{-# LANGUAGE CPP #-}
{-# LANGUAGE ViewPatterns #-}
module Main where
import Data.Foldable
import Data.Traversable
import Control.Applicative
import Control.Monad
import System.Directory
import System.FilePath
import System.IO
import Prelude

import System.IO.Temp
import System.Process
import Test.Tasty
import Test.Tasty.HUnit
import qualified Data.Text.Lazy.IO as TL
import qualified Data.Attoparsec.Text.Lazy as ATL

import GHC.RTS.TimeAllocProfile

#if !MIN_VERSION_directory(1, 2, 3)
import Control.Exception
#endif

main :: IO ()
main = withSystemTempDirectory "test" $ \dir -> withCurrentDirectory dir $
  defaultMain $ testCaseSteps "Regression tests" $ \step -> do
    step "Generating profiling reports"
    profiles <- generateProfiles
    for_ profiles $ \profile -> do
      step $ "Parsing " ++ profile
      assertProfile profile

generateProfiles :: IO [FilePath]
generateProfiles = do
  withFile "hello.hs" WriteMode $ \h ->
    hPutStrLn h "main = putStrLn \"Hello, World!\""
  void $ readProcess "ghc" ["-prof", "-rtsopts", "-fforce-recomp", "hello.hs"] ""
  for profilingFlags $ \(name, flag) -> do
    void $ readProcess "./hello" ["+RTS", flag, "-RTS"] ""
    let profName = "hello" <.> name <.> "prof"
    renameFile "hello.prof" profName
    return profName

profilingFlags :: [(String, String)]
profilingFlags =
  [ ("standard", "-p")
  , ("detailed", "-P")
  , ("full", "-pa")
  ]

assertProfile :: FilePath -> Assertion
assertProfile path = do
  text <- TL.readFile path
  case ATL.parse timeAllocProfile text of
    ATL.Done {} -> return ()
    ATL.Fail _ _ reason -> assertFailure reason

#if !MIN_VERSION_directory(1, 2, 3)
withCurrentDirectory :: FilePath -> IO a -> IO a
withCurrentDirectory dir io = bracket
  (getCurrentDirectory <* setCurrentDirectory dir)
  (setCurrentDirectory)
  (const io)
#endif