{-# LANGUAGE CPP, OverloadedStrings, NamedFieldPuns, MultiParamTypeClasses #-}
module Test.Hls.Util
  (
      codeActionSupportCaps
    , dummyLspFuncs
    , expectCodeAction
    , expectDiagnostic
    , expectNoMoreDiagnostics
    , failIfSessionTimeout
    , flushStackEnvironment
    , fromAction
    , fromCommand
    , getHspecFormattedConfig
    , ghcVersion, GhcVersion(..)
    , hlsCommand
    , hlsCommandExamplePlugin
    , hlsCommandVomit
    , ignoreForGhcVersions
    , inspectCodeAction
    , inspectCommand
    , inspectDiagnostic
    , knownBrokenForGhcVersions
    , logConfig
    , logFilePath
    , noLogConfig
    , setupBuildToolFiles
    , waitForDiagnosticsFrom
    , waitForDiagnosticsFromSource
    , waitForDiagnosticsFromSourceWithTimeout
    , withFileLogging
    , withCurrentDirectoryInTmp
  )
where

import           Control.Exception (throwIO, catch)
import           Control.Monad
import           Control.Monad.IO.Class
import           Control.Applicative.Combinators (skipManyTill, (<|>))
import           Control.Lens ((^.))
import           Data.Default
import           Data.List (intercalate)
import           Data.List.Extra (find)
import           Data.Maybe
import qualified Data.Text as T
import           Language.Haskell.LSP.Core
import           Language.Haskell.LSP.Messages (FromServerMessage(NotLogMessage))
import           Language.Haskell.LSP.Types
import qualified Language.Haskell.LSP.Test as Test
import qualified Language.Haskell.LSP.Types.Lens as L
import qualified Language.Haskell.LSP.Types.Capabilities as C
import           System.Directory
import           System.Environment
import           System.Time.Extra (Seconds, sleep)
import           System.FilePath
import qualified System.Log.Logger as L
import           System.IO.Temp
import           System.IO.Unsafe
import           Test.Hspec.Runner
import           Test.Hspec.Core.Formatters hiding (Seconds)
import           Test.Tasty (TestTree)
import           Test.Tasty.ExpectedFailure (ignoreTestBecause, expectFailBecause)
import           Test.Tasty.HUnit (assertFailure)
import           Text.Blaze.Renderer.String (renderMarkup)
import           Text.Blaze.Internal hiding (null)


noLogConfig :: Test.SessionConfig
noLogConfig = Test.defaultConfig { Test.logMessages = False }

logConfig :: Test.SessionConfig
logConfig = Test.defaultConfig { Test.logMessages = True }

codeActionSupportCaps :: C.ClientCapabilities
codeActionSupportCaps = def { C._textDocument = Just textDocumentCaps }
  where
    textDocumentCaps = def { C._codeAction = Just codeActionCaps }
    codeActionCaps = C.CodeActionClientCapabilities (Just True) (Just literalSupport)
    literalSupport = C.CodeActionLiteralSupport def

withFileLogging :: FilePath -> IO a -> IO a
withFileLogging logFile f = do
  let logDir = "./test-logs"
      logPath = logDir </> logFile

  dirExists <- doesDirectoryExist logDir
  unless dirExists $ createDirectory logDir

  exists <- doesFileExist logPath
  when exists $ removeFile logPath

  setupLogger (Just logPath) ["hie"] L.DEBUG

  f

-- ---------------------------------------------------------------------

setupBuildToolFiles :: IO ()
setupBuildToolFiles = do
  forM_ files setupDirectFilesIn

setupDirectFilesIn :: FilePath -> IO ()
setupDirectFilesIn f =
  writeFile (f ++ "hie.yaml") hieYamlCradleDirectContents


