/**
* This function takes in objects of class gpsPoint where both latitude and
* longitude are already set and calculates distance in metres between them
*
* @param \exercises\gps\entities\gpsPoint $gpsPoint1
* @param \exercises\gps\entities\gpsPoint $gpsPoint2
* @return float , distance rounded to metres
* @throws \Exception
*/
public static function getDistanceBetweenTwoPoints(gpsPoint $gpsPoint1, gpsPoint $gpsPoint2)
{
$latitudePointA = deg2rad($gpsPoint1->getLatitude());
$longitudePointA = deg2rad($gpsPoint1->getLongitude());
$latitudePointB = deg2rad($gpsPoint2->getLatitude());
$longitudePointB = deg2rad($gpsPoint2->getLongitude());
$longitudeDelta = $longitudePointA - $longitudePointB;
$haversineFormula = atan2(sqrt(pow(cos($latitudePointB) * sin($longitudeDelta), 2) + pow(cos($latitudePointA) * sin($latitudePointB) - sin($latitudePointA) * cos($latitudePointB) * cos($longitudeDelta), 2)), sin($latitudePointA) * sin($latitudePointB) + cos($latitudePointA) * cos($latitudePointB) * cos($longitudeDelta));
$arcDistanceInMetres = $haversineFormula * self::radiusOfEarthInMetres;
return round($arcDistanceInMetres);
}
/**
*
* Uses the customers returned array from getCustomerDataFromJSONFile. The method
* checks each customer against the gpsPointA and allowed distance to filter out
* customers living within a specified distance.
*
* @return array
* @throws \Exception
*/
public function getCustomersWithinASpecifiedDistanceFromPointA()
{
if ($this->gpsPointA == NULL) {
throw new \Exception("Please set the coordinates of Point A first.");
} elseif ($this->distance == NULL) {
throw new \Exception("Please enter the distance first.");
}
$customers = $this->getCustomerDataFromJSONFile();
$filteredCustomers = array();
foreach ($customers as $key => $customer) {
$gpsPointB = new gpsPoint();
$gpsPointB->setLatitude($customer['latitude']);
$gpsPointB->setLongitude($customer['longitude']);
$calculatedDistanceBetweenPointBAndA = distanceBetweenTwoGPSPoints::getDistanceBetweenTwoPoints($this->gpsPointA, $gpsPointB);
if ($calculatedDistanceBetweenPointBAndA <= $this->distance) {
$filteredCustomers[$key]['name'] = $customer['name'];
$filteredCustomers[$key]['distance'] = $calculatedDistanceBetweenPointBAndA;
}
unset($calculatedDistanceBetweenPointBAndA);
unset($gpsPointB);
}
return $filteredCustomers;
}
