/**
 * llmindex.io — multilingual templates (checkable cross-lingual outputs, 0-999 range)
 * Author:  Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 * License: Proprietary — © Simon-Pierre Boucher, all rights reserved
 *
 * Hardened: full 0-999 number-word space in French (including the irregular
 * 70-99 zone: soixante-dix, quatre-vingts…) and Spanish (quinientos,
 * setecientos, novecientos…), both directions (number→words and words→number).
 * Hyphen/space orthography variants are normalized at grading time.
 */
import { ANSWER_FORMAT_INSTRUCTIONS } from '../answer';
import type { Rng } from '../rng';
import type { ItemTemplate } from '../types';

const FR_UNITS = [
  'zéro', 'un', 'deux', 'trois', 'quatre', 'cinq', 'six', 'sept', 'huit', 'neuf', 'dix',
  'onze', 'douze', 'treize', 'quatorze', 'quinze', 'seize', 'dix-sept', 'dix-huit', 'dix-neuf',
];

function frBelowHundred(n: number): string {
  if (n < 20) return FR_UNITS[n]!;
  const tensNames: Record<number, string> = {
    20: 'vingt', 30: 'trente', 40: 'quarante', 50: 'cinquante', 60: 'soixante',
  };
  if (n < 70) {
    const t = Math.floor(n / 10) * 10;
    const u = n % 10;
    if (u === 0) return tensNames[t]!;
    if (u === 1) return `${tensNames[t]!} et un`;
    return `${tensNames[t]!}-${FR_UNITS[u]!}`;
  }
  if (n < 80) {
    if (n === 71) return 'soixante et onze';
    return `soixante-${FR_UNITS[n - 60]!}`;
  }
  if (n === 80) return 'quatre-vingts';
  if (n < 100) return `quatre-vingt-${FR_UNITS[n - 80]!}`;
  throw new Error('frBelowHundred supports 0-99');
}

/** French number words, 0-999. */
export function numToFrench(n: number): string {
  if (n < 0 || n > 999) throw new Error('numToFrench supports 0-999');
  if (n < 100) return frBelowHundred(n);
  const hundreds = Math.floor(n / 100);
  const rest = n % 100;
  const hundredPart =
    hundreds === 1 ? 'cent' : rest === 0 ? `${FR_UNITS[hundreds]!} cents` : `${FR_UNITS[hundreds]!} cent`;
  return rest === 0 ? hundredPart : `${hundredPart} ${frBelowHundred(rest)}`;
}

const ES_UNITS = [
  'cero', 'uno', 'dos', 'tres', 'cuatro', 'cinco', 'seis', 'siete', 'ocho', 'nueve', 'diez',
  'once', 'doce', 'trece', 'catorce', 'quince', 'dieciséis', 'diecisiete', 'dieciocho', 'diecinueve',
  'veinte', 'veintiuno', 'veintidós', 'veintitrés', 'veinticuatro', 'veinticinco', 'veintiséis',
  'veintisiete', 'veintiocho', 'veintinueve',
];

function esBelowHundred(n: number): string {
  if (n < 30) return ES_UNITS[n]!;
  const tensNames: Record<number, string> = {
    30: 'treinta', 40: 'cuarenta', 50: 'cincuenta', 60: 'sesenta', 70: 'setenta', 80: 'ochenta', 90: 'noventa',
  };
  const t = Math.floor(n / 10) * 10;
  const u = n % 10;
  return u === 0 ? tensNames[t]! : `${tensNames[t]!} y ${ES_UNITS[u]!}`;
}

const ES_HUNDREDS: Record<number, string> = {
  1: 'ciento', 2: 'doscientos', 3: 'trescientos', 4: 'cuatrocientos', 5: 'quinientos',
  6: 'seiscientos', 7: 'setecientos', 8: 'ochocientos', 9: 'novecientos',
};

/** Spanish number words, 0-999. */
export function numToSpanish(n: number): string {
  if (n < 0 || n > 999) throw new Error('numToSpanish supports 0-999');
  if (n < 100) return esBelowHundred(n);
  if (n === 100) return 'cien';
  const hundreds = Math.floor(n / 100);
  const rest = n % 100;
  return rest === 0 ? ES_HUNDREDS[hundreds]! : `${ES_HUNDREDS[hundreds]!} ${esBelowHundred(rest)}`;
}

export const multilingualNumword: ItemTemplate = {
  id: 'multilingual.numword-v2',
  domain: 'multilingual',
  description:
    'Compute a 3-digit arithmetic result and spell it in French or Spanish — full 0-999 space including the irregular French 70-99 zone.',
  paramSpace: 2 * 900 * 900,
  render(rng: Rng, perturbSeed: string) {
    const lang = rng.pick(['French', 'Spanish'] as const);
    const a = rng.int(47, 499);
    const b = rng.int(47, 460);
    const sum = a + b;
    const expected = lang === 'French' ? numToFrench(sum) : numToSpanish(sum);
    return {
      templateId: this.id,
      domain: this.domain,
      prompt:
        `Compute ${a} + ${b}, then write the result out in ${lang} number words (lowercase). ` +
        `Answer with the ${lang} words only.\n\n${ANSWER_FORMAT_INSTRUCTIONS}`,
      answerKey: expected,
      grading: 'exact',
      perturbSeed,
    };
  },
};

export const multilingualWordToNum: ItemTemplate = {
  id: 'multilingual.wordnum-v1',
  domain: 'multilingual',
  description:
    'Reverse direction: read numbers spelled in French AND Spanish, combine them arithmetically, answer with digits.',
  paramSpace: 900 * 900,
  render(rng: Rng, perturbSeed: string) {
    const a = rng.int(61, 999); // includes the irregular French zone often
    const b = rng.int(31, 999);
    const op = rng.pick(['+', '−'] as const);
    const result = op === '+' ? a + b : a - b;
    return {
      templateId: this.id,
      domain: this.domain,
      prompt:
        `A number is written in French: « ${numToFrench(a)} ». Another is written in Spanish: « ${numToSpanish(b)} ». ` +
        `Compute (French number) ${op} (Spanish number). Answer with digits only.\n\n${ANSWER_FORMAT_INSTRUCTIONS}`,
      answerKey: String(result),
      grading: 'numeric',
      perturbSeed,
    };
  },
};