{-# LANGUAGE DeriveGeneric              #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE OverloadedStrings          #-}

-- |
-- Module      :  Codec.Scale.Test.SingleFieldStructSpec
-- Copyright   :  Aleksandr Krupenkin 2016-2021
-- License     :  Apache-2.0
--
-- Maintainer  :  mail@akru.me
-- Stability   :  experimental
-- Portability :  unportable
--
-- Ported to Haskell rust test spec:
-- https://github.com/paritytech/parity-scale-codec/blob/master/tests/single_field_struct_encoding.rs
--

module Codec.Scale.Test.SingleFieldStructSpec where

import           Data.ByteString  as BS (pack)
import           Data.Default     (def)
import           Data.Word        (Word32, Word64)
import qualified GHC.Generics     as GHC (Generic)
import           Test.Hspec

import           Codec.Scale
import           Codec.Scale.Skip

newtype S = S { x1 :: Word32 }
    deriving (Eq, Ord, Show, Encode, Decode)

data SSkip = SSkip
    { s1 :: Skip Word32
    , x2 :: Word32
    , s2 :: Skip Word32
    }
    deriving (Eq, Ord, Show, GHC.Generic)

instance Generic SSkip
instance Encode SSkip
instance Decode SSkip

newtype Sc = Sc { x3 :: Compact Word32 }
    deriving (Eq, Ord, Show, Encode, Decode)

newtype U = U Word32
    deriving (Eq, Ord, Show, Enum, Num, Real, Integral, Encode, Decode)

newtype U2 = U2 { a :: Word64 }
    deriving (Eq, Ord, Show, Encode, Decode)

data USkip = USkip (Skip Word32) Word32 (Skip Word32)
    deriving (Eq, Ord, Show, GHC.Generic)

instance Generic USkip
instance Encode USkip
instance Decode USkip

newtype Uc = Uc (Compact Word32)
    deriving (Eq, Ord, Show, Encode, Decode)

newtype Ucas = Ucas (Compact U)
    deriving (Eq, Ord, Show, Encode, Decode)

spec :: Spec
spec = parallel $ do
    describe "Single field struct encoding" $ do
        let x = 3
            s = S x
            s_skip = SSkip def x def
            sc = Sc (Compact x)
            u = U x
            u_skip = USkip def x def
            uc = Uc (Compact x)
            ucom = Compact u
            ucas = Ucas (Compact u)

            s_encoded = BS.pack [3, 0, 0, 0]
            s_skip_encoded = BS.pack [3, 0, 0, 0]
            sc_encoded = BS.pack [12]
            u_encoded = BS.pack [3, 0, 0, 0]
            u_skip_encoded = BS.pack [3, 0, 0, 0]
            uc_encoded = BS.pack [12]
            ucom_encoded = BS.pack [12]
            ucas_encoded = BS.pack [12]

        it "encoding" $ do
            encode s `shouldBe` s_encoded
            encode s_skip `shouldBe` s_skip_encoded
            encode sc `shouldBe` sc_encoded
            encode u `shouldBe` u_encoded
            encode u_skip `shouldBe` u_skip_encoded
            encode uc `shouldBe` uc_encoded
            encode ucom `shouldBe` ucom_encoded
            encode ucas `shouldBe` ucas_encoded

        it "decoding" $ do
            Right s `shouldBe` decode s_encoded
            Right s_skip `shouldBe` decode s_skip_encoded
            Right sc `shouldBe` decode sc_encoded
            Right u `shouldBe`  decode u_encoded
            Right u_skip `shouldBe` decode u_skip_encoded
            Right uc `shouldBe` decode uc_encoded
            Right ucom `shouldBe` decode ucom_encoded
            Right ucas `shouldBe` decode ucas_encoded