// The one nutrient key of the catalogue (20 FD-02a, FD-08 schema rule): every nutrient column of food.food_version carries the
// FAO/INFOODS tag of what it holds and its unit per 100 g or 100 ml. Each importer keeps one table from its own codes to
// these columns (import/*.ts); the open tables (FD-57) publish this key with every set, so a row can be read by tag.
// Carbohydrate has three tags, told apart by the version's carbohydrate_definition: total (CHOCDF, by difference),
// available (CHOAVL, by difference) and available as monosaccharide equivalents (CHOAVLM, by analysis).
export const infoodsColumns = {
  enerc_kcal: { tag: 'ENERC', unit: 'kcal' },
  enerc_kj: { tag: 'ENERC', unit: 'kJ' },
  procnt_g: { tag: 'PROCNT', unit: 'g' },
  fat_g: { tag: 'FAT', unit: 'g' },
  chocdf_g: { tag: 'CHOCDF', unit: 'g' },
  fibtg_g: { tag: 'FIBTG', unit: 'g' },
  sugar_g: { tag: 'SUGAR', unit: 'g' },
  sugad_g: { tag: 'SUGAD', unit: 'g' },
  fasat_g: { tag: 'FASAT', unit: 'g' },
  na_mg: { tag: 'NA', unit: 'mg' },
  chole_mg: { tag: 'CHOLE', unit: 'mg' },
  k_mg: { tag: 'K', unit: 'mg' },
  ca_mg: { tag: 'CA', unit: 'mg' },
  fe_mg: { tag: 'FE', unit: 'mg' },
  vitd_ug: { tag: 'VITD', unit: 'µg' },
  alc_g: { tag: 'ALC', unit: 'g' },
  caffn_mg: { tag: 'CAFFN', unit: 'mg' },
  water_g: { tag: 'WATER', unit: 'g' },
  polyl_g: { tag: 'POLYL', unit: 'g' },
} as const;
export type InfoodsColumn = keyof typeof infoodsColumns;

export const carbohydrateTags = { total: 'CHOCDF', available: 'CHOAVL', available_mono: 'CHOAVLM' } as const;
export type CarbohydrateDefinition = keyof typeof carbohydrateTags;

// The INFOODS tag of one value of a version: the column's tag, and for carbohydrate the tag its definition names.
export function infoodsTag(column: InfoodsColumn, carbohydrateDefinition: CarbohydrateDefinition) {
  return column === 'chocdf_g' ? carbohydrateTags[carbohydrateDefinition] : infoodsColumns[column].tag;
}