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

const BASE = '/api';
const TOKEN_KEY = 'gold-bank:token';
/** Must match stores/session.ts — the act-as target, if any. */
const ACTING_AS_KEY = 'gold-bank:actingAs';

/**
 * 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;
  }
}

/**
 * «ورود به حساب مشتری» — the customer a sales expert is working inside.
 *
 * Read from storage rather than the store for the same reason as the token: this
 * module must not depend on Pinia. The server treats this as a request, not a
 * fact: it re-checks on every call that the customer is actually referred by
 * this expert, so a forged value is a 403 and reveals nothing.
 */
function readActingAsId(): string | null {
  try {
    const raw = sessionStorage.getItem(ACTING_AS_KEY);
    if (!raw) return null;
    const parsed = JSON.parse(raw) as { id?: unknown };
    return typeof parsed?.id === 'string' && parsed.id ? parsed.id : null;
  } catch {
    return null;
  }
}

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

  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}` } : {}),
      // Sent on every request while impersonating, which is what makes the whole
      // app render from the customer's point of view — the reference achieved
      // the same by swapping the bearer token in its axios interceptor
      // (henza_pwa plugins/axios.ts:18 via getUserToken()).
      ...(actingAs ? { 'X-Act-As-Customer': actingAs } : {}),
      ...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 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;
}

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[];
  images: Array<{ url: string }>;
  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 | null;
  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;
}
/**
 * D24 — "گزارش", the account statement.
 *
 * The field names are the reference's (henza_pwa/src/type/accounting.ts), so
 * the ported components bind exactly as they did. Money and weights travel as
 * decimal STRINGS, never as JS numbers, so no figure is rounded in transit.
 */
export interface ReportRow {
  id: number;
  /** The ledger entry id; what the detail call is keyed on. */
  factor_Code: string;
  sh_factor: string;
  tarikh: string;
  /** Gold in / out, as separate positive columns. */
  geram_v: string;
  geram_kh: string;
  rial_v: string;
  rial_kh: string;
  /** Running balances AFTER this row. Signed: negative means in credit. */
  tahesab_T: string;
  tahesab_P: string;
  /** No foreign-currency ledger in the target — always zero (REP-01). */
  rial_V2: string;
  rial_Kh2: string;
  tahesabP2: string;
  sourceType: string;
  note: string | null;
}

export interface ReportPage {
  result: ReportRow[];
  count: number;
  page: number;
  limit: number;
}

/** One document's detail. Fields the target cannot know are null, not invented. */
export interface ReportDetailRow {
  factor_Code: string;
  sh_factor: string;
  tarikh: string;
  vazn: string;
  ayar: number | null;
  no: string;
  sh_sharti: string | null;
  name_az: string | null;
  tabdil750_v: string;
  tabdil750_kh: string;
  fi: string | null;
  fiF: string | null;
  Darsad_Talayee: string | null;
  accountName: string | null;
  bankName: string | null;
  transferTo: string | null;
  receivedAt: string | null;
  note: string | null;
  nO_kar: null;
  jens_felez: null;
  Darsad: null;
  maliatDarsad: null;
}

export interface ReportBalance {
  arz: string;
  mandeh: string;
}
/** GET /customer/me/accounting-balance. Signed like the app: positive = owes. */
export interface AccountingBalance {
  source: 'accounting' | 'stored' | 'none'
  gold: string | null
  rial: string | null
  at: string | null
  provider: string | null
}

/** POST /customer/me/wage-quote — one variant's making charge for the signed-in customer. */
export interface WageQuote {
  variantId: string
  variantPercent: string
  customerPercent: string
  promotionPercent: string
  finalPercent: string
}

function iamAppUrl(path: string) {
  const base = import.meta.env.BASE_URL || '/'
  const prefix = base.endsWith('/') ? base : `${base}/`
  return `${window.location.origin}${prefix}${path.replace(/^\//, '')}`
}

