/// <summary>
/// Gets the availability of a specified cell.
/// </summary>
/// <param name="cell">The cell.</param>
/// <returns>
/// The availability of the specified cell.
/// </returns>
public static Availability GetAvailability(
this IAvailabilityCheckCell cell)
{
if (cell == null)
{
throw new ArgumentNullException(nameof(cell));
}
var availabilityCheckStatus = cell.GetAvailabilityCheckStatus();
switch (availabilityCheckStatus)
{
case AvailabilityCheckStatus.AvailabilityCheckMissing:
case AvailabilityCheckStatus.Unchecked:
return(cell.DefaultAvailability);
case AvailabilityCheckStatus.DeterminedSubjectIsEnabled:
return(Availability.Enabled);
case AvailabilityCheckStatus.DeterminedSubjectIsDisabled:
return(Availability.Disabled);
default:
return(Availability.Unknown);
}
}
private async Task CheckAvailabilityOfCellIfNecessaryAsync(
IAvailabilityCheckCell cell)
{
// NOTE: THIS CODE IS A NEAR DUPLICATE OF THE SYNC METHOD ABOVE; NO GOOD WAY TO D.R.Y. IT OUT
var availabilityCheckStatus = cell.GetAvailabilityCheckStatus();
if (availabilityCheckStatus == AvailabilityCheckStatus.AvailabilityCheckMissing)
{
// no-op
}
else if (availabilityCheckStatus == AvailabilityCheckStatus.Unchecked)
{
CellAvailabilityCheckEventBase availabilityCheckEvent;
try
{
var availabilityCheck = cell.AvailabilityCheck;
var availabilityCheckResult = await this.protocolFactory.GetProtocolAndExecuteViaReflectionAsync <AvailabilityCheckResult>(availabilityCheck.Operation);
string message = null;
if (availabilityCheckResult.MessageOp != null)
{
message = await this.protocolFactory.GetProtocolAndExecuteViaReflectionAsync <string>(availabilityCheckResult.MessageOp);
}
var availability = await this.protocolFactory.GetProtocolAndExecuteViaReflectionAsync <Availability>(availabilityCheckResult.AvailabilityOp);
if (availability == Availability.Disabled)
{
availabilityCheckEvent = new CellAvailabilityCheckDeterminedCellDisabledEvent(this.timestampUtc, null, message);
}
else if (availability == Availability.Enabled)
{
availabilityCheckEvent = new CellAvailabilityCheckDeterminedCellEnabledEvent(this.timestampUtc, null, message);
}
else
{
throw new NotSupportedException(Invariant($"This {nameof(Availability)} is not supported: {availability}."));
}
}
catch (Exception ex)
{
// The "proper" exception for a protocol to throw is an OpExecutionFailedExceptionBase.
// Protocol authors might not comply.
availabilityCheckEvent = new CellAvailabilityCheckFailedEvent(this.timestampUtc, ex.ToString());
}
cell.Record(availabilityCheckEvent);
}
else if (cell.AvailabilityCheckEvents.Last().TimestampUtc != this.timestampUtc)
{
throw new InvalidOperationException("Something went wrong. The cell was checked for availability, but the recorded timestamp doesn't match this timestamp.");
}
}