/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.common.geo;

/**
 * To facilitate maximizing the use of common code between GeoPoint and projected CRS
 * we introduced this ElasticPoint as an interface of commonality.
 */
public interface SpatialPoint extends Comparable<SpatialPoint> {
    double getX();

    double getY();

    default String toWKT() {
        // Code designed to mimic WellKnownText.toWKT, with much less stack depth and object creation
        return "POINT (" + getX() + " " + getY() + ")";
    }

    @Override
    default int compareTo(SpatialPoint other) {
        if (this.getClass().equals(other.getClass())) {
            double xd = this.getX() - other.getX();
            double yd = this.getY() - other.getY();
            return (xd == 0) ? comparison(yd) : comparison(xd);
        } else {
            // TODO: Rather separate based on CRS, but since we don't have that yet, we use class name
            // The sort order here is unimportant and does not (yet) introduce BWC issues, so we are free to change it later with CRS
            return this.getClass().getSimpleName().compareTo(other.getClass().getSimpleName());
        }
    }

    private int comparison(double delta) {
        return delta == 0 ? 0 : delta < 0 ? -1 : 1;
    }
}