{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE DataKinds #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

module Main (main) where

import Test.Tasty (testGroup, TestTree)
import Test.Tasty.TH (defaultMainGenerator)
import Test.Tasty.QuickCheck (Positive(..), testProperty, (===), Property)

import Data.CReal.Internal
import Data.CReal.Extra ()

import Floating (floating)
import Ord (ord)

-- How many binary digits to use for comparisons TODO: Test with many different
-- precisions
type Precision = 10

infixr 1 ==>
(==>) :: Bool -> Bool -> Bool
False ==> _ = True
True ==> b = b

{-# ANN test_floating "HLint: ignore Use camelCase" #-}
test_floating :: [TestTree]
test_floating = [floating (undefined :: CReal Precision)]

{-# ANN test_ord "HLint: ignore Use camelCase" #-}
test_ord :: [TestTree]
test_ord = [ ord (undefined :: CReal Precision) ]

prop_decimalDigits :: Positive Int -> Bool
prop_decimalDigits (Positive p) = let d = decimalDigitsAtPrecision p
                                  in 10^d >= (2^p :: Integer) &&
                                     (d > 0 ==> 10^(d-1) < (2^p :: Integer))

prop_showIntegral :: Integer -> Property
prop_showIntegral i = show i === show (fromInteger i :: CReal 0)

prop_shiftL :: CReal Precision -> Int -> Property
prop_shiftL x s = x `shiftL` s === x * 2 ** fromIntegral s

prop_shiftR :: CReal Precision -> Int -> Property
prop_shiftR x s = x `shiftR` s === x / 2 ** fromIntegral s

prop_showNumDigits :: Positive Int -> Rational -> Property
prop_showNumDigits (Positive places) x =
  let s = rationalToDecimal places x
  in length (dropWhile (/= '.') s) === places + 1

main :: IO ()
main = $(defaultMainGenerator)