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.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

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.diagram.ui.DiagramModelHints;
import org.simantics.district.network.ModelledCRS;
import org.simantics.district.network.ui.DNEdgeBuilder;
import org.simantics.district.network.ui.NetworkDrawingParticipant;
import org.simantics.g2d.canvas.Hints;
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;

public class NetworkDrawingNode extends G2DNode {

    private static final long serialVersionUID = -3475301184009620573L;
    
    private Point2D currentMousePos = null;
    
    private List<Point2D> nodes = new ArrayList<>();

    private Resource diagramResource;

    private boolean committed;

    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 boolean scaleStroke = true;
    
    @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) {
        if (nodes.isEmpty())
            return;
        
        Path2D path = new Path2D.Double();
        Iterator<Point2D> nodeIter = nodes.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 (currentMousePos != null)
            path.lineTo(currentMousePos.getX(), currentMousePos.getY());
        
        Color old = g2d.getColor();
        Stroke oldStroke = g2d.getStroke();
        
        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.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)) {
            Point2D start = null;
            Point2D end = null;
            Iterator<Point2D> nodeIter = nodes.iterator();
            while (nodeIter.hasNext()) {
                if (end == null) {
                    start = nodeIter.next();
                } else {
                    start = end;
                }
                end = nodeIter.next();
                
                createEdge(start, end);
            }
            
            nodes.clear();
            committed = true;
            
            repaint();
            
            return true;
        }
        return super.mouseDoubleClicked(e);
    }

    private void createEdge(Point2D start, Point2D end) {
        
        double padding = GeometryUtils.getScale(getTransform());
        
        /*
         *  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 };
        
        DNEdgeBuilder builder = new DNEdgeBuilder(diagramResource, diagram);
        Simantics.getSession().asyncRequest(new WriteRequest() {
            
            @Override
            public void perform(WriteGraph graph) throws DatabaseException {
                builder.create(graph, startCoords, endCoords, 1 / 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 (committed) {
                committed = false;
                return false;
            }
            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());
                nodes.add(new Point2D.Double(localPos.getX(), localPos.getY()));
            }
            repaint();
            return true;
        }
        return super.mouseClicked(e);
    }
    
    private IToolMode getToolMode() {
        return participant.getHint(Hints.KEY_TOOL);
    }

    @Override
    protected boolean mouseMoved(MouseMovedEvent e) {
        IToolMode mode = getToolMode();
        if (mode == Hints.CONNECTTOOL || e.hasAnyModifier(MouseEvent.ALT_MASK | MouseEvent.ALT_GRAPH_MASK)) {
            boolean repaint = false;
            Point2D p = NodeUtil.worldToLocal(this, e.controlPosition, new Point2D.Double());
            if (participant.pickHoveredElement(p)) {
                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) {
            nodes.clear();
            repaint();
            return true;
        }
        return super.keyPressed(e);
            
    }
}