module Handler.CreateChallenge where

import Import
import Yesod.Form.Bootstrap3 (BootstrapFormLayout (..), renderBootstrap3,
                              bfs)

import Handler.Shared
import Handler.Runner
import Handler.Extract

import GEval.Core
import GEval.OptionsParser
import GEval.EvaluationScheme
import GEval.Validation

import Gonito.ExtractMetadata (getLastCommitMessage)

import System.Directory (doesFileExist)
import System.FilePath.Find as SFF
import System.FilePath
import qualified Data.Text as T

import Data.Time.Clock (secondsToDiffTime)
import Data.Time.LocalTime (timeOfDayToTime, TimeOfDay, timeToTimeOfDay)

import PersistSHA1

import qualified Data.ByteString as S
import qualified Data.ByteString.Lazy as L

import Data.Conduit.Binary (sinkLbs, sourceFile)

getCreateChallengeR :: Handler Html
getCreateChallengeR = do
    (formWidget, formEnctype) <- generateFormPost createChallengeForm
    defaultLayout $ do
        setTitle "Welcome To Yesod!"
        $(widgetFile "create-challenge")

postCreateChallengeR :: Handler TypedContent
postCreateChallengeR = do
    ((result, _), _) <- runFormPost createChallengeForm
    let challengeData = case result of
            FormSuccess res -> Just res
            _ -> Nothing
        Just (name, publicUrl, publicBranch, publicGitAnnexRemote,
                    privateUrl, privateBranch, privateGitAnnexRemote,
                    mDeadlineDay, mDeadlineTime) = challengeData

    let mDeadline = combineMaybeDayAndTime mDeadlineDay mDeadlineTime

    userId <- requireAuthId
    user <- runDB $ get404 userId
    if userIsAdmin user
      then
       do
        let name' = T.strip name

        if isLocalIdAcceptable name'
          then
            runViewProgress $ doCreateChallenge name'
                                                (T.strip publicUrl)
                                                (T.strip publicBranch)
                                                (T.strip <$> publicGitAnnexRemote)
                                                (T.strip privateUrl)
                                                (T.strip privateBranch)
                                                (T.strip <$> privateGitAnnexRemote)
                                                mDeadline
          else
            runViewProgress $ (flip err) "unexpected challenge ID (use only lower-case letters, digits and hyphens, start with a letter)"
      else
        runViewProgress $ (flip err) "MUST BE AN ADMIN TO CREATE A CHALLENGE"

doCreateChallenge :: Text -> Text -> Text -> Maybe Text -> Text -> Text -> Maybe Text -> Maybe UTCTime -> Channel -> Handler ()
doCreateChallenge name publicUrl publicBranch publicGitAnnexRemote privateUrl privateBranch privateGitAnnexRemote mDeadline chan = do
  maybePublicRepoId <- cloneRepo (RepoCloningSpec {
                                    cloningSpecRepo = RepoSpec {
                                        repoSpecUrl = publicUrl,
                                          repoSpecBranch = publicBranch,
                                          repoSpecGitAnnexRemote = publicGitAnnexRemote},
                                      cloningSpecReferenceRepo = RepoSpec {
                                        repoSpecUrl = publicUrl,
                                          repoSpecBranch = publicBranch,
                                          repoSpecGitAnnexRemote = publicGitAnnexRemote}}) chan
  case maybePublicRepoId of
    Just publicRepoId -> do
      publicRepo <- runDB $ get404 publicRepoId
      publicRepoDir <- getRepoDir publicRepoId
      maybePrivateRepoId <- cloneRepo (RepoCloningSpec {
                                         cloningSpecRepo = RepoSpec {
                                             repoSpecUrl = privateUrl,
                                             repoSpecBranch = privateBranch,
                                             repoSpecGitAnnexRemote = privateGitAnnexRemote},
                                         cloningSpecReferenceRepo = RepoSpec {
                                             repoSpecUrl =(T.pack $ publicRepoDir),
                                             repoSpecBranch = (repoBranch publicRepo),
                                             repoSpecGitAnnexRemote = (repoGitAnnexRemote publicRepo)}}) chan
      case maybePrivateRepoId of
        Just privateRepoId -> do
          isValidated <- validateChallenge privateRepoId chan
          when isValidated $ addChallenge name publicRepoId privateRepoId mDeadline chan
        Nothing -> return ()
    Nothing -> return ()

