private LandingCheck GetPreviousLandingCheck(RocketId currentRocketId, DateTime currentTimestamp)
{
LandingCheck previousLandingCheck = null;
foreach (var(rocketId, landingCheck) in _landingChecks)
{
if (IsSameRocket(currentRocketId, rocketId))
{
continue;
}
if (IsAfterCurrentCheck(currentTimestamp, landingCheck))
{
continue;
}
if (IsOlderThanAlreadyFound(previousLandingCheck, landingCheck))
{
continue;
}
previousLandingCheck = landingCheck;
}
return(previousLandingCheck);
}
private static bool IsOlderThanAlreadyFound(LandingCheck previousLandingCheck, LandingCheck landingCheck)
{
if (previousLandingCheck is null)
{
return(false);
}
return(landingCheck.Timestamp < previousLandingCheck.Timestamp);
}
/// <summary>
/// Verifies if given landing position is eligible for landing.
/// </summary>
/// <param name="rocketId">Rocket identifier.</param>
/// <param name="position">Potential landing position to check.</param>
/// <returns></returns>
public async Task <string> VerifyPosition(RocketId rocketId, LandingPosition position)
{
if (IsOutOfPlatform(position))
{
return(OutputMessages.OutOfPlatform);
}
var landingCheck = new LandingCheck(rocketId, position, _dateTimeProvider.DateTimeUtcNow);
var landingCheckRequest = new LandingCheckRequest(landingCheck);
await _landingCheckChannel.WriteAsync(landingCheckRequest);
var potentialClashPosition = await landingCheckRequest.GetResultAsync();
return(IsClashWithPrevious(position, potentialClashPosition)
? OutputMessages.Clash
: OutputMessages.OkForLanding);
}
public LandingCheckRequest(LandingCheck landingCheck)
{
LandingCheck = landingCheck;
_taskCompletionSource = new TaskCompletionSource <LandingPosition>(TaskCreationOptions.None);
}
private static bool IsAfterCurrentCheck(DateTime currentTimestamp, LandingCheck landingCheck)
{
return(landingCheck.Timestamp >= currentTimestamp);
}
public LandingPosition GetPotentialClashPosition(LandingCheck landingCheck)
{
var previousLandingCheck = GetPreviousLandingCheck(landingCheck.RocketId, landingCheck.Timestamp);
return(previousLandingCheck?.LandingPosition);
}
public void AddLandingCheck(LandingCheck landingCheck)
{
_landingChecks[landingCheck.RocketId] = landingCheck;
}
