package org.simantics.district.network.ui;

import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.util.List;

import org.simantics.district.network.ui.adapters.DistrictNetworkVertexElement;
import org.simantics.district.network.ui.nodes.DistrictNetworkVertexNode;
import org.simantics.district.network.ui.nodes.NetworkDrawingNode;
import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;
import org.simantics.g2d.canvas.impl.SGNodeReflection.SGInit;
import org.simantics.g2d.diagram.IDiagram;
import org.simantics.g2d.diagram.handler.PickContext;
import org.simantics.g2d.diagram.handler.PickRequest;
import org.simantics.g2d.diagram.participant.AbstractDiagramParticipant;
import org.simantics.g2d.element.IElement;
import org.simantics.scenegraph.g2d.G2DNode;
import org.simantics.scenegraph.g2d.G2DParentNode;
import org.simantics.utils.datastructures.hints.IHintContext.Key;
import org.simantics.utils.datastructures.hints.IHintContext.KeyOf;

public class NetworkDrawingParticipant extends AbstractDiagramParticipant {

    @Dependency
    PickContext pick;
    
    /**
     * A hint key for terminal pick distance in control pixels.
     * @see #PICK_DIST
     */
    public static final Key KEY_PICK_DISTANCE = new KeyOf(Double.class, "PICK_DISTANCE");

    /**
     * Default terminal pick distance in control pixels.
     * @see #DEFAULT_PICK_DISTANCE
     */
    public static final double PICK_DIST = 10;
    
    private NetworkDrawingNode node;
    
    @SGInit
    public void initSG(G2DParentNode parent) {
        node = parent.addNode("networkDrawingNode", NetworkDrawingNode.class);
        node.setNetworkDrawingParticipant(this);
    }
    
    @Override
    protected void onDiagramSet(IDiagram newDiagram, IDiagram oldDiagram) {
        node.setDiagram(newDiagram);
    }

    public boolean pickHoveredElement(Point2D currentMousePos) {
        PickRequest req = new PickRequest(currentMousePos.getX(), currentMousePos.getY());
        List<IElement> pickables = new ArrayList<IElement>();
        pick.pick(diagram, req, pickables);
        
        List<IElement> snap = new ArrayList<>(diagram.getSnapshot());
        
        snap.removeAll(pickables);
        
        boolean changed = false;
        for (IElement sn : snap) {
            G2DNode node = sn.getHint(DistrictNetworkVertexElement.KEY_DN_VERTEX_NODE);
            if (node instanceof DistrictNetworkVertexNode) {
                if (((DistrictNetworkVertexNode) node).hover(false) && !changed) {
                    changed = true;
                }
            }
        }
        
        for (IElement elem : pickables) {
            G2DNode node = elem.getHint(DistrictNetworkVertexElement.KEY_DN_VERTEX_NODE);
            if (node instanceof DistrictNetworkVertexNode) {
                if (((DistrictNetworkVertexNode) node).hover(true) && !changed) {
                    changed = true;
                }
            }
        }
        return changed;
    }

}