{-# OPTIONS_GHC -fno-warn-unused-do-bind #-}

-- | Test behavior of the executable, polling files for changes
module Test.Polling(pollingTest) where

import Control.Concurrent
import Control.Exception.Extra
import Control.Monad
import Data.Char
import Data.List.Extra
import System.FilePath
import System.Directory.Extra
import System.Process
import System.Console.CmdArgs
import System.Time.Extra

import Test.Tasty
import Test.Tasty.HUnit

import Ghcid
import Session
import Wait
import Language.Haskell.Ghcid.Util

pollingTest :: TestTree
pollingTest  = testCase "Scripted Test" $ do
    setVerbosity Loud
    tdir <- fmap (</> ".ghcid") getTemporaryDirectory
    try_ $ removeDirectoryRecursive tdir
    createDirectoryIfMissing True tdir
    withCurrentDirectory tdir $ do
        ref <- newEmptyMVar
        let require predi = do
                res <- takeMVarDelay ref 5
                predi res
                outStr "."
                sleep 1
        -- t <- myThreadId
        writeFile "Main.hs" "main = print 1"
        writeFile ".ghci" ":set -fwarn-unused-binds \n:load Main"
        -- otherwise GHC warns about .ghci being accessible by others
        try_ $ system "chmod og-w . .ghci"

        withSession $ \session -> withWaiterPoll $ \waiter -> bracket (
          forkIO $ runGhcid session waiter [] [] "ghci" [] Nothing (return (100, 50)) False $ \msg ->
            unless (isLoading $ map snd msg) $ putMVarNow ref $ map snd msg
          ) killThread $ \_ -> do
            require requireAllGood
            testScript require
            outStrLn "\nSuccess"

isLoading :: [String] -> Bool
isLoading ("Reloading...":_) = True
isLoading (x:_) | "Loading" `isPrefixOf` x && "..." `isSuffixOf` x = True
isLoading _ = False

putMVarNow :: MVar a -> a -> IO ()
putMVarNow ref x = do
    b <- tryPutMVar ref x
    unless b $ error "Had a message and a new one arrived"

takeMVarDelay :: MVar a -> Double -> IO a
takeMVarDelay _ i | i <= 0 = error "timed out"
takeMVarDelay x i = do
    b <- tryTakeMVar x
    case b of
        Nothing -> sleep 0.1 >> takeMVarDelay x (i-0.1)
        Just v -> return v

--(===) :: (Eq a, Show a) => a -> a -> IO ()
--(===) a b = unless (a == b) $ error $ "Mismatch\nLHS: " ++ show a ++ "\nRHS: " ++ show b

-- | The all good message
requireAllGood :: [String] -> IO ()
requireAllGood got = map (take (length allGoodMessage)) (filter (not . null) got) @?= [allGoodMessage]

--requireNonIndents :: [String] -> [String] -> IO ()
--requireNonIndents want got = [x | x@(c:_) <- got, not $ isSpace c] @?= want
--
--requirePrefix :: [String] -> [String] -> IO ()
--requirePrefix want got = take (length want) got @?= want

-- | Since different versions of GHCi give different messages, we only try to find what we require anywhere in the obtained messages
requireSimilar :: [String] -> [String] -> IO ()
requireSimilar want got = let
  allGot = ignoreSpacesAndWeird $ concat got
  in all (`isInfixOf` allGot) (map ignoreSpacesAndWeird want) @? (show (filter (not . null) got) ++ " does not contain " ++ show want)

-- | Spacing and quotes tend to be different on different GHCi versions
ignoreSpacesAndWeird :: String -> String
ignoreSpacesAndWeird = lower . filter (\x -> isLetter x || isDigit x || x == ':')

---------------------------------------------------------------------
-- ACTUAL TEST SUITE

testScript :: (([String] -> IO ()) -> IO ()) -> IO ()
testScript require = do
    writeFile <- return $ \name x -> do print ("writeFile",name,x); writeFile name x
    renameFile <- return $ \from to -> do print ("renameFile",from,to); renameFile from to

    writeFile "Main.hs" "x"
    require $ requireSimilar ["Main.hs:1:1"," Parse error: naked expression at top level"]
    writeFile "Util.hs" "module Util where"
    writeFile "Main.hs" "import Util\nmain = print 1"
    require requireAllGood
    writeFile "Util.hs" "module Util where\nx"
    require $ requireSimilar ["Util.hs:2:1","Parse error: naked expression at top level"]
    writeFile "Util.hs" "module Util() where\nx = 1"
    require $ requireSimilar ["Util.hs:2:1","Warning: Defined but not used: `x'"]

    -- check warnings persist properly
    writeFile "Main.hs" "import Util\nx"
    require $ requireSimilar ["Main.hs:2:1","Parse error: naked expression at top level"
                             ,"Util.hs:2:1","Warning: Defined but not used: `x'"]
    writeFile "Main.hs" "import Util\nmain = print 2"
    require $ requireSimilar ["Util.hs:2:1","Warning: Defined but not used: `x'"]
    writeFile "Main.hs" "main = print 3"
    require requireAllGood
    writeFile "Main.hs" "import Util\nmain = print 4"
    require $ requireSimilar ["Util.hs:2:1","Warning: Defined but not used: `x'"]
    writeFile "Util.hs" "module Util where"
    require requireAllGood

    -- check recursive modules work
    writeFile "Util.hs" "module Util where\nimport Main"
    require $ requireSimilar ["imports form a cycle","Main.hs","Util.hs"]
    writeFile "Util.hs" "module Util where"
    require requireAllGood

    -- check renaming files works
    -- note that due to GHC bug #9648 we can't save down a new file
    renameFile "Util.hs" "Util2.hs"
    require $ requireSimilar ["Main.hs:1:8:","Could not find module `Util'"]
    renameFile "Util2.hs" "Util.hs"
    require requireAllGood
    -- after this point GHC bugs mean nothing really works too much