/**
 * Noun pluralization for count measurements in recipes.
 *
 * Each entry has a singular and plural form. Entries are sorted
 * longest-first so that "garlic clove" matches before "clove",
 * "bell pepper" before "pepper", etc.
 */

const PLURALS = [
  { singular: 'portobello mushroom', plural: 'portobello mushrooms' },
  { singular: 'chile pepper', plural: 'chile peppers' },
  { singular: 'garlic clove', plural: 'garlic cloves' },
  { singular: 'bell pepper', plural: 'bell peppers' },
  { singular: 'egg white', plural: 'egg whites' },
  { singular: 'egg yolk', plural: 'egg yolks' },
  { singular: 'egg yoke', plural: 'egg yokes' },
  { singular: 'tortilla', plural: 'tortillas' },
  { singular: 'mushroom', plural: 'mushrooms' },
  { singular: 'biscuit', plural: 'biscuits' },
  { singular: 'potato', plural: 'potatoes' },
  { singular: 'tomato', plural: 'tomatoes' },
  { singular: 'pepper', plural: 'peppers' },
  { singular: 'hoagie', plural: 'hoagies' },
  { singular: 'banana', plural: 'bananas' },
  { singular: 'carrot', plural: 'carrots' },
  { singular: 'onion', plural: 'onions' },
  { singular: 'lemon', plural: 'lemons' },
  { singular: 'apple', plural: 'apples' },
  { singular: 'clove', plural: 'cloves' },
  { singular: 'lime', plural: 'limes' },
  { singular: 'egg', plural: 'eggs' },
];

/**
 * Check if text ends with a known singular or plural noun.
 * Case-insensitive, word-boundary-aware (the noun must appear at a
 * word boundary in the text).
 *
 * @param {string} textBefore - text preceding the count measurement
 * @returns {{ singular: string, plural: string, matchStart: number, matchLength: number } | null}
 */
function matchPlural(textBefore) {
  if (!textBefore) return null;
  const trimmed = textBefore.trimEnd();
  if (!trimmed) return null;
  const lower = trimmed.toLowerCase();

  for (const entry of PLURALS) {
    // Try both singular and plural forms
    for (const form of [entry.singular, entry.plural]) {
      if (lower.length < form.length) continue;

      const tail = lower.slice(-form.length);
      if (tail !== form) continue;

      // Check word boundary: either start of string or preceded by non-word char
      const beforeIdx = lower.length - form.length;
      if (beforeIdx > 0 && /\w/.test(lower[beforeIdx - 1])) continue;

      return {
        singular: entry.singular,
        plural: entry.plural,
        matchStart: trimmed.length - form.length,
        matchLength: form.length,
      };
    }
  }

  return null;
}

module.exports = { PLURALS, matchPlural };