feat(ADM-018): completed feature

project/frontend/src/contexts/AuthContext.tsx

@@ -0,0 +1,80 @@
+'use client';
+import { createContext, useContext, useState, useEffect, useCallback } from 'react';
+
+interface User {
+  id: string;
+  email: string;
+  role: string;
+}
+
+interface AuthContextValue {
+  user: User | null;
+  loading: boolean;
+  login: (email: string, password: string) => Promise<{ ok: boolean; error?: string }>;
+  register: (email: string, password: string) => Promise<{ ok: boolean; error?: string }>;
+  logout: () => Promise<void>;
+}
+
+const AuthContext = createContext<AuthContextValue | null>(null);
+
+export function AuthProvider({ children }: { children: React.ReactNode }) {
+  const [user, setUser] = useState<User | null>(null);
+  const [loading, setLoading] = useState(true);
+
+  useEffect(() => {
+    fetch('/api/auth/me')
+      .then((r) => r.json())
+      .then((data) => {
+        setUser(data.user ?? null);
+      })
+      .catch(() => setUser(null))
+      .finally(() => setLoading(false));
+  }, []);
+
+  const login = useCallback(async (email: string, password: string) => {
+    const res = await fetch('/api/auth/login', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ email, password }),
+      credentials: 'include',
+    });
+    const data = await res.json();
+    if (!res.ok) {
+      return { ok: false, error: data.error?.message || 'Error de login' };
+    }
+    setUser(data);
+    return { ok: true };
+  }, []);
+
+  const register = useCallback(async (email: string, password: string) => {
+    const res = await fetch('/api/auth/register', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ email, password }),
+      credentials: 'include',
+    });
+    const data = await res.json();
+    if (!res.ok) {
+      return { ok: false, error: data.error?.message || 'Error de registro' };
+    }
+    setUser(data);
+    return { ok: true };
+  }, []);
+
+  const logout = useCallback(async () => {
+    await fetch('/api/auth/logout', { method: 'POST' });
+    setUser(null);
+  }, []);
+
+  return (
+    <AuthContext.Provider value={{ user, loading, login, register, logout }}>
+      {children}
+    </AuthContext.Provider>
+  );
+}
+
+export function useAuth() {
+  const ctx = useContext(AuthContext);
+  if (!ctx) throw new Error('useAuth must be used within AuthProvider');
+  return ctx;
+}

project/frontend/src/contexts/CartContext.tsx

@@ -0,0 +1,88 @@
+'use client';
+import { createContext, useContext, useState, useEffect, useCallback } from 'react';
+
+export interface CartItem {
+  variantId: string;
+  productId: string;
+  productName: string;
+  quantity: number;
+  priceCents: number;
+  imageUrl?: string;
+}
+
+interface CartContextValue {
+  items: CartItem[];
+  addItem: (item: CartItem) => void;
+  removeItem: (variantId: string) => void;
+  changeQuantity: (variantId: string, quantity: number) => void;
+  clearCart: () => void;
+  itemCount: number;
+  subtotalCents: number;
+}
+
+const CartContext = createContext<CartContextValue | null>(null);
+
+export function CartProvider({ children }: { children: React.ReactNode }) {
+  const [items, setItems] = useState<CartItem[]>([]);
+
+  useEffect(() => {
+    try {
+      const stored = localStorage.getItem('mdv_cart');
+      if (stored) setItems(JSON.parse(stored));
+    } catch {}
+  }, []);
+
+  const persist = useCallback((newItems: CartItem[]) => {
+    setItems(newItems);
+    localStorage.setItem('mdv_cart', JSON.stringify(newItems));
+  }, []);
+
+  const addItem = useCallback((item: CartItem) => {
+    setItems((prev) => {
+      const existing = prev.find((i) => i.variantId === item.variantId);
+      const next = existing
+        ? prev.map((i) => i.variantId === item.variantId ? { ...i, quantity: i.quantity + item.quantity } : i)
+        : [...prev, item];
+      localStorage.setItem('mdv_cart', JSON.stringify(next));
+      return next;
+    });
+  }, []);
+
+  const removeItem = useCallback((variantId: string) => {
+    setItems((prev) => {
+      const next = prev.filter((i) => i.variantId !== variantId);
+      localStorage.setItem('mdv_cart', JSON.stringify(next));
+      return next;
+    });
+  }, []);
+
+  const changeQuantity = useCallback((variantId: string, quantity: number) => {
+    setItems((prev) => {
+      const next = quantity <= 0
+        ? prev.filter((i) => i.variantId !== variantId)
+        : prev.map((i) => i.variantId === variantId ? { ...i, quantity } : i);
+      localStorage.setItem('mdv_cart', JSON.stringify(next));
+      return next;
+    });
+  }, []);
+
+  const clearCart = useCallback(() => {
+    setItems([]);
+    localStorage.removeItem('mdv_cart');
+  }, []);
+
+  const itemCount = items.reduce((sum, i) => sum + i.quantity, 0);
+  const subtotalCents = items.reduce((sum, i) => sum + i.priceCents * i.quantity, 0);
+
+  return (
+    <CartContext.Provider value={{ items, addItem, removeItem, changeQuantity, clearCart, itemCount, subtotalCents }}>
+      {children}
+    </CartContext.Provider>
+  );
+}
+
+export function useCart() {
+  const ctx = useContext(CartContext);
+  if (!ctx) throw new Error('useCart must be used within CartProvider');
+  return ctx;
+}