--[[

	Knit.CreateController(controller): Controller
	Knit.AddControllers(folder): Controller[]
	Knit.AddControllersDeep(folder): Controller[]
	Knit.GetService(serviceName): Service
	Knit.GetController(controllerName): Controller
	Knit.Start(): Promise<void>
	Knit.OnStart(): Promise<void>

--]]

local KnitClient = {}

KnitClient.Version = script.Parent.Version.Value
KnitClient.Player = game:GetService("Players").LocalPlayer
KnitClient.Controllers = {}
KnitClient.Util = script.Parent.Util

local Promise = require(KnitClient.Util.Promise)
local Thread = require(KnitClient.Util.Thread)
local Loader = require(KnitClient.Util.Loader)
local Ser = require(KnitClient.Util.Ser)
local ClientRemoteSignal = require(KnitClient.Util.Remote.ClientRemoteSignal)
local ClientRemoteProperty = require(KnitClient.Util.Remote.ClientRemoteProperty)
local TableUtil = require(KnitClient.Util.TableUtil)

local services = {}
local servicesFolder = script.Parent:WaitForChild("Services")

local started = false
local startedComplete = false
local onStartedComplete = Instance.new("BindableEvent")

local function BuildService(serviceName, folder)
	local service = {}
	if (folder:FindFirstChild("RF")) then
		for _, rf in ipairs(folder.RF:GetChildren()) do
			if (rf:IsA("RemoteFunction")) then
				service[rf.Name] = function(self, ...)
					return Ser.DeserializeArgsAndUnpack(rf:InvokeServer(Ser.SerializeArgsAndUnpack(...)))
				end
				service[rf.Name .. "Promise"] = function(self, ...)
					local args = Ser.SerializeArgs(...)
					return Promise.new(function(resolve)
						resolve(Ser.DeserializeArgsAndUnpack(rf:InvokeServer(table.unpack(args, 1, args.n))))
					end)
				end
			end
		end
	end
	if (folder:FindFirstChild("RE")) then
		for _, re in ipairs(folder.RE:GetChildren()) do
			if (re:IsA("RemoteEvent")) then
				service[re.Name] = ClientRemoteSignal.new(re)
			end
		end
	end
	if (folder:FindFirstChild("RP")) then
		for _, rp in ipairs(folder.RP:GetChildren()) do
			if (rp:IsA("ValueBase") or rp:IsA("RemoteEvent")) then
				service[rp.Name] = ClientRemoteProperty.new(rp)
			end
		end
	end
	services[serviceName] = service
	return service
end

function KnitClient.CreateController(controller)
	assert(type(controller) == "table", "Controller must be a table; got " .. type(controller))
	assert(
		type(controller.Name) == "string",
		"Controller.Name must be a string; got " .. type(controller.Name)
	)
	assert(#controller.Name > 0, "Controller.Name must be a non-empty string")
	assert(
		KnitClient.Controllers[controller.Name] == nil,
		"Service \"" .. controller.Name .. "\" already exists"
	)
	TableUtil.Extend(controller, {
		_knit_is_controller = true,
	})
	KnitClient.Controllers[controller.Name] = controller
	return controller
end

function KnitClient.AddControllers(folder)
	return Loader.LoadChildren(folder)
end

function KnitClient.AddControllersDeep(folder)
	return Loader.LoadDescendants(folder)
end

function KnitClient.GetService(serviceName)
	assert(type(serviceName) == "string", "ServiceName must be a string; got " .. type(serviceName))
	local folder = servicesFolder:FindFirstChild(serviceName)
	assert(folder ~= nil, "Could not find service \"" .. serviceName .. "\"")
	return services[serviceName] or BuildService(serviceName, folder)
end

function KnitClient.GetController(controllerName)
	return KnitClient.Controllers[controllerName]
end

function KnitClient.Start()

	if started then
		return Promise.Reject("Knit already started")
	end

	started = true

	local controllers = KnitClient.Controllers

	return Promise.new(function(resolve)

		-- Init:
		local promisesStartControllers = {}
		for _, controller in pairs(controllers) do
			if (type(controller.KnitInit) == "function") then
				table.insert(
					promisesStartControllers,
					Promise.new(function(r)
						controller:KnitInit()
						r()
					end)
				)
			end
		end

		resolve(Promise.All(promisesStartControllers))

	end):Then(function()

		-- Start:
		for _, controller in pairs(controllers) do
			if (type(controller.KnitStart) == "function") then
				Thread.SpawnNow(controller.KnitStart, controller)
			end
		end

		startedComplete = true
		onStartedComplete:Fire()

		Thread.Spawn(function()
			onStartedComplete:Destroy()
		end)

	end)

end

function KnitClient.OnStart()
	if startedComplete then
		return Promise.Resolve()
	else
		return Promise.new(function(resolve)
			if startedComplete then
				resolve()
				return
			end
			onStartedComplete.Event:Wait()
			resolve()
		end)
	end
end

return KnitClient