#!/usr/bin/env runhaskell
{-

shelltestrunner - a handy tool for testing command-line programs.

See shelltestrunner.cabal.

(c) Simon Michael 2009, released under GNU GPLv3

-}

module Main
where
import Control.Concurrent (forkIO)
import Control.Concurrent.MVar (newEmptyMVar, putMVar, takeMVar)
import Control.Monad (liftM,when)
import Data.List (partition, intercalate)
import Data.Maybe (fromJust,isJust,maybe,isNothing,catMaybes)
import qualified Test.HUnit (Test)
import System.Console.ParseArgs hiding (args)
import System.Environment (withArgs)
import System.Exit (ExitCode(..),exitWith)
import System.IO (Handle, hGetContents, hPutStr)
import System.Process (runInteractiveCommand, waitForProcess)
import Test.Framework (defaultMain)
import Test.Framework.Providers.HUnit (hUnitTestToTests)
import Test.HUnit hiding (Test)
import Text.ParserCombinators.Parsec
import Text.Printf (printf)
import Text.RegexPR
import Debug.Trace
strace :: Show a => a -> a
strace a = trace (show a) a


version :: String
version = "0.6" -- keep synced with .cabal

data ArgId = HelpFlag
           | VersionFlag
           | DebugFlag
           | ImplicitTestsFlag
           | ExecutableArg
             deriving (Ord, Eq, Show)

argspec :: [Arg ArgId]
argspec = [
  Arg {argIndex = HelpFlag,
       argName  = Just "help",
       argAbbr  = Just 'h',
       argData  = Nothing,
       argDesc  = "show help"
      }
 ,Arg {argIndex = VersionFlag,
       argName  = Just "version",
       argAbbr  = Just 'V',
       argData  = Nothing,
       argDesc  = "show version"
      }
 ,Arg {argIndex = DebugFlag,
       argName  = Just "debug",
       argAbbr  = Just 'd',
       argData  = Nothing,
       argDesc  = "show verbose debugging output"
      }
 ,Arg {argIndex = ImplicitTestsFlag,
       argName  = Just "implicit-tests",
       argAbbr  = Just 'i',
       argData  = Nothing,
       argDesc  = "provide implicit tests for all omitted fields"
      }
 ,Arg {argIndex = ExecutableArg,
       argName  = Nothing,
       argAbbr  = Nothing,
       argData  = argDataRequired "executable" ArgtypeString,
       argDesc  = "executable program or shell command to test"
      }
 ]

data ShellTest = ShellTest {
     testname         :: String
    ,commandargs      :: String
    ,stdin            :: Maybe String
    ,stdoutExpected   :: Maybe Matcher
    ,stderrExpected   :: Maybe Matcher
    ,exitCodeExpected :: Maybe Matcher
    } deriving (Show)

type Regex = String

data Matcher = Lines String
             | Numeric String
             | PositiveRegex Regex
             | NegativeRegex Regex
               deriving (Show)

main :: IO ()
main = do
  args <- parseArgsIO ArgsTrailing argspec
  -- parseargs issue: exits at first gotArg if there's no exe argument
  when (args `gotArg` VersionFlag) printVersion
  when (args `gotArg` HelpFlag) $ printHelp args
  let (unprocessedopts, testfiles) = partition ((=="-").take 1) $ argsRest args
  when (args `gotArg` DebugFlag) $ do
         putStrLn $ "testing executable: " ++ (show $ fromJust $ getArgString args ExecutableArg)
         putStrLn $ "unprocessed options: " ++ show unprocessedopts
         putStrLn $ "test files: " ++ show testfiles
  shelltests <- liftM concat $ mapM (parseShellTestFile args) testfiles
  withArgs unprocessedopts $ defaultMain $ concatMap (hUnitTestToTests.shellTestToHUnitTest args) shelltests

printVersion :: IO ()
printVersion = putStrLn version >> exitWith ExitSuccess

printHelp :: Args ArgId -> IO ()
printHelp args = putStrLn (argsUsage args) >> exitWith ExitSuccess

-- parsing

parseShellTestFile :: Args ArgId -> FilePath -> IO [ShellTest]
parseShellTestFile args f = do
  when (args `gotArg` DebugFlag) $ putStrLn $ "parsing file: " ++ f
  ts <- liftM (either (error.show) id) $ parseFromFile (many shelltestp) f
  let ts' | length ts > 1 = [t{testname=testname t++":"++show n} | (n,t) <- zip ([1..]::[Int]) ts]
          | otherwise     = ts
  when (args `gotArg` DebugFlag) $ putStrLn $ "parsed tests: " ++ show ts'
  return ts'

shelltestp :: Parser ShellTest
shelltestp = do
  st <- getParserState
  let f = sourceName $ statePos st
  many commentlinep
  c <- commandargsp
  i <- optionMaybe inputp
  o <- optionMaybe expectedoutputp
  e <- optionMaybe expectederrorp
  x <- optionMaybe expectedexitcodep
  when (null c && (isNothing i) && (null $ catMaybes [o,e,x])) $ fail "empty test file"
  return ShellTest{testname=f,commandargs=c,stdin=i,stdoutExpected=o,stderrExpected=e,exitCodeExpected=x}

linep,commentlinep,commandargsp,delimiterp,inputp,whitespacep :: Parser String

linep = anyChar `manyTill` newline

commentlinep = char '#' >> anyChar `manyTill` newline

commandargsp = linep

delimiterp = choice [try $ string "<<<", try $ string ">>>", (eof >> return "")]

inputp = string "<<<" >> newline >> (liftM unlines) (linep `manyTill` (lookAhead delimiterp))

