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

const BASE = '/api';
const TOKEN_KEY = 'gold-bank:token';

/**
 * Called when the API rejects our token. Wired up in main.ts rather than
 * imported from the store, so this module stays free of a Pinia dependency
 * (the client is used before Pinia is active during app bootstrap).
 */
let onUnauthorized: (() => void) | null = null;
export function setUnauthorizedHandler(fn: () => void) {
  onUnauthorized = fn;
}

/** Thrown for a 401 so callers can tell "session gone" from any other failure. */
export class UnauthorizedError extends Error {
  constructor(path: string) {
    super(`API ${path} rejected the session (401)`);
    this.name = 'UnauthorizedError';
  }
}

function readToken(): string | null {
  try {
    return localStorage.getItem(TOKEN_KEY);
  } catch {
    // Private mode / blocked storage — treat as logged out rather than throwing.
    return null;
  }
}

async function request<T>(path: string, options?: RequestInit): Promise<T> {
  const token = readToken();

  const res = await fetch(`${BASE}${path}`, {
    ...options,
    headers: {
      'Content-Type': 'application/json',
      // Customer JWT from POST /customer/auth/verify-otp. The API derives the
      // customer from this, never from an id in the URL.
      ...(token ? { Authorization: `Bearer ${token}` } : {}),
      ...options?.headers,
    },
  });

  if (res.status === 401) {
    // Expired or revoked: drop the session and send the user to login, so no
    // stale personal data stays on screen behind a dead token.
    onUnauthorized?.();
    throw new UnauthorizedError(path);
  }

  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 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;
}


/**
 * D21 — a sales expert signed into the app. Ordinary customers get
 * `isSalesExpert: false` and neither expert screen is shown to them.
 */
export interface ExpertIdentity {
  isSalesExpert: boolean;
  type: 'customer' | 'sales-expert';
}

/** One of the expert's referred customers ("انتخاب مشتری"). */
export interface ExpertCustomer {
  id: string;
  /** Legacy key the reference's card bound to. */
  name: string;
  fullName: string;
  mobile: string;
  phone: string | null;
  store_name: string | null;
  pasazh_name: string | null;
  gram_level: string;
  remain: string;
  rial_remain: string;
  active: number;
  createdAt: string;
}

/** One row of "سفارش مشتریان". */
export interface ExpertChildOrder {
  id: string;
  orderNumber: string;
  status: string;
  /** Total order weight — the reference's `item.w` (ChildOrders.vue:55). */
  w: string;
  totalGoldWeightGrams: string;
  createdAt: string;
  items: OrderItemDetail[];
  customer: { id: string; name: string; mobile: string } | null;
}
export const api = {
  listProducts: () => request<ProductSummary[]>('/catalog/products'),

  /**
   * Step 1 of login — ports henza_server ApiMobileController::userAuth.
   * Always resolves `{ sent: true }`, even for an unregistered number, so the
   * endpoint cannot be used to discover which numbers are customers.
   */
  requestOtp: (username: string) =>
    request<{ sent: boolean }>('/customer/auth/request-otp', {
      method: 'POST',
      body: JSON.stringify({ username }),
    }),

  /**
   * Step 2 — ports ApiMobileController::userVerfiy. The server compares the
   * code and returns a token plus that one customer. A wrong, expired or
   * already-used code is a 401.
   */
  verifyOtp: (username: string, password: string) =>
    request<{ token: string; customer: { id: string; mobile: string } }>(
      '/customer/auth/verify-otp',
      { method: 'POST', body: JSON.stringify({ username, password }) },
    ),

  // The three reads below identify the customer by TOKEN. They replaced
  // /customers/:id, /:id/orders and /:id/ledger-entries, which took the id from
  // the URL and let anyone read anyone (SEC-08).
  getMe: () => request<CustomerDetail>('/customer/me'),
  getMyOrders: () => request<OrderDetail[]>('/customer/me/orders'),
  getMyLedgerEntries: () => request<LedgerEntrySummary[]>('/customer/me/ledger-entries'),

  createOrder: (dto: CreateOrderDto) => request<OrderSummary>('/orders', { method: 'POST', body: JSON.stringify(dto) }),
  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'),

  // ── D21: sales-expert screens ────────────────────────────────────────
  // All three scope themselves on the AdminUser id inside the token; no id
  // ever travels from the client. An ordinary customer gets 403 on the first
  // two, and `isSalesExpert: false` from whoami so the menu entries stay hidden.
  getExpertIdentity: () => request<ExpertIdentity>('/expert/whoami'),
  getExpertCustomers: (search?: string | null) =>
    request<ExpertCustomer[]>('/expert/my-customers', {
      method: 'POST',
      body: JSON.stringify({ search: search ?? null }),
    }),
  getExpertChildOrders: (page = 1, search?: string | null) =>
    request<{ rows: ExpertChildOrder[]; total: number; page: number; limit: number }>(
      '/expert/child-orders',
      { method: 'POST', body: JSON.stringify({ page, search: search ?? null }) },
    ),
};