♻️(frontend) Separate mutations from queries for auth logic

Introduces dedicated mutations
(for authentication/user operations)
separating them from queries to align with best practices
for data fetching and state management.

Queries remain responsible for READ operations, while mutations
now handle CREATE, UPDATE, and DELETE actions (for user data)
improving separation of concerns.

Signed-off-by: Robin Weber <[email protected]>

Author: rvveber

src/frontend/apps/impress/src/features/auth/api/index.ts

@@ -1,2 +1,3 @@
 export * from './useAuthQuery';
+export * from './useAuthMutation';
 export * from './types';

src/frontend/apps/impress/src/features/auth/api/useAuthMutation.ts

@@ -0,0 +1,80 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+
+import { APIError, errorCauses, fetchAPI } from '@/api';
+
+import { User } from './types';
+import { KEY_AUTH } from './useAuthQuery';
+
+// Mutations are separated from queries to allow for better separation of concerns.
+// Mutations are responsible for C (CREATE), U (UPDATE), and D (DELETE) in CRUD.
+
+// --- Create ---
+function createUser(): Promise<User> {
+  throw new Error('Not yet implemented.');
+}
+
+// --- Update ---
+async function updateUser(
+  user: { id: User['id'] } & Partial<Omit<User, 'id'>>,
+): Promise<User> {
+  const response = await fetchAPI(`users/${user.id}/`, {
+    method: 'PATCH',
+    headers: {
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify(user),
+  });
+  if (!response.ok) {
+    throw new APIError(
+      `Failed to update user profile for user ${user.id}`,
+      await errorCauses(response, user),
+    );
+  }
+  return response.json() as Promise<User>;
+}
+
+// --- Delete ---
+function deleteUser(): Promise<User> {
+  throw new Error('Not yet implemented.');
+}
+
+// NOTE: Consider renaming useAuthMutation to useUserMutation for clarity.
+export function useAuthMutation() {
+  const queryClient = useQueryClient();
+
+  const createMutation = useMutation<User, APIError, User>({
+    mutationFn: createUser,
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: [KEY_AUTH] });
+    },
+    onError: (error) => {
+      console.error('Error creating user', error);
+    },
+  });
+
+  const updateMutation = useMutation<User, APIError, User>({
+    mutationFn: updateUser,
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: [KEY_AUTH] });
+    },
+    onError: (error) => {
+      console.error('Error updating user', error);
+    },
+  });
+
+  const deleteMutation = useMutation<User, APIError, User>({
+    mutationFn: deleteUser,
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: [KEY_AUTH] });
+    },
+    onError: (error) => {
+      console.error('Error deleting user', error);
+    },
+  });
+
+  return {
+    create: createMutation.mutateAsync,
+    update: updateMutation.mutateAsync,
+    delete: deleteMutation.mutateAsync,
+  };
+}