-- ---------------------------------------------------------------------

files :: [FilePath]
files =
  [  "./test/testdata/"
   -- , "./test/testdata/addPackageTest/cabal-exe/"
   -- , "./test/testdata/addPackageTest/hpack-exe/"
   -- , "./test/testdata/addPackageTest/cabal-lib/"
   -- , "./test/testdata/addPackageTest/hpack-lib/"
   -- , "./test/testdata/addPragmas/"
   -- , "./test/testdata/badProjects/cabal/"
   -- , "./test/testdata/completion/"
   -- , "./test/testdata/definition/"
   -- , "./test/testdata/gototest/"
   -- , "./test/testdata/redundantImportTest/"
   -- , "./test/testdata/wErrorTest/"
  ]

data GhcVersion
  = GHC810
  | GHC88
  | GHC86
  | GHC84
  deriving (Eq,Show)

ghcVersion :: GhcVersion
#if (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(8,10,0,0)))
ghcVersion = GHC810
#elif (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(8,8,0,0)))
ghcVersion = GHC88
#elif (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(8,6,0,0)))
ghcVersion = GHC86
#elif (defined(MIN_VERSION_GLASGOW_HASKELL) && (MIN_VERSION_GLASGOW_HASKELL(8,4,0,0)))
ghcVersion = GHC84
#endif

knownBrokenForGhcVersions :: [GhcVersion] -> String -> TestTree -> TestTree
knownBrokenForGhcVersions vers reason
    | ghcVersion `elem` vers =  expectFailBecause reason
    | otherwise = id

ignoreForGhcVersions :: [GhcVersion] -> String -> TestTree -> TestTree
ignoreForGhcVersions vers reason
    | ghcVersion `elem` vers =  ignoreTestBecause reason
    | otherwise = id

logFilePath :: String
logFilePath = "hls-" ++ show ghcVersion ++ ".log"

-- | The command to execute the version of hls for the current compiler.
--
-- Both @stack test@ and @cabal new-test@ setup the environment so @hls@ is
-- on PATH. Cabal seems to respond to @build-tool-depends@ specifically while
-- stack just puts all project executables on PATH.
hlsCommand :: String
hlsCommand = unsafePerformIO $ do
  testExe <- fromMaybe "haskell-language-server" <$> lookupEnv "HLS_TEST_EXE"
  pure $ testExe ++ " --lsp -d -j2 -l test-logs/" ++ logFilePath

hlsCommandVomit :: String
hlsCommandVomit = hlsCommand ++ " --vomit"

hlsCommandExamplePlugin :: String
hlsCommandExamplePlugin = hlsCommand ++ " --example"

-- ---------------------------------------------------------------------

hieYamlCradleDirectContents :: String
hieYamlCradleDirectContents = unlines
  [ "# WARNING: THIS FILE IS AUTOGENERATED IN test/utils/TestUtils.hs. IT WILL BE OVERWRITTEN ON EVERY TEST RUN"
  , "cradle:"
  , "  direct:"
  , "    arguments:"
  , "      - -i."
  ]


-- ---------------------------------------------------------------------

getHspecFormattedConfig :: String -> IO Config
getHspecFormattedConfig name = do
  -- https://circleci.com/docs/2.0/env-vars/#built-in-environment-variables
  isCI <- isJust <$> lookupEnv "CI"

  -- Only use the xml formatter on CI since it hides console output
  if isCI
    then do
      let subdir = "test-results" </> name
      createDirectoryIfMissing True subdir

      return $ defaultConfig { configFormatter = Just xmlFormatter
                             , configOutputFile = Right $ subdir </> "results.xml"
                             }
    else return defaultConfig

-- | A Hspec formatter for CircleCI.
-- Originally from https://github.com/LeastAuthority/hspec-jenkins
xmlFormatter :: Formatter
xmlFormatter = silent {
    headerFormatter = do
      writeLine "<?xml version='1.0' encoding='UTF-8'?>"
      writeLine "<testsuite>"
  , exampleSucceeded
  , exampleFailed
  , examplePending
  , footerFormatter = writeLine "</testsuite>"
  }
  where

#if MIN_VERSION_hspec(2,5,0)
    exampleSucceeded path _ =
#else
    exampleSucceeded path =
#endif
      writeLine $ renderMarkup $ testcase path ""

#if MIN_VERSION_hspec(2,5,0)
    exampleFailed path _ err =
#else
    exampleFailed path (Left err) =
      writeLine $ renderMarkup $ testcase path $
        failure ! message (show err) $ ""
    exampleFailed path (Right err) =
#endif
      writeLine $ renderMarkup $ testcase path $
        failure ! message (reasonAsString err) $ ""