data ChallengeUpdateType = MajorChange | MinorChange | ChallengePatch
                           deriving (Eq, Enum, Bounded)

instance Show ChallengeUpdateType where
  show MajorChange = "major change"
  show MinorChange = "minor change"
  show ChallengePatch = "patch"

fetchChallengeData :: (MonadIO m, PersistUniqueRead backend, BaseBackend backend ~ SqlBackend) => Key Challenge -> ReaderT backend m (Repo, Repo, Maybe UTCTime)
fetchChallengeData challengeId = do
  challenge <- get404 challengeId
  publicRepo <- get404 $ challengePublicRepo challenge
  privateRepo <- get404 $ challengePrivateRepo challenge
  version <- getBy404 $ UniqueVersionByCommit $ challengeVersion challenge

  return (publicRepo, privateRepo, versionDeadline $ entityVal $ version)

getChallengeUpdateR :: ChallengeId -> Handler Html
getChallengeUpdateR challengeId = do
  (publicRepo, privateRepo, mDeadline) <- runDB $ fetchChallengeData challengeId
  (formWidget, formEnctype) <- generateFormPost $ updateChallengeForm publicRepo privateRepo mDeadline
  defaultLayout $ do
    setTitle "Welcome To Yesod!"
    $(widgetFile "update-challenge")

postChallengeUpdateR :: ChallengeId -> Handler TypedContent
postChallengeUpdateR challengeId = do
    (publicRepo, privateRepo, mDeadline) <- runDB $ fetchChallengeData challengeId
    ((result, _), _) <- runFormPost $ updateChallengeForm publicRepo privateRepo mDeadline
    let challengeData = case result of
            FormSuccess res -> Just res
            _ -> Nothing
        Just (updateType, publicUrl, publicBranch, publicGitAnnexRemote,
                          privateUrl, privateBranch, privateGitAnnexRemote,
                          mDeadlineDay, mDeadlineTime) = challengeData

    let mNewDeadline = combineMaybeDayAndTime mDeadlineDay mDeadlineTime

    userId <- requireAuthId
    user <- runDB $ get404 userId
    if userIsAdmin user
      then
       do
         runViewProgress $ doChallengeUpdate challengeId
                                             updateType
                                             mNewDeadline
                                             publicUrl
                                             publicBranch
                                             publicGitAnnexRemote
                                             privateUrl
                                             privateBranch
                                             privateGitAnnexRemote
      else
        runViewProgress $ (flip err) "MUST BE AN ADMIN TO UPDATE A CHALLENGE"

combineMaybeDayAndTime :: Maybe Day -> Maybe TimeOfDay -> Maybe UTCTime
combineMaybeDayAndTime mDeadlineDay mDeadlineTime =
  case mDeadlineDay of
    Just deadlineDay -> Just $ UTCTime {
      utctDay = deadlineDay,
      utctDayTime = fromMaybe (secondsToDiffTime 24 * 60 * 60 - 1) $ timeOfDayToTime <$> mDeadlineTime }
    Nothing -> Nothing

doChallengeUpdate :: ChallengeId -> ChallengeUpdateType -> Maybe UTCTime
                    -> Text -> Text -> Maybe Text
                    -> Text -> Text -> Maybe Text
                    -> Channel -> Handler ()
doChallengeUpdate challengeId
                  updateType
                  newDeadline
                  publicUrl
                  publicBranch
                  publicGitAnnexRemote
                  privateUrl
                  privateBranch
                  privateGitAnnexRemote
                  chan = do

  challenge <- runDB $ get404 challengeId
  (Entity _ version) <- runDB $ getBy404 $ UniqueVersionByCommit $ challengeVersion challenge
  let (newMajor, newMinor, newPatch) = incrementVersion updateType (versionMajor version,
                                                                    versionMinor version,
                                                                    versionPatch version)

  msg chan ("UPDATING TO VERSION: " ++ (pack $ show newMajor) ++ "." ++ (pack $ show newMinor) ++ "." ++ (pack $ show newPatch))

  userId <- requireAuthId
  (Just publicRepoId) <- getPossiblyExistingRepo (\_ _ _ -> return True)
                                                userId
                                                challengeId
                                                RepoSpec {
                                                  repoSpecUrl = publicUrl,
                                                  repoSpecBranch = publicBranch,
                                                  repoSpecGitAnnexRemote = publicGitAnnexRemote}
                                                chan

