/**
 * Orgnr (Organisasjonsnummer, Norwegian organisation number).
 *
 * The Organisasjonsnummer is a 9-digit number with a straightforward check
 * mechanism.
 *
 * Source
 *   https://nn.wikipedia.org/wiki/Organisasjonsnummer
 *   https://no.wikipedia.org/wiki/Organisasjonsnummer
 *
 * ENTITY
 */

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: 'Norwegian Organization Number',
  localName: 'Organisasjonsnummer',
  abbreviation: 'Orgnr',

  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 !== 9) {
      return { isValid: false, error: new exceptions.InvalidLength() };
    }
    if (!strings.isdigits(value)) {
      return { isValid: false, error: new exceptions.InvalidFormat() };
    }

    const sum = weightedSum(value, {
      weights: [3, 2, 7, 6, 5, 4, 3, 2, 1],
      modulus: 11,
    });

    if (sum !== 0) {
      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;