// SPDX-FileCopyrightText: Copyright (c) Kitware Inc.
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkLiveInsituLink.h"

#include "vtkAlgorithm.h"
#include "vtkClientSocket.h"
#include "vtkCommand.h"
#include "vtkCommunicationErrorCatcher.h"
#include "vtkExtractsDeliveryHelper.h"
#include "vtkLogger.h"
#include "vtkMultiProcessStream.h"
#include "vtkNetworkAccessManager.h"
#include "vtkNew.h"
#include "vtkObjectFactory.h"
#include "vtkPVDataInformation.h"
#include "vtkPVSessionBase.h"
#include "vtkPVVersionQuick.h"
#include "vtkPVXMLElement.h"
#include "vtkPVXMLParser.h"
#include "vtkProcessModule.h"
#include "vtkSMInsituStateLoader.h"
#include "vtkSMMessage.h"
#include "vtkSMProxy.h"
#include "vtkSMProxyIterator.h"
#include "vtkSMSessionProxyManager.h"
#include "vtkSMSourceProxy.h"
#include "vtkServerSocket.h"
#include "vtkSmartPointer.h"
#include "vtkSocketCommunicator.h"
#include "vtkSocketController.h"
#include "vtkTrivialProducer.h"

#include <cassert>
#include <map>
#include <set>
#include <sstream>
#include <string>
#include <vtksys/SystemInformation.hxx>
#include <vtksys/SystemTools.hxx>

// #define vtkLiveInsituLinkDebugMacro(x) cerr x << endl;
#define vtkLiveInsituLinkDebugMacro(x)

namespace
{
void TimeFromStream(void* remoteArg, int remoteArgLength, double* time, vtkIdType* timeStep)
{
  vtkMultiProcessStream stream;
  const unsigned char* data = static_cast<const unsigned char*>(remoteArg);
  stream.SetRawData(data, remoteArgLength);
  stream >> *time >> *timeStep;
}

void TriggerRMI(vtkMultiProcessController* controller, int tag, double time, vtkIdType timeStep)
{
  vtkMultiProcessStream stream;
  stream << time << timeStep;
  unsigned char* data = nullptr;
  unsigned int dataSize;
  stream.GetRawData(data, dataSize);
  controller->TriggerRMI(1, data, dataSize, tag);
  delete[] data;
}

void TriggerRMIOnAllChildren(
  vtkMultiProcessController* controller, int tag, double time, vtkIdType timeStep)
{
  vtkMultiProcessStream stream;
  stream << time << timeStep;
  unsigned char* data = nullptr;
  unsigned int dataSize;
  stream.GetRawData(data, dataSize);
  controller->TriggerRMIOnAllChildren(data, dataSize, tag);
  delete[] data;
}

void InitializeConnectionRMI(void* localArg, void* vtkNotUsed(remoteArg),
  int vtkNotUsed(remoteArgLength), int vtkNotUsed(remoteProcessId))
{
  vtkLiveInsituLink* self = reinterpret_cast<vtkLiveInsituLink*>(localArg);
  self->InsituConnect(nullptr);
}

void DropLiveInsituConnectionRMI(void* localArg, void* vtkNotUsed(remoteArg),
  int vtkNotUsed(remoteArgLength), int vtkNotUsed(remoteProcessId))
{
  vtkLiveInsituLink* self = reinterpret_cast<vtkLiveInsituLink*>(localArg);
  self->DropLiveInsituConnection();
}

void UpdateRMI(
  void* localArg, void* remoteArg, int remoteArgLength, int vtkNotUsed(remoteProcessId))
{
  double time;
  vtkIdType timeStep;
  TimeFromStream(remoteArg, remoteArgLength, &time, &timeStep);
  vtkLiveInsituLink* self = reinterpret_cast<vtkLiveInsituLink*>(localArg);
  assert(self->GetProcessType() == vtkLiveInsituLink::LIVE);
  self->OnInsituUpdate(time, timeStep);
}