  (Just privateRepoId) <- getPossiblyExistingRepo (\_ _ _ -> return True)
                                                 userId
                                                 challengeId
                                                 RepoSpec {
                                                   repoSpecUrl = privateUrl,
                                                   repoSpecBranch = privateBranch,
                                                   repoSpecGitAnnexRemote = privateGitAnnexRemote}
                                                 chan

  isValidated <- validateChallenge privateRepoId chan

  when isValidated $
     do
        privateRepo <- runDB $ get404 $ privateRepoId
        repoDir <- getRepoDir privateRepoId
        (Just versionDescription) <- liftIO $ getLastCommitMessage repoDir
        theNow <- liftIO getCurrentTime
        let commit = (repoCurrentCommit privateRepo)

        mAlreadyExistingVersion <- runDB $ getBy $ UniqueVersionByCommit commit
        case mAlreadyExistingVersion of
          Just (Entity versionId _) -> do
                                       runDB $ update versionId [VersionDeadline =. newDeadline,
                                                                 VersionMajor =. newMajor,
                                                                 VersionMinor =. newMinor,
                                                                 VersionPatch =. newPatch,
                                                                 VersionDescription =. versionDescription,
                                                                 VersionStamp =. theNow]

          Nothing -> do
                     _ <- runDB $ insert $ Version (Just challengeId)
                                                  commit
                                                  newDeadline
                                                  newMajor
                                                  newMinor
                                                  newPatch
                                                  versionDescription
                                                  theNow
                     return ()

        (title, description, mImage) <- extractChallengeMetadata publicRepoId chan

        runDB $ update challengeId [ChallengePublicRepo =. publicRepoId,
                                    ChallengePrivateRepo =. privateRepoId,
                                    ChallengeVersion =. commit,
                                    ChallengeTitle =. title,
                                    ChallengeDescription =. description,
                                    ChallengeImage =. mImage]

        updateTests challengeId chan

        return ()
  return ()

incrementVersion :: ChallengeUpdateType -> (Int, Int, Int) -> (Int, Int, Int)
incrementVersion MajorChange (major, _, _) = (major + 1, 0, 0)
incrementVersion MinorChange (major, minor, _) = (major, minor + 1, 0)
incrementVersion ChallengePatch (major, minor, patch) = (major, minor, patch + 1)


defaultMajorVersion :: Int
defaultMajorVersion = 1

defaultMinorVersion :: Int
defaultMinorVersion = 0

defaultPatchVersion :: Int
defaultPatchVersion = 0

defaultInitialDescription :: Text
defaultInitialDescription = "initial version"

extractChallengeMetadata :: Key Repo -> Channel -> Handler (Text, Text, Maybe ByteString)
extractChallengeMetadata publicRepoId chan = do
  publicRepoDir <- getRepoDir publicRepoId
  let readmeFilePath = publicRepoDir </> readmeFile
  doesReadmeExist <- liftIO $ doesFileExist readmeFilePath
  (title, description) <- if doesReadmeExist
                           then
                            liftIO $ extractTitleAndDescription readmeFilePath
                           else do
                            err chan "README was not found"
                            return (defaultTitle, defaultDescription)

  let imageFilePath = publicRepoDir </> imageFile
  doesImageFileExists <- liftIO $ doesFileExist imageFilePath
  mImage <- if doesImageFileExists
             then do
               fileBytes <- liftIO $ runResourceT $ sourceFile imageFilePath $$ sinkLbs
               return $ Just (S.pack . L.unpack $ fileBytes)
             else do
               return Nothing

  return (T.pack $ title, T.pack $ description, mImage)

addChallenge :: Text -> (Key Repo) -> (Key Repo) -> Maybe UTCTime -> Channel -> Handler ()
addChallenge name publicRepoId privateRepoId deadline chan = do
  msg chan "adding challenge..."

