{-# LANGUAGE CPP #-}
import Test.HUnit
import ProjectM36.Base
import ProjectM36.Persist (DiskSync(NoDiskSync))
import ProjectM36.TransactionGraph.Persist
import ProjectM36.TransactionGraph as TG
import ProjectM36.Transaction
import ProjectM36.DateExamples
import System.IO.Temp
import System.Exit
import System.Directory
import Data.Either
import Data.UUID.V4 (nextRandom)
import System.FilePath
import TutorialD.Interpreter.DatabaseContextExpr
import qualified Data.Map as M
import qualified Data.Set as S
import Data.Time.Clock
import Data.Time.Calendar
import ProjectM36.Client as C
import ProjectM36.Relation
import ProjectM36.Transaction.Persist

main :: IO ()           
main = do 
  tcounts <- runTestTT testList
  if errors tcounts + failures tcounts > 0 then exitFailure else exitSuccess
  
testList :: Test
testList = TestList [testBootstrapDB, 
                     testDBSimplePersistence,
                     testFunctionPersistence,
                     testMerkleHashValidation]
                    

stamp' :: UTCTime
stamp' = UTCTime (fromGregorian 1980 01 01) (secondsToDiffTime 1000)

{- bootstrap a database, ensure that it can be read -}
testBootstrapDB :: Test
testBootstrapDB = TestCase $ withSystemTempDirectory "m36testdb" $ \tempdir -> do
  let dbdir = tempdir </> "dbdir"
  freshId <- nextRandom

  _ <- bootstrapDatabaseDir NoDiskSync dbdir (bootstrapTransactionGraph stamp' freshId dateExamples)
  loadedGraph <- transactionGraphLoad dbdir emptyTransactionGraph Nothing
  assertBool "transactionGraphLoad" $ isRight loadedGraph

{- create a database with several transactions, ensure that all transactions can be read -}
testDBSimplePersistence :: Test
testDBSimplePersistence = TestCase $ withSystemTempDirectory "m36testdb" $ \tempdir -> do
  let dbdir = tempdir </> "dbdir"
  freshId <- nextRandom

  let graph = bootstrapTransactionGraph stamp' freshId dateExamples
  _ <- bootstrapDatabaseDir NoDiskSync dbdir graph
  case transactionForHead "master" graph of
    Nothing -> assertFailure "Failed to retrieve head transaction for master branch."
    Just headTrans -> 
          case interpretDatabaseContextExpr (concreteDatabaseContext headTrans) (transactionId headTrans) graph "x:=s" of
            Left err -> assertFailure (show err)
            Right context' -> do
              freshId' <- nextRandom
              let newdiscon = DisconnectedTransaction (transactionId headTrans) (Schemas context' M.empty) False
                  addTrans = addDisconnectedTransaction stamp' freshId' "master" newdiscon graph
              --add a transaction to the graph
              case addTrans of
                Left err -> assertFailure (show err)
                Right (_, graph') -> do
                  --persist the new graph
                  _ <- transactionGraphPersist NoDiskSync dbdir [freshId'] graph'
                  --reload the graph from the filesystem and confirm that the transaction is present
                  graphErr <- transactionGraphLoad dbdir emptyTransactionGraph Nothing
                  let mapEq graphArg = S.map transactionId (transactionsForGraph graphArg)
                  case graphErr of
                    Left err -> assertFailure (show err)
                    Right graph'' -> assertBool "graph equality" (mapEq graph'' == mapEq graph')

testMerkleHashValidation :: Test
testMerkleHashValidation = TestCase $
  -- add a commit and validate the hashes successfully
  withSystemTempDirectory "m36testdb" $ \tempdir -> do
  let dbdir = tempdir </> "dbdir"
      connInfo = InProcessConnectionInfo (MinimalPersistence dbdir) emptyNotificationCallback []
  conn <- assertIOEither $ connectProjectM36 connInfo
  sess <- assertIOEither $ createSessionAtHead conn "master"
  Right _ <- executeDatabaseContextExpr sess conn (Assign "x" (ExistingRelation relationTrue))
  Right _ <- commit sess conn
  val <- C.validateMerkleHashes sess conn
  assertEqual "merkle success" (Right ()) val

