module Main where

import MiniWindows.Normalize
  ( Window (Window)
  , coversMinute
  , isNormalized
  , normalizeWindows
  )
import System.Exit (die)
import Test.QuickCheck
  ( Gen
  , Property
  , chooseInt
  , forAll
  , isSuccess
  , listOf
  , quickCheckResult
  )

newtype WindowList = WindowList [Window]
  deriving (Show)

genWindow :: Gen Window
genWindow = do
  startMinute <- chooseInt (0, 59)
  endMinute <- chooseInt (startMinute + 1, 60)
  pure (Window startMinute endMinute)

genWindowList :: Gen WindowList
genWindowList = WindowList <$> listOf genWindow

prop_exampleMerge :: Bool
prop_exampleMerge =
  normalizeWindows [Window 0 10, Window 8 14, Window 20 24, Window 24 30]
    == [Window 0 14, Window 20 30]

prop_idempotent :: Property
prop_idempotent =
  forAll genWindowList $ \(WindowList windows) ->
    normalizeWindows (normalizeWindows windows) == normalizeWindows windows

prop_resultIsNormalized :: Property
prop_resultIsNormalized =
  forAll genWindowList $ \(WindowList windows) ->
    isNormalized (normalizeWindows windows)

prop_preservesCoverage :: Property
prop_preservesCoverage =
  forAll genWindowList $ \(WindowList windows) ->
    all
      (\minute -> coversMinute minute windows == coversMinute minute (normalizeWindows windows))
      [0 .. 60]

main :: IO ()
main = do
  exampleResult <- quickCheckResult prop_exampleMerge
  idempotentResult <- quickCheckResult prop_idempotent
  normalizedResult <- quickCheckResult prop_resultIsNormalized
  coverageResult <- quickCheckResult prop_preservesCoverage

  if all isSuccess [exampleResult, idempotentResult, normalizedResult, coverageResult] then
    putStrLn "test passed"
  else
    die "unexpected QuickCheck result"