export default function listingRequestTranslator(
  headerParams,
  pathParams,
  queryParams,
  body
) {

  const {
    id
  } = pathParams || {};

  const {
    limit = 20,
    offset = 0,

    species_id,
    breed_id,
    sex,
    min_price,
    max_price,
    status
  } = queryParams || {};

  // -----------------------------
  // BASE WHERE CLAUSE
  // -----------------------------
  const where = {
    deleted: false
  };

  // -----------------------------
  // PATH FILTER (single listing)
  // -----------------------------
  if (id) {
    where.id = id;
  }

  // -----------------------------
  // FILTERS (denormalized columns)
  // -----------------------------
  if (species_id) {
    where.filter_species_id = species_id;
  }

  if (breed_id) {
    where.filter_breed_id = breed_id;
  }

  if (sex) {
    where.filter_sex = sex;
  }

  if (status) {
    where.status = status;
  }

  // -----------------------------
  // BUILD QUERY JSON
  // -----------------------------
  const query = {
    type: 'json',
    op: 'SELECT',
    table: 'listings',

    where,

    orderBy: [
      { column: 'created_at', direction: 'desc' }
    ],

    limit: Math.min(Number(limit), 100),
    offset: Number(offset)
  };

  // -----------------------------
  // PRICE RANGE (handled separately)
  // -----------------------------
  // JSON executor extension point:
  // price range is encoded as a special where clause
  if (min_price !== undefined || max_price !== undefined) {
    query.whereRange = {
      column: 'price',
      min: min_price !== undefined ? Number(min_price) : undefined,
      max: max_price !== undefined ? Number(max_price) : undefined
    };
  }

  return query;
}