Multiuser support (#60)

auth.ts

@@ -0,0 +1,44 @@
+import NextAuth from "next-auth"
+import Credentials from "next-auth/providers/credentials"
+import { getUser } from "./app/actions/data"
+import { signInSchema } from "./lib/zod"
+import { SafeUser, SessionUser } from "./lib/types"
+ 
+export const { handlers, signIn, signOut, auth } = NextAuth({
+  trustHost: true,
+  providers: [
+    Credentials({
+      credentials: {
+        username: {},
+        password: {},
+      },
+      authorize: async (credentials) => {
+        const { username, password } = await signInSchema.parseAsync(credentials)
+        
+        // Pass the plaintext password to getUser for verification
+        const user = await getUser(username, password)
+ 
+        if (!user) {
+          throw new Error("Invalid credentials.")
+        }
+ 
+        const safeUser: SessionUser = { id: user.id }
+        return safeUser
+      },
+    }),
+  ],
+  callbacks: {
+    jwt: async ({ token, user }) => {
+      if (user) {
+        token.id = (user as SessionUser).id
+      }
+      return token
+    },
+    session: async ({ session, token }) => {
+      if (session?.user) {
+        session.user.id = token.id as string
+      }
+      return session
+    }
+  }
+})