/**
 * PIB (Poreski Identifikacioni Broj, Montenegro tax number).
 *
 * This number consists of 8 digits.
 *
 * Source
 *   http://www.pretraga.crps.me:8083/
 *   https://www.vatify.eu/montenegro-vat-number.html
 *
 * ENTITY
 */
import * as exceptions from '../exceptions';
import { strings } from '../util';
import { Validator, ValidateReturn } from '../types';
import { weightedSum } from '../util/checksum';

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

const impl: Validator = {
  name: 'Montenegro tax number',
  localName: 'Poreski Identifikacioni Broj',
  abbreviation: 'PIB',

  compact(input: string): string {
    const [value, err] = clean(input);

    if (err) {
      throw err;
    }

    return value;
  },

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

    return value;
  },

  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, 7);

    const sum = weightedSum(front, {
      weights: [8, 7, 6, 5, 4, 3, 2],
      modulus: 11,
    });

    if (String(((11 - sum) % 11) % 10) !== check) {
      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;