module Main (main) where

import Control.Applicative
import System.Process           (readProcess)
import Test.QuickCheck
import Test.QuickCheck.Monadic
import Test.Tasty
import Test.Tasty.QuickCheck
import Text.Parsec              (parse)

import Language.Bash.Expand     (braceExpand)
import Language.Bash.Parse.Word (word)
import Language.Bash.Word       (unquote)

-- TODO sequence
braceExpr :: Gen String
braceExpr = concat <$> listOf charset
  where
    charset = oneof $
        [ elements ["{", ",", "}"]
        , elements ["\\ ", "\\{", "\\,", "\\}"]
        , (:[]) <$> elements ['a'..'z']
        ]

expandWithBash :: String -> IO String
expandWithBash str = do
    expn <- readProcess "/usr/bin/env" ["bash", "-c", "echo " ++ str] ""
    return $ filter (`notElem` "\r\n") expn

testExpand :: String -> [String]
testExpand s = case parse word "" s of
    Left  e -> error (show e)
    Right w -> map unquote (braceExpand w)

-- Tests brace expansion.
prop_expandsLikeBash :: Property
prop_expandsLikeBash = monadicIO $ forAllM braceExpr $ \str -> do
    bash <- run $ expandWithBash str
    let check = unwords . filter (not . null) $ testExpand str
    assert (bash == check)

tests :: TestTree
tests = testProperty "brace expansion" prop_expandsLikeBash

main :: IO ()
main = defaultMain tests