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 }; iamBootstrapUrl?: string }>(
      '/customer/auth/verify-otp',
      { method: 'POST', body: JSON.stringify({ username, password }) },
    ),

  ssoStart: () =>
    request<{ enabled: boolean; authorize_url: string | null }>(
      `/customer/auth/sso/start?redirect_uri=${encodeURIComponent(iamAppUrl('auth/iam/callback'))}`,
    ),

  ssoCallback: (code: string, state: string) =>
    request<{ token: string; customer: { id: string; mobile: string } }>('/customer/auth/sso/callback', {
      method: 'POST',
      body: JSON.stringify({ code, state }),
    }),

  ssoLogoutUrl: () =>
    request<{ logout_url: string | null }>(
      `/customer/auth/sso/logout-url?return_url=${encodeURIComponent(iamAppUrl(''))}`,
    ),

  endSharedSession: () =>
    request<{ ended: number }>('/customer/auth/logout', { method: 'POST', body: '{}' }),

  // 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'),
  /** D27 §12 — this customer's balance, read from the accounting software on every call. */
  getAccountingBalance: () => request<AccountingBalance>('/customer/me/accounting-balance'),
  getMyOrders: () => request<OrderDetail[]>('/customer/me/orders'),
  getMyLedgerEntries: () => request<LedgerEntrySummary[]>('/customer/me/ledger-entries'),
  /** The making charge the server will charge for these variants (MON-08). */
  getWageQuotes: (variantIds: string[]) =>
    request<WageQuote[]>('/customer/me/wage-quote', { method: 'POST', body: JSON.stringify({ variantIds }) }),
  /** Favourite product ids, newest first — legacy get-favorites (FAV-01). */
  getFavorites: () => request<{ ids: string[] }>('/customer/me/favorites'),
  /** Legacy add-to-fav: adds or removes; answers the new state. */
  toggleFavorite: (productId: string) =>
    request<{ favorite: boolean }>('/customer/me/favorites/toggle', {
      method: 'POST',
      body: JSON.stringify({ productId }),
    }),
  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 }) },
    ),

  // ── complete_profile ─────────────────────────────────────────────────
  // Ports POST /major/complete (henza_server Major/CustomerController::complete)
  // and the PWA's document uploads, which went through the same file/create the
  // admin used but behind the customer guard (routes/api.php:95).
  /**
   * Uploads one document and resolves its stored id, which is what
   * completeProfile sends. multipart/form-data, so it bypasses `request()` —
   * that helper forces a JSON content-type, and setting it here would break
   * the multipart boundary.
   */
  uploadDocument: async (file: File, purpose: string): Promise<{ id: string; url: string }> => {
    const body = new FormData();
    body.append('file', file);
    body.append('purpose', purpose);

    const token = readToken();
    // This route bypasses `request()`, so the act-as header has to be repeated
    // here — without it an expert uploading a customer's documents would file
    // them against their OWN account, silently and with no error.
    const actingAs = readActingAsId();
    const res = await fetch(`${BASE}/customer/me/documents`, {
      method: 'POST',
      // No Content-Type: the browser sets it with the boundary.
      headers: {
        ...(token ? { Authorization: `Bearer ${token}` } : {}),
        ...(actingAs ? { 'X-Act-As-Customer': actingAs } : {}),
      },
      body,
    });

    if (res.status === 401) {
      onUnauthorized?.();
      throw new UnauthorizedError('/customer/me/documents');
    }
    if (!res.ok) {
      throw new Error(`آپلود فایل ناموفق بود (${res.status})`);
    }
    return res.json();
  },

  /**
   * The three ids keep the reference's snake_case keys so the payload matches
   * what henza_pwa sent (completeProfile.vue:136-140).
   */
  completeProfile: (payload: {
    business_license_image_id: string;
    shop_image_id: string;
    ncode_image_id: string;
  }) =>
    request<{ ok: boolean }>('/customer/me/complete-profile', {
      method: 'POST',
      body: JSON.stringify(payload),
    }),

  // ── report / report detail (D24) ─────────────────────────────────────
  // The reference proxied an external accounting system
  // (henza_server Customer/TahesabController). These read the target's own
  // ledger instead — no external call — and the customer comes from the token.
  getReport: (page = 1) =>
    request<ReportPage>(`/customer/me/report?page=${page}`),
  getReportDetailList: (page = 1) =>
    request<{ result: ReportDetailRow[]; page: number; limit: number }>(
      `/customer/me/report/detail?page=${page}`,
    ),
  getReportBalances: () =>
    request<{ status: number; message: string; result: ReportBalance[] }>(
      '/customer/me/report/balances',
    ),
  getReportDocument: (id: string) =>
    request<{ result: ReportDetailRow[]; page: number; limit: number }>(
      `/customer/me/report/${encodeURIComponent(id)}`,
    ),
};