public static async Task <Direction> WalkDistance(GeoCoordinate source, GeoCoordinate target)
{
if (source == target)
{
return(new Direction());
}
var cachedValue = LookupCache(source, target);
if (cachedValue != null)
{
return(cachedValue);
}
double straightLineDistance = source.GetDistanceTo(target);
if (straightLineDistance < PlanMinimumInMeters)
{
return(defaultWalkDistance(straightLineDistance));
}
var res = await directionsService.WalkDistanceAsync(source.Latitude, source.Longitude, target.Latitude, target.Longitude);
if (res == null)
{
res = defaultWalkDistance(straightLineDistance, true);
}
AddToCache(source, target, res);
return(res);
}