void PostProcessRMI(
  void* localArg, void* remoteArg, int remoteArgLength, int vtkNotUsed(remoteProcessId))
{
  double time;
  vtkIdType timeStep;
  TimeFromStream(remoteArg, remoteArgLength, &time, &timeStep);
  vtkLiveInsituLink* self = reinterpret_cast<vtkLiveInsituLink*>(localArg);
  assert(self->GetProcessType() == vtkLiveInsituLink::LIVE);
  self->OnInsituPostProcess(time, timeStep);
}

void LiveChangedRMI(void* localArg, void* vtkNotUsed(remoteArg), int vtkNotUsed(remoteArgLength),
  int vtkNotUsed(remoteProcessId))
{
  vtkLiveInsituLink* self = reinterpret_cast<vtkLiveInsituLink*>(localArg);
  assert(self->GetProcessType() == vtkLiveInsituLink::INSITU);
  self->OnLiveChanged();
}

/// Notifications from Live server to Live client.
//----------------------------------------------------------------------------
void NotifyClientDisconnected(vtkWeakPointer<vtkPVSessionBase> liveSession, unsigned int proxyId)
{
  if (liveSession)
  {
    vtkSMMessage message;
    message.set_global_id(proxyId);
    message.set_location(vtkPVSession::CLIENT);
    message.SetExtension(ProxyState::xml_group, "Catalyst_Communication");
    message.SetExtension(ProxyState::xml_name, "Catalyst_Communication");

    // Add custom user_data
    ProxyState_UserData* user_data = message.AddExtension(ProxyState::user_data);
    user_data->set_key("LiveAction");
    Variant* variant = user_data->add_variant();
    variant->set_type(Variant::INT); // Arbitrary
    variant->add_integer(vtkLiveInsituLink::DISCONNECTED);

    // Send message
    liveSession->NotifyAllClients(&message);
  }
}

//----------------------------------------------------------------------------
void NotifyClientConnected(
  vtkWeakPointer<vtkPVSessionBase> liveSession, unsigned int proxyId, const char* insituXMLState)
{
  if (liveSession)
  {
    vtkSMMessage message;
    message.set_global_id(proxyId);
    message.set_location(vtkPVSession::CLIENT);
    message.SetExtension(ProxyState::xml_group, "Catalyst_Communication");
    message.SetExtension(ProxyState::xml_name, "Catalyst_Communication");

    // Add custom user_data
    ProxyState_UserData* user_data = message.AddExtension(ProxyState::user_data);
    user_data->set_key("LiveAction");
    Variant* variant = user_data->add_variant();
    variant->set_type(Variant::INT); // Arbitrary
    variant->add_integer(vtkLiveInsituLink::CONNECTED);
    variant->add_txt(insituXMLState);

    // Send message
    liveSession->NotifyAllClients(&message);
  }
}

//----------------------------------------------------------------------------
void NotifyClientIdMapping(vtkWeakPointer<vtkPVSessionBase> liveSession, unsigned int proxyId,
  int numberOfIds, vtkTypeUInt32* idMapTable)
{
  if (liveSession)
  {
    // here we may let the client know exactly what extracts were updated, if
    // all were not updated. Currently we just assume all extracts are
    // redelivered and modified.
    vtkSMMessage message;
    message.set_global_id(proxyId);
    message.set_location(vtkPVSession::CLIENT);
    message.SetExtension(ProxyState::xml_group, "Catalyst_Communication");
    message.SetExtension(ProxyState::xml_name, "Catalyst_Communication");

    // Add custom user_data
    ProxyState_UserData* user_data = message.AddExtension(ProxyState::user_data);
    user_data->set_key("IdMapping");
    Variant* variant = user_data->add_variant();
    variant->set_type(Variant::IDTYPE); // Arbitrary

    for (int i = 0; i < numberOfIds; ++i)
    {
      variant->add_idtype(idMapTable[i]);
    }

