/*******************************************************************************
 * Copyright (c) 2007, 2012 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.modeling.typicals;

import java.util.Map;

import org.simantics.db.MetadataI;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.changeset.GenericChangeListener;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.genericrelation.DependenciesRelation.DependencyChangesRequest;
import org.simantics.db.layer0.genericrelation.DependencyChanges;
import org.simantics.db.layer0.genericrelation.DependencyChanges.Change;
import org.simantics.db.layer0.genericrelation.DependencyChanges.ComponentAddition;
import org.simantics.db.layer0.genericrelation.DependencyChanges.ComponentModification;
import org.simantics.db.layer0.genericrelation.DependencyChanges.ComponentRemoval;
import org.simantics.diagram.content.ConnectionUtil;
import org.simantics.diagram.stubs.DiagramResource;
import org.simantics.layer0.Layer0;
import org.simantics.modeling.ModelingResources;
import org.simantics.structural.stubs.StructuralResource2;
import org.simantics.utils.datastructures.MapSet;
import org.simantics.utils.ui.ErrorLogger;

import gnu.trove.set.hash.THashSet;

/**
 * This listener needs to discover if changes are made to typical diagram
 * templates.
 * 
 * It uses DependencyChange contents to find out if the changes affect any
 * dependencies of typical diagram templates.
 * 
 * @author Tuukka Lehtonen
 * 
 * @see SyncTypicalTemplatesToInstances
 * @deprecated not to be used anymore, will be removed
 */
public class TypicalDiagramTemplateListener extends GenericChangeListener<DependencyChangesRequest, DependencyChanges> {

    private static final boolean   DEBUG = false;

    Layer0                         L0;
    StructuralResource2            STR;
    DiagramResource                DIA;
    ModelingResources              MOD;

    THashSet<Resource>             visited  = new THashSet<Resource>();
    THashSet<Resource>             typicals = new THashSet<Resource>();

    /**
     * For optimizing the synchronization visual element properties (transform)
     */
    MapSet<Resource, Resource>     changedElementsByDiagram = new MapSet.Hash<Resource, Resource>();

    @Override
    public void onEvent(ReadGraph graph, MetadataI metadata, DependencyChanges event) throws DatabaseException {
        this.L0 = Layer0.getInstance(graph);
        this.STR = StructuralResource2.getInstance(graph);
        this.DIA = DiagramResource.getInstance(graph);
        this.MOD = ModelingResources.getInstance(graph);

        visited.clear();
        typicals.clear();
        try {
            processChanges(graph, event);
        } finally {
            // Clear unwanted references
            visited.clear();
            typicals.clear();
            visited.compact();
        }
    }

    private void processChanges(ReadGraph graph, DependencyChanges event) throws DatabaseException {
        for (Map.Entry<Resource, Change[]> entry : event.modelChanges.entrySet()) {
            Change[] changes = entry.getValue();
            if (changes == null)
                continue;

            if (DEBUG)
                for (Change change : changes)
                    System.out.println("CH: -" + change.toString(graph));

            for (Change c : changes) {
                if (c instanceof ComponentAddition) {
                    // element/module addition
                    ComponentAddition add = (ComponentAddition) c;
                    resolveDependentTypicalDiagrams(graph, add.component, false);
                } else if (c instanceof ComponentRemoval) {
                    // element/module removal
                    ComponentRemoval rm = (ComponentRemoval) c;
                    resolveDependentTypicalDiagrams(graph, rm.parent, false);
                } else if (c instanceof ComponentModification) {
                    // element transform changes
                    // module property changes
                    ComponentModification mod = (ComponentModification) c;
                    resolveDependentTypicalDiagrams(graph, mod.component, true);
                }
            }
        }

        if (!typicals.isEmpty())
            scheduleSynchronization(graph, typicals.toArray(Resource.NONE));
    }

    private void scheduleSynchronization(ReadGraph graph, final Resource[] templates) {
        MapSet<Resource, Resource> changes = this.changedElementsByDiagram;
        this.changedElementsByDiagram = new MapSet.Hash<Resource, Resource>();

        graph.asyncRequest(new SyncTypicalTemplatesToInstances(null, templates, changes), e -> {
            if (e != null)
                ErrorLogger.defaultLogError("Typical template diagram synchronization to instances failes, see exception for details.", e);
        });
    }

    private void resolveDependentTypicalDiagrams(ReadGraph graph, Resource component, boolean modification) throws DatabaseException {
        if (visited.contains(component))
            return;

        if (graph.isInstanceOf(component, DIA.Diagram)) {
            addVisited(component, graph.hasStatement(component, MOD.DiagramHasInstance));
        } else if (graph.isInstanceOf(component, STR.Composite)) {
            Resource diagram = graph.getPossibleObject(component, MOD.CompositeToDiagram);
            addVisited(diagram, diagram != null && graph.hasStatement(diagram, MOD.DiagramHasInstance));
        } else if (graph.isInstanceOf(component, STR.Component)) {
            Resource parent = graph.getPossibleObject(component, L0.PartOf);
            if (parent != null) {
                if (graph.isInstanceOf(component, DIA.Element)) {
                    addVisited(parent, graph.hasStatement(parent, MOD.DiagramHasInstance));
                    if (modification)
                        changedElementsByDiagram.add(parent, component);
                } else {
                    Resource diagram = graph.getPossibleObject(parent, MOD.CompositeToDiagram);
                    if (diagram != null) {
                        addVisited(diagram, graph.hasStatement(diagram, MOD.DiagramHasInstance));
                        if (modification) {
                            Resource element = graph.getPossibleObject(component, MOD.ComponentToElement);
                            if (element != null)
                                changedElementsByDiagram.add(diagram, element);
                        }
                    }
                }
            }
        } else {
            // handle changes to properties of components/elements ??
        }

        if (modification) {
            // Recognize changes in template diagram connections.
            if (graph.isInstanceOf(component, DIA.RouteNode)) {
                Resource connection = ConnectionUtil.tryGetConnection(graph, component);
                if (connection != null) {
                    Resource parent = graph.getPossibleObject(connection, L0.PartOf);
                    if (parent != null) {
                        boolean isTypical = graph.hasStatement(parent, MOD.DiagramHasInstance);
                        addVisited(parent, isTypical);
                        if (isTypical)
                            changedElementsByDiagram.add(parent, connection);
                    }
                }
            }
        }

        addVisited(component, false);
    }

    private void addVisited(Resource r, boolean isTypical) {
        if (r != null && visited.add(r)) {
            if (DEBUG)
                System.out.println("Visited: " + r);
            if (isTypical) {
                typicals.add(r);
                if (DEBUG)
                    System.out.println("Added typical: " + r);
            }
        }
    }

}