module Main where

import Prelude hiding (assert)
import GHC.Exts (fromList)
import Test.QuickCheck.Instances
import Test.Tasty
import Test.Tasty.Runners
import Test.Tasty.HUnit
import Test.Tasty.QuickCheck
import Acc
import qualified Test.QuickCheck as QuickCheck
import qualified Data.List.NonEmpty as NonEmpty


main =
  defaultMain $ 
  testGroup "All tests" [
    testProperty "Acc converted to list and reconstructed from it converts to the same list again" $
      \ (acc :: Acc Int) -> let
        list =
          toList acc
        acc' :: Acc Int
        acc' =
          fromList list
        list' =
          toList acc'
        in list === list'
    ,
    testProperty "foldl" $
      \ (acc :: Acc Int) ->
        foldl (flip (:)) [] acc ===
        foldl (flip (:)) [] (toList acc)
    ,
    testProperty "foldl'" $
      \ (acc :: Acc Int) ->
        foldl' (flip (:)) [] acc ===
        foldl' (flip (:)) [] (toList acc)
    ,
    testProperty "foldr" $
      \ (acc :: Acc Int) ->
        foldr (:) [] acc ===
        foldr (:) [] (toList acc)
    ,
    testProperty "foldr'" $
      \ (acc :: Acc Int) ->
        foldr' (:) [] acc ===
        foldr' (:) [] (toList acc)
    ,
    testProperty "foldMap" $
      \ (acc :: Acc Int) ->
        foldMap (: []) acc ===
        foldMap (: []) (toList acc)
    ,
    testProperty "foldMap'" $
      \ (acc :: Acc Int) ->
        foldMap' (: []) acc ===
        foldMap' (: []) (toList acc)
    ,
    testProperty "toNonEmpty" $
      \ (acc :: Acc Int) ->
        Acc.toNonEmpty acc ===
        NonEmpty.nonEmpty (toList acc)
    ]

instance Arbitrary a => Arbitrary (Acc a) where
  arbitrary =
    accGen arbitrary

accGen :: Gen a -> Gen (Acc a)
accGen aGen =
  oneof [
    listAccGen aGen,
    appendAccGen aGen,
    pureAccGen aGen
    ]

listAccGen :: Gen a -> Gen (Acc a)
listAccGen aGen =
  fromList <$> listOf aGen

appendAccGen :: Gen a -> Gen (Acc a)
appendAccGen aGen =
  (<>) <$> accGen aGen <*> accGen aGen

pureAccGen :: Gen a -> Gen (Acc a)
pureAccGen aGen =
  pure <$> aGen