Add luckperms context support for worldgroup.

[benwoo1110]

LuckPerms has a context feature (https://luckperms.net/wiki/Context) which allow you to define permission per world/server etc. This PR add the ability to have permission per-world group which can allow more efficient context setup in some cases. E.g. instead of needing to set 3 context world survival survival_nether and survival_the_end, we can set context 1 for world group survival.

[nicegamer7]

Is the API something that has to be enabled by the user? Or is this an actual error?

Just wondering because it might be annoying if someone purposefully disables the API and gets a warning every time they start their server.

[benwoo1110]

If luckperms is installed (checking alr done above), it should always be enabled unless luckperms crashed on their server.

[nicegamer7]

Okay, looks good then.

[nicegamer7]

Actually I just took a look at ContextCalculator's Javadoc, do you know if the calculation is thread-safe?

[benwoo1110]

it needs to be thread-safe bcu calls may be async. Source code has 3 pointers to take note:

https://github.com/lucko/LuckPerms/blob/5ea2aee2f49a317e8b6aa242ded2fe81384343ed/api/src/main/java/net/luckperms/api/context/ContextCalculator.java#L39-L53

[nicegamer7]

Yeah that's what I read, I was asking if the code you wrote is thread-safe.

[benwoo1110]

Multiverse-Inventories/src/main/java/com/onarandombox/multiverseinventories/AbstractWorldGroupManager.java

Lines 54 to 66 in f704fa2

	worldName = worldName.toLowerCase();
	List<WorldGroup> worldGroups = new ArrayList<>();
	for (WorldGroup worldGroup : getGroupNames().values()) {
	if (worldGroup.containsWorld(worldName)) {
	worldGroups.add(worldGroup);
	}
	}
	// Only use the default group for worlds managed by MV-Core
	if (worldGroups.isEmpty() && plugin.getMVIConfig().isDefaultingUngroupedWorlds() &&
	plugin.getCore().getMVWorldManager().isMVWorld(worldName)) {
	Logging.finer("Returning default group for world: " + worldName);
	worldGroups.add(getDefaultGroup());
	}

hmm yea getGroupsForWorld does have the chance of modifying... I think using getGroups then filter is a safer option since makes a copy