fix(nav): fix exam flow navigation

chore(zustand): refactor auth code for zustand store

stores/authStore.ts

@@ -1,7 +1,7 @@
 "use client";
 
 import { create } from "zustand";
-import { UserData } from "@/types/auth";
+import { LoginForm, RegisterForm, UserData } from "@/types/auth";
 import { API_URL } from "@/lib/auth";
 
 // Cookie utilities
@@ -32,12 +32,19 @@ const setCookie = (
   }
 };
 
+interface APIError extends Error {
+  response?: any;
+}
+
 interface AuthState {
   token: string | null;
   isLoading: boolean;
   hydrated: boolean;
   user: UserData | null;
+  error: string | null;
 
+  login: (form: LoginForm) => Promise<void>;
+  register: (form: RegisterForm) => Promise<void>;
   setToken: (token: string | null) => void;
   fetchUser: () => Promise<void>;
   logout: () => void;
@@ -48,6 +55,7 @@ export const useAuthStore = create<AuthState>((set, get) => ({
   token: null,
   isLoading: true,
   hydrated: false,
+  error: null,
   user: null,
 
   setToken: (newToken) => {
@@ -55,6 +63,61 @@ export const useAuthStore = create<AuthState>((set, get) => ({
     setCookie("authToken", newToken);
   },
 
+  login: async (form: LoginForm) => {
+    set({ isLoading: true, error: null });
+    try {
+      const response = await fetch(`${API_URL}/auth/login/`, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(form),
+      });
+
+      const data = await response.json();
+
+      if (!response.ok) {
+        throw new Error(data.message || "Login failed");
+      }
+
+      setCookie("authToken", data.token);
+      set({ token: data.token, isLoading: false });
+    } catch (err: any) {
+      set({
+        error: err?.message || "Login failed",
+        isLoading: false,
+      });
+      throw err;
+    }
+  },
+  register: async (form: RegisterForm) => {
+    set({ isLoading: true, error: null });
+    try {
+      const response = await fetch(`${API_URL}/auth/register/`, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(form),
+      });
+
+      const data = await response.json();
+
+      if (!response.ok) {
+        const error: APIError = new Error(
+          data?.detail || "Registration failed"
+        );
+        error.response = data;
+        throw error;
+      }
+
+      setCookie("authToken", data.token);
+      set({ token: data.token, isLoading: false });
+    } catch (err: any) {
+      set({
+        error: err?.message || "Registration failed",
+        isLoading: false,
+      });
+      throw err;
+    }
+  },
+
   fetchUser: async () => {
     const token = get().token;
     if (!token) return;
@@ -67,6 +130,7 @@ export const useAuthStore = create<AuthState>((set, get) => ({
       if (!res.ok) throw new Error("Failed to fetch user info");
 
       const data: UserData = await res.json();
+      console.log(data);
       set({ user: data });
     } catch (err) {
       console.error("Error fetching user:", err);