    // Send message
    liveSession->NotifyAllClients(&message);
  }
}

//----------------------------------------------------------------------------
void NotifyClientDataInformationNextTimestep(vtkWeakPointer<vtkPVSessionBase> liveSession,
  unsigned int proxyId,
  const std::map<std::pair<vtkTypeUInt32, unsigned int>, std::string>& information,
  vtkIdType timeStep)
{
  if (liveSession)
  {
    // here we may let the client know exactly what extracts were updated, if
    // all were not updated. Currently we just assume all extracts are
    // redelivered and modified.
    vtkSMMessage message;
    message.set_global_id(proxyId);
    message.set_location(vtkPVSession::CLIENT);
    message.SetExtension(ProxyState::xml_group, "Catalyst_Communication");
    message.SetExtension(ProxyState::xml_name, "Catalyst_Communication");

    // Add custom user_data
    ProxyState_UserData* user_data = message.AddExtension(ProxyState::user_data);
    user_data->set_key("LiveAction");
    Variant* variant = user_data->add_variant();
    variant->set_type(Variant::INT); // Arbitrary
    variant->add_integer(vtkLiveInsituLink::NEXT_TIMESTEP_AVAILABLE);
    variant->add_idtype(timeStep);

    // Add custom user_data for data information
    if (!information.empty())
    {
      ProxyState_UserData* dataInfo = message.AddExtension(ProxyState::user_data);
      dataInfo->set_key("UpdateDataInformation");
      std::map<std::pair<vtkTypeUInt32, unsigned int>, std::string>::const_iterator iter;
      for (iter = information.begin(); iter != information.end(); iter++)
      {
        Variant* variant2 = dataInfo->add_variant();
        variant2->set_type(Variant::PROXY); // Arbitrary
        variant2->add_proxy_global_id(iter->first.first);
        variant2->add_port_number(iter->first.second);
        variant2->add_binary(iter->second);
      }
    }

    // Send message
    liveSession->NotifyAllClients(&message);
  }
}
}

class vtkLiveInsituLink::vtkInternals
{
public:
  struct Key
  {
    std::string Group;
    std::string Name;
    int Port;
    std::string ToString() const
    {
      std::ostringstream key;
      key << this->Group.c_str() << ":" << this->Name.c_str() << ":" << this->Port;
      return key.str();
    }
    bool operator<(const Key& other) const
    {
      return this->Group < other.Group || this->Name < other.Name || this->Port < other.Port;
    }
    Key()
      : Port(0)
    {
    }
    Key(const char* group, const char* name, int port)
      : Group(group)
      , Name(name)
      , Port(port)
    {
    }
  };

  bool IsNew(vtkTypeUInt32 proxyId, unsigned int port, vtkPVDataInformation* info)
  {
    vtkIdType id = static_cast<vtkIdType>(proxyId) * 100 + static_cast<vtkIdType>(port);
    vtkClientServerStream stream;
    info->CopyToStream(&stream);
    size_t length = 0;
    const unsigned char* data = nullptr;
    stream.GetData(&data, &length);
    std::string rawData((const char*)data, length);

    // Search if existing value is the same
    std::map<vtkIdType, std::string>::iterator iter;
    iter = this->LastSentDataInformationMap.find(id);
    if ((iter != this->LastSentDataInformationMap.end()) && (iter->second == rawData))
    {
      return false;
    }

    // Store the new MTime
    this->LastSentDataInformationMap[id] = rawData;

    return true;
  }

  typedef std::map<Key, vtkSmartPointer<vtkTrivialProducer>> ExtractsMap;
  ExtractsMap Extracts;
  std::map<vtkIdType, std::string> LastSentDataInformationMap;
};

vtkStandardNewMacro(vtkLiveInsituLink);
//----------------------------------------------------------------------------
vtkLiveInsituLink::vtkLiveInsituLink()
  : Hostname(nullptr)
  , InsituPort(0)
  , ProcessType(INSITU)
  , ProxyId(0)
  , InsituXMLStateChanged(false)
  , ExtractsChanged(false)
  , SimulationPaused(0)
  , InsituXMLState(nullptr)
  , URL(nullptr)
  , Internals(new vtkInternals())
{
  this->SetHostname("localhost");
}

