package org.simantics.district.network.ui;

import java.awt.geom.Rectangle2D;
import java.util.Collection;

import org.simantics.databoard.Bindings;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.request.ObjectsWithType;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.util.Layer0Utils;
import org.simantics.diagram.stubs.DiagramResource;
import org.simantics.diagram.synchronization.IModifiableSynchronizationContext;
import org.simantics.diagram.synchronization.SynchronizationHints;
import org.simantics.diagram.synchronization.graph.AddElement;
import org.simantics.diagram.synchronization.graph.GraphSynchronizationHints;
import org.simantics.diagram.synchronization.graph.layer.GraphLayerManager;
import org.simantics.district.network.DistrictNetworkUtil;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.g2d.diagram.IDiagram;
import org.simantics.layer0.Layer0;

public class DNEdgeBuilder {
    
    private Resource diagramResource;
    private IDiagram diagram;
    private GraphLayerManager glm;

    public DNEdgeBuilder(Resource diagramResource, IDiagram diagram) {
        this.diagramResource = diagramResource;
        this.diagram = diagram;
        
        IModifiableSynchronizationContext context = diagram.getHint(SynchronizationHints.CONTEXT);
        glm = context.get(GraphSynchronizationHints.GRAPH_LAYER_MANAGER);
    }

    public void create(WriteGraph graph, double[] start, double[] end, double padding) throws DatabaseException {
        
        DistrictNetworkResource DN = DistrictNetworkResource.getInstance(graph);
        
        // 1. Get diagram edge to construct
        Resource edge = getOrCreateEdge(graph);
        
        // 1.1 Give running name to connection and increment the counter attached to the diagram.
        AddElement.claimFreshElementName(graph, diagramResource, edge);
        
        // 2. Add vertices
        Collection<Resource> vertices = graph.syncRequest(new ObjectsWithType(diagramResource, Layer0.getInstance(graph).ConsistsOf, DistrictNetworkResource.getInstance(graph).Vertex));
        Resource startVertex = getOrCreateVertex(graph, vertices, start, padding);
        Resource endVertex = getOrCreateVertex(graph, vertices, end, padding);
        
        graph.claim(edge, DN.HasStartVertex, startVertex);
        graph.claim(edge, DN.HasEndVertex, endVertex);
        
        // 7. Put the element on all the currently active layers if possible.
        if (glm != null) {
            putOnActiveLayer(graph, edge);
            putOnActiveLayer(graph, startVertex);
            putOnActiveLayer(graph, endVertex);
        }
        
        Layer0Utils.addCommentMetadata(graph, "Added edge " + edge);
        graph.markUndoPoint();
    }
    
    private void putOnActiveLayer(WriteGraph graph, Resource res) throws DatabaseException {
        glm.removeFromAllLayers(graph, res);
        glm.putElementOnVisibleLayers(diagram, graph, res);
    }

    private Resource getOrCreateVertex(WriteGraph graph, Collection<Resource> vertices, double[] coords, double padding) throws DatabaseException {
        Resource vertex = null;
        double halfPadding = padding / 2;
        for (Resource vertx : vertices) {
            double[] existingCoords = graph.getRelatedValue2(vertx, DiagramResource.getInstance(graph).HasLocation, Bindings.DOUBLE_ARRAY);
            Rectangle2D existing = new Rectangle2D.Double(existingCoords[0] - halfPadding, existingCoords[1] - halfPadding, padding, padding);
            Rectangle2D tobecreated = new Rectangle2D.Double(coords[0] - halfPadding, coords[1] - halfPadding, padding, padding);
            if (existing.intersects(tobecreated)) {
                vertex = vertx;
                break;
            }
        }
        if (vertex == null) {
            vertex = DistrictNetworkUtil.createVertex(graph, diagramResource, coords); 
            AddElement.claimFreshElementName(graph, diagramResource, vertex);
        }
        return vertex;
    }

    private Resource getOrCreateEdge(WriteGraph graph) throws DatabaseException {
        return DistrictNetworkUtil.createEdge(graph, diagramResource);
    }

}