const GERMAN_NUMBER_WORDS = new Map([
  ['null', '0'],
  ['ein', '1'],
  ['eins', '1'],
  ['eine', '1'],
  ['einen', '1'],
  ['einem', '1'],
  ['einer', '1'],
  ['zwei', '2'],
  ['drei', '3'],
  ['vier', '4'],
  ['fuenf', '5'],
  ['funf', '5'],
  ['fünf', '5'],
  ['sechs', '6'],
  ['sieben', '7'],
  ['acht', '8'],
  ['neun', '9'],
  ['zehn', '10'],
  ['elf', '11'],
  ['zwoelf', '12'],
  ['zwolf', '12'],
  ['zwölf', '12'],
  ['dreizehn', '13'],
  ['vierzehn', '14'],
  ['fuenfzehn', '15'],
  ['funfzehn', '15'],
  ['fünfzehn', '15'],
  ['sechzehn', '16'],
  ['siebzehn', '17'],
  ['achtzehn', '18'],
  ['neunzehn', '19'],
  ['zwanzig', '20'],
  ['dreissig', '30'],
  ['dreißig', '30'],
  ['vierzig', '40'],
  ['fuenfzig', '50'],
  ['funfzig', '50'],
  ['fünfzig', '50'],
  ['sechzig', '60'],
  ['siebzig', '70'],
  ['achtzig', '80'],
  ['neunzig', '90'],
  ['hundert', '100'],
  ['einhundert', '100'],
  ['tausend', '1000'],
  ['eintausend', '1000'],
  ['zweitausend', '2000']
]);

const GERMAN_ONES = [
  ['', ''],
  ['ein', 'eins'],
  ['zwei'],
  ['drei'],
  ['vier'],
  ['fuenf', 'funf', 'fünf'],
  ['sechs'],
  ['sieben'],
  ['acht'],
  ['neun']
];

const GERMAN_TENS = {
  20: ['zwanzig'],
  30: ['dreissig', 'dreißig'],
  40: ['vierzig'],
  50: ['fuenfzig', 'funfzig', 'fünfzig'],
  60: ['sechzig'],
  70: ['siebzig'],
  80: ['achtzig'],
  90: ['neunzig']
};

for (const [tensValue, tensWords] of Object.entries(GERMAN_TENS)) {
  const tens = Number(tensValue);
  for (let one = 1; one <= 9; one += 1) {
    for (const oneWord of GERMAN_ONES[one]) {
      for (const tenWord of tensWords) {
        GERMAN_NUMBER_WORDS.set(`${oneWord}und${tenWord}`, String(tens + one));
      }
    }
  }
}

function stripGermanNumberSeparators(value) {
  return String(value || '')
    .replace(/[\s.-]+/g, '');
}

export function canonicalizeNumberAnswer(value) {
  const raw = String(value || '').trim().toLowerCase();
  if (!raw) return '';

  const compact = stripGermanNumberSeparators(raw);
  if (/^\d+$/.test(compact)) {
    return String(Number(compact));
  }

  return GERMAN_NUMBER_WORDS.get(compact) || '';
}

export function normalizeComparableWithNumberWords(value, baseNormalizer) {
  const rawCanonical = canonicalizeNumberAnswer(value);
  if (rawCanonical) return rawCanonical;

  const normalized = baseNormalizer(String(value || ''));
  const normalizedCanonical = canonicalizeNumberAnswer(normalized);
  return normalizedCanonical || normalized;
}