//----------------------------------------------------------------------------
vtkLiveInsituLink::~vtkLiveInsituLink()
{
  this->SetHostname(nullptr);
  this->SetURL(nullptr);

  delete[] this->InsituXMLState;
  this->InsituXMLState = nullptr;

  delete this->Internals;
  this->Internals = nullptr;
}

//----------------------------------------------------------------------------
bool vtkLiveInsituLink::Initialize(vtkSMSessionProxyManager* pxm)
{
  if (this->Proc0NodesController || this->ExtractsDeliveryHelper != nullptr)
  {
    // already initialized. all's well.
    // (this->Proc0NodesController is non-existant on satellites)
    return true;
  }

  this->InsituProxyManager = pxm;

  bool retVal = true;
  switch (this->ProcessType)
  {
    case LIVE:
      // LIVE always has a true return value
      this->InitializeLive();
      break;

    case INSITU:
      retVal = this->InitializeInsitu();
      break;
  }
  return retVal;
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::InitializeLive()
{
  // This method gets called on the DataServer nodes.
  // On the root-node, we need to setup the server-socket to accept connections
  // from VTK Insitu code.
  // On satellites, we need to setup MPI-RMI handlers to ensure that the
  // satellites respond to a VTK Insitu connection setup correctly.
  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();
  // int numProcs = pm->GetNumberOfLocalPartitions();

  vtkLiveInsituLinkDebugMacro(<< myId << ": InitializeLive");
  if (myId == 0)
  {
    // save the visualization session reference so that we can communicate back to
    // the client.
    this->LiveSession = vtkPVSessionBase::SafeDownCast(pm->GetActiveSession());

    vtkNetworkAccessManager* nam = pm->GetNetworkAccessManager();

    // if the Insitu connection ever drops, we need to communicate to the
    // client on the LiveSession that the catalyst server no longer
    // exists.
    nam->AddObserver(
      vtkCommand::ConnectionClosedEvent, this, &vtkLiveInsituLink::OnConnectionClosedEvent);

    std::ostringstream url;
    url << "tcp://localhost:" << this->InsituPort << "?"
        << "listen=true&nonblocking=true&"
        << "handshake=paraview.insitu." << PARAVIEW_VERSION;
    this->SetURL(url.str().c_str());

    const auto hostname = std::string(vtksys::SystemInformation().GetHostname());
    vtkLogF(INFO, "Listening for primary Catalyst connection on `%s:%d`", hostname.c_str(),
      this->InsituPort);
    if (vtkMultiProcessController* proc0NodesController = nam->NewConnection(this->URL))
    {
      // controller would generally be nullptr, however due to magically timing,
      // the insitu lib may indeed connect just as we setup the socket, so we
      // handle that case.
      this->InsituConnect(proc0NodesController);
      proc0NodesController->Delete();
    }
    else
    {
      nam->AddObserver(
        vtkCommand::ConnectionCreatedEvent, this, &vtkLiveInsituLink::OnConnectionCreatedEvent);
    }
  }
  else
  {
    vtkMultiProcessController* parallelController =
      vtkMultiProcessController::GetGlobalController();

    // add callback to listen to "events" from root node.
    // the command channel between sim and vis nodes is only setup on the root
    // nodes (there are socket connections between satellites for data x'fer but
    // not for any other kind of communication.
    parallelController->AddRMICallback(&InitializeConnectionRMI, this, INITIALIZE_CONNECTION);
    parallelController->AddRMICallback(&UpdateRMI, this, UPDATE_RMI_TAG);
    parallelController->AddRMICallback(&PostProcessRMI, this, POSTPROCESS_RMI_TAG);
    parallelController->AddRMICallback(&DropLiveInsituConnectionRMI, this, DROP_CAT2PV_CONNECTION);
  }
}

//----------------------------------------------------------------------------
bool vtkLiveInsituLink::InitializeInsitu()
{
  // vtkLiveInsituLink::Initialize() should not call this method unless
  // Proc0NodesController==nullptr.
  assert(this->Proc0NodesController == nullptr);

