/**
 * RUC (Registro Único de Contribuyentes, Peruvian company tax number).
 *
 * The RUC (Registro Único de Contribuyentes) is the tax number of Peru assigned
 * to legal and natural persons. The number consists of 11 digits, the first two
 * indicate the kind of number, for personal numbers it is followed by the DNI
 * and a check digit.
 *
 * Source
 *    http://www.sunat.gob.pe/legislacion/ruc/
 *    https://consultarelruc.pe/
 *
 * ENTITY TAX
 */

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

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

const impl: Validator = {
  name: 'Peruvian Company Tax Number',
  localName: 'Registro Único de Contribuyentes',
  abbreviation: 'RUC',

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

    if (err) {
      throw err;
    }

    return value;
  },

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

    if (value.length === 9) {
      return strings.splitAt(value, 8).join('-');
    }
    return value;
  },

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

    if (error) {
      return { isValid: false, error };
    }
    if (value.length !== 11) {
      return { isValid: false, error: new exceptions.InvalidLength() };
    }
    if (!strings.isdigits(value)) {
      return { isValid: false, error: new exceptions.InvalidFormat() };
    }
    if (!['10', '15', '16', '17', '20'].includes(value.substr(0, 2))) {
      return { isValid: false, error: new exceptions.InvalidComponent() };
    }

    const [front, check] = strings.splitAt(value, 10);
    const sum = weightedSum(front, {
      weights: [5, 4, 3, 2, 7, 6, 5, 4, 3, 2],
      modulus: 11,
    });

    if (String((11 - sum) % 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;