{-# LANGUAGE PatternGuards, ScopedTypeVariables, RecordWildCards, ViewPatterns #-}

-- | Check the <TEST> annotations within source and hint files.
module Test.Annotations(testAnnotations) where

import Control.Arrow
import Data.Char
import Data.List
import Data.Maybe
import Data.Function

import Settings
import Util
import Idea
import Apply
import HSE.All
import Test.Util


-- Input, Output
-- Output = Nothing, should not match
-- Output = Just xs, should match xs
data Test = Test SrcLoc String (Maybe String)

testAnnotations :: [Setting] -> FilePath -> IO ()
testAnnotations setting file = do
    tests <- parseTestFile file
    mapM_ f tests
    where
        f (Test loc inp out) = do
            ideas <- applyHintFile defaultParseFlags setting file $ Just inp
            let good = case out of
                    Nothing -> null ideas
                    Just x -> length ideas == 1 &&
                              seq (length (show ideas)) True && -- force, mainly for hpc
                              isJust (ideaTo $ head ideas) && -- detects parse failure
                              match x (head ideas)
            let bad =
                    [failed $
                        ["TEST FAILURE (" ++ show (length ideas) ++ " hints generated)"
                        ,"SRC: " ++ showSrcLoc loc
                        ,"INPUT: " ++ inp] ++
                        map ((++) "OUTPUT: " . show) ideas ++
                        ["WANTED: " ++ fromMaybe "<failure>" out]
                        | not good] ++
                    [failed
                        ["TEST FAILURE (BAD LOCATION)"
                        ,"SRC: " ++ showSrcLoc loc
                        ,"INPUT: " ++ inp
                        ,"OUTPUT: " ++ show i]
                        | i@Idea{..} <- ideas, let SrcLoc{..} = getPointLoc ideaSpan, srcFilename == "" || srcLine == 0 || srcColumn == 0]
            if null bad then passed else sequence_ bad

        match "???" _ = True
        match x y | "@" `isPrefixOf` x = a == show (ideaSeverity y) && match (ltrim b) y
            where (a,b) = break isSpace $ tail x
        match x y = on (==) norm (fromMaybe "" $ ideaTo y) x

        -- FIXME: Should use a better check for expected results
        norm = filter $ \x -> not (isSpace x) && x /= ';'


parseTestFile :: FilePath -> IO [Test]
parseTestFile file = do
    src <- readFile file
    return $ f False $ zip [1..] $ lines src
    where
        open = isPrefixOf "<TEST>"
        shut = isPrefixOf "</TEST>"

        f False ((i,x):xs) = f (open x) xs
        f True  ((i,x):xs)
            | shut x = f False xs
            | null x || "-- " `isPrefixOf` x = f True xs
            | "\\" `isSuffixOf` x, (_,y):ys <- xs = f True $ (i,init x++"\n"++y):ys
            | otherwise = parseTest file i x : f True xs
        f _ [] = []


parseTest file i x = uncurry (Test (SrcLoc file i 0)) $ f x
    where
        f x | Just x <- stripPrefix "<COMMENT>" x = first ("--"++) $ f x
        f (' ':'-':'-':xs) | null xs || " " `isPrefixOf` xs = ("", Just $ dropWhile isSpace xs)
        f (x:xs) = first (x:) $ f xs
        f [] = ([], Nothing)