Multiuser support (#60)

lib/server-helpers.ts

@@ -0,0 +1,40 @@
+import { auth } from '@/auth'
+import 'server-only'
+import { User, UserId } from './types'
+import { loadUsersData } from '@/app/actions/data'
+import { randomBytes, scryptSync } from 'crypto'
+
+export async function getCurrentUserId(): Promise<UserId | undefined> {
+  const session = await auth()
+  const user = session?.user
+  return user?.id
+}
+
+export async function getCurrentUser(): Promise<User | undefined> {
+  const currentUserId = await getCurrentUserId()
+  if (!currentUserId) {
+    return undefined
+  }
+  const usersData = await loadUsersData()
+  return usersData.users.find((u) => u.id === currentUserId)
+}
+export function saltAndHashPassword(password: string, salt?: string): string {
+  if (password.length === 0) throw new Error('Password must not be empty')
+  salt = salt || randomBytes(16).toString('hex')
+  const hash = scryptSync(password, salt, 64).toString('hex')
+  return `${salt}:${hash}`
+}
+
+export function verifyPassword(password?: string, storedHash?: string): boolean {
+  // if both password and storedHash is undefined, return true
+  if (!password && !storedHash) return true
+  // else if either password or storedHash is undefined, return false
+  if (!password || !storedHash) return false
+
+  // Split the stored hash into its salt and hash components
+  const [salt, hash] = storedHash.split(':')
+  // Hash the input password with the same salt
+  const newHash = saltAndHashPassword(password, salt).split(':')[1]
+  // Compare the new hash with the stored hash
+  return newHash === hash
+}