  --read graph from disk
  conn' <- assertIOEither $ connectProjectM36 connInfo
  sess' <- assertIOEither $ createSessionAtHead conn' "master"

  val' <- C.validateMerkleHashes sess' conn'
  assertEqual "merkle read again success" (Right ()) val'

  --alter the on-disk representation and check that the hash validation fails
  eGraph <- transactionGraphLoad dbdir emptyTransactionGraph Nothing
  case eGraph of
    Left err -> assertFailure $ "failed to load graph" ++ show err
    Right graph -> do
      let trans = transactionHeadsForGraph graph M.! "master"
          updatedTrans = Transaction (transactionId trans) (transactionInfo trans) updatedSchemas
          transactionDir' = dbdir </> show (transactionId trans)
          updatedSchemas =
            case schemas trans of
              Schemas ctx sschemas ->
                let updatedContext = ctx {
                      relationVariables = M.insert "malicious" (ExistingRelation relationFalse) (relationVariables ctx)
                      } in
                Schemas updatedContext sschemas
          maliciousGraph = TransactionGraph malHeads malTransSet
          malHeads = M.insert "master" updatedTrans (transactionHeadsForGraph graph)
          malTransSet = S.insert updatedTrans (transactionsForGraph graph)
          malMerkleHash = calculateMerkleHash updatedTrans maliciousGraph
          regMerkleHash = merkleHash (transactionInfo trans)
      --validate and fail
      let val'' = TG.validateMerkleHashes maliciousGraph
      assertEqual "loaded graph merkle hashes" (Left [MerkleValidationError (transactionId trans) regMerkleHash malMerkleHash]) val''
      --delete existing transaction directory
      removeDirectoryRecursive transactionDir'
      writeTransaction NoDiskSync dbdir updatedTrans

      --read graph from disk
      eConnFail <- connectProjectM36 connInfo
      case eConnFail of
        Left err -> 
          assertEqual "open connection merkle validation" (DatabaseValidationError [MerkleValidationError (transactionId trans) regMerkleHash malMerkleHash]) err
        Right _ -> assertFailure "open connection validation" 



--only Haskell-scripted dbc and atom functions can be serialized                   
testFunctionPersistence :: Test
#if !defined(PM36_HASKELL_SCRIPTING)
testFunctionPersistence = TestCase $ pure ()
#else
testFunctionPersistence = TestCase $
 withSystemTempDirectory "m36testdb" $ \tempdir -> do
  let dbdir = tempdir </> "dbdir"
      connInfo = InProcessConnectionInfo (MinimalPersistence dbdir) emptyNotificationCallback []
  conn <- assertIOEither $ connectProjectM36 connInfo
  sess <- assertIOEither $ createSessionAtHead conn "master"
  let intTCons = PrimitiveTypeConstructor "Int" IntAtomType
      addfunc = AddAtomFunction "testdisk" [
        intTCons, 
        ADTypeConstructor "Either" [ADTypeConstructor "AtomFunctionError" [],
                                    intTCons]] "(\\(x:_) -> pure x) :: [Atom] -> Either AtomFunctionError Atom"
  _ <- assertIOEither $ executeDatabaseContextIOExpr sess conn addfunc
  _ <- assertIOEither $ commit sess conn
  --close conn - pauses indefinitely on Windows
  --re-open the connection to reload the graph
  conn2 <- assertIOEither $ connectProjectM36 connInfo
  sess2 <- assertIOEither $ createSessionAtHead conn2 "master"
  
  res <- executeRelationalExpr sess2 conn2 (MakeRelationFromExprs Nothing (TupleExprs () [TupleExpr (M.singleton "a" (FunctionAtomExpr "testdisk" [NakedAtomExpr (IntAtom 3)] ()))]))
  let expectedRel = mkRelationFromList (attributesFromList [Attribute "a" IntAtomType]) [[IntAtom 3]]
  assertEqual "testdisk dbc function run" expectedRel res

#endif  

assertIOEither :: (Show a) => IO (Either a b) -> IO b
assertIOEither x = do
  ret <- x
  case ret of
    Left err -> assertFailure (show err) >> undefined
    Right val -> pure val