Furniture

[DavidRieman]

How would one go about making furniture like Couches and Beds? For example, you walk into a room and, after the room description, see:
"A comfy couch, occupied by: Abe and Bob."
or
"A comfy couch, currently empty."

(Not to be confused with #145 [Furnishings] which intentionally only have descriptions and no detailed interactive Behaviors.)

These days, like most interesting world interactions, this would be accomplished through Behaviors. There could be a SittableBehavior which provides automatic context-commands like "sit in" / "sit on" / "sit". The behavior could have a MaxOccupants property to cancel attempts to sit with "There is no more room there for you" or whatnot. From here, we have to consider some options:

1. It could track (with a weak reference?) the occupants. It could listen to OnMovementEvent to remove their tracked occupant, and log out events to do the same, etc. This has the benefit of simply letting the player keep access to room context commands (like exit "e" command to go east), but may make some other later tasks harder.
2. It could make the player a sub-Thing of the furniture Thing, and give context commands like "stand up" / "stand" that you have to use to exit the furniture, in order to leave it. This probably has the most "consistent" experience with what could be "vehicles" and the like, but with the minor drawback that if we wanted the player to still be able to type "e" to leave east, the furniture has to know about their own parent (room) context commands and automatically eject the player before having them try to execute that "e".

Suppose one also wants to give furniture game-specific benefits like improved recovery rates... Given the above options:

1. We'd probably have to have a WhileSittingApplyEffectBehavior that synchronizes the OLC-data-driven Effect to be placed on the player that does not have a time-based expiration but somehow guarantees the Effect goes away when they no longer meet the condition of sitting in that particular furniture. Maybe that would imply a ConditionalEffect base class that takes a configurable function arg that returns true/false depending on whether the condition is still being met. Then the Behavior would pass a lambda targeting the furniture Thing. But this wouldn't work well with persistence either. Hmm, I think this way is proving too complicated and edge-casey.
2. The same properties or Behaviors that apply increased recovery rates to a room would get applied here, whatever those methods prove to be in the end. So while we don't have the answer on that either yet, at least it's a shared problem this way.

So I'm leaning option 2, as it also gives a more incremental approach - we can make the furniture enterable/exitable and then later add conveniences for auto-leaving furniture through mirrored exit commands or whatnot (if we even want that).