  (title, description, mImage) <- extractChallengeMetadata publicRepoId chan

  privateRepo <- runDB $ get404 privateRepoId
  time <- liftIO getCurrentTime

  let commit=repoCurrentCommit $ privateRepo

  challengeId <- runDB $ insert $ Challenge {
    challengePublicRepo=publicRepoId,
    challengePrivateRepo=privateRepoId,
    challengeName=name,
    challengeTitle=title,
    challengeDescription=description,
    challengeStamp=time,
    challengeImage=mImage,
    challengeStarred=False,
    challengeArchived=Just False,
    challengeVersion=commit}

  _ <- runDB $ insert $ Version {
    versionChallenge=Just challengeId,
    versionCommit=commit,
    versionDeadline=deadline,
    versionMajor=defaultMajorVersion,
    versionMinor=defaultMinorVersion,
    versionPatch=defaultPatchVersion,
    versionDescription=defaultInitialDescription,
    versionStamp=time}

  updateTests challengeId chan

  return ()

updateTests :: (Key Challenge) -> Channel -> Handler ()
updateTests challengeId chan = do
  challenge <- runDB $ get404 challengeId
  let repoId = challengePrivateRepo challenge
  repoDir <- getRepoDir repoId
  repo <- runDB $ get404 repoId
  let commit = repoCurrentCommit repo
  testDirs <- liftIO $ findTestDirs repoDir
  mapM_ (checkTestDir chan challengeId challenge commit) testDirs
  msg chan (T.pack $ show testDirs)
  return ()

expectedFileName :: FilePath
expectedFileName = "expected.tsv"

doesExpectedExist :: FilePath -> IO Bool
doesExpectedExist fp = do
  efs <- mapM (\ext -> findFilePossiblyCompressed (fp </> expectedFileName -<.> ext)) extensionsHandled
  return $ not $ null $ catMaybes efs

checkTestDir :: Channel -> (Key Challenge) -> Challenge -> SHA1 -> FilePath -> Handler ()
checkTestDir chan challengeId challenge commit testDir = do
  expectedExists <- liftIO $ doesExpectedExist testDir
  if expectedExists
    then do
      msg chan $ concat ["Test dir ", (T.pack testDir), " found."]
      checksum <- liftIO $ gatherSHA1 testDir
      challengeRepoDir <- getRepoDir $ challengePrivateRepo challenge
      optionsParsingResult <- liftIO $ getOptions [
        "--expected-directory", challengeRepoDir,
        "--test-name", takeFileName testDir]
      case optionsParsingResult of
       Left _ -> do
         err chan "Cannot read metric"
         return ()
       Right opts -> do
         _ <- runDB $ mapM (insertOrUpdateTest testDir challengeId (SHA1 checksum) commit opts)  $ zip [1..] (gesMetrics $ geoSpec opts)
         return ()
    else
      msg chan $ concat ["Test dir ", (T.pack testDir), " does not have expected results."]
  return ()

insertOrUpdateTest :: (MonadIO m, PersistUniqueRead backend, PersistStoreWrite backend, BaseBackend backend ~ SqlBackend) => FilePath -> Key Challenge -> SHA1 -> SHA1 -> GEvalOptions -> (Int, EvaluationScheme) -> ReaderT backend m ()
insertOrUpdateTest testDir challengeId checksum commit opts (priority, metric) = do
  let name=T.pack $ takeFileName testDir
  mAlreadyExistingTest <- getBy $ UniqueChallengeNameMetricChecksum challengeId name metric checksum
  case mAlreadyExistingTest of
    Just (Entity testId _) -> update testId [TestCommit=.commit,
                                            TestPrecision=.(gesPrecision $ geoSpec opts),
                                            TestPriority=.Just priority]
    Nothing -> do
                _ <- insert $ Test {
                  testChallenge=challengeId,
                  testMetric=metric,
                  testName=name,
                  testChecksum=checksum,
                  testCommit=commit,
                  testActive=True,
                  testPrecision=gesPrecision $ geoSpec opts,
                  testPriority=Just priority}
                return ()

