// single definition of the cart item shape - imported by every page script
// that touches the cart. price_cents is authoritative naming; the server
// re-prices from the catalog at checkout regardless.

export interface CartItem {
  slug: string;
  name: string;
  name_en: string;
  price_cents: number;
  image: string;
  unit_size: number;
  unit: string;
  stock: number;
  qty: number;
}

const KEY = 'cart';

export function getCart(): CartItem[] {
  try {
    const raw = JSON.parse(localStorage.getItem(KEY) || '[]');
    if (!Array.isArray(raw)) return [];
    return raw.filter(it => it && typeof it.slug === 'string' && Number.isFinite(it.price_cents) && Number.isInteger(it.qty) && it.qty > 0).map(it => ({
      ...it,
      unit_size: it.unit_size || 100,
      unit: it.unit || 'g',
      stock: it.stock || 99,
      image: resolveImage(it.image || ''),
      name_en: it.name_en || it.name || '',
    }));
  } catch {
    return [];
  }
}

function save(cart: CartItem[]) {
  localStorage.setItem(KEY, JSON.stringify(cart));
  window.dispatchEvent(new CustomEvent('cart-updated'));
}

function resolveImage(raw: string): string {
  try {
    const arr = JSON.parse(raw);
    return arr?.[0] || raw || '/images/logo.png';
  } catch { return raw || '/images/logo.png'; }
}

export function addToCart(item: Omit<CartItem, 'qty'>, qty = 1) {
  const cart = getCart();
  const existing = cart.find(it => it.slug === item.slug);
  const resolved = { ...item, unit_size: item.unit_size || 100, unit: item.unit || 'g', stock: item.stock || 99, image: resolveImage(item.image) };
  const limit = resolved.stock;
  if (existing) {
    existing.qty = Math.min(limit, existing.qty + qty);
  } else {
    cart.push({ ...resolved, qty: Math.min(limit, Math.max(1, qty)) });
  }
  save(cart);
}

export function setQty(index: number, qty: number) {
  const cart = getCart();
  if (!cart[index]) return;
  const limit = cart[index].stock;
  const newQty = Math.min(limit, Math.max(0, qty));
  if (newQty < 1) {
    cart.splice(index, 1);
  } else {
    cart[index].qty = newQty;
  }
  save(cart);
}

export function removeItem(index: number) {
  const cart = getCart();
  cart.splice(index, 1);
  save(cart);
}

export function clearCart() {
  save([]);
}

export function cartCount(): number {
  return getCart().reduce((sum, it) => sum + it.qty, 0);
}

export function cartSubtotalCents(): number {
  return getCart().reduce((sum, it) => sum + it.price_cents * it.qty, 0);
}

export function formatLv(cents: number): string {
  return (cents / 100).toFixed(2) + ' EUR';
}

export function escapeHtml(s: string): string {
  return s.replace(/[&<>"']/g, c => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c]!));
}