-- 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. An additional grant
-- of patent rights can be found in the PATENTS file in the same directory.


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

module Duckling.AmountOfMoney.ID.Rules
  ( rules
  ) where

import Data.Maybe
import Data.String
import Prelude

import Duckling.AmountOfMoney.Helpers
import Duckling.AmountOfMoney.Types (Currency(..), AmountOfMoneyData(..))
import Duckling.Dimensions.Types
import Duckling.Numeral.Helpers (isNatural, isPositive)
import Duckling.Numeral.Types (NumeralData (..))
import Duckling.Types
import qualified Duckling.AmountOfMoney.Types as TAmountOfMoney
import qualified Duckling.Numeral.Types as TNumeral

ruleUnitAmount :: Rule
ruleUnitAmount = Rule
  { name = "<unit> <amount>"
  , pattern =
    [ Predicate isCurrencyOnly
    , Predicate isPositive
    ]
  , prod = \case
      (Token AmountOfMoney AmountOfMoneyData{TAmountOfMoney.currency = c}:
       Token Numeral NumeralData{TNumeral.value = v}:
       _) -> Just . Token AmountOfMoney . withValue v $ currencyOnly c
      _ -> Nothing
  }

ruleDollar :: Rule
ruleDollar = Rule
  { name = "$"
  , pattern =
    [ regex "dolar?"
    ]
  , prod = \_ -> Just . Token AmountOfMoney $ currencyOnly Dollar
  }

ruleIdr :: Rule
ruleIdr = Rule
  { name = "IDR"
  , pattern =
    [ regex "rp\\.?|rupiah"
    ]
  , prod = \_ -> Just . Token AmountOfMoney $ currencyOnly IDR
  }

rulePounds :: Rule
rulePounds = Rule
  { name = "£"
  , pattern =
    [ regex "pound( sterling)?"
    ]
  , prod = \_ -> Just . Token AmountOfMoney $ currencyOnly Pound
  }

ruleIntersect :: Rule
ruleIntersect = Rule
  { name = "intersect"
  , pattern =
    [ Predicate isWithoutCents
    , Predicate isNatural
    ]
  , prod = \tokens -> case tokens of
      (Token AmountOfMoney fd:
       Token Numeral NumeralData{TNumeral.value = c}:
       _) -> Just . Token AmountOfMoney $ withCents c fd
      _ -> Nothing
  }

ruleJpy :: Rule
ruleJpy = Rule
  { name = "JPY"
  , pattern =
    [ regex "¥\\."
    ]
  , prod = \_ -> Just . Token AmountOfMoney $ currencyOnly JPY
  }

rules :: [Rule]
rules =
  [ ruleUnitAmount
  , ruleDollar
  , ruleIdr
  , ruleIntersect
  , ruleJpy
  , rulePounds
  ]