gatherSHA1 :: FilePath -> IO ByteString
gatherSHA1 testDir = do
  files <- SFF.find always isTestDirHashedFile testDir
  gatherSHA1ForCollectionOfFiles files

isTestDirHashedFile :: FindClause Bool
isTestDirHashedFile = fileType ==? RegularFile


findTestDirs :: FilePath -> IO [FilePath]
findTestDirs = SFF.find never testDirFilter

never :: FindClause Bool
never = depth ==? 0

testDirFilter :: FindClause Bool
testDirFilter = (fileType ==? Directory) &&? (SFF.fileName ~~? "dev-*" ||? SFF.fileName ~~? "test-*")

createChallengeForm :: Form (Text, Text, Text, Maybe Text, Text, Text, Maybe Text, Maybe Day, Maybe TimeOfDay)
createChallengeForm = renderBootstrap3 BootstrapBasicForm $ (,,,,,,,,)
    <$> areq textField (fieldWithTooltip MsgChallengeName MsgChallengeNameTooltip) Nothing
    <*> areq textField (bfs MsgPublicUrl) Nothing
    <*> areq textField (bfs MsgBranch) (Just "master")
    <*> aopt textField (bfs MsgGitAnnexRemote) Nothing
    <*> areq textField (bfs MsgPrivateUrl) Nothing
    <*> areq textField (bfs MsgBranch) (Just "dont-peek")
    <*> aopt textField (bfs MsgGitAnnexRemote) Nothing
    <*> aopt dayField (bfs MsgChallengeDeadlineDay) Nothing
    <*> aopt timeFieldTypeTime (fieldWithTooltip MsgChallengeDeadlineTime MsgChallengeDeadlineTooltip) Nothing


updateChallengeForm :: Repo -> Repo -> Maybe UTCTime -> Form (ChallengeUpdateType,
                                                          Text, Text, Maybe Text,
                                                          Text, Text, Maybe Text,
                                                          Maybe Day, Maybe TimeOfDay)
updateChallengeForm publicRepo privateRepo mDeadline = renderBootstrap3 BootstrapBasicForm $ (,,,,,,,,)
    <$> areq (radioField optionsEnum) "change type" (Just ChallengePatch)
    <*> areq textField (bfs MsgPublicUrl) (Just $ repoUrl publicRepo)
    <*> areq textField (bfs MsgBranch) (Just $ repoBranch publicRepo)
    <*> aopt textField (bfs MsgGitAnnexRemote) (Just $ repoGitAnnexRemote publicRepo)
    <*> areq textField (bfs MsgPrivateUrl) (Just $ repoUrl privateRepo)
    <*> areq textField (bfs MsgBranch) (Just $ repoBranch privateRepo)
    <*> aopt textField (bfs MsgGitAnnexRemote) (Just $ repoGitAnnexRemote privateRepo)
    <*> aopt dayField (bfs MsgChallengeDeadlineDay) (Just $ utctDay <$> mDeadline)
    <*> aopt timeFieldTypeTime (fieldWithTooltip MsgChallengeDeadlineTime MsgChallengeDeadlineTooltip)
                               (Just $ timeToTimeOfDay <$> utctDayTime <$> mDeadline)

-- Validate whether a challenge is correct.
-- Contrary to `GEval.Validate.validationChallenge` do not
-- throw an exception (just return `False`)
validateChallenge :: RepoId  -- ID of the private repository
                    -> Channel
                    -> Handler Bool -- returns false if not validated
validateChallenge repoId chan = do
  msg chan "Validating the challenge..."

  repoDir <- getRepoDir repoId

  optionsParsingResult <- liftIO $ getOptions [
    "--expected-directory", repoDir]

  case optionsParsingResult of
    Left _ -> do
      err chan "Cannot read metric"
      return False
    Right opts -> do
      result <- liftIO (try $ validationChallenge repoDir (geoSpec opts) :: IO (Either SomeException ()))
      case result of
        Left ex -> do
          err chan (T.pack $ "Invalid challenge!!! " ++ (show ex))
          return False
        Right _ -> return True