private static RsvpAggregate Reduce(RsvpAggregate state, MeetupRsvpDeclinedEvent @event)
{
var memberId = @event.MemberId;
state.MembersGoing.Remove(memberId);
state.MembersWaiting.Remove(memberId);
state.MembersNotGoing.TryAdd(memberId);
if (AvailableSpots(state) && state.MembersWaiting.Any())
{
var firstMemberWaiting = state.MembersWaiting.First();
state.MembersGoing.Add(firstMemberWaiting);
state.MembersWaiting.Remove(firstMemberWaiting);
}
return(state);
}
private static RsvpAggregate Reduce(RsvpAggregate state, MeetupRsvpAcceptedEvent @event)
{
var memberId = @event.MemberId;
state.MembersGoing.Remove(memberId);
state.MembersNotGoing.Remove(memberId);
state.MembersWaiting.Remove(memberId);
if (AvailableSpots(state))
{
state.MembersGoing.Add(memberId);
}
else
{
state.MembersWaiting.Add(memberId);
}
return(state);
}
private static RsvpAggregate Reduce(RsvpAggregate state, MeetupNumberOfSpotsChangedEvent @event)
{
var numberOfSpotsDiff = @event.NumberOfSpots - state.NumberOfSpots;
if (numberOfSpotsDiff > 0)
{
var membersWaiting = state.MembersWaiting.Take(numberOfSpotsDiff);
state.MembersGoing.AddRange(membersWaiting);
state.MembersWaiting.RemoveRange(membersWaiting);
}
else
{
var membersGoing = state.MembersGoing.TakeLast(Math.Abs(numberOfSpotsDiff));
state.MembersWaiting.InsertRange(0, membersGoing);
state.MembersGoing.RemoveRange(membersGoing);
}
state.NumberOfSpots = @event.NumberOfSpots;
return(state);
}
public static RsvpAggregate Reduce(RsvpAggregate state, object @event)
{
switch (@event)
{
case MeetupRsvpOpenedEvent rsvpOpened:
state.NumberOfSpots = rsvpOpened.NumberOfSpots;
break;
case MeetupRsvpAcceptedEvent rsvpAccepted:
state = Reduce(state, rsvpAccepted);
break;
case MeetupRsvpDeclinedEvent rsvpDeclined:
state = Reduce(state, rsvpDeclined);
break;
case MeetupNumberOfSpotsChangedEvent spotsChanged:
state = Reduce(state, spotsChanged);
break;
}
return(state);
}
private static bool AvailableSpots(RsvpAggregate state) => state.NumberOfSpots > state.MembersGoing.Count;
public static RsvpAggregate Reduce(this RsvpAggregate aggregate, object @event) => RsvpAggregate.Reduce(aggregate, @event);