/*******************************************************************************
 * 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.layer0.adapter.impl;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Set;
import java.util.concurrent.atomic.AtomicInteger;

import org.simantics.db.AsyncReadGraph;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.Statement;
import org.simantics.db.common.primitiverequest.Superrelations;
import org.simantics.db.common.procedure.adapter.TransientCacheAsyncMultiListener;
import org.simantics.db.common.request.ReadRequest;
import org.simantics.db.common.request.ResourceAsyncMultiRead;
import org.simantics.db.common.utils.NameUtils;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.procedure.AsyncMultiProcedure;
import org.simantics.db.procedure.AsyncProcedure;
import org.simantics.layer0.Layer0;

public class EntitySubgraphExtent extends TypeSubgraphExtent {

	public static boolean DEBUG = false;

	static class DefinedRelationSet extends ResourceAsyncMultiRead<Resource> {

		public DefinedRelationSet(Resource type) {
			super(type);
		}

		public void forType(AsyncReadGraph graph, Resource type, final AsyncMultiProcedure<Resource> procedure, final AtomicInteger ready) {

			final Layer0 l0 = graph.getService(Layer0.class);

			ready.incrementAndGet();

			graph.forEachObject(type, l0.HasPropertyDefinition, new AsyncMultiProcedure<Resource>() {

				@Override
				public void execute(AsyncReadGraph graph, Resource def) {

					ready.incrementAndGet();

					graph.forPossibleObject(def, l0.ConcernsRelation, new AsyncProcedure<Resource>() {

						@Override
						public void execute(AsyncReadGraph graph, Resource relation) {
							if(relation != null) procedure.execute(graph, relation);
							if(ready.decrementAndGet() == 0) procedure.finished(graph);
						}

						@Override
						public void exception(AsyncReadGraph graph, Throwable throwable) {
							throwable.printStackTrace();
						}

					});

				}

				@Override
				public void finished(AsyncReadGraph graph) {

					if(ready.decrementAndGet() == 0) procedure.finished(graph);

				}

				@Override
				public void exception(AsyncReadGraph graph, Throwable throwable) {
					throwable.printStackTrace();
				}

			});

		}

		@Override
		public void perform(AsyncReadGraph graph, final AsyncMultiProcedure<Resource> procedure) {

			final AtomicInteger ready = new AtomicInteger(1);

			forType(graph, resource, procedure, ready);

			graph.forSupertypes(resource, new AsyncProcedure<Set<Resource>>() {

				@Override
				public void execute(AsyncReadGraph graph, Set<Resource> types) {

					for(Resource type : types) forType(graph, type, procedure, ready);

					if(ready.decrementAndGet() == 0) procedure.finished(graph);

				}

				@Override
				public void exception(AsyncReadGraph graph, Throwable throwable) {
					throwable.printStackTrace();
				}

			});

		}

	}

	@Override
	public void accept(AsyncReadGraph graph, final Resource resource, final AsyncProcedure<Classifier> procedure, final Callback callback) {

		final AtomicInteger ready = new AtomicInteger(1);

		class Result extends TransientCacheAsyncMultiListener<Resource> implements Classifier {

			final ArrayList<Resource> predicates = new ArrayList<Resource>();

			@Override
			public void exception(AsyncReadGraph graph, Throwable throwable) {
				throwable.printStackTrace();
			}

			@Override
			public void execute(AsyncReadGraph graph, Resource predicate) {
				synchronized(predicates) {
					predicates.add(predicate);
				}
			}

			@Override
			public void finished(AsyncReadGraph graph) {
				if(ready.decrementAndGet() == 0) procedure.execute(graph, this);
			}

			@Override
			public void classify(AsyncReadGraph graph, final Statement statement, ExtentStatus objectExtent, final Callback callback) {

				if(DEBUG) {
					graph.asyncRequest(new ReadRequest() {

						@Override
						public void run(ReadGraph graph) throws DatabaseException {
							System.out.println("classify " + NameUtils.toString(graph, statement));
						}

					});
				}

				// TODO haxx
				final Resource p = statement.getPredicate();
				if(graph.getService(Layer0.class).PartOf.equals(p) && !ExtentStatus.INTERNAL.equals(objectExtent)) return; 
				// TODO haxx2
				if(ExtentStatus.EXCLUDED.equals(objectExtent)) return;

				if(predicates.contains(p)) {
					callback.statement(statement, true);

					if(DEBUG) {
						graph.asyncRequest(new ReadRequest() {

							@Override
							public void run(ReadGraph graph) throws DatabaseException {
								System.out.println("-accept " + NameUtils.toString(graph, statement));
							}

						});
					}

					return;
				}

				graph.forDirectSuperrelations(p, new AsyncMultiProcedure<Resource>() {

					@Override
					public void exception(AsyncReadGraph graph, Throwable throwable) {
						throwable.printStackTrace();
					}

					@Override
					public void execute(AsyncReadGraph graph, final Resource superRelation) {


						if(predicates.contains(superRelation)) {
							callback.statement(statement, true);

							if(DEBUG) {
								graph.asyncRequest(new ReadRequest() {

									@Override
									public void run(ReadGraph graph) throws DatabaseException {
										System.out.println("-accept " + NameUtils.toString(graph, statement));
									}

								});
							}

							return;
						}

						graph.asyncRequest(new Superrelations(superRelation), new AsyncProcedure<Set<Resource>>() {

							@Override
							public void exception(AsyncReadGraph graph, Throwable t) {
								t.printStackTrace();
							}

							@Override
							public void execute(AsyncReadGraph graph, Set<Resource> supers) {

								if(!Collections.disjoint(supers, predicates)) {

									if(DEBUG) {
										graph.asyncRequest(new ReadRequest() {

											@Override
											public void run(ReadGraph graph) throws DatabaseException {
												System.out.println("-accept " + NameUtils.toString(graph, statement));
											}

										});
									}

									callback.statement(statement, true);

								}

							}

						});

					}

					@Override
					public void finished(AsyncReadGraph graph) {
					}

				});

			}

		};

		final Result result = new Result();

		graph.forEachPrincipalType(resource, new AsyncMultiProcedure<Resource>() {

			@Override
			public void execute(AsyncReadGraph graph, Resource type) {
				ready.incrementAndGet();
				graph.asyncRequest(new DefinedRelationSet(type), result);
			}

			@Override
			public void finished(AsyncReadGraph graph) {
				if(ready.decrementAndGet() == 0) procedure.execute(graph, result);
			}

			@Override
			public void exception(AsyncReadGraph graph, Throwable throwable) {
				throwable.printStackTrace();
			}

		});

	}

}