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

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.geom.Line2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;

import org.simantics.scenegraph.ParentNode;
import org.simantics.scenegraph.g2d.G2DNode;
import org.simantics.scenegraph.g2d.nodes.spatial.RTreeNode;
import org.simantics.scenegraph.utils.NodeUtil;
import org.simantics.utils.datastructures.Pair;

public class DistrictNetworkEdgeArrayNode extends G2DNode implements DeferredNode {

    private static final long serialVersionUID = -8377444630205663419L;

    public static final String NODE_KEY = "DISTRICT_NETWORK_EDGE_ARRAY";

    private static final String RENDERER_ID = "edgeArrayDeferredRenderer";

    private DistrictNetworkEdgeNode edgeNode = null;
    private Double arrowLength;
    private Path2D arrowPath;

    @Override
    public void render(Graphics2D g2d) {
        ParentNode<?> root = (ParentNode<?>) NodeUtil.getNearestParentOfType(this, RTreeNode.class);
        DeferredRenderingNode deferred = root != null ? (DeferredRenderingNode) root.getNode(RENDERER_ID) : null;
        if (deferred != null)
            deferred.deferNode(g2d.getTransform(), this);
        else
            renderDeferred(g2d);
    }

    @Override
    public void renderDeferred(Graphics2D g2d) {

        // Draw arrow
        if (arrowLength != null) {
            double scale = DistrictNetworkEdgeNode.scaleStroke ? (Double) g2d.getRenderingHint(DistrictRenderingHints.KEY_VIEW_SCALE_UNDER_SPATIAL_ROOT) : 1.0;
            g2d.setColor(Color.BLACK);
            float lw = DistrictNetworkEdgeNode.STROKE.getLineWidth() / (float)scale;
            g2d.setStroke(new BasicStroke(lw, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));

            double l = arrowLength;
            double w = 2 * (double) lw * Math.signum(l);
            if (Math.abs(w) > Math.abs(l)) w = l;
            double offset = 2 * (double) lw;

            int zoomLevel = (Integer) g2d.getRenderingHint(DistrictRenderingHints.KEY_VIEW_ZOOM_LEVEL);
            
            Point2D centerPoint = edgeNode.getCenterPoint(zoomLevel);
            Point2D direction = edgeNode.getDirection(zoomLevel);
            double centerX = centerPoint.getX(), centerY = centerPoint.getY();
            double deltaX = direction.getX(), deltaY = direction.getY();

            // Ensure the line is always rendered on top of the edge
            // to prevent overlap with static info rendered below it.
            double odx = offset * deltaY;
            double ody = offset * deltaX;
            if (odx < 0) {
                odx = -odx;
                ody = -ody;
            }

            double x0 = centerX - l/2 * deltaX + ody;
            double y0 = centerY - l/2 * deltaY - odx;
            double x1 = centerX + (l/2 - w) * deltaX + ody;
            double y1 = centerY + (l/2 - w) * deltaY - odx;

            g2d.draw(new Line2D.Double(x0, y0, x1, y1));

            arrowPath = new Path2D.Double();
            arrowPath.moveTo(x1 + w * deltaX, y1 + w * deltaY);
            arrowPath.lineTo(x1 + w * deltaY, y1 - w * deltaX);
            arrowPath.lineTo(x1 - w * deltaY, y1 + w * deltaX);
            arrowPath.closePath();
            g2d.fill(arrowPath);
        }
    }

    @Override
    public Rectangle2D getBoundsInLocal() {
        return null;
    }
    
    public void setEdgeNode(DistrictNetworkEdgeNode edgeNode) {
        this.edgeNode = edgeNode;
    }

    public void setArrowLength(Double length) {
        this.arrowLength = length;
    }

    public static Pair<String, Class<DeferredRenderingNode>> renderer() {
        return Pair.make(RENDERER_ID, DeferredRenderingNode.class);
    }

}