/**
 *
 * The CLABE (Clave Bancaria Estandarizada)
 *
 * Spanish for "standardized banking cipher" or "standardized bank code") is a banking standard for the numbering of
 * bank accounts in Mexico. This standard is a requirement for the sending and receiving of domestic inter-bank
 * electronic funds transfer since June 1, 2004.
 *
 * Sources:
 *   http://m.sat.gob.mx/contabilidadelectronica/Paginas/documentos/bancos_nacionales.pdf
 *
 * BANK
 */

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

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

const impl: Validator = {
  name: 'Mexican Standardized Bank Code',
  localName: 'Clave Bancaria Estandarizada',
  abbreviation: 'CLABE',
  compact(input: string): string {
    const [value, err] = clean(input);

    if (err) {
      throw err;
    }

    return value.toLocaleUpperCase();
  },

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

    return value;
  },

  /**
   * Check if the number is a valid CLABE.
   * This checks the length, formatting and other contraints. It does not check
   * for control letter.
   */
  validate(input: string): ValidateReturn {
    const [value, error] = clean(input);

    if (error) {
      return { isValid: false, error };
    }
    if (value.length !== 18) {
      return { isValid: false, error: new exceptions.InvalidLength() };
    }
    if (!strings.isdigits(value)) {
      return { isValid: false, error: new exceptions.InvalidComponent() };
    }

    const [bankCode, cityCode, account, checksum] = strings.splitAt(
      value,
      3,
      6,
      17,
    );

    if (banksMap[parseInt(bankCode, 10)] === undefined) {
      return { isValid: false, error: new exceptions.InvalidComponent() };
    }
    if (cities[parseInt(cityCode, 10)] === undefined) {
      return { isValid: false, error: new exceptions.InvalidComponent() };
    }
    if (!strings.isdigits(account)) {
      return { isValid: false, error: new exceptions.InvalidComponent() };
    }

    const sum =
      (10 -
        weightedSum(value.substr(0, 17), {
          weights: [3, 7, 1],
          modulus: 10,
        })) %
      10;

    if (checksum !== String(sum)) {
      return { isValid: false, error: new exceptions.InvalidChecksum() };
    }

    // const add = (sum, digit, i) => sum + (parseInt(digit, 10) * [3, 7, 1][i % 3]) % 10;
    // const compute = () => (10 - (clabeNum17.split('').slice(0, 17).reduce(add, 0) % 10)) % 10;
    // return /^[0-9]{17,18}$/.test(clabeNum17) ? compute() : null;

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

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