  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();
  int numProcs = pm->GetNumberOfLocalPartitions();

  if (!pm->GetSymmetricMPIMode() && numProcs > 1)
  {
    vtkErrorMacro("Running in parallel without symmetric mode is not supported. "
                  "Aborting for debugging purposes.");
    abort();
  }

  bool retVal = false;
  if (myId == 0)
  {
    vtkNetworkAccessManager* nam = pm->GetNetworkAccessManager();

    std::ostringstream url;
    url.imbue(std::locale::classic());
    url << "tcp://" << this->Hostname << ":" << this->InsituPort << "?"
        << "timeout=0&handshake=paraview.insitu." << PARAVIEW_VERSION;
    this->SetURL(url.str().c_str());
    // Suppress any error messages while attempting to connect to ParaView
    // visualization engine.
    int display_errors = vtkObject::GetGlobalWarningDisplay();
    vtkObject::GlobalWarningDisplayOff();
    vtkMultiProcessController* proc0NodesController = nam->NewConnection(this->URL);
    vtkObject::SetGlobalWarningDisplay(display_errors);
    if (numProcs > 1)
    {
      int connection_established = proc0NodesController != nullptr ? 1 : 0;
      pm->GetGlobalController()->Broadcast(&connection_established, 1, 0);
    }
    if (proc0NodesController)
    {
      // controller would generally be nullptr, however due to magically timing,
      // the insitu lib may indeed connect just as we setup the socket, so we
      // handle that case.
      this->InsituConnect(proc0NodesController);
      proc0NodesController->Delete();
      retVal = true;
    }
    // nothing to do, no server to connect to.
  }
  else
  {
    int connection_established = 0;
    pm->GetGlobalController()->Broadcast(&connection_established, 1, 0);
    if (connection_established)
    {
      this->InsituConnect(nullptr);
      retVal = true;
    }
  }
  return retVal;
}

//----------------------------------------------------------------------------
// Callback on Visualization process when a simulation connects to it.
void vtkLiveInsituLink::OnConnectionCreatedEvent()
{
  assert(this->ProcessType == LIVE);

  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  vtkNetworkAccessManager* nam = pm->GetNetworkAccessManager();
  if (vtkMultiProcessController* proc0NodesController = nam->NewConnection(this->URL))
  {
    this->InsituConnect(proc0NodesController);
    proc0NodesController->Delete();
  }
}

//----------------------------------------------------------------------------
// Callback on Visualization process when a connection dies during
// ProcessEvents().
void vtkLiveInsituLink::OnConnectionClosedEvent(vtkObject*, unsigned long, void* calldata)
{
  vtkObject* object = reinterpret_cast<vtkObject*>(calldata);
  vtkMultiProcessController* proc0NodesController = vtkMultiProcessController::SafeDownCast(object);
  if (proc0NodesController && this->Proc0NodesController == proc0NodesController)
  {
    // drop connection.

    // since this is called only on root node, we need to tell all satellites to
    // drop the connection too.
    vtkMultiProcessController* parallelController =
      vtkMultiProcessController::GetGlobalController();
    int numProcs = parallelController->GetNumberOfProcesses();

    if (numProcs > 1)
    {
      assert(parallelController->GetLocalProcessId() == 0);
      parallelController->TriggerRMIOnAllChildren(DROP_CAT2PV_CONNECTION);
    }
    this->DropLiveInsituConnection();
    NotifyClientDisconnected(this->LiveSession, this->ProxyId);
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::DropLiveInsituConnection()
{
  // smart pointers below
  this->Proc0NodesController = nullptr;
  this->ExtractsDeliveryHelper = nullptr;
  this->SimulationPaused = 0;
  vtkDebugMacro("Catalyst and ParaView should now be disconnected");
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::InsituConnect(vtkMultiProcessController* proc0NodesController)
{
  assert(this->Proc0NodesController == nullptr);
  assert(this->ExtractsDeliveryHelper.GetPointer() == nullptr);

  this->Proc0NodesController = proc0NodesController;

  this->ExtractsDeliveryHelper = vtkSmartPointer<vtkExtractsDeliveryHelper>::New();
  this->ExtractsDeliveryHelper->SetProcessIsProducer(this->ProcessType == LIVE ? false : true);

