//Get Offset needs current location to know whether to apply 30W rule
public static Location CalculateHashLocation(Location currentLocation, Location offset)
{
var lat = currentLocation.Latitude > 0 ? Math.Floor(currentLocation.Latitude) + offset.Latitude : Math.Ceiling(currentLocation.Latitude) - offset.Latitude;
var lon = currentLocation.Longitude > 0 ? Math.Floor(currentLocation.Longitude) + offset.Longitude : Math.Ceiling(currentLocation.Longitude) - offset.Longitude;
var loc = new Location(lat, lon);
return(loc);
}
private static Location CalculateGlobalHash(Location offset)
{
var latDecimalPart = offset.Latitude;
var lonDecimalPart = offset.Longitude;
var globalLat = latDecimalPart * 180 - 90;
var globalLon = lonDecimalPart * 360 - 180;
var loc = new Location(globalLat, globalLon);
return(loc);
}
/// <summary>
/// If a location is east of 30w, returns previous date. Otherwise returns same date
/// </summary>
/// <param name="date"></param>
/// <param name="location"></param>
/// <returns></returns>
public static DateTime Get30WCompliantDate(DateTime date, Location location)
{
//Check 30W rule
var djDate = date;
if (location.Longitude >= -30)
{
djDate = date.AddDays(-1);
Debug.WriteLine($"Using 30W rule. Selected date: {date} DJDate: {djDate}");
}
else
{
Debug.WriteLine($"Not using 30W rule. Selected date: {date} DJDate: {djDate}");
}
return(djDate);
}
//This bearing is relative to true north and doesn't use declination
//Thanks to http://www.movable-type.co.uk/scripts/latlong.html
public double GetBearingRelativeToTrueNorth(Location currentLocation, Location destination)
{
var lat1 = currentLocation.Latitude.ToRadians();
var lon1 = currentLocation.Longitude.ToRadians();
var lat2 = destination.Latitude.ToRadians();
var lon2 = destination.Longitude.ToRadians();
var dlon = lon2 - lon1;
var y = Math.Sin(dlon) * Math.Cos(lat2);
var x = (Math.Cos(lat1) * Math.Sin(lat2)) - (Math.Sin(lat1) * Math.Cos(lat2) * Math.Cos(dlon));
var bearing = Math.Atan2(y, x);
var bearingInDegrees = bearing.ToDegrees();
var normalisedBearing = (bearingInDegrees + 360) % 360;
return(normalisedBearing);
}
public static async Task <Response <HashLocation> > GetHashData(DateTime date, Location currentLocation)
{
var date30W = DowJonesDates.Get30WCompliantDate(date, currentLocation);
var djDate = DowJonesDates.GetApplicableDJDate(date30W);
var djia = await Webclient.GetDjia(djDate);
if (!djia.Success)
{
return(new Response <HashLocation>(null, false, djia.Message));
}
var offset = CalculateOffset(date, djia.Data);
var loc = CalculateHashLocation(currentLocation, offset);
var hash = new HashLocation(loc.Latitude, loc.Longitude, date, false, false);
return(new Response <HashLocation>(hash, true, "Hashes calculated successfully"));
}
public double CalculateDistance(Location start, Location end)
{
var distance = Xamarin.Essentials.Location.CalculateDistance(start.ToEssentialsLocation(), end.ToEssentialsLocation(), DistanceUnits.Kilometers);
return(distance);
}