/*******************************************************************************
 * 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 java.util.concurrent.atomic.AtomicInteger;

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

import gnu.trove.procedure.TIntProcedure;

final public class Types extends UnaryQuery<InternalProcedure<IntSet>> {
	
    Types(final int resource) {
        super(resource);
    }

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

 	@Override
 	public Object compute(final ReadGraphImpl graph, final InternalProcedure<IntSet> procedure) throws DatabaseException {
		computeForEach(graph, id, this, procedure);
		return getResult();
 	}

 	public static void computeForEach(final ReadGraphImpl graph, int id, Types entry, final InternalProcedure<IntSet> procedure) throws DatabaseException {

 		if(entry != null)
 			if(entry.isReady())
 				System.err.println("asd");
 		
 		assert(procedure != null);

 		QueryProcessor processor = graph.processor;

 		processor.querySupport.ensureLoaded(graph, id);
 		
 		int ret = processor.querySupport.getSingleInstance(id);
 		if(ret > 0) {

 			TypeHierarchy.queryEach(graph, ret, processor, entry, null, new InternalProcedure<IntSet>() {

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

 					if(entry != null) entry.addOrSet(graph, types, processor);
 					procedure.execute(graph, types);

 				}

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

 			});

 		}
 		
 		final int instanceOf = processor.getInstanceOf();
        final int inherits = processor.getInherits();
        final int subrelationOf = processor.getSubrelationOf();

        final IntSet result = new IntSet(processor.querySupport);
        
        final TIntProcedure addToResult = new TIntProcedure() {
            @Override
            public boolean execute(int r) {
            	synchronized(result) {
            		result.add(r);
            	}
                return true;
            }
        };
        
        final AtomicInteger finishes = new AtomicInteger(0);
        
        SyncIntProcedure instanceOfProcedure = new SyncIntProcedure() {
            
            @Override
            public void run(ReadGraphImpl graph) throws DatabaseException {
            	
                if(finishes.addAndGet(1) == 3) {
                    if(entry != null) entry.addOrSet(graph, result, processor);
                    procedure.execute(graph, result);
            	}
                
            }
            
            @Override
            public void execute(ReadGraphImpl graph, int i) throws DatabaseException {
                
            	synchronized(result) {
            		result.add(i);
            	}
                
                inc();

                QueryCache.runnerSuperTypes(graph, i, entry, null, new InternalProcedure<IntSet>() {

                    @Override
                    public void execute(ReadGraphImpl graph, IntSet types) throws DatabaseException {
                        types.forEach(addToResult);
                        dec(graph);
                    }
    				
    				@Override
    				public void exception(ReadGraphImpl graph, Throwable t) throws DatabaseException {
    					procedure.exception(graph, t);
                        dec(graph);
    	            }

                });
                
            }

            @Override
            public void finished(ReadGraphImpl graph) throws DatabaseException {
                dec(graph);
            }
            
        }; 
        
        SyncIntProcedure inheritsProcedure = new SyncIntProcedure() {
            
            @Override
            public void run(ReadGraphImpl graph) throws DatabaseException {

            	int current = finishes.addAndGet(1);
            	if(current == 3) {
                    if(entry != null) entry.addOrSet(graph, result, processor);
                    procedure.execute(graph, result);
            	}
                
            }
            
            @Override
            public void execute(ReadGraphImpl graph, int i) throws DatabaseException {
                
                inc();

                QueryCache.runnerTypes(graph, i, entry, null, new InternalProcedure<IntSet>() {

                    @Override
                    public void execute(ReadGraphImpl graph, IntSet types) throws DatabaseException {
                        types.forEach(addToResult);
                        dec(graph);
                    }
    				
    				@Override
    				public void exception(ReadGraphImpl graph, Throwable t) throws DatabaseException {
    					procedure.exception(graph, t);
                        dec(graph);
    	            }

                });
                
            }

            @Override
            public void finished(ReadGraphImpl graph) throws DatabaseException {

                dec(graph);

            }
            
        }; 

        SyncIntProcedure subrelationOfProcedure = new SyncIntProcedure() {

            @Override
            public void run(ReadGraphImpl graph) throws DatabaseException {

            	int current = finishes.addAndGet(1);
            	if(current == 3) {
                    if(entry != null) entry.addOrSet(graph, result, processor);
                    procedure.execute(graph, result);
            	}
                
            }
            
            @Override
            public void execute(ReadGraphImpl graph, int i) throws DatabaseException {
                
                inc();
                
                QueryCache.runnerTypes(graph, i, entry, null, new InternalProcedure<IntSet>() {

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

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

                });
                
            }

            @Override
            public void finished(ReadGraphImpl graph) throws DatabaseException {
                
                dec(graph);

            }
            
        }; 
        
        processor.querySupport.getObjects(graph, id, instanceOf, instanceOfProcedure);
        instanceOfProcedure.finished(graph);
        processor.querySupport.getObjects(graph, id, inherits, inheritsProcedure);
        inheritsProcedure.finished(graph);
        processor.querySupport.getObjects(graph, id, subrelationOf, subrelationOfProcedure);
        subrelationOfProcedure.finished(graph);
        
        if(entry != null) entry.finish();
        
    }
    
    @Override
    public String toString() {
    	return "Types[" + id + "]";
    }
    
    private void addOrSet(ReadGraphImpl graph, final IntSet value, QueryProcessor provider) {
    	
        assert(!isReady());

        setResult(value);
        
    }
    
    void finish() {

    	IntSet result = getResult(); 
    	result.trim();
    	setReady();
    	
    }
    
    @Override
    final public Object performFromCache(ReadGraphImpl graph, InternalProcedure<IntSet> procedure) throws DatabaseException {
        
    	assert(isReady());
    	
    	if(handleException(graph, procedure)) return EXCEPTED;
    	
    	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);
    }
    
}