#if MIN_VERSION_hspec(2,5,0)
    examplePending path _ reason =
#else
    examplePending path reason =
#endif
      writeLine $ renderMarkup $ testcase path $
        case reason of
          Just desc -> skipped ! message desc  $ ""
          Nothing -> skipped ""

    failure, skipped :: Markup -> Markup
    failure = customParent "failure"
    skipped = customParent "skipped"

    name, className, message :: String -> Attribute
    name = customAttribute "name" . stringValue
    className = customAttribute "classname" . stringValue
    message = customAttribute "message" . stringValue

    testcase :: Path -> Markup -> Markup
    testcase (xs,x) = customParent "testcase" ! name x ! className (intercalate "." xs)

    reasonAsString :: FailureReason -> String
    reasonAsString NoReason = "no reason given"
    reasonAsString (Reason x) = x
    reasonAsString (ExpectedButGot Nothing expected got) = "Expected " ++ expected ++ " but got " ++ got
    reasonAsString (ExpectedButGot (Just src) expected got) = src ++ " expected " ++ expected ++ " but got " ++ got
#if MIN_VERSION_hspec(2,5,0)
    reasonAsString (Error Nothing err ) = show err
    reasonAsString (Error (Just s) err) = s ++ show err
#endif

-- ---------------------------------------------------------------------

flushStackEnvironment :: IO ()
flushStackEnvironment = do
  -- We need to clear these environment variables to prevent
  -- collisions with stack usages
  -- See https://github.com/commercialhaskell/stack/issues/4875
  unsetEnv "GHC_PACKAGE_PATH"
  unsetEnv "GHC_ENVIRONMENT"
  unsetEnv "HASKELL_PACKAGE_SANDBOX"
  unsetEnv "HASKELL_PACKAGE_SANDBOXES"

-- ---------------------------------------------------------------------

dummyLspFuncs :: Default a => LspFuncs a
dummyLspFuncs = LspFuncs { clientCapabilities = def
                         , config = return (Just def)
                         , sendFunc = const (return ())
                         , getVirtualFileFunc = const (return Nothing)
                         , persistVirtualFileFunc = \uri -> return (uriToFilePath (fromNormalizedUri uri))
                         , reverseFileMapFunc = return id
                         , publishDiagnosticsFunc = mempty
                         , flushDiagnosticsBySourceFunc = mempty
                         , getNextReqId = pure (IdInt 0)
                         , rootPath = Nothing
                         , getWorkspaceFolders = return Nothing
                         , withProgress = \_ _ f -> f (const (return ()))
                         , withIndefiniteProgress = \_ _ f -> f
                         }

-- | Like 'withCurrentDirectory', but will copy the directory over to the system
-- temporary directory first to avoid haskell-language-server's source tree from
-- interfering with the cradle
withCurrentDirectoryInTmp :: FilePath -> IO a -> IO a
withCurrentDirectoryInTmp dir f =
  withTempCopy dir $ \newDir ->
    withCurrentDirectory newDir f

withTempCopy :: FilePath -> (FilePath -> IO a) -> IO a
withTempCopy srcDir f = do
  withSystemTempDirectory "hls-test" $ \newDir -> do
    copyDir srcDir newDir
    f newDir

copyDir :: FilePath -> FilePath -> IO ()
copyDir src dst = do
  cnts <- listDirectory src
  forM_ cnts $ \file -> do
    unless (file `elem` ignored) $ do
      let srcFp = src </> file
          dstFp = dst </> file
      isDir <- doesDirectoryExist srcFp
      if isDir
        then createDirectory dstFp >> copyDir srcFp dstFp
        else copyFile srcFp dstFp
  where ignored = ["dist", "dist-newstyle", ".stack-work"]

fromAction :: CAResult -> CodeAction
fromAction (CACodeAction action) = action
fromAction _ = error "Not a code action"

fromCommand :: CAResult -> Command
fromCommand (CACommand command) = command
fromCommand _ = error "Not a command"

onMatch :: [a] -> (a -> Bool) -> String -> IO a
onMatch as predicate err = maybe (fail err) return (find predicate as)

inspectDiagnostic :: [Diagnostic] -> [T.Text] -> IO Diagnostic
inspectDiagnostic diags s = onMatch diags (\ca -> all (`T.isInfixOf` (ca ^. L.message)) s) err
    where err = "expected diagnostic matching '" ++ show s ++ "' but did not find one"

expectDiagnostic :: [Diagnostic] -> [T.Text] -> IO ()
expectDiagnostic diags s = void $ inspectDiagnostic diags s

