import type { CreateOrderDto, CustomerBalanceDto } from '@gold-bank/shared-types';

const BASE = '/api';

async function request<T>(path: string, options?: RequestInit): Promise<T> {
  const res = await fetch(`${BASE}${path}`, {
    headers: { 'Content-Type': 'application/json' },
    ...options,
  });
  if (!res.ok) {
    const body = await res.text();
    throw new Error(`API ${path} failed (${res.status}): ${body}`);
  }
  return res.json();
}

export interface ProductImageSummary {
  id: string;
  url: string;
  sortOrder: number;
  role: 'FEATURED' | 'FEATURED_MOBILE' | 'GALLERY' | 'GALLERY_MOBILE';
}

export interface ProductVariantSummary {
  id: string;
  title: string;
  rashWeightGrams: string;
  defaultWagePercent: string;
  /// On-hand stock and the "orderable at zero stock" flag. Both exist on
  /// ProductVariant and are already returned by GET /catalog/products (the
  /// catalog service includes every variant field) — declared here so the UI
  /// can read them.
  qty?: number;
  isPreOrder?: boolean;
  /// The gallery image chosen for this variant in the admin panel. It is one of
  /// the product's OWN images — the same ProductImage row, not a copy — so
  /// several variants (e.g. different weights of one design) may share it.
  /// Null when no picture was picked; callers fall back to the product image.
  imageId?: string | null;
  image?: ProductImageSummary | null;
}

export interface CategorySummary {
  id: string;
  title: string;
  parentId: string | null;
}

export interface BrandSummary {
  id: string;
  title: string;
}

export interface CollectionSummary {
  id: string;
  title: string;
  description: string | null;
  isActive: boolean;
}

export interface ProductSummary {
  id: string;
  title: string;
  description: string | null;
  /// Legacy Product.product_code — the human-facing code. Already returned by
  /// GET /catalog/products.
  productCode?: string | null;
  variants: ProductVariantSummary[];
  /// Returned sorted by sortOrder, so images[0] really is the product's main
  /// photo rather than whichever row the database happened to hand back.
  images: ProductImageSummary[];
  category: CategorySummary | null;
  brand: BrandSummary | null;
  collections: Array<{ collectionId: string; collection: CollectionSummary }>;
}

export interface LedgerEntrySummary {
  id: string;
  currency: string;
  direction: string;
  sourceType: string;
  amount: string;
  confirmed: boolean;
  createdAt: string;
  note: string | null;
}

export interface CustomerSummary {
  id: string;
  fullName: string;
  mobile: string;
  goldDebtGrams: string;
  fiatDebtRial: string;
  goldCreditLimitGrams: string;
  isActive: boolean;
  isArchived: boolean;
}

export interface OrderSummary {
  id: string;
  orderNumber: string;
  status: string;
  totalGoldWeightGrams: string;
  isSuspendedOverCreditLimit: boolean;
}

export interface OrderItemDetail {
  id: string;
  productVariantId: string;
  quantity: number;
  rashWeightGramsSnapshot: string;
  wagePercentSnapshot: string;
  discountPercentSnapshot: string;
  computedWeightGrams: string;
  flatRialCharge: string;
}

export interface OrderDetail {
  id: string;
  orderNumber: string;
  status: string;
  totalGoldWeightGrams: string;
  wageWeightGrams: string;
  flatRialCharge: string;
  isSuspendedOverCreditLimit: boolean;
  deliveredAt: string | null;
  createdAt: string;
  items: OrderItemDetail[];
}

export interface CustomerDetail {
  id: string;
  fullName: string;
  mobile: string;
  nationalCode: string;
  cityId: string | null;
  goldCreditLimitGrams: string;
  goldDebtGrams: string;
  fiatDebtRial: string;
  verificationStep: string;
  createdAt: string;
}

export interface GoldPriceQuote {
  id: string;
  karatPerMille: number;
  pricePerGramRial: string;
  source: string;
  quotedAt: string;
}

/** One admin-uploaded home banner slide — raw shape as saved by the admin
 *  panel's manage/Const.vue "اسلایدر موبایل" tab (image + optional link). */
export interface AdminSlide {
  image: string;
  link: string;
}

export const api = {
  listProducts: () => request<ProductSummary[]>('/catalog/products'),
  listCustomers: () => request<CustomerSummary[]>('/customers'),
  getCustomer: (id: string) => request<CustomerDetail>(`/customers/${id}`),
  getBalance: (customerId: string) => request<CustomerBalanceDto>(`/accounting/customers/${customerId}/balance`),
  getLedgerEntries: (customerId: string) => request<LedgerEntrySummary[]>(`/customers/${customerId}/ledger-entries`),
  createOrder: (dto: CreateOrderDto) => request<OrderSummary>('/orders', { method: 'POST', body: JSON.stringify(dto) }),
  getCustomerOrders: (customerId: string) => request<OrderDetail[]>(`/customers/${customerId}/orders`),
  getLatestGoldPrice: (karatPerMille = 750) => request<GoldPriceQuote>(`/pricing/latest?karatPerMille=${karatPerMille}`),
  /** GET /home/slider — public, no auth. Empty array when the admin hasn't
   *  configured any slides (the caller falls back to a derived hero). */
  getHomeSlider: () => request<AdminSlide[]>('/home/slider'),
};