{-# LANGUAGE OverloadedStrings #-}

import           Control.Concurrent.Async
import           Foreign.Marshal.Alloc
import           Foreign.Ptr
import           Foreign.Storable
import           Network.GRPC.Unsafe
import           Network.GRPC.Unsafe.ByteBuffer
import           Network.GRPC.Unsafe.Constants
import           Network.GRPC.Unsafe.Metadata
import           Network.GRPC.Unsafe.Op
import           Network.GRPC.Unsafe.Time
import           Test.Tasty
import           Test.Tasty.HUnit               as HU

import           LowLevelTests
import           UnsafeTests

assertCqEventComplete :: Event -> IO ()
assertCqEventComplete e = do
  eventCompletionType e HU.@?= OpComplete
  eventSuccess e HU.@?= True

testPayloadClient :: IO ()
testPayloadClient = do
  client <- grpcInsecureChannelCreate "localhost:50051" nullPtr reserved
  cq <- grpcCompletionQueueCreate reserved
  withMetadataArrayPtr $ \initialMetadataRecv -> do
    withMetadataArrayPtr $ \trailingMetadataRecv -> do
      withByteBufferPtr $ \clientRecvBB -> do
        deadline <- secondsToDeadline 5
        pluckDeadline <- secondsToDeadline 10
        clientCall <- grpcChannelCreateCall
                        client (Call nullPtr) propagateDefaults cq
                        "/foo" "localhost" deadline reserved
        --send request
        withOpArray 6 $ \ops -> do
          opSendInitialMetadataEmpty ops 0
          withByteStringAsByteBuffer "hello world" $ \requestPayload -> do
            opSendMessage ops 1 requestPayload
            opSendCloseClient ops 2
            opRecvInitialMetadata ops 3 initialMetadataRecv
            opRecvMessage ops 4 clientRecvBB
            statusCodePtr <- createStatusCodePtr
            let cstringCapacity = 32
            cStringPtr <- malloc
            cstring <- mallocBytes cstringCapacity
            poke cStringPtr cstring
            opRecvStatusClient ops 5 trailingMetadataRecv statusCodePtr
                               cStringPtr
                               cstringCapacity
            --send client request
            requestError <- grpcCallStartBatch clientCall ops 6 (tag 1) reserved
            clientRequestCqEvent <- grpcCompletionQueuePluck
                                      cq (tag 1) pluckDeadline reserved
            assertCqEventComplete clientRequestCqEvent
            requestError HU.@?= CallOk
            free cstring
            free cStringPtr
            destroyStatusCodePtr statusCodePtr
        --verify response received
        responseRecv <- peek clientRecvBB
        responseRecvBS <- copyByteBufferToByteString responseRecv
        responseRecvBS HU.@?= "hello you"
        grpcCompletionQueueShutdown cq
        grpcCallDestroy clientCall
        --TODO: the grpc test drains the cq here
        grpcCompletionQueueDestroy cq
        grpcChannelDestroy client

testPayloadServer :: IO ()
testPayloadServer = do
  server <- grpcServerCreate nullPtr reserved
  cq <- grpcCompletionQueueCreate reserved
  grpcServerRegisterCompletionQueue server cq reserved
  _ <- grpcServerAddInsecureHttp2Port server "localhost:50051"
  grpcServerStart server
  serverCallPtr <- malloc
  withMetadataArrayPtr $ \requestMetadataRecv -> do
    withByteBufferPtr $ \recvBufferPtr -> do
      callDetails <- createCallDetails
      requestMetadataRecv' <- peek requestMetadataRecv
      recvRequestError <- grpcServerRequestCall
                            server serverCallPtr callDetails
                            requestMetadataRecv' cq cq (tag 101)
      pluckDeadline' <- secondsToDeadline 10
      requestCallCqEvent <- grpcCompletionQueuePluck cq (tag 101)
                                                     pluckDeadline'
                                                     reserved
      assertCqEventComplete requestCallCqEvent
      recvRequestError HU.@?= CallOk
      destroyCallDetails callDetails
      --receive request
      withOpArray 2 $ \recvOps -> do
        opSendInitialMetadataEmpty recvOps 0
        opRecvMessage recvOps 1 recvBufferPtr
        serverCall <- peek serverCallPtr
        recvBatchError <- grpcCallStartBatch serverCall recvOps 2
                                             (tag 102) reserved
        recvBatchError HU.@?= CallOk
        pluckDeadline'' <- secondsToDeadline 10
        recvCqEvent <- grpcCompletionQueuePluck cq (tag 102)
                                                pluckDeadline''
                                                reserved
        assertCqEventComplete recvCqEvent
      --send response
      withOpArray 3 $ \respOps -> do
        withByteStringAsByteBuffer "hello you" $ \respbb -> do
          cancelledPtr <- malloc
          opRecvCloseServer respOps 0 cancelledPtr
          opSendMessage respOps 1 respbb
          opSendStatusServer respOps 2 0 (MetadataKeyValPtr nullPtr)
                             GrpcStatusOk "ok"
          serverCall <- peek serverCallPtr
          respBatchError <- grpcCallStartBatch serverCall respOps 3
                                               (tag 103) reserved
          respBatchError HU.@?= CallOk
          pluckDeadline''' <- secondsToDeadline 10
          respCqEvent <- grpcCompletionQueuePluck cq (tag 103)
                                                  pluckDeadline'''
                                                  reserved
          assertCqEventComplete respCqEvent
      --verify data was received
      serverRecv <- peek recvBufferPtr
      serverRecvBS <- copyByteBufferToByteString serverRecv
      serverRecvBS HU.@?= "hello world"
      --shut down
      grpcServerShutdownAndNotify server cq (tag 0)
      pluckDeadline'''' <- secondsToDeadline 10
      shutdownEvent <- grpcCompletionQueuePluck cq (tag 0) pluckDeadline''''
                                                reserved
      assertCqEventComplete shutdownEvent
      grpcServerCancelAllCalls server
      grpcServerDestroy server
      grpcCompletionQueueShutdown cq
      grpcCompletionQueueDestroy cq
      free serverCallPtr

-- | Straightforward translation of the gRPC core test end2end/tests/payload.c
-- This is intended to test the low-level C bindings, so we use only a few
-- minimal abstractions on top of it.
testPayload :: TestTree
testPayload = testCase "low-level C bindings request/response " $ do
  grpcInit
  withAsync testPayloadServer $ \a1 -> do
    withAsync testPayloadClient $ \a2 -> do
      wait a1
      wait a2
  grpcShutdown
  putStrLn "Done."

allTests :: TestTree
allTests = testGroup "All tests"
  [ testPayload
  , unsafeTests
  , lowLevelTests
  ]

main :: IO ()
main = defaultMain allTests