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

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Stroke;
import java.awt.geom.AffineTransform;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.TimeUnit;

import org.simantics.Simantics;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.request.WriteRequest;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.request.Write;
import org.simantics.diagram.elements.DiagramNodeUtil;
import org.simantics.diagram.ui.DiagramModelHints;
import org.simantics.district.network.DNEdgeBuilder;
import org.simantics.district.network.DistrictNetworkUtil;
import org.simantics.district.network.ModelledCRS;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.district.network.ui.NetworkDrawingParticipant;
import org.simantics.g2d.canvas.Hints;
import org.simantics.g2d.canvas.ICanvasContext;
import org.simantics.g2d.canvas.IToolMode;
import org.simantics.g2d.diagram.IDiagram;
import org.simantics.scenegraph.g2d.G2DNode;
import org.simantics.scenegraph.g2d.events.EventTypes;
import org.simantics.scenegraph.g2d.events.KeyEvent.KeyPressedEvent;
import org.simantics.scenegraph.g2d.events.MouseEvent;
import org.simantics.scenegraph.g2d.events.MouseEvent.MouseClickEvent;
import org.simantics.scenegraph.g2d.events.MouseEvent.MouseDoubleClickedEvent;
import org.simantics.scenegraph.g2d.events.MouseEvent.MouseMovedEvent;
import org.simantics.scenegraph.utils.GeometryUtils;
import org.simantics.scenegraph.utils.NodeUtil;
import org.simantics.utils.threads.ThreadUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class NetworkDrawingNode extends G2DNode {

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

    static class DrawingNode {

        private List<Point2D> routeNodes = new ArrayList<>();
    }

    private static final long serialVersionUID = -3475301184009620573L;
    
    private Point2D currentMousePos = null;

    private List<DrawingNode> nodes = new ArrayList<>();
    private DrawingNode currentRouteNode = null;

    private Resource diagramResource;

    private NetworkDrawingParticipant participant;

    private IDiagram diagram;

    private static final Stroke DASHED_STROKE = new BasicStroke(2.0f,
            BasicStroke.CAP_ROUND,
            BasicStroke.JOIN_ROUND,
            4.0f, new float[]{4.0f}, 0.0f);

    private static final Color BLUE_ALPHA = new Color(0, 0, 255, 100);
    private static final Color RED_ALPHA = new Color(255, 0, 0, 100);

    private boolean scaleStroke = true;
    private AffineTransform lastViewTransform = new AffineTransform();

    @Override
    public void init() {
        super.init();
        addEventHandler(this);
    }
    
    public void setNetworkDrawingParticipant(NetworkDrawingParticipant participant) {
        this.participant = participant;
    }
    
    public void setDiagram(IDiagram diagram) {
        if (diagram != null) {
            this.diagram = diagram;
            this.diagramResource = diagram.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE);
        }
    }

    @Override
    public void render(Graphics2D g2d) {
        // Must store this for hover info functionality
        lastViewTransform = g2d.getTransform();

        if (nodes.isEmpty())
            return;

        Color old = g2d.getColor();
        Stroke oldStroke = g2d.getStroke();

        Iterator<DrawingNode> dnodeIterator = nodes.iterator();
        while (dnodeIterator.hasNext()) {
            Path2D path = new Path2D.Double();
            DrawingNode dnode = dnodeIterator.next();
            Iterator<Point2D> nodeIter = dnode.routeNodes.iterator();
            if (nodeIter.hasNext()) {
                Point2D node = nodeIter.next();
                path.moveTo(node.getX(), node.getY());
            }
            while (nodeIter.hasNext()) {
                Point2D node = nodeIter.next();
                path.lineTo(node.getX(), node.getY());
            }
            if (!dnodeIterator.hasNext()) {
                if (currentMousePos != null)
                    path.lineTo(currentMousePos.getX(), currentMousePos.getY());
            }
            
            if (DASHED_STROKE != null) {
                if (scaleStroke && DASHED_STROKE instanceof BasicStroke) {
                    BasicStroke bs = GeometryUtils.scaleStroke(DASHED_STROKE, (float) (1.0 / GeometryUtils.getScale(g2d.getTransform())));
                    g2d.setStroke(bs);
                } else {
                    g2d.setStroke(DASHED_STROKE);
                }
            }
            
