import { Customer } from './customerApi';

export interface Favorite {
  item_id: number;
  name: string;
  status: 'available' | 'reserved' | 'sold';
  created_at: string;
}

async function expectOk(res: Response, action: string): Promise<Response> {
  if (res.ok) return res;
  const detail = await res.json().catch(() => ({}));
  throw new Error(detail.error || action);
}

export async function fetchFavorites(): Promise<Favorite[]> {
  const res = await fetch('/api/customers/me/favorites');
  // A signed-out visitor legitimately has none; anything else is a real error.
  if (res.status === 401) return [];
  await expectOk(res, 'failed to load favorites');
  return res.json();
}

export async function addFavorite(itemId: number): Promise<void> {
  await expectOk(
    await fetch(`/api/customers/me/favorites/${itemId}`, { method: 'POST' }),
    'failed to save favorite'
  );
}

export async function removeFavorite(itemId: number): Promise<void> {
  await expectOk(
    await fetch(`/api/customers/me/favorites/${itemId}`, { method: 'DELETE' }),
    'failed to remove favorite'
  );
}

export async function setFavoriteAlerts(enabled: boolean): Promise<Customer> {
  const res = await expectOk(
    await fetch('/api/customers/me/favorite-alerts', {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ enabled })
    }),
    'failed to update notification preference'
  );
  return res.json();
}