/// <summary>
/// Cancel a previously scheduled event.
/// </summary>
/// <param name="evt">The event to cancel</param>
/// <returns>Returns true if the given event was successfully removed form the event queue</returns>
public bool CancelEvent(IScheduledEvent evt)
{
if (_eventQueue.Remove(evt))
{
Console.WriteLine($"{DateTime.Now} : Cancelled {evt.GetType().Name} previously scheduled @ {evt.ScheduledTime}");
return(true);
}
return(false);
}
/// <summary>
/// Schedule a new event by adding it to the event queue.
/// </summary>
/// <param name="evt">The event to schedule</param>
/// <exception cref="InvalidOperationException">thrown if evt is in the past</exception>
public void Schedule(IScheduledEvent evt)
{
if (evt.ScheduledTime <= DateTime.Now)
{
throw new InvalidOperationException("A passed event cannot be scheduled.");
}
_eventQueue.Enqueue(evt);
Console.WriteLine($"{DateTime.Now} : Scheduled new {evt.GetType().Name} @ {evt.ScheduledTime}");
}
/// <summary>
/// Called when update interval is elapsed.
/// Check the queue to trigger the next event if required.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void OnTimerElapsed(object sender, ElapsedEventArgs e)
{
// While there is event that should be triggered at this time
while (_eventQueue.Peek()?.ScheduledTime <= e.SignalTime)
{
IScheduledEvent evt = _eventQueue.Dequeue();
Console.WriteLine($"{DateTime.Now} : {evt.GetType().Name} triggered");
evt.Trigger(this);
}
}
