<?php
    /*function getDistance($lat1, $lon1, $lat2, $lon2, $unit = 'km')
    {
        $earthRadius = 6371; // Radius of Earth in KM
    
        $dLat = deg2rad($lat2 - $lat1);
        $dLon = deg2rad($lon2 - $lon1);
    
        $a = sin($dLat / 2) * sin($dLat / 2) +
             cos(deg2rad($lat1)) * cos(deg2rad($lat2)) *
             sin($dLon / 2) * sin($dLon / 2);
    
        $c = 2 * atan2(sqrt($a), sqrt(1 - $a));
    
        $distance = $earthRadius * $c;
    
        switch ($unit) {
            case 'm':
                return $distance * 1000; // Meters
            case 'mile':
                return $distance * 0.621371; // Miles
            default:
                return $distance; // Kilometers
        }
    }
    
    $lat1 = 22.2873822103603;
$lon1 = 70.81028732937214;

$lat2 = 21.523839182433587;
$lon2 = 70.45683028925237;

echo "Distance: " . round(getDistance($lat1, $lon1, $lat2, $lon2, 'km'), 2) . " KM";
echo "<br>";
echo "Distance: " . round(getDistance($lat1, $lon1, $lat2, $lon2, 'm'), 2) . " Meters";*/


function getRoadDistance($originLat, $originLng, $destLat, $destLng)
{
    $url = "https://router.project-osrm.org/route/v1/driving/"
        . $originLng . "," . $originLat . ";"
        . $destLng . "," . $destLat
        . "?overview=false";

    $ch = curl_init();

    curl_setopt_array($ch, [
        CURLOPT_URL => $url,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT => 30,
        CURLOPT_SSL_VERIFYPEER => false
    ]);

    $response = curl_exec($ch);

    if (curl_errno($ch)) {
        return [
            'status'  => false,
            'message' => curl_error($ch)
        ];
    }

    curl_close($ch);

    $data = json_decode($response, true);

    if (!isset($data['routes'][0])) {
        return [
            'status'  => false,
            'message' => 'Route not found.'
        ];
    }

    $route = $data['routes'][0];

    return [
        'status'         => true,
        'distance_m'     => $route['distance'],
        'distance_km'    => round($route['distance'] / 1000, 2),
        'duration_sec'   => $route['duration'],
        'duration_min'   => round($route['duration'] / 60, 1),
        'duration_hr'    => gmdate("H:i:s", $route['duration'])
    ];
}


$busLat = 22.2873822103603;
$busLng = 70.81028732937214;

$schoolLat = 21.523839182433587;
$schoolLng = 70.45683028925237;

$result = getRoadDistance($busLat, $busLng, $schoolLat, $schoolLng);

if ($result['status']) {

    echo "Road Distance : " . $result['distance_km'] . " KM<br>";
    echo "Distance (Meters) : " . $result['distance_m'] . "<br>";
    echo "Travel Time : " . $result['duration_min'] . " Minutes<br>";
    echo "Duration : " . $result['duration_hr'];

} else {

    echo "Error : " . $result['message'];

}
?>