Implement login, add useUser hook

services/user/findUserById.ts

@@ -0,0 +1,23 @@
+import DBClient from '@/prisma/DBClient';
+import { z } from 'zod';
+import GetUserSchema from './schema/GetUserSchema';
+
+const findUserById = async (id: string) => {
+  const user: z.infer<typeof GetUserSchema> | null =
+    await DBClient.instance.user.findUnique({
+      where: { id },
+      select: {
+        id: true,
+        username: true,
+        email: true,
+        firstName: true,
+        lastName: true,
+        dateOfBirth: true,
+        createdAt: true,
+      },
+    });
+
+  return user;
+};
+
+export default findUserById;