  vtkMultiProcessController* parallelController = vtkMultiProcessController::GetGlobalController();
  int numProcs = parallelController->GetNumberOfProcesses();
  int myId = parallelController->GetLocalProcessId();

  vtkDebugMacro("Catalyst and ParaView should now be connected");

  if (myId == 0)
  {
    assert(proc0NodesController != nullptr);
  }
  else
  {
    assert(proc0NodesController == nullptr);
  }

  switch (this->ProcessType)
  {
    case LIVE:
    {
      // LIVE side is the "slave" side in this relationship. We listen to
      // commands from INSITU.
      int num_procs_paraview = 0;
      int num_procs_catalyst = 0;
      if (myId == 0)
      {
        unsigned int size = 0;
        proc0NodesController->Receive(&size, 1, 1, 8000);

        delete[] this->InsituXMLState;
        this->InsituXMLState = new char[size + 1];
        proc0NodesController->Receive(this->InsituXMLState, size, 1, 8001);
        this->InsituXMLState[size] = 0;
        this->InsituXMLStateChanged = false;

        // setup RMI callbacks.
        proc0NodesController->AddRMICallback(&UpdateRMI, this, UPDATE_RMI_TAG);
        proc0NodesController->AddRMICallback(&PostProcessRMI, this, POSTPROCESS_RMI_TAG);

        // setup M2N connection.
        int otherProcs;
        proc0NodesController->Send(&numProcs, 1, 1, 8002);
        proc0NodesController->Receive(&otherProcs, 1, 1, 8003);

        if (numProcs > 1)
        {
          parallelController->TriggerRMIOnAllChildren(INITIALIZE_CONNECTION);
          parallelController->Broadcast(&otherProcs, 1, 0);
        }

        num_procs_paraview = numProcs;
        num_procs_catalyst = otherProcs;
      }
      else
      {
        int otherProcs = 0;
        parallelController->Broadcast(&otherProcs, 1, 0);
        num_procs_paraview = numProcs;
        num_procs_catalyst = otherProcs;
      }

      this->ExtractsDeliveryHelper->SetNumberOfVisualizationProcesses(num_procs_paraview);
      this->ExtractsDeliveryHelper->SetNumberOfSimulationProcesses(num_procs_catalyst);
      assert(num_procs_catalyst > 0 && num_procs_paraview > 0);
      if (myId == 0)
      {
        // we'll piggy back on proc0NodesController to deliver extracts as well for this rank.
        this->ExtractsDeliveryHelper->SetSimulation2VisualizationController(
          vtkSocketController::SafeDownCast(proc0NodesController));

        // communicate between satellites to help them setup the catalyst-to-paraview socket
        // connections.
        if (std::min(num_procs_paraview, num_procs_catalyst) > 1)
        {
          vtkMultiProcessStream connectionMsg;
          std::vector<vtkMultiProcessStream> allConnectionMsgs;
          parallelController->Gather(connectionMsg, allConnectionMsgs, 0);
          connectionMsg.Reset();
          for (const auto& msg : allConnectionMsgs)
          {
            connectionMsg << msg;
          }
          proc0NodesController->Send(connectionMsg, 1, 98211);
        }
      }
      else if (myId < std::min(num_procs_paraview, num_procs_catalyst))
      {
        assert(myId != 0);

        // create a server-socket.
        vtkNew<vtkServerSocket> socket;
        socket->CreateServer(0);

        const auto hostname = std::string(vtksys::SystemInformation().GetHostname());
        vtkLogF(INFO, "Awaiting secondary Catalyst connection on `%s:%d` for data x-fer",
          hostname.c_str(), socket->GetServerPort());