expectedoutputp :: Parser Matcher
expectedoutputp = try $ do
  string ">>>" >> optional (char '1')
  whitespacep
  choice [positiveregexmatcherp, negativeregexmatcherp, linesmatcherp]

expectederrorp :: Parser Matcher
expectederrorp = try $ do
  string ">>>2"
  whitespacep
  choice [positiveregexmatcherp, negativeregexmatcherp, linesmatcherp]

expectedexitcodep :: Parser Matcher
expectedexitcodep = do
  string ">>>="
  whitespacep
  choice [positiveregexmatcherp, negativeregexmatcherp, numericmatcherp]

negativeregexmatcherp :: Parser Matcher
negativeregexmatcherp = do
  char '!'
  PositiveRegex r <- positiveregexmatcherp
  return $ NegativeRegex r

positiveregexmatcherp :: Parser Matcher
positiveregexmatcherp = do
  char '/'
  r <- many $ noneOf "/"
  char '/'
  whitespacep
  newline
  return $ PositiveRegex r

linesmatcherp :: Parser Matcher
linesmatcherp = do
  whitespacep
  newline
  (liftM $ Lines . unlines) (linep `manyTill` (lookAhead delimiterp))

numericmatcherp :: Parser Matcher
numericmatcherp = do
  s <- many1 $ oneOf "0123456789"
  whitespacep
  newline
  return $ Numeric s

whitespacep = many $ oneOf " \t"

-- running

shellTestToHUnitTest :: Args ArgId -> ShellTest -> Test.HUnit.Test
shellTestToHUnitTest args ShellTest{testname=n,commandargs=c,stdin=i,stdoutExpected=o_expected,
                                    stderrExpected=e_expected,exitCodeExpected=x_expected} = 
 n ~: do
  let exe = fromJust $ getArgString args ExecutableArg
      cmd = unwords [exe,c]
      (o_expected',e_expected',x_expected') =
          case (args `gotArg` ImplicitTestsFlag) of
            True  -> (case o_expected of
                       Just m -> Just m
                       _ -> Just $ Lines ""
                    ,case e_expected of Just m -> Just m
                                        _      -> Just $ Lines  ""
                    ,case x_expected of Just m -> Just m
                                        _      -> Just $ Numeric "0")
            False -> (o_expected,e_expected,x_expected)
  when (args `gotArg` DebugFlag) $ do
    putStrLn $ "running test: " ++ n
    putStrLn $ "running command: " ++ cmd

  -- run the command, passing it the stdin if any, and reading the
  -- stdout/stderr/exit code.  This has to be done carefully.
  (ih,oh,eh,ph) <- runInteractiveCommand cmd
  when (isJust i) $ forkIO (hPutStr ih $ fromJust i) >> return ()
  o <- newEmptyMVar
  e <- newEmptyMVar
  forkIO $ oh `hGetContentsStrictlyAnd` putMVar o
  forkIO $ eh `hGetContentsStrictlyAnd` putMVar e
  x_actual <- waitForProcess ph >>= return.fromExitCode
  o_actual <- takeMVar o
  e_actual <- takeMVar e

  let failuremsg
       -- when a bad exe is provided, we don't want to show all the test
       -- failures. This should work on all posix systems at least.
       -- Really we should report a test error here, not a failure.
       | x_actual == 127 = cmd ++ ": command not found"
       | otherwise = addnewline $ intercalate "\n" $ filter (not . null) [
                   if (maybe True (o_actual `matches`) o_expected')
                   then "" 
                   else showExpectedActual "stdout"    (fromJust o_expected') o_actual
                  ,if (maybe True (e_actual `matches`) e_expected')
                   then "" 
                   else showExpectedActual "stderr"    (fromJust e_expected') e_actual
                  ,if (maybe True (show x_actual `matches`) x_expected')
                   then ""
                   else showExpectedActual "exit code" (fromJust x_expected') (show x_actual)
                  ]
  assertString failuremsg
      where addnewline "" = ""
            addnewline s  = "\n"++s

hGetContentsStrictlyAnd :: Handle -> (String -> IO b) -> IO b
hGetContentsStrictlyAnd h f = hGetContents h >>= \c -> length c `seq` f c

matches :: String -> Matcher -> Bool
matches s (PositiveRegex r) = s `containsRegex` r
matches s (NegativeRegex r) = not $ s `containsRegex` r
matches s (Numeric p)       = s == p
matches s (Lines p)         = s == p

showExpectedActual :: String -> Matcher -> String -> String
showExpectedActual field e a =
    printf "**Expected %s:%s**Got %s:\n%s" field (showMatcher e) field a

showMatcher :: Matcher -> String
showMatcher (PositiveRegex r) = " /"++r++"/\n"
showMatcher (NegativeRegex r) = " !/"++r++"/\n"
showMatcher (Numeric s)       = "\n"++s++"\n"
showMatcher (Lines s)         = "\n"++s


-- utils

-- toExitCode :: Int -> ExitCode
-- toExitCode 0 = ExitSuccess
-- toExitCode n = ExitFailure n

fromExitCode :: ExitCode -> Int
fromExitCode ExitSuccess     = 0
fromExitCode (ExitFailure n) = n

strip,lstrip,rstrip,dropws :: String -> String
strip = lstrip . rstrip
lstrip = dropws
rstrip = reverse . dropws . reverse
dropws = dropWhile (`elem` " \t")

containsRegex :: String -> String -> Bool
containsRegex s r = case matchRegexPR (""++r) s of
                      Just _ -> True
                      _ -> False