/**
 * TVA (taxe sur la valeur ajoutée, Luxembourgian VAT number).
 *
 * The n° TVA (Numéro d'identification à la taxe sur la valeur ajoutée) is
 * used for tax purposes in Luxembourg. The number consists of 8 digits of
 * which the last two are check digits.
 *
 * Source
 *
 * ENTITY
 */

import * as exceptions from '../exceptions';
import { strings } from '../util';
import { Validator, ValidateReturn } from '../types';

function clean(input: string): ReturnType<typeof strings.cleanUnicode> {
  return strings.cleanUnicode(input, ' :-.', 'LU');
}

const impl: Validator = {
  name: 'Luxembourgian VAT Number',
  localName: "Numéro d'Identification à la Taxe sur la Valeur Ajoutée",
  abbreviation: 'n° TVA',
  compact(input: string): string {
    const [value, err] = clean(input);

    if (err) {
      throw err;
    }

    return value;
  },

  format(input: string): string {
    const [value] = clean(input);

    return strings.splitAt(value, 3, 6).join(' ');
  },

  validate(input: string): ValidateReturn {
    const [value, error] = clean(input);

    if (error) {
      return { isValid: false, error };
    }
    if (value.length !== 8) {
      return { isValid: false, error: new exceptions.InvalidLength() };
    }
    if (!strings.isdigits(value)) {
      return { isValid: false, error: new exceptions.InvalidFormat() };
    }

    const [front, check] = strings.splitAt(value, -2);

    if (parseInt(front, 10) % 89 !== parseInt(check, 10)) {
      return { isValid: false, error: new exceptions.InvalidChecksum() };
    }

    return {
      isValid: true,
      compact: value,
      isIndividual: false,
      isCompany: true,
    };
  },
};

export const { name, localName, abbreviation, validate, format, compact } =
  impl;