        // communicate into to 0 so it can communicate that to Catalyst processes.
        vtkMultiProcessStream connectionMsg;
        connectionMsg << 98210 << hostname.c_str() << socket->GetServerPort();
        std::vector<vtkMultiProcessStream> not_used;
        parallelController->Gather(connectionMsg, not_used, 0);

        auto clientSocket = socket->WaitForConnection();
        if (!clientSocket)
        {
          abort();
        }
        vtkNew<vtkSocketController> sim2vis;
        if (auto comm = vtkSocketCommunicator::SafeDownCast(sim2vis->GetCommunicator()))
        {
          comm->SetSocket(clientSocket);
          comm->ServerSideHandshake();
        }
        vtkLogF(
          INFO, "Catalyst process connected on `%s:%d`", hostname.c_str(), socket->GetServerPort());
        clientSocket->Delete();
        this->ExtractsDeliveryHelper->SetSimulation2VisualizationController(sim2vis);
      }
      else if (std::min(num_procs_paraview, num_procs_catalyst) > 1)
      {
        std::vector<vtkMultiProcessStream> tmp;
        parallelController->Gather(vtkMultiProcessStream(), tmp, 0);
      }

      NotifyClientConnected(this->LiveSession, this->ProxyId, this->InsituXMLState);
      break;
    }
    case INSITU:
    {
      int num_procs_paraview = 0;
      int num_procs_catalyst = 0;
      if (myId == 0)
      {
        // send startup state to the visualization process.
        vtkPVXMLElement* xml = this->InsituProxyManager->SaveXMLState();

        // Filter XML to remove any view/representation/timeKeeper/animation proxy
        vtkLiveInsituLink::FilterXMLState(xml);

        std::ostringstream xml_string;
        xml->PrintXML(xml_string, vtkIndent());
        xml->Delete();

        unsigned int size = static_cast<unsigned int>(xml_string.str().size());
        proc0NodesController->Send(&size, 1, 1, 8000);
        proc0NodesController->Send(
          xml_string.str().c_str(), static_cast<vtkIdType>(xml_string.str().size()), 1, 8001);

        proc0NodesController->AddRMICallback(&LiveChangedRMI, this, LIVE_CHANGED);

        // setup M2N connection.
        int otherProcs;
        proc0NodesController->Receive(&otherProcs, 1, 1, 8002);
        proc0NodesController->Send(&numProcs, 1, 1, 8003);
        parallelController->Broadcast(&otherProcs, 1, 0);
        num_procs_paraview = otherProcs;
        num_procs_catalyst = numProcs;
      }
      else
      {
        int otherProcs = 0;
        parallelController->Broadcast(&otherProcs, 1, 0);
        num_procs_paraview = otherProcs;
        num_procs_catalyst = numProcs;
      }
      this->ExtractsDeliveryHelper->SetNumberOfVisualizationProcesses(num_procs_paraview);
      this->ExtractsDeliveryHelper->SetNumberOfSimulationProcesses(num_procs_catalyst);
      assert(num_procs_catalyst > 0 && num_procs_paraview > 0);

      // connect to the sim-nodes for data x'fer.
      if (myId == 0)
      {
        // we'll piggy back on proc0NodesController to deliver extracts.
        this->ExtractsDeliveryHelper->SetSimulation2VisualizationController(
          vtkSocketController::SafeDownCast(proc0NodesController));

        // communicate between satellites.
        if (std::min(num_procs_paraview, num_procs_catalyst) > 1)
        {
          vtkMultiProcessStream connectionMsg;
          proc0NodesController->Receive(connectionMsg, 1, 98211);
          parallelController->Broadcast(connectionMsg, 0);
        }
      }
      else if (std::min(num_procs_catalyst, num_procs_paraview) > 1)
      {
        vtkMultiProcessStream connectionMsg;
        parallelController->Broadcast(connectionMsg, 0);

        for (int cc = 0; cc < num_procs_paraview && cc < num_procs_catalyst; ++cc)
        {
          vtkMultiProcessStream msg;
          connectionMsg >> msg;
          if (myId == cc && !msg.Empty())
          {
            std::string hostname;
            int port, tag;
            msg >> tag >> hostname >> port;
            assert(tag == 98210);
            vtkNew<vtkSocketController> sim2vis;
            if (!sim2vis->ConnectTo(hostname.c_str(), port))
            {
              abort();
            }
            this->ExtractsDeliveryHelper->SetSimulation2VisualizationController(sim2vis);
            break;
          }
        }
      }
      parallelController->Barrier();
      break;
    }
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::InsituUpdate(double time, vtkIdType timeStep)
{
  assert(this->ProcessType == INSITU);