            g2d.setColor(BLUE_ALPHA);
            g2d.draw(path);
            
            g2d.setColor(RED_ALPHA);
            BasicStroke stroke = GeometryUtils.scaleStroke(DASHED_STROKE, (float) (1.0 / GeometryUtils.getScale(g2d.getTransform())));
            g2d.setStroke(stroke);
            Point2D currentPoint = path.getCurrentPoint();
            g2d.draw(new Rectangle2D.Double(currentPoint.getX() - 0.0001 / 2, currentPoint.getY() - 0.0001 / 2, 0.0001, 0.0001));
        }
        
        g2d.setStroke(oldStroke);
        g2d.setColor(old);
    }

    @Override
    public Rectangle2D getBoundsInLocal() {
        return null;
    }
    
    @Override
    public int getEventMask() {
        return EventTypes.AnyMask;
    }
    
    @Override
    protected boolean mouseDoubleClicked(MouseDoubleClickedEvent e) {
        // nodes to path2d
        IToolMode mode = getToolMode();
        if (mode == Hints.CONNECTTOOL || e.hasAnyModifier(MouseEvent.ALT_MASK | MouseEvent.ALT_GRAPH_MASK)) {
            // ok, new routenode starts from here
            Point2D localPos = NodeUtil.worldToLocal(this, e.controlPosition, new Point2D.Double());
            Point2D.Double pos = new Point2D.Double(localPos.getX(), localPos.getY());
            if (currentRouteNode != null) {
                //currentRouteNode.routeNodes.add(pos);
                currentRouteNode = new DrawingNode();
                currentRouteNode.routeNodes.add(pos);
                nodes.add(currentRouteNode);
            } else {
                // ok, this must be creation of dh_point
                double scale = getTransform().getScaleY();
                double x = ModelledCRS.xToLongitude(pos.getX() / scale);
                double y = ModelledCRS.yToLatitude(-pos.getY() / scale);
                
                boolean leftButton = e.button == MouseEvent.LEFT_BUTTON;
                
                ThreadUtils.getNonBlockingWorkExecutor().schedule(() -> {
                    Simantics.getSession().asyncRequest(new Write() {
                        
                        @Override
                        public void perform(WriteGraph graph) throws DatabaseException {
                            graph.markUndoPoint();
                            Resource mapping = null;
                            if (leftButton) {
                            	mapping = graph.getSingleObject(diagramResource, DistrictNetworkResource.getInstance(graph).LeftClickDefaultMapping);
                            } else {
                            	mapping = graph.getSingleObject(diagramResource, DistrictNetworkResource.getInstance(graph).RightClickDefaultMapping);
                            }
                            if (mapping == null) {
                            	mapping = graph.getSingleObject(diagramResource, DistrictNetworkResource.getInstance(graph).VertexDefaultMapping);
                            }
                            DistrictNetworkUtil.createVertex(graph, diagramResource, new double[] { x, y }, Double.MAX_VALUE, mapping);
                        }
                    });
                }, 100, TimeUnit.MILLISECONDS);
            }
            repaint();
            return true;
        }
        return super.mouseDoubleClicked(e);
    }

    private void createEdge(DrawingNode node) {
        
        Point2D start = node.routeNodes.get(0);
        Point2D end = node.routeNodes.get(node.routeNodes.size() - 1);
        
        double currentPadding = DistrictNetworkVertexNode.width;
        AffineTransform test = getTransform();
        ICanvasContext ctx = DiagramNodeUtil.getCanvasContext(this);
        AffineTransform tr = ctx.getHintStack().getHint(Hints.KEY_CANVAS_TRANSFORM);
        AffineTransform testing = new AffineTransform(tr); 
        testing.concatenate(test);
        double calculateScaleRecip = DistrictNetworkNodeUtils.calculateScaleRecip(testing);
        double padding = currentPadding * calculateScaleRecip;
        /*
         *  To convert y-coordinates to map coordinates in ruler, use:
         *    double val = (y-offsetY)/scaleY;
         *    val = Math.toDegrees(Math.atan(Math.sinh(Math.toRadians(val))));
         *    String str = formatValue(val);
         */
        // TODO: fix scale
        double scaleY = getTransform().getScaleY();
        double scaleX = getTransform().getScaleX();
        
