private async Task <IEnumerable <Location> > GetLocationsByCoordinates(double latitude, double longitude, double?radiusInKm, string iso3Code)
{
string geohash = null;
var locationsCount = 0;
IEnumerable <Location> locations = null;
const int locationsLimit = 20;
var shouldSearchIteratively = !radiusInKm.HasValue;
radiusInKm = radiusInKm ?? 8;
//Try to get locations in radius if there are not locations in this radius,
//increase it and try again until you find location or the radius exceeds the maximum allowed
do
{
var geohashLevel = DistanceHelper.GetGeohashLevelByRadius(radiusInKm.Value);
geohash = _geohasher.Encode(latitude, longitude, precision: geohashLevel);
locations = await _locationRepository.GetLocationsByFilterAsync(geohash, iso3Code);
if (locations.Any())
{
var locationDistances = new Dictionary <Guid, double>();
foreach (var location in locations)
{
var distance = DistanceHelper.GetDistanceInKmBetweenTwoPoints(
latitude, longitude, location.Latitude.Value,
location.Longitude.Value);
if (distance <= radiusInKm.Value)
{
locationDistances.Add(location.Id, distance);
}
}
//Additional precise filtering
locations = locations
.Where(l => locationDistances.ContainsKey(l.Id))
.OrderBy(l => locationDistances[l.Id]);
}
locationsCount = locations.Count();
radiusInKm *= 2;
} while (shouldSearchIteratively && radiusInKm.Value <= MaxRadiusInKm && locationsCount < locationsLimit);
return(locations);
}
public async Task <Guid[]> GetPartnerIdsInRadiusByCoordinatesAsync(double radiusInKm, double longitude, double latitude)
{
if (latitude < -90 || latitude > 90 || longitude < -180 || longitude > 180)
{
throw new ArgumentException("Invalid argument value for get near partners request");
}
var geohashLevel = DistanceHelper.GetGeohashLevelByRadius(radiusInKm);
var geohash = _geohasher.Encode(latitude, longitude, precision: geohashLevel);
var locations = await _locationRepository.GetLocationsByGeohashAsync(geohash);
var result = locations
.Where(l => DistanceHelper.GetDistanceInKmBetweenTwoPoints(latitude, longitude, l.Latitude.Value,
l.Longitude.Value) <= radiusInKm)
.Select(l => l.PartnerId)
.Distinct()
.ToArray();
return(result);
}