-- Copyright (c) 2016-present, Facebook, Inc.
-- All rights reserved.
--
-- This source code is licensed under the BSD-style license found in the
-- LICENSE file in the root directory of this source tree.


{-# LANGUAGE GADTs #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedStrings #-}

module Duckling.Volume.NL.Rules
  ( rules
  ) where

import Data.String
import Data.Text (Text)
import Prelude

import Duckling.Dimensions.Types
import Duckling.Types
import Duckling.Regex.Types (GroupMatch(..))
import Duckling.Volume.Helpers
import Duckling.Numeral.Helpers (isPositive)
import qualified Duckling.Volume.Types as TVolume
import qualified Duckling.Numeral.Types as TNumeral

volumes :: [(Text, String, TVolume.Unit)]
volumes = [ ("<latent vol> ml"    , "m(illi)?l(iter)?" , TVolume.Millilitre)
          , ("<vol> hl"           , "h(ecto)?l(iter)?"   , TVolume.Hectolitre)
          , ("<vol> liters"       , "l(iters?)?"    , TVolume.Litre)
          ]

rulesVolumes :: [Rule]
rulesVolumes = map go volumes
  where
    go :: (Text, String, TVolume.Unit) -> Rule
    go (name, regexPattern, u) = Rule
      { name = name
      , pattern =
        [ regex regexPattern
        ]
      , prod = \_ -> Just . Token Volume $ unitOnly u
      }

fractions :: [(Text, String, Double)]
fractions = [ ("half", "halve", 1/2)
            ]

rulesFractionalVolume :: [Rule]
rulesFractionalVolume = map go fractions
  where
    go :: (Text, String, Double) -> Rule
    go (name, regexPattern, f) = Rule
      { name = name
      , pattern =
        [ regex regexPattern
        , Predicate isUnitOnly
        ]
      , prod = \case
        (_:
         Token Volume TVolume.VolumeData{TVolume.unit = Just u}:
         _) ->
          Just . Token Volume $ volume u f
        _ -> Nothing
      }

rules :: [Rule]
rules =
  [
  ]
  ++ rulesVolumes
  ++ rulesFractionalVolume