import { BadRequestException } from '@nestjs/common';
import { ExternalGroup, ProviderName } from './providers/accounting-provider';

/**
 * The admin-editable configuration of the accounting integration (D27),
 * stored as one Setting row. Every `accounting.*` Setting key is refused by
 * the generic `const` routes (admin-misc), so the only way in or out is the
 * dedicated, `config.accounting`-guarded screen — and even that never returns
 * a token.
 */

export const ACCOUNTING_SETTING_PREFIX = 'accounting.';
export const ACCOUNTING_CONFIG_KEY = 'accounting.config';
export const ACCOUNTING_STATE_KEY = 'accounting.state';

/** Keys the generic `const` settings routes must never read or write. */
export function isAccountingSettingKey(key: string) {
  return key.trim().toLowerCase().startsWith(ACCOUNTING_SETTING_PREFIX);
}

export type ProviderChoice = 'none' | ProviderName;

export interface StoredConnection {
  baseUrl: string;
  /** AES-GCM sealed (secret-box.ts). Never leaves the server. */
  tokenSealed: string | null;
  /** PEM CA of a self-signed installation; verification is never turned off. */
  caCert: string | null;
  timeoutMs: number;
}

export interface AccountingFeatures {
  /** F1 — customer import/link and push. */
  customers: boolean;
  /** F2 — balance pull; the customer sees the accounting balance. */
  balances: boolean;
  /** F6 — «گزارش» reads the accounting statement. */
  report: boolean;
  /** F4 — کارساخته ↔ product sync and the out-of-stock lock. */
  products: boolean;
  /** F3 — order documents. */
  documents: boolean;
}

export interface AccountingConfig {
  provider: ProviderChoice;
  tahesab: StoredConnection & { dbName: string };
  zarrin: StoredConnection & { balanceOwesWhen: 'negative' | 'positive' };
  features: AccountingFeatures;
  intervals: {
    customersMinutes: number;
    balancesMinutes: number;
    productsMinutes: number;
  };
  mapping: {
    /** Account groups imported into the app; empty = every group. */
    importCustomerGroups: ExternalGroup[];
    /** Group a customer created from the app is put in. */
    newCustomerGroup: ExternalGroup | null;
    /** Zarrin: group (گروه ساخته) for a product created in the admin… */
    newKarSakhteGroup: ExternalGroup | null;
    /** …overridden per app category. */
    categoryGroups: { categoryId: string; group: ExternalGroup }[];
    /** Zarrin: item type (گرمی/تعدادی…) for a product created in the admin. */
    newKarSakhteType: ExternalGroup | null;
    /** Purity the app's grams are in. */
    karat: number;
  };
  /** How far back «گزارش» reads the accounting statement. */
  report: { windowDays: number };
  /** F3 — the order status at (or past) which the temporary document (پیش‌فاکتور) is posted. */
  documents: { triggerStatus: DocumentTriggerStatus };
}

/** Order statuses in the order an order passes them; SUSPENDED/CANCELLED never trigger. */
export const DOCUMENT_TRIGGER_STATUSES = [
  'PLACED',
  'ADMIN_APPROVED',
  'SOURCING',
  'PREPARING',
  'DELIVERED_TO_AGENT',
  'DELIVERED_TO_CUSTOMER',
] as const;
export type DocumentTriggerStatus = (typeof DOCUMENT_TRIGGER_STATUSES)[number];

/** 1-based place of a status in DOCUMENT_TRIGGER_STATUSES; 0 = never triggers. */
export function documentStatusRank(status: string): number {
  return DOCUMENT_TRIGGER_STATUSES.indexOf(status as DocumentTriggerStatus) + 1;
}

export const DEFAULT_TIMEOUT_MS = 20_000;

export function defaultConfig(): AccountingConfig {
  return {
    provider: 'none',
    tahesab: { baseUrl: '', tokenSealed: null, caCert: null, timeoutMs: DEFAULT_TIMEOUT_MS, dbName: 'TahesabDB' },
    zarrin: { baseUrl: '', tokenSealed: null, caCert: null, timeoutMs: DEFAULT_TIMEOUT_MS, balanceOwesWhen: 'negative' },
    features: { customers: false, balances: false, report: false, products: false, documents: false },
    intervals: { customersMinutes: 60, balancesMinutes: 10, productsMinutes: 30 },
    mapping: {
      importCustomerGroups: [],
      newCustomerGroup: null,
      newKarSakhteGroup: null,
      categoryGroups: [],
      newKarSakhteType: null,
      karat: 750,
    },
    report: { windowDays: 365 },
    // The point the debt is recognised — the behaviour before the rule existed.
    documents: { triggerStatus: 'DELIVERED_TO_AGENT' },
  };
}

/** Stored JSON → a complete config, tolerating rows written by older code. */
export function withDefaults(raw: unknown): AccountingConfig {
  const d = defaultConfig();
  const r = (raw && typeof raw === 'object' ? raw : {}) as Partial<AccountingConfig>;
  return {
    provider: r.provider === 'tahesab' || r.provider === 'zarrin' ? r.provider : 'none',
    tahesab: { ...d.tahesab, ...(r.tahesab ?? {}) },
    zarrin: { ...d.zarrin, ...(r.zarrin ?? {}) },
    features: { ...d.features, ...(r.features ?? {}) },
    intervals: { ...d.intervals, ...(r.intervals ?? {}) },
    mapping: { ...d.mapping, ...(r.mapping ?? {}) },
    report: { ...d.report, ...(r.report ?? {}) },
    documents: { ...d.documents, ...(r.documents ?? {}) },
  };
}

// ── input validation ────────────────────────────────────────────────────

export function cleanUrl(v: unknown, label: string): string {
  const s = typeof v === 'string' ? v.trim() : '';
  if (!s) return '';
  let u: URL;
  try {
    u = new URL(s);
  } catch {
    throw new BadRequestException(`${label}: آدرس معتبر نیست`);
  }
  if (u.protocol !== 'http:' && u.protocol !== 'https:') {
    throw new BadRequestException(`${label}: آدرس باید با http:// یا https:// شروع شود`);
  }
  if (u.username || u.password) throw new BadRequestException(`${label}: آدرس نباید نام کاربری/رمز داشته باشد`);
  return s;
}

export function cleanCa(v: unknown): string | null {
  const s = typeof v === 'string' ? v.trim() : '';
  if (!s) return null;
  if (!s.includes('-----BEGIN CERTIFICATE-----')) {
    throw new BadRequestException('گواهی CA باید با قالب PEM (BEGIN CERTIFICATE) باشد');
  }
  return s;
}

export function cleanInt(v: unknown, label: string, min: number, max: number, fallback: number): number {
  if (v === undefined || v === null || v === '') return fallback;
  const n = Number(v);
  if (!Number.isInteger(n) || n < min || n > max) {
    throw new BadRequestException(`${label}: عدد صحیح بین ${min} و ${max}`);
  }
  return n;
}

export function cleanGroup(v: unknown): ExternalGroup | null {
  if (!v || typeof v !== 'object') return null;
  const g = v as Record<string, unknown>;
  const id = g.id === undefined || g.id === null ? '' : String(g.id).trim();
  const name = typeof g.name === 'string' ? g.name.trim() : '';
  if (!id && !name) return null;
  return { id, name };
}

export function cleanGroups(v: unknown): ExternalGroup[] {
  return Array.isArray(v) ? v.map(cleanGroup).filter((g): g is ExternalGroup => !!g) : [];
}

export function cleanBool(v: unknown, fallback: boolean): boolean {
  return typeof v === 'boolean' ? v : fallback;
}