import { Config, SUUID } from './types';

import { restoreUUID } from './translate';

// Adapted from UUID validate.ts
// https://github.com/uuidjs/uuid/blob/main/src/regex.ts
// https://github.com/uuidjs/uuid/blob/main/src/validate.ts
export const REGEX = /^(?:[0-9a-f]{8}-[0-9a-f]{4}-[1-8][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$/i;

export function validateUUID(uuid: unknown):boolean {
  return typeof uuid === 'string' && REGEX.test(uuid);
}

export const isSubset = (sourceSet: string, testSet: string):boolean => {
  // TODO - replace with Set.isSuperset once widely available
  const aSet = new Set(sourceSet);
  return testSet
    .split('')
    .every((letter) => aSet.has(letter));
};

/**
 * Confirm if string is a valid id. Checks length and alphabet.
 * If the second parameter is true it will translate to standard UUID
 *  and check the result for UUID validity.
 *  HOF takes a config and returns the validate function.
 */
const validate = (config:Config) => (shortId: SUUID, rigorous = false) => {
  if (!shortId || typeof shortId !== 'string') return false;
  const isCorrectLength = config.consistentLength
    ? shortId.length === config.maxLength
    : shortId.length <= config.maxLength;
  const isAlphabetSubset = isSubset(config.alphabet, shortId);
  return isCorrectLength
    && isAlphabetSubset
    // Only validate if subset isconfirmed or any-base will throw error
    && (rigorous
      ? validateUUID(restoreUUID(config, shortId))
      : true);
};

export default validate;