module Data.Bitcoin.PaymentChannel.Internal.Bitcoin.Amount where
import qualified Data.Serialize as Ser
import qualified Data.Serialize.Put as SerPut
import qualified Data.Serialize.Get as SerGet
import Data.Word
import Data.Ratio
newtype BitcoinAmount = BitcoinAmount Integer
deriving (Eq, Ord)
instance Show BitcoinAmount where
show amount = show (toInteger amount) ++ " satoshi"
instance Num BitcoinAmount where
(BitcoinAmount a1) * (BitcoinAmount a2) = BitcoinAmount (fromIntegral . capTo21Mill $ a1*a2)
(BitcoinAmount a1) + (BitcoinAmount a2) = BitcoinAmount (fromIntegral . capTo21Mill $ a1+a2)
(BitcoinAmount a1) (BitcoinAmount a2) = BitcoinAmount (fromIntegral . capTo21Mill $ a1a2)
abs = id
signum (BitcoinAmount 0) = BitcoinAmount 0
signum (BitcoinAmount _) = BitcoinAmount 1
fromInteger = BitcoinAmount . fromIntegral . capTo21Mill
instance Enum BitcoinAmount where
toEnum = BitcoinAmount . fromIntegral . capTo21Mill . fromIntegral
fromEnum (BitcoinAmount amount) = fromIntegral amount
instance Real BitcoinAmount where
toRational (BitcoinAmount amount) = toRational amount
instance Integral BitcoinAmount where
toInteger (BitcoinAmount int) = int
quotRem (BitcoinAmount a1) (BitcoinAmount a2) =
( BitcoinAmount (fromIntegral . capTo21Mill $ res1)
, BitcoinAmount (fromIntegral . capTo21Mill $ res2)
)
where (res1,res2) = quotRem a1 a2
instance Bounded BitcoinAmount where
minBound = BitcoinAmount 0
maxBound = BitcoinAmount $ round $ (21e6 :: Ratio Integer) * (1e8 :: Ratio Integer)
capTo21Mill :: Integer -> Word64
capTo21Mill i = fromIntegral $
max 0 cappedValue
where
cappedValue = min i $ fromIntegral (maxBound :: BitcoinAmount)
instance Ser.Serialize BitcoinAmount where
put = SerPut.putWord64le . fromIntegral . toInteger
get = BitcoinAmount . fromIntegral <$> SerGet.getWord64le