        double startLat = ModelledCRS.yToLatitude(-start.getY() / scaleY);
        double startLon = ModelledCRS.xToLongitude(start.getX() / scaleX);
        
        double endLat = ModelledCRS.yToLatitude(-end.getY() / scaleY);
        double endLon = ModelledCRS.xToLongitude(end.getX() / scaleX);
        
        double[] startCoords = new double[] { startLon, startLat };
        double[] endCoords = new double[] { endLon, endLat };
        
        double[] detailedGeometryCoords = new double[node.routeNodes.size() * 2];
        int i = 0;
        for (Point2D p : node.routeNodes) {
            double lat = ModelledCRS.yToLatitude(-p.getY() / scaleY);
            double lon = ModelledCRS.xToLongitude(p.getX() / scaleX);
            detailedGeometryCoords[i++] = lon;
            detailedGeometryCoords[i++] = lat;
        }

        DNEdgeBuilder builder = new DNEdgeBuilder(diagramResource, diagram);
        Simantics.getSession().asyncRequest(new WriteRequest() {

            @Override
            public void perform(WriteGraph graph) throws DatabaseException {
                builder.create(graph, startCoords, Double.MAX_VALUE, endCoords, Double.MAX_VALUE, detailedGeometryCoords, padding);
            }
        });

    }

    @Override
    protected boolean mouseClicked(MouseClickEvent e) {
        // check ToolMode
        IToolMode mode = getToolMode();
        if (mode == Hints.CONNECTTOOL || e.hasAnyModifier(MouseEvent.ALT_MASK | MouseEvent.ALT_GRAPH_MASK)) {
            if (e.button == MouseEvent.RIGHT_BUTTON && !nodes.isEmpty()) {
                nodes.remove(nodes.size() - 1);
            } else if (e.button == MouseEvent.LEFT_BUTTON) {
                Point2D localPos = NodeUtil.worldToLocal(this, e.controlPosition, new Point2D.Double());
                if (currentRouteNode == null && canStartEdge(localPos)) {
                    // ok, we can start from here
                    currentRouteNode = new DrawingNode();
                    currentRouteNode.routeNodes.add(new Point2D.Double(localPos.getX(), localPos.getY()));
                    nodes.add(currentRouteNode);
                } else if (currentRouteNode != null && canStartEdge(localPos)) {
                    // let's commit our new routenode
                    currentRouteNode.routeNodes.add(new Point2D.Double(localPos.getX(), localPos.getY()));
                    Iterator<DrawingNode> nodeIter = nodes.iterator();
                    while (nodeIter.hasNext()) {
                        createEdge(nodeIter.next());
                    }
                    currentRouteNode = null;
                    nodes.clear();
                } else if (currentRouteNode != null) {
                    currentRouteNode.routeNodes.add(new Point2D.Double(localPos.getX(), localPos.getY()));
                }
            }
            repaint();
            return true;
        }
        return super.mouseClicked(e);
    }

    private boolean canStartEdge(Point2D currentPos) {
        return participant.isHoveringOverNode(currentPos, lastViewTransform);
    }

    private IToolMode getToolMode() {
        return participant.getHint(Hints.KEY_TOOL);
    }

    @Override
    protected boolean mouseMoved(MouseMovedEvent e) {
        IToolMode mode = getToolMode();
        boolean repaint = false;
        Point2D p = NodeUtil.worldToLocal(this, e.controlPosition, new Point2D.Double());
        boolean isConnectionTool = mode == Hints.CONNECTTOOL || e.hasAnyModifier(MouseEvent.ALT_MASK | MouseEvent.ALT_GRAPH_MASK);
        // To boost pan perf hovering is only considered if no mouse button is pressed)
        if (e.buttons == 0 && participant.pickHoveredElement(p, isConnectionTool, lastViewTransform)) {
            repaint = true;
        }
        if (!nodes.isEmpty()) {
            currentMousePos = p;
            repaint();
            return true;
        }
        currentMousePos = null;
        if (repaint == true)
            repaint();
        return super.mouseMoved(e);
    }

    @Override
    protected boolean keyPressed(KeyPressedEvent e) {
        if (e.keyCode == java.awt.event.KeyEvent.VK_ESCAPE) {
            currentRouteNode = null;
            nodes.clear();
            repaint();
            return true;
        }
        return super.keyPressed(e);
    }
}