init.lua

local ReplicatedStorage = game:GetService("ReplicatedStorage")

type SystemInfo = {
	name: string,
	phase: any,
	system: (...any) -> ...any,
}

type HookArgs = {
	scheduler: any,
	system: SystemInfo,
	nextFn: (...any) -> ...any,
}

type PhaseBeganArgs = {
	scheduler: any,
	phase: any,
}

type SystemsAddRemove = {
	scheduler: any,
	system: SystemInfo,
}

type SystemsReplace = {
	scheduler: any,
	new: SystemInfo,
	old: SystemInfo,
}

type Plugin = {
	build: (self: Plugin, scheduler: any) -> (),
	new: (module: ModuleScript?) -> Plugin,
}

type ConnectionObject = {
	Disconnect: (() -> ())?,
	Destroy: (() -> ())?,
	disconnect: (() -> ())?,
	destroy: (() -> ())?,
} | () -> ()

type CustomEvent = {
	Connect: (...any) -> ConnectionObject,
	[any]: any,
} | {
	on: (...any) -> ConnectionObject,
	[any]: any,
} | {
	connect: (...any) -> ConnectionObject,
	[any]: any,
}

type Library = {
	useDeltaTime: () -> number,
	useEvent: (
		instance: Instance | { [string]: CustomEvent } | CustomEvent,
		event: string | RBXScriptSignal | CustomEvent
	) -> () -> (number, ...any),
	useThrottle: (seconds: number, discriminator: any?) -> boolean,

	Plugin: Plugin,
}

local topoRuntime
local export = {} :: any

local hooks = {
	"useDeltaTime",
	"useEvent",
	"useThrottle",
	"log",
}

local function setHooks(package)
	topoRuntime = require(package:FindFirstChild("topoRuntime", true)) :: any

	for _, hook in hooks do
		local module = package:FindFirstChild(hook, true)
		export[hook] = require(module) :: any
	end
end

-- When using Matter, we must use the topoRuntime in the library
if ReplicatedStorage:FindFirstChild("Packages") then
	for _, package in ReplicatedStorage.Packages._Index:GetChildren() do
		if
			string.find(package.Name, "matter%-ecs_matter")
			or string.find(package.Name, "evaera_matter")
		then
			setHooks(package)
			break
		end
	end
end

if not topoRuntime then
	setHooks(script)
end

local Plugin = {}
Plugin.__index = Plugin

function Plugin:build(scheduler: any)
	if not scheduler._systemState then
		scheduler._systemState = {}
	end

	if not scheduler._systemLogs then
		scheduler._systemLogs = {}
	end

	local phaseDetails = {}

	for _, phase in scheduler._orderedPhases do
		if not phaseDetails[phase] then
			phaseDetails[phase] = {
				lastTime = os.clock(),
				generation = false,
			}
		end

		local details = phaseDetails[phase]

		details.currentTime = os.clock()
		details.deltaTime = details.currentTime - details.lastTime
		details.lastTime = details.currentTime

		details.generation = not details.generation
	end

	scheduler:_addHook(scheduler.Hooks.PhaseAdd, function(args: PhaseBeganArgs)
		local phase = args.phase

		if not phaseDetails[phase] then
			phaseDetails[phase] = {
				currentTime = os.clock(),
				deltaTime = 0,
				lastTime = os.clock(),
				generation = false,
			}
		end

		local details = phaseDetails[phase]

		details.currentTime = os.clock()
		details.deltaTime = details.currentTime - details.lastTime
		details.lastTime = details.currentTime

		details.generation = not details.generation
	end)

	scheduler:_addHook(
		scheduler.Hooks.PhaseBegan,
		function(args: PhaseBeganArgs)
			local phase = args.phase

			if not phaseDetails[phase] then
				phaseDetails[phase] = {
					currentTime = os.clock(),
					deltaTime = 0,
					lastTime = os.clock(),
					generation = false,
				}
			end

			local details = phaseDetails[phase]

			details.currentTime = os.clock()
			details.deltaTime = details.currentTime - details.lastTime
			details.lastTime = details.currentTime

			details.generation = not details.generation
		end
	)

	scheduler:_addHook(
		scheduler.Hooks.SystemAdd,
		function(info: SystemsAddRemove)
			local systemFn = info.system.system

			if not scheduler._systemState[systemFn] then
				scheduler._systemState[systemFn] = {}
			end

			if not scheduler._systemLogs[systemFn] then
				scheduler._systemLogs[systemFn] = {}
			end
		end
	)

	scheduler:_addHook(
		scheduler.Hooks.SystemRemove,
		function(info: SystemsAddRemove)
			local systemFn = info.system.system

			scheduler._systemState[systemFn] = nil
			scheduler._systemLogs[systemFn] = nil
		end
	)

	scheduler:_addHook(
		scheduler.Hooks.SystemReplace,
		function(info: SystemsReplace)
			local newSystem = info.new.system
			local oldSystem = info.old.system

			scheduler._systemState[newSystem] =
				scheduler._systemState[oldSystem]
			scheduler._systemLogs[newSystem] = scheduler._systemLogs[oldSystem]
			scheduler._systemState[oldSystem] = nil
			scheduler._systemLogs[oldSystem] = nil
		end
	)

	scheduler:_addHook(scheduler.Hooks.OuterSystemCall, function(args: HookArgs)
		local systemFn = args.system.system
		local phase = args.system.phase

		local details = phaseDetails[phase]

		return function()
			topoRuntime.start({
				system = scheduler._systemState[systemFn],
				frame = {
					generation = details.generation,
					deltaTime = details.deltaTime,
					logs = scheduler._systemLogs[systemFn],
				},
				currentSystem = systemFn,
			}, function()
				local thread = coroutine.create(function()
					args.nextFn()
				end)

				local _startTime = os.clock()
				local _success, _err = coroutine.resume(thread)
			end)
		end
	end)
end

function Plugin.new(module)
	if module then
		setHooks(module)
	end

	return setmetatable({}, Plugin)
end

export.Plugin = Plugin

return export :: Library