{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeApplications #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

module Test.QuickCheck.Quid.Representations.LatinSpec
    where

import Data.Function
    ( (&) )
import Data.List
    ( uncons )
import Internal.Test.QuickCheck.Quid
    ( Quid, arbitraryQuid, naturalToQuid, shrinkQuid )
import Internal.Test.QuickCheck.Quid.Representations.Latin
    ( Latin (..)
    , LatinChar (..)
    , LatinString
    , charToLatinChar
    , latinCharToChar
    )
import Numeric.Natural
    ( Natural )
import Test.Hspec
    ( Spec, describe, it, parallel )
import Test.Hspec.Unit
    ( UnitTestData (..), unitTests )
import Test.QuickCheck
    ( Arbitrary (..), Property, property, shrinkMapBy, (===) )
import Test.QuickCheck.Classes.Hspec
    ( testLawsMany )

import Prelude hiding
    ( (^) )

import qualified Prelude
import qualified Test.QuickCheck.Classes as Laws

spec :: Spec
spec = do

    parallel $ describe "Lawfulness of type class instances" $ do
        testLawsMany @(Latin Quid)
            [ Laws.showLaws
            , Laws.showReadLaws
            ]

    parallel $ describe "Properties" $ do
        it "prop_latinCharToChar_uncons_show" $
            prop_latinCharToChar_uncons_show
                & property
        it "prop_roundTrip_LatinChar_Char" $
            prop_roundTrip_LatinChar_Char
                & property
        it "prop_roundTrip_LatinString_Quid" $
            prop_roundTrip_LatinString_Quid
                & property

    parallel $ describe "Unit tests" $ do
        unitTests_show_latin_naturalToQuid

--------------------------------------------------------------------------------
-- Properties
--------------------------------------------------------------------------------

prop_latinCharToChar_uncons_show :: LatinChar -> Property
prop_latinCharToChar_uncons_show c =
    Just (latinCharToChar c) === fmap fst (uncons (show c))

prop_roundTrip_LatinChar_Char :: LatinChar -> Property
prop_roundTrip_LatinChar_Char c =
    charToLatinChar (latinCharToChar c) === Just c

prop_roundTrip_LatinString_Quid :: LatinString -> Property
prop_roundTrip_LatinString_Quid latinString =
    show (read @(Latin Quid) expectedOutput) === expectedOutput
  where
    expectedOutput :: String
    expectedOutput = show latinString

--------------------------------------------------------------------------------
-- Unit tests
--------------------------------------------------------------------------------

unitTests_show_latin_naturalToQuid :: Spec
unitTests_show_latin_naturalToQuid = unitTests
    "unitTests_show_latin_naturalToQuid"
    (show . Latin . naturalToQuid)
    (mkTest <$> tests)
  where
    mkTest :: (Natural, String) -> UnitTestData Natural String
    mkTest (params, result) = UnitTestData {params, result = show result}

    (^) :: Natural -> Natural -> Natural
    (^) = (Prelude.^)

    tests =
        [ ( 0, "A")
        , ( 1, "B")
        , (24, "Y")
        , (25, "Z")

        , (26 +  0, "AA")
        , (26 +  1, "AB")
        , (26 + 24, "AY")
        , (26 + 25, "AZ")

        , (2 * 26 +  0, "BA")
        , (2 * 26 +  1, "BB")
        , (2 * 26 + 24, "BY")
        , (2 * 26 + 25, "BZ")

        , (26 * 26 +  0, "ZA")
        , (26 * 26 +  1, "ZB")
        , (26 * 26 + 24, "ZY")
        , (26 * 26 + 25, "ZZ")

        , (26                                          , "AA")
        , (26 + 26^2                                   , "AAA")
        , (26 + 26^2 + 26^3                            , "AAAA")
        , (26 + 26^2 + 26^3 + 26^4                     , "AAAAA")
        , (26 + 26^2 + 26^3 + 26^4 + 26^5              , "AAAAAA")
        , (26 + 26^2 + 26^3 + 26^4 + 26^5 + 26^6       , "AAAAAAA")
        , (26 + 26^2 + 26^3 + 26^4 + 26^5 + 26^6 + 26^7, "AAAAAAAA")

        , (26                                                  - 1, "Z")
        , (26 + 26^2                                           - 1, "ZZ")
        , (26 + 26^2 + 26^3                                    - 1, "ZZZ")
        , (26 + 26^2 + 26^3 + 26^4                             - 1, "ZZZZ")
        , (26 + 26^2 + 26^3 + 26^4 + 26^5                      - 1, "ZZZZZ")
        , (26 + 26^2 + 26^3 + 26^4 + 26^5 + 26^6               - 1, "ZZZZZZ")
        , (26 + 26^2 + 26^3 + 26^4 + 26^5 + 26^6 + 26^7        - 1, "ZZZZZZZ")
        , (26 + 26^2 + 26^3 + 26^4 + 26^5 + 26^6 + 26^7 + 26^8 - 1, "ZZZZZZZZ")
        ]

--------------------------------------------------------------------------------
-- Arbitrary instances
--------------------------------------------------------------------------------

instance Arbitrary (Latin Quid) where
    arbitrary = Latin <$> arbitraryQuid
    shrink = shrinkMapBy Latin unLatin shrinkQuid