--!strict
local MarketplaceService = game:GetService("MarketplaceService")
local Players = game:GetService("Players")

type PlayerData = { coins: number, purchaseIds: { string } }
type ReceiptInfo = {
	PlayerId: number,
	ProductId: number,
	PurchaseId: string,
	CurrencySpent: number,
	CurrencyType: Enum.CurrencyType,
	PlaceIdWherePurchased: number,
}

local MAX_REMEMBERED_PURCHASES = 100

-- Provided by your data layer (ProfileStore profile.Data, etc.).
local function getLoadedData(_player: Player): PlayerData?
	return nil
end
local function saveNow(_player: Player): boolean
	return true
end

local PRODUCTS: { [number]: (Player, PlayerData) -> () } = {
	[1234567] = function(_player, data) -- 100 coins
		data.coins += 100
	end,
}

local function processReceipt(receipt: ReceiptInfo): Enum.ProductPurchaseDecision
	local player = Players:GetPlayerByUserId(receipt.PlayerId)
	if not player then
		return Enum.ProductPurchaseDecision.NotProcessedYet -- granted on their next visit
	end

	local data = getLoadedData(player)
	local deadline = os.clock() + 20
	while not data and player.Parent == Players and os.clock() < deadline do
		task.wait(0.5)
		data = getLoadedData(player)
	end
	if not data then
		return Enum.ProductPurchaseDecision.NotProcessedYet
	end

	if table.find(data.purchaseIds, receipt.PurchaseId) then
		return Enum.ProductPurchaseDecision.PurchaseGranted -- already granted earlier
	end

	local handler = PRODUCTS[receipt.ProductId]
	if not handler then
		warn(`No handler for product {receipt.ProductId}`)
		return Enum.ProductPurchaseDecision.NotProcessedYet
	end

	local ok, err = pcall(handler, player, data)
	if not ok then
		warn(`Grant failed for {receipt.PurchaseId}: {err}`)
		return Enum.ProductPurchaseDecision.NotProcessedYet
	end

	table.insert(data.purchaseIds, receipt.PurchaseId)
	while #data.purchaseIds > MAX_REMEMBERED_PURCHASES do
		table.remove(data.purchaseIds, 1)
	end

	if not saveNow(player) then
		return Enum.ProductPurchaseDecision.NotProcessedYet -- the idempotency list prevents a double grant
	end
	return Enum.ProductPurchaseDecision.PurchaseGranted
end

MarketplaceService.ProcessReceipt = processReceipt :: any

--!strict
local MarketplaceService = game:GetService("MarketplaceService")
local Players = game:GetService("Players")

local VIP_PASS_ID = 987654

local function grantVip(player: Player)
	player:SetAttribute("VIP", true) -- apply perks from one place
end

local function checkPass(player: Player)
	local ok, owns = pcall(MarketplaceService.UserOwnsGamePassAsync, MarketplaceService, player.UserId, VIP_PASS_ID)
	if ok and owns then
		grantVip(player)
	end
end

Players.PlayerAdded:Connect(checkPass)
for _, player in Players:GetPlayers() do
	task.spawn(checkPass, player)
end

-- Fires on the server too; re-verify ownership rather than trusting `purchased` alone.
MarketplaceService.PromptGamePassPurchaseFinished:Connect(function(player, passId, purchased)
	if purchased and passId == VIP_PASS_ID then
		checkPass(player)
	end
end)