEntry parent, final ListenerBase listener, final InternalProcedure<IntSet> procedure) throws DatabaseException {
        QueryCache.runnerTypeHierarchy(graph, r, parent, listener, procedure);
    }

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

 	@Override
 	public IntSet compute(ReadGraphImpl graph, final InternalProcedure<IntSet> procedure) throws DatabaseException {

 		QueryProcessor processor = graph.processor;
 		
        final IntSet result = new IntSet(processor.querySupport, id);
        
        final TIntProcedure addToResult = new TIntProcedure() {
            @Override
            public boolean execute(int r) {
            	result.add(r);
                return true;
            }
        };
        
        QueryCache.runnerSuperTypes(graph, id, TypeHierarchy.this, null, new InternalProcedure<IntSet>() {

        	@Override
        	public void execute(ReadGraphImpl graph, IntSet types) throws DatabaseException {

        		types.forEach(addToResult);
        		addOrSet(graph, result, processor);
        		procedure.execute(graph, result); 

        	}

        	@Override
        	public void exception(ReadGraphImpl graph, Throwable t) throws DatabaseException {
        		procedure.exception(graph, t);
        	}

        });
        
        return result;
                        
    }
    
    @Override
    public String toString() {
    	return "TypeHierarchy[" + id + "]";
    }

    private void addOrSet(ReadGraphImpl graph, final IntSet value, QueryProcessor provider) {
    	
        assert(!isReady());

        synchronized(this) {
        
            value.trim();
            setResult(value);
            setReady();
        
        }
        
    }

    @Override
    public Object performFromCache(ReadGraphImpl graph, InternalProcedure<IntSet> procedure) throws DatabaseException {
    	
    	assert(isReady());

    	if(handleException(graph, procedure)) return null;
    	
    	IntSet result = getResult();
    	
        procedure.execute(graph, result);
        
        return result;
        
    }
    
    @Override
    public void recompute(ReadGraphImpl graph) throws DatabaseException {
    
        compute(graph, new InternalProcedure<IntSet>() {

        	@Override
        	public void execute(ReadGraphImpl graph, IntSet result) {
        	}

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

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

}