function normalizeSearchText(value) {
  return String(value ?? '').trim().toLocaleLowerCase().replace(/\s+/g, ' ');
}

function ingredientNames(recipe) {
  return (recipe.ingredientGroups ?? [])
    .flatMap((group) => group.items ?? [])
    .map((item) => item.name)
    .filter(Boolean);
}

export function rankRecipeMatch(recipe, query) {
  const normalizedQuery = normalizeSearchText(query);
  if (!normalizedQuery) return { score: 0, matchedIngredients: [] };

  const ingredients = ingredientNames(recipe);
  const matchedIngredients = ingredients.filter((name) => (
    normalizeSearchText(name).includes(normalizedQuery)
  ));
  const hasExactIngredient = matchedIngredients.some((name) => (
    normalizeSearchText(name) === normalizedQuery
  ));
  const title = normalizeSearchText(recipe.title);
  const tags = (recipe.tags ?? []).map(normalizeSearchText);
  const summary = normalizeSearchText(recipe.summary);

  let score = 0;
  if (hasExactIngredient) score = 500;
  else if (matchedIngredients.length > 0) score = 400;
  else if (title === normalizedQuery) score = 350;
  else if (title.includes(normalizedQuery)) score = 300;
  else if (tags.includes(normalizedQuery)) score = 250;
  else if (tags.some((tag) => tag.includes(normalizedQuery))) score = 200;
  else if (summary.includes(normalizedQuery)) score = 100;

  return { score, matchedIngredients };
}

export function searchRecipes(recipes, query) {
  if (!normalizeSearchText(query)) {
    return recipes.map((recipe) => ({ recipe, score: 0, matchedIngredients: [] }));
  }

  return recipes
    .map((recipe, index) => ({ recipe, index, ...rankRecipeMatch(recipe, query) }))
    .filter(({ score }) => score > 0)
    .sort((a, b) => b.score - a.score || a.index - b.index)
    .map(({ recipe, score, matchedIngredients }) => ({ recipe, score, matchedIngredients }));
}