inspectCodeAction :: [CAResult] -> [T.Text] -> IO CodeAction
inspectCodeAction cars s = fromAction <$> onMatch cars predicate err
    where predicate (CACodeAction ca) = all (`T.isInfixOf` (ca ^. L.title)) s
          predicate _ = False
          err = "expected code action matching '" ++ show s ++ "' but did not find one"

expectCodeAction :: [CAResult] -> [T.Text] -> IO ()
expectCodeAction cars s = void $ inspectCodeAction cars s

inspectCommand :: [CAResult] -> [T.Text] -> IO Command
inspectCommand cars s = fromCommand <$> onMatch cars predicate err
    where predicate (CACommand command) = all  (`T.isInfixOf` (command ^. L.title)) s
          predicate _ = False
          err = "expected code action matching '" ++ show s ++ "' but did not find one"

waitForDiagnosticsFrom :: TextDocumentIdentifier -> Test.Session [Diagnostic]
waitForDiagnosticsFrom doc = do
    diagsNot <- skipManyTill Test.anyMessage Test.message :: Test.Session PublishDiagnosticsNotification
    let (List diags) = diagsNot ^. L.params . L.diagnostics
    if doc ^. L.uri /= diagsNot ^. L.params . L.uri
       then waitForDiagnosticsFrom doc
       else return diags

waitForDiagnosticsFromSource :: TextDocumentIdentifier -> String -> Test.Session [Diagnostic]
waitForDiagnosticsFromSource doc src = do
    diagsNot <- skipManyTill Test.anyMessage Test.message :: Test.Session PublishDiagnosticsNotification
    let (List diags) = diagsNot ^. L.params . L.diagnostics
    let res = filter matches diags
    if doc ^. L.uri /= diagsNot ^. L.params . L.uri || null res
       then waitForDiagnosticsFromSource doc src
       else return res
  where
    matches :: Diagnostic -> Bool
    matches d = d ^. L.source == Just (T.pack src)

-- | wait for @timeout@ seconds and report an assertion failure
-- if any diagnostic messages arrive in that period
expectNoMoreDiagnostics :: Seconds -> TextDocumentIdentifier -> String -> Test.Session ()
expectNoMoreDiagnostics timeout doc src = do
    diags <- waitForDiagnosticsFromSourceWithTimeout timeout doc src
    unless (null diags) $
        liftIO $ assertFailure $
            "Got unexpected diagnostics for " <> show (doc ^. L.uri) <>
            " got " <> show diags

-- | wait for @timeout@ seconds and return diagnostics for the given @document and @source.
-- If timeout is 0 it will wait until the session timeout
waitForDiagnosticsFromSourceWithTimeout :: Seconds -> TextDocumentIdentifier -> String -> Test.Session [Diagnostic]
waitForDiagnosticsFromSourceWithTimeout timeout document source = do
    when (timeout > 0) $ do
        -- Give any further diagnostic messages time to arrive.
        liftIO $ sleep timeout
        -- Send a dummy message to provoke a response from the server.
        -- This guarantees that we have at least one message to
        -- process, so message won't block or timeout.
        void $ Test.sendRequest (CustomClientMethod "non-existent-method") ()
    handleMessages
  where
    matches :: Diagnostic -> Bool
    matches d = d ^. L.source == Just (T.pack source)

    handleMessages = handleDiagnostic <|> handleCustomMethodResponse <|> ignoreOthers
    handleDiagnostic = do
        diagsNot <- Test.message :: Test.Session PublishDiagnosticsNotification
        let fileUri = diagsNot ^. L.params . L.uri
            (List diags) = diagsNot ^. L.params . L.diagnostics
            res = filter matches diags
        if fileUri == document ^. L.uri && not (null res)
            then return diags else handleMessages
    handleCustomMethodResponse =
        -- the CustomClientMethod triggers a RspCustomServer
        -- handle that and then exit
        void (Test.satisfyMaybe responseForNonExistentMethod) >> return []

    responseForNonExistentMethod notif
        | NotLogMessage logMsg <- notif,
          "non-existent-method" `T.isInfixOf` (logMsg ^. L.params . L.message)  = Just notif
        | otherwise = Nothing

    ignoreOthers = void Test.anyMessage >> handleMessages

failIfSessionTimeout :: IO a -> IO a
failIfSessionTimeout action = action `catch` errorHandler
    where errorHandler :: Test.SessionException -> IO a
          errorHandler e@(Test.Timeout _) = assertFailure $ show e
          errorHandler e = throwIO e