// ========================================
// STATE MANAGEMENT — LocalStorage Store
// ========================================
const STORE_KEYS = { CART: "mtextile_cart", WISHLIST: "mtextile_wishlist", USER: "mtextile_user", ORDERS: "mtextile_orders" };

function _get(key) { try { return JSON.parse(localStorage.getItem(key)) || null; } catch { return null; } }
function _set(key, val) { localStorage.setItem(key, JSON.stringify(val)); }

// === CART ===
function getCart() { return _get(STORE_KEYS.CART) || []; }
function saveCart(cart) { _set(STORE_KEYS.CART, cart); document.dispatchEvent(new CustomEvent("cartUpdated", { detail: { cart } })); }

function addToCart(productId, size, color, qty = 1) {
    const cart = getCart();
    const existing = cart.find(i => i.productId === productId && i.size === size && i.color === color);
    if (existing) { existing.quantity += qty; }
    else { cart.push({ productId, size, color, quantity: qty, addedAt: Date.now() }); }
    saveCart(cart);
    return cart;
}

function removeFromCart(productId, size, color) {
    let cart = getCart();
    cart = cart.filter(i => !(i.productId === productId && i.size === size && i.color === color));
    saveCart(cart);
    return cart;
}

function updateCartQty(productId, size, color, qty) {
    const cart = getCart();
    const item = cart.find(i => i.productId === productId && i.size === size && i.color === color);
    if (item) {
        if (qty <= 0) return removeFromCart(productId, size, color);
        item.quantity = qty;
        saveCart(cart);
    }
    return cart;
}

function clearCart() { saveCart([]); }

function getCartCount() { return getCart().reduce((sum, i) => sum + i.quantity, 0); }

function getCartTotal() {
    const cart = getCart();
    let subtotal = 0, discount = 0;
    cart.forEach(item => {
        const product = getProductById(item.productId);
        if (product) {
            subtotal += product.price * item.quantity;
            if (product.oldPrice) discount += (product.oldPrice - product.price) * item.quantity;
        }
    });
    return { subtotal, discount, shipping: 0, total: subtotal };
}

// === WISHLIST ===
function getWishlist() { return _get(STORE_KEYS.WISHLIST) || []; }
function saveWishlist(wl) { _set(STORE_KEYS.WISHLIST, wl); document.dispatchEvent(new CustomEvent("wishlistUpdated", { detail: { wishlist: wl } })); }

function toggleWishlist(productId) {
    let wl = getWishlist();
    const idx = wl.indexOf(productId);
    if (idx > -1) { wl.splice(idx, 1); } else { wl.push(productId); }
    saveWishlist(wl);
    return wl;
}

function isInWishlist(productId) { return getWishlist().includes(productId); }

// === USER AUTHENTICATION ===
const USERS_KEY = "mtextile_users";
const SESSION_KEY = "mtextile_session";

function getUsers() { return _get(USERS_KEY) || []; }
function setUsers(users) { _set(USERS_KEY, users); }

function getCurrentUser() {
    return _get(SESSION_KEY);
}

function isLoggedIn() {
    return getCurrentUser() !== null;
}

function registerUser(name, phone, password) {
    const users = getUsers();
    if (users.find(u => u.phone === phone)) {
        return { success: false, message: "Bu telefon raqam allaqachon ro'yxatdan o'tgan." };
    }
    const newUser = { id: Date.now(), name, phone, password, email: "", addresses: [] };
    users.push(newUser);
    setUsers(users);
    _set(SESSION_KEY, newUser); // Auto login
    return { success: true };
}

function loginUser(phone, password) {
    const users = getUsers();
    const user = users.find(u => (u.phone === phone || u.email === phone) && u.password === password);
    if (!user) {
        return { success: false, message: "Telefon raqam yoki parol noto'g'ri." };
    }
    _set(SESSION_KEY, user);
    return { success: true };
}

function logoutUser() {
    localStorage.removeItem(SESSION_KEY);
    localStorage.removeItem('mtextile_auth'); // Clean up old legacy keys
    localStorage.removeItem('stylestore_auth'); // Used in older structure
    localStorage.removeItem('stylestore_session');
}

function getUser() {
    // For backwards compatibility and profile edits
    return getCurrentUser() || { name: "", phone: "", email: "", addresses: [] };
}

function saveUser(data) {
    const currentUser = getCurrentUser();
    if (!currentUser) return; // Must be logged in to save profile

    // Update session
    const updated = { ...currentUser, ...data };
    _set(SESSION_KEY, updated);

    // Update DB
    const users = getUsers();
    const index = users.findIndex(u => u.id === currentUser.id);
    if (index > -1) {
        users[index] = updated;
        setUsers(users);
    }
}

// === ORDERS ===
function getOrders() { return _get(STORE_KEYS.ORDERS) || []; }

function getUserOrders() {
    const allOrders = getOrders();
    const currentUser = getCurrentUser();
    if (!currentUser) return [];
    return allOrders.filter(o => o.userId === currentUser.id);
}

function addOrder(orderData) {
    const orders = getOrders();
    const currentUser = getCurrentUser();

    const order = {
        id: "ORD-" + Date.now().toString(36).toUpperCase(),
        userId: currentUser ? currentUser.id : 'guest',
        ...orderData,
        status: "Kutilmoqda",
        createdAt: new Date().toISOString(),
        items: getCart().map(item => {
            const p = getProductById(item.productId);
            return { ...item, name: p?.name, price: p?.price, image: p?.images?.[0] };
        }),
        totals: getCartTotal()
    };
    orders.unshift(order);
    _set(STORE_KEYS.ORDERS, orders);
    clearCart();
    return order;
}

// === PROMO CODES ===
const PROMO_CODES = {
    "YANGI10": { discount: 10, type: "percent", desc: "10% chegirma" },
    "STYLE20": { discount: 20, type: "percent", desc: "20% chegirma" },
};

function applyPromo(code) {
    const promo = PROMO_CODES[code.toUpperCase()];
    if (!promo) return { valid: false, message: "Noto'g'ri promo-kod" };
    return { valid: true, ...promo };
}