  if (!this->InsituProxyManager)
  {
    vtkErrorMacro("Please call vtkLiveInsituLink::Initialize(vtkSMSessionProxyManager*) "
                  "before using vtkLiveInsituLink::InsituUpdate().");
    return;
  }

  if (!this->ExtractsDeliveryHelper.GetPointer())
  {
    // We are not connected to ParaView LIVE. That can happen if the
    // ParaView LIVE was not ready the last time we attempted to connect
    // to it, or ParaView LIVE disconnected. We make a fresh attempt to
    // connect to it.
    assert(this->ProcessType == INSITU);

    this->Initialize(this->InsituProxyManager);
    if (!this->ExtractsDeliveryHelper.GetPointer())
    {
      // ParaView LIVE is still not ready. Another time.
      return;
    }
  }

  // Okay, ParaView LIVE connection is currently valid, but it may
  // break, so add error interceptor.
  vtkCommunicationErrorCatcher catcher(this->Proc0NodesController);

  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();
  int numProcs = pm->GetNumberOfLocalPartitions();

  char* buffer = nullptr;
  int buffer_size = 0;

  vtkMultiProcessStream extractsPauseMessage;
  std::vector<vtkTypeUInt32> idMappingInStateLoading;

  if (myId == 0)
  {
    // steps to perform:
    // 1. Check with LIVE root-node to see if it has new INSITU
    //    state updates. If so receive them and broadcast to all satellites.
    // 2. Update the InsituProxyManager using the most recent XML state we
    //    have.
    if (this->Proc0NodesController)
    {
      // Notify LIVE root-node.
      ::TriggerRMI(this->Proc0NodesController, UPDATE_RMI_TAG, time, timeStep);

      // Get status of the state. Did it change? If so receive the state and
      // broadcast it to satellites.
      this->Proc0NodesController->Receive(&buffer_size, 1, 1, 8010);
      if (buffer_size > 0)
      {
        vtkLiveInsituLinkDebugMacro(<< "receiving modified state from Vis");
        buffer = new char[buffer_size + 1];
        this->Proc0NodesController->Receive(buffer, buffer_size, 1, 8011);
        buffer[buffer_size] = 0;
      }

      // Get the information about extracts. When the extracts have changed or
      // not is encoded in the stream itself.
      this->Proc0NodesController->Receive(extractsPauseMessage, 1, 8012);
    }

    if (numProcs > 1)
    {
      pm->GetGlobalController()->Broadcast(&buffer_size, 1, 0);
      if (buffer_size > 0)
      {
        pm->GetGlobalController()->Broadcast(buffer, buffer_size, 0);
      }
      pm->GetGlobalController()->Broadcast(extractsPauseMessage, 0);
    }
  }
  else
  {
    assert(numProcs > 1);
    pm->GetGlobalController()->Broadcast(&buffer_size, 1, 0);
    if (buffer_size > 0)
    {
      buffer = new char[buffer_size + 1];
      pm->GetGlobalController()->Broadcast(buffer, buffer_size, 0);
      buffer[buffer_size] = 0;
    }
    pm->GetGlobalController()->Broadcast(extractsPauseMessage, 0);
  }

  // ** here on, all the code is executed on all processes (root and
  // satellites).

  vtkSmartPointer<vtkPVXMLElement> xmlState;
  if (buffer && buffer_size > 0)
  {
    vtkNew<vtkPVXMLParser> parser;
    if (parser->Parse(buffer))
    {
      xmlState = parser->GetRootElement();
    }
  }
  delete[] buffer;

  int drop_connection = catcher.GetErrorsRaised() ? 1 : 0;
  if (numProcs > 1)
  {
    pm->GetGlobalController()->Broadcast(&drop_connection, 1, 0);
  }

  if (drop_connection)
  {
    this->DropLiveInsituConnection();
    return;
  }

  if (xmlState)
  {
    vtkNew<vtkSMInsituStateLoader> loader;
    loader->KeepIdMappingOn();
    loader->SetSessionProxyManager(this->InsituProxyManager);
    this->InsituProxