import { authFetch } from "../../../utils/authFetch";

interface VatRate {
  countryCode: string;
  standardRate: number;
}

const normalizeVatRate = (rate: number | null | undefined): number | null => {
  if (rate == null || Number.isNaN(rate)) return null;
  return rate > 1 ? rate / 100 : rate;
};

const toNumber = (v: any): number | null => {
  if (v == null) return null;
  const n = typeof v === 'string' ? Number(v) : (typeof v === 'number' ? v : Number(v));
  return Number.isFinite(n) ? n : null;
};

const getCode = (row: any): string => {
  const raw = row?.countryCode ?? row?.code ?? row?.country ?? row?.country_code;
  return typeof raw === 'string' ? raw.toUpperCase() : '';
};

const getRateRaw = (row: any): number | null => {
  // support multiple field names and string numbers
  const raw = row?.standardRate ?? row?.rate ?? row?.ratePercent ?? row?.standard_rate;
  const num = toNumber(raw);
  return num;
};

const getRateNormalized = (row: any): number | null => {
  const num = getRateRaw(row);
  return normalizeVatRate(num);
};

/**
 * Fetches the standard VAT rate for a given ISO country code.
 * Returns null if not found or on any error.
 */
export async function getStandardVatRate(countryCode: string): Promise<number | null> {
  try {
    const url = `${process.env.NEXT_PUBLIC_API_BASE_URL}/api/tax/vat-rates`;
    console.info('[VAT] getStandardVatRate -> GET', url, { countryCode });
    const res = await authFetch(url, { method: "GET" });
    console.info('[VAT] getStandardVatRate status:', res.status);
    if (!res.ok) return null;

    const raw = await res.json().catch(() => null);
    const arr = Array.isArray(raw?.data) ? raw.data : (Array.isArray(raw) ? raw : []);
    console.info('[VAT] getStandardVatRate parsed length:', Array.isArray(arr) ? arr.length : 0);
    if (!Array.isArray(arr) || arr.length === 0) return null;

    const upper = countryCode.toUpperCase();
    const match = arr.find((r: any) => getCode(r) === upper);
    const normalized = match ? getRateNormalized(match) : null;
    console.info('[VAT] getStandardVatRate match:', {
      upper,
      resolvedCode: match ? getCode(match) : null,
      rawRate: match ? getRateRaw(match) : null,
      normalized
    });
    return normalized;
  } catch (e) {
    console.error('[VAT] getStandardVatRate error:', e);
    return null;
  }
}

export type VatRateEntry = { code: string; rate: number | null }

export async function getVatRates(): Promise<VatRateEntry[]> {
  try {
    const url = `${process.env.NEXT_PUBLIC_API_BASE_URL}/api/tax/vat-rates`;
    console.info('[VAT] getVatRates -> GET', url);
    const res = await authFetch(url, { method: 'GET' });
    console.info('[VAT] getVatRates status:', res.status);
    if (!res.ok) return [];
    const raw = await res.json().catch(() => null);
    const arr = Array.isArray(raw?.data) ? raw.data : (Array.isArray(raw) ? raw : []);
    console.info('[VAT] getVatRates parsed length:', Array.isArray(arr) ? arr.length : 0);
    if (!Array.isArray(arr) || arr.length === 0) return [];
    const mapped = arr.map((r: any) => ({
      code: getCode(r),
      rate: getRateNormalized(r)
    })).filter((r: VatRateEntry) => !!r.code);
    console.info('[VAT] getVatRates mapped sample:', mapped.slice(0, 5));
    return mapped;
  } catch (e) {
    console.error('[VAT] getVatRates error:', e);
    return [];
  }
}