{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE TypeFamilies #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Hcompta.Format.JCC.Amount where

import           Control.DeepSeq
import           Data.Bool
import           Data.Data
import           Data.Eq (Eq(..))
-- import qualified Data.Foldable
-- import qualified Data.List
-- import           Data.Map.Strict (Map)
import           Data.Ord (Ord(..), Ordering(..))
-- import           Data.String (IsString)
-- import           Data.Text (Text)
-- import qualified Data.Text as Text
import           Data.Typeable ()
import           Prelude ((.), seq)
-- import           Prelude (($), (.), Bounded(..), Int, Num(..), flip, seq, error)
import           Text.Show (Show(..))

import qualified Hcompta.Amount as Amount
import qualified Hcompta.Filter as Filter
import qualified Hcompta.Polarize as Polarize
import qualified Hcompta.Quantity as Quantity
import qualified Hcompta.Unit as Unit
import qualified Hcompta.Format.JCC.Amount.Style as Style
import           Hcompta.Format.JCC.Quantity (Quantity)
import           Hcompta.Format.JCC.Unit (Unit(..))

-- * Type 'Style'

type Style    = Style.Style
type Styles   = Style.Styles
type Styled t = Style.Styled t

-- * Type 'Amount'

data Amount
 =   Amount
 { amount_unit     :: !Unit
 , amount_quantity :: !Quantity
 } deriving (Data, Show, Typeable)
instance Amount.Amount Amount where
	type Amount_Quantity Amount = Quantity
	type Amount_Unit     Amount = Unit
	amount_quantity = amount_quantity
	amount_unit     = amount_unit
instance Filter.Amount Amount where
	type Amount_Quantity Amount = Quantity
	type Amount_Unit     Amount = Unit
	amount_quantity = Polarize.polarize . amount_quantity
	amount_unit     = amount_unit
instance NFData Amount where
	rnf (Amount q u) = rnf q `seq` rnf u
instance Quantity.Zero Amount where
	quantity_zero = Amount Unit.unit_empty Quantity.quantity_zero
	quantity_null = (==) Quantity.quantity_zero . amount_quantity

amount_style :: Styles -> Amount -> Style
amount_style styles = Style.style styles . amount_unit

style :: Styles -> Amount -> Styled Amount
style styles amt = (amount_style styles amt, amt)

sign :: Amount -> Ordering
sign a =
	case amount_quantity a of
	 0         -> EQ
	 q | q < 0 -> LT
	 _         -> GT

-- ** Constructors

amount :: Amount
amount =
	Amount
	 { amount_quantity = Quantity.quantity_zero
	 , amount_unit     = ""
	 }

-- ** Tests

-- | Return 'True' if and only if 'Amount'’s 'Quantity' is zero.
--
--  NOTE: the 'Amount'’s 'amount_quantity' MUST have been rounded
--        at 'Amount'’s 'amount_style'’s 'Style.precision'.
null :: Amount -> Bool
null = Quantity.quantity_null . amount_quantity