feat: storage and token limiting

lib/auth-client.ts

@@ -1,6 +1,12 @@
+import { stripeClient } from "@better-auth/stripe/client"
 import { createAuthClient } from "better-auth/client"
 import { emailOTPClient } from "better-auth/client/plugins"
 
 export const authClient = createAuthClient({
-  plugins: [emailOTPClient()],
+  plugins: [
+    emailOTPClient(),
+    stripeClient({
+      subscription: true,
+    }),
+  ],
 })

lib/auth.ts

@@ -1,6 +1,7 @@
 import config from "@/lib/config"
 import { createUserDefaults } from "@/models/defaults"
 import { getSelfHostedUser, getUserByEmail } from "@/models/users"
+import { stripe } from "@better-auth/stripe"
 import { User } from "@prisma/client"
 import { betterAuth } from "better-auth"
 import { prismaAdapter } from "better-auth/adapters/prisma"
@@ -11,6 +12,7 @@ import { headers } from "next/headers"
 import { redirect } from "next/navigation"
 import { prisma } from "./db"
 import { resend, sendOTPCodeEmail } from "./email"
+import { isStripeEnabled, stripeClient } from "./stripe"
 
 export type UserProfile = {
   id: string
@@ -18,6 +20,7 @@ export type UserProfile = {
   email: string
   avatar?: string
   storageUsed?: number
+  tokenBalance?: number
 }
 
 export const auth = betterAuth({
@@ -65,6 +68,13 @@ export const auth = betterAuth({
         await sendOTPCodeEmail({ email, otp })
       },
     }),
+    isStripeEnabled(stripeClient)
+      ? stripe({
+          stripeClient: stripeClient!,
+          stripeWebhookSecret: config.stripe.webhookSecret,
+          createCustomerOnSignUp: true,
+        })
+      : { id: "stripe", endpoints: {} },
     nextCookies(), // make sure this is the last plugin in the array
   ],
 })

lib/config.ts

@@ -13,6 +13,8 @@ const envSchema = z.object({
   RESEND_API_KEY: z.string().default("please-set-your-resend-api-key-here"),
   RESEND_FROM_EMAIL: z.string().default("TaxHacker <user@localhost>"),
   RESEND_AUDIENCE_ID: z.string().default(""),
+  STRIPE_SECRET_KEY: z.string().default(""),
+  STRIPE_WEBHOOK_SECRET: z.string().default(""),
 })
 
 const env = envSchema.parse(process.env)
@@ -40,6 +42,10 @@ const config = {
     loginUrl: "/enter",
     disableSignup: env.DISABLE_SIGNUP === "true" || env.SELF_HOSTED_MODE === "true",
   },
+  stripe: {
+    secretKey: env.STRIPE_SECRET_KEY,
+    webhookSecret: env.STRIPE_WEBHOOK_SECRET,
+  },
   email: {
     apiKey: env.RESEND_API_KEY,
     from: env.RESEND_FROM_EMAIL,

lib/files.ts

@@ -1,6 +1,7 @@
 import { File, Transaction, User } from "@prisma/client"
 import { access, constants, readdir, stat } from "fs/promises"
 import path from "path"
+import config from "./config"
 
 export const FILE_UPLOAD_PATH = path.resolve(process.env.UPLOAD_PATH || "./uploads")
 export const FILE_UNSORTED_DIRECTORY_NAME = "unsorted"
@@ -70,3 +71,10 @@ export async function getDirectorySize(directoryPath: string) {
   await calculateSize(directoryPath)
   return totalSize
 }
+
+export function isEnoughStorageToUploadFile(user: User, fileSize: number) {
+  if (config.selfHosted.isEnabled || user.storageLimit < 0) {
+    return true
+  }
+  return user.storageUsed + fileSize <= user.storageLimit
+}

lib/stripe.ts

@@ -0,0 +1,13 @@
+import Stripe from "stripe"
+import config from "./config"
+
+export const stripeClient: Stripe | null = config.stripe.secretKey
+  ? new Stripe(config.stripe.secretKey, {
+      apiVersion: "2025-03-31.basil",
+    })
+  : null
+
+// Type guard to check if Stripe is initialized
+export const isStripeEnabled = (client: Stripe | null): client is Stripe => {
+  return client !== null
+}

lib/utils.ts

@@ -2,12 +2,14 @@ import { clsx, type ClassValue } from "clsx"
 import slugify from "slugify"
 import { twMerge } from "tailwind-merge"
 
+const LOCALE = "en-US"
+
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs))
 }
 
 export function formatCurrency(total: number, currency: string) {
-  return new Intl.NumberFormat("en-US", {
+  return new Intl.NumberFormat(LOCALE, {
     style: "currency",
     currency: currency,
     minimumFractionDigits: 2,
@@ -28,6 +30,12 @@ export function formatBytes(bytes: number) {
   return `${parseFloat(value.toFixed(2))} ${sizes[i]}`
 }
 
+export function formatNumber(number: number) {
+  return new Intl.NumberFormat(LOCALE, {
+    useGrouping: true,
+  }).format(number)
+}
+
 export function codeFromName(name: string, maxLength: number = 16) {
   const code = slugify(name, {
     replacement: "_",