<?php

namespace App\Support\Geo;

class Haversine
{
    public const EARTH_RADIUS_METERS = 6371000;

    public static function distanceMeters(
        float $fromLatitude,
        float $fromLongitude,
        float $toLatitude,
        float $toLongitude
    ): float {
        $fromLat = deg2rad($fromLatitude);
        $toLat = deg2rad($toLatitude);
        $deltaLat = deg2rad($toLatitude - $fromLatitude);
        $deltaLng = deg2rad($toLongitude - $fromLongitude);

        $a = sin($deltaLat / 2) ** 2
            + cos($fromLat) * cos($toLat) * sin($deltaLng / 2) ** 2;
        $c = 2 * atan2(sqrt($a), sqrt(max(0, 1 - $a)));

        return self::EARTH_RADIUS_METERS * $c;
    }
}