package org.simantics.district.network;

import org.geotools.referencing.GeodeticCalculator;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.exception.DatabaseException;
import org.simantics.layer0.Layer0;

public class ModelledCRS implements CRS {

    private GeodeticCalculator calculator;

    public ModelledCRS(ReadGraph graph, Resource type) throws DatabaseException, FactoryException {
        String code = graph.getRelatedValue2(type, Layer0.getInstance(graph).HasLabel, Bindings.STRING);
        CoordinateReferenceSystem crs = org.geotools.referencing.CRS.decode(code);
        
        this.calculator = new GeodeticCalculator(crs);
    }
    
    @Override
    public double calculateDistance(double[] start, double[] end) {
        calculator.setStartingGeographicPoint(start[0], start[1]);
        calculator.setDestinationGeographicPoint(end[0], end[1]);
        double dist = calculator.getOrthodromicDistance();
        return dist;
    }

    // TODO: these only work with Spherical Mercator
    public static double xToLongitude(double x) {
        return x;
    }

    public static double yToLatitude(double y) {
        double rad = Math.toRadians(y);
        double sinh = Math.sinh(rad);
        double atan = Math.atan(sinh);
        double finald = Math.toDegrees(atan);
        return finald;
    }

    public static double longitudeToX(double lon) {
        return lon;
    }
    
    private static double asinh(double x) {
        return Math.log(x + Math.sqrt(x*x + 1.0));
    }
    
    public static double latitudeToY(double lat) {
        double frad = Math.toRadians(lat);
        double ftan = Math.tan(frad);
        double fsin = asinh(ftan);
        double f = Math.toDegrees(fsin);
        return f;
    }
}