module Test.Falderal.Formatter.Haskell (format) where

--
-- Test.Falderal.Formatter.Haskell -- Haskell compiler for Falderal
--

import Test.Falderal.Common

--
-- Formatting function which compiles a Falderal file to Haskell source.
--
-- XXX tests should be partitioned before this is called, but this should
-- be able to handle multiple Haskell-implemented functionalities.
--

format _ blocks =
    (prelude blocks) ++ (formatBlocks blocks) ++ postlude

formatBlocks (test@(Test id [(HaskellTest moduleName functionName)] desc text expectation _):rest) =
    let
        fn = moduleName ++ "." ++ functionName
    in
        "    (" ++ (show id) ++ ", " ++ fn ++ ", " ++ (show text) ++ "),\n" ++ (formatBlocks rest)
formatBlocks (_:rest) =
    formatBlocks rest
formatBlocks [] =
    ""

gatherImports ((Test id [(HaskellTest moduleName functionName)] _ _ _ _):rest) mNames
    | moduleName `elem` mNames = gatherImports rest mNames
    | otherwise =
        "import qualified " ++ moduleName ++ "\n" ++ gatherImports rest (moduleName:mNames) 
gatherImports (_:rest) mNames =
    gatherImports rest mNames
gatherImports [] _ =
    ""

prelude blocks =
    "-- This file was automatically generated by Test.Falderal.Formatter.Haskell\n\
    \-- Edit at your own risk!\n\
    \\n\
    \import qualified Control.Exception as Exc\n\
    \" ++ (gatherImports blocks []) ++ "\
    \\n\
    \runFun testFun inputText = do\n\
    \  Exc.catch (Exc.evaluate (Left $! (testFun inputText)))\n\
    \            (\\exception -> return (Right (show (exception :: Exc.SomeException))))\n\
    \\n\
    \getKind (Left _) = \"output\"\n\
    \getKind (Right _) = \"exception\"\n\
    \getText (Left x) = x\n\
    \getText (Right x) = x\n\
    \report [] = do\n\
    \    return ()\n\
    \report ((-1,_,_):rest) =\n\
    \    report rest\n\
    \report ((id,fun,input):rest) = do\n\
    \    result <- runFun (fun) input\n\
    \    numLines <- return $ length $ lines $ getText result\n\
    \    putStrLn (getKind result)\n\
    \    putStrLn (show id)\n\
    \    putStrLn (show numLines)\n\
    \    case numLines of\n\
    \        0 -> do\n\
    \            report rest\n\
    \        _ -> do\n\
    \            putStrLn (getText result)\n\
    \            report rest\n\
    \\n\
    \main = report [\n"

postlude =
    "    (-1,id,\"\")\n\
    \    ]\n"