package org.simantics.district.network.ui.adapters;

import java.awt.Color;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.Collection;
import java.util.Collections;

import org.simantics.district.network.ModelledCRS;
import org.simantics.district.network.ui.DistrictNetworkEdge;
import org.simantics.district.network.ui.nodes.DistrictNetworkEdgeNode;
import org.simantics.g2d.connection.handler.ConnectionHandler;
import org.simantics.g2d.diagram.handler.PickRequest.PickPolicy;
import org.simantics.g2d.diagram.handler.Topology.Connection;
import org.simantics.g2d.element.ElementClass;
import org.simantics.g2d.element.ElementUtils;
import org.simantics.g2d.element.IElement;
import org.simantics.g2d.element.SceneGraphNodeKey;
import org.simantics.g2d.element.handler.InternalSize;
import org.simantics.g2d.element.handler.Outline;
import org.simantics.g2d.element.handler.Pick;
import org.simantics.g2d.element.handler.SceneGraph;
import org.simantics.g2d.element.handler.impl.ConnectionSelectionOutline;
import org.simantics.g2d.element.handler.impl.DefaultTransform;
import org.simantics.g2d.element.handler.impl.SimpleElementLayers;
import org.simantics.maps.MapScalingTransform;
import org.simantics.scenegraph.g2d.G2DParentNode;
import org.simantics.scenegraph.g2d.nodes.SVGNode;
import org.simantics.utils.datastructures.hints.IHintContext.Key;
import org.simantics.utils.datastructures.hints.IHintContext.KeyOf;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DistrictNetworkEdgeElement {

    public static final Key KEY_DN_EDGE = new KeyOf(DistrictNetworkEdge.class, "DN_EDGE");
    public static final Key KEY_DN_EDGE_NODE = new SceneGraphNodeKey(DistrictNetworkEdgeNode.class, "DN_EDGE_NODE");
    public static final Key KEY_DN_EDGE_SYMBOL_NODE = new SceneGraphNodeKey(DistrictNetworkEdgeNode.class, "DN_EDGE_SYMBOL_NODE");

    public static final ElementClass CLASS =
            ElementClass.compile(
                    DefaultTransform.INSTANCE,
                    DNEdgeInternalSize.INSTANCE,
                    DNEdgeSceneGraph.INSTANCE,
                    DNEdgeConnectionHandler.INSTANCE,
                    SimpleElementLayers.INSTANCE,
                    // TODO: do we need this and does it work?
                    ConnectionSelectionOutline.INSTANCE,
                    DistrictNetworkAdditionalColor.INSTANCE
            ).setId(DistrictNetworkEdgeElement.class.getSimpleName());

    static final class DNEdgeSceneGraph implements SceneGraph {

        public static final DNEdgeSceneGraph INSTANCE = new DNEdgeSceneGraph();

        private static final long serialVersionUID = 68135568495835923L;

        @Override
        public void init(IElement edgeElement, G2DParentNode parent) {
            DistrictNetworkEdge edge = edgeElement.getHint(KEY_DN_EDGE);
            if (edge == null) {
                cleanup(edgeElement);
            } else {
                DistrictNetworkEdgeNode node = edgeElement.getHint(KEY_DN_EDGE_NODE);
                if (node == null) {
                    node = parent.addNode(ElementUtils.generateNodeId(edgeElement), DistrictNetworkEdgeNode.class);
                    edgeElement.setHint(KEY_DN_EDGE_NODE, node);
                    
                    SVGNode symbol = node.addNode(ElementUtils.generateNodeId(edgeElement), SVGNode.class);
                    edgeElement.setHint(KEY_DN_EDGE_SYMBOL_NODE, symbol);
                }
                
                node.setColor(ElementUtils.getAdditionalColor(edgeElement, Color.BLUE));
                
                node.setDNEdge(edge);
                AffineTransform at = ElementUtils.getTransform(edgeElement);
                if (at != null)
                    node.setTransform(at);
            }
        }

        @Override
        public void cleanup(IElement edge) {
            ElementUtils.removePossibleNode(edge, KEY_DN_EDGE_SYMBOL_NODE);
            ElementUtils.removePossibleNode(edge, KEY_DN_EDGE_NODE);
            edge.removeHint(KEY_DN_EDGE_NODE);
            edge.removeHint(KEY_DN_EDGE_SYMBOL_NODE);
        }
    }

    static final class DNEdgeInternalSize implements InternalSize, Outline, Pick {

        private static final Logger LOGGER = LoggerFactory.getLogger(DNEdgeInternalSize.class);

        private static final long serialVersionUID = -7346653820911240628L;

        public static final DNEdgeInternalSize INSTANCE = new DNEdgeInternalSize();

        @Override
        public Rectangle2D getBounds(IElement e, Rectangle2D size) {
            DistrictNetworkEdge edge = e.getHint(KEY_DN_EDGE);
            if (size == null)
                size = new Rectangle2D.Double();
            if (edge != null)
                size.setFrame(DistrictNetworkEdgeNode.calculatePath(edge, null).getBounds2D());
            else
                LOGGER.debug("Element {} does not have edge!", e);

            return size;
        }

        @Override
        public Shape getElementShape(IElement e) {
            DistrictNetworkEdge edge = e.getHint(KEY_DN_EDGE);
            if (edge != null) {
                return DistrictNetworkEdgeNode.calculatePath(edge, null);
            } else {
                return getBounds(e, null);
            }
        }

        @Override
        public boolean pickTest(IElement e, Shape s, PickPolicy policy) {
            DistrictNetworkEdge edge = e.getHint(KEY_DN_EDGE);
            if (edge != null) {
                Rectangle2D bounds = getBounds(s);
                switch (policy) {
                case PICK_CONTAINED_OBJECTS:    return pickContainedObjects(edge, bounds);
                case PICK_INTERSECTING_OBJECTS: return pickIntersectingObjects(edge, bounds);
                }
                return false;
            }

            return false;
        }

        private boolean pickContainedObjects(DistrictNetworkEdge edge, Rectangle2D bounds) {
            double bminx = bounds.getMinX() / MapScalingTransform.getScaleX();
            double bminy = bounds.getMinY() / MapScalingTransform.getScaleY();
            double bmaxx = bounds.getMaxX() / MapScalingTransform.getScaleX();
            double bmaxy = bounds.getMaxY() / MapScalingTransform.getScaleY();

            double bsminx = ModelledCRS.xToLongitude(bminx);
            double bsminy = ModelledCRS.yToLatitude(-bminy); // Invert for Simantics diagram coordinate system
            double bsmaxx = ModelledCRS.xToLongitude(bmaxx);
            double bsmaxy = ModelledCRS.yToLatitude(-bmaxy); // Invert for Simantics diagram coordinate system

            double boundsMinY = Math.min(bsminy, bsmaxy);
            double boundsMaxY = Math.max(bsminy, bsmaxy);

            Point2D start = edge.getStartPoint();
            Point2D end = edge.getEndPoint();

            double eminx = Math.min(start.getX(), end.getX());
            double eminy = Math.min(start.getY(), end.getY());
            double emaxx = Math.max(start.getX(), end.getX());
            double emaxy = Math.max(start.getY(), end.getY());

            return eminx >= bsminx && eminy >= boundsMinY && emaxx <= bsmaxx && emaxy <= boundsMaxY;
        }

        private boolean pickIntersectingObjects(DistrictNetworkEdge edge, Rectangle2D bounds) {
            double tolerance = (bounds.getHeight() + bounds.getHeight()) * 1 / MapScalingTransform.getScaleX();
            Line2D line = new Line2D.Double(edge.getStartPoint(), edge.getEndPoint());
            double sx = bounds.getCenterX() / MapScalingTransform.getScaleX();
            double sy = bounds.getCenterY() / MapScalingTransform.getScaleY();
            double ssx = ModelledCRS.xToLongitude(sx);
            double ssy = ModelledCRS.yToLatitude(-sy); // Invert for Simantics diagram coordinate system
            double distSq = line.ptSegDistSq(ssx, ssy);
//            System.out.println("s: " + sx + ", " + sy);
//            System.out.println("ss: " + ssx + ", " + ssy);
//            System.out.println("p1: " + edge.getStartPoint());
//            System.out.println("p2: " + edge.getEndPoint());
//            System.out.println("line: " + "(" + line.getX1() + ", " + line.getY1() + ", " + line.getX2() + ", " + line.getY2() + ")");
//            System.out.println("distance from line is " + Math.sqrt(distSq) + " with tolerance " + tolerance);
            return distSq <= tolerance * tolerance;
        }

        private Rectangle2D getBounds(Shape shape) {
            if (shape instanceof Rectangle2D)
                return (Rectangle2D) shape;
            return shape.getBounds2D();
        }

    }

    static class DNEdgeConnectionHandler implements ConnectionHandler {

        private static final long serialVersionUID = -6882671891381761687L;

        public static final DNEdgeConnectionHandler INSTANCE = new DNEdgeConnectionHandler();

        @Override
        public Collection<IElement> getChildren(IElement connection, Collection<IElement> result) {
            return Collections.emptyList();
        }

        @Override
        public Collection<IElement> getBranchPoints(IElement connection, Collection<IElement> result) {
            return Collections.emptyList();
        }

        @Override
        public Collection<IElement> getSegments(IElement connection, Collection<IElement> result) {
            return Collections.emptyList();
        }

        @Override
        public Collection<Connection> getTerminalConnections(IElement connection, Collection<Connection> result) {
            return Collections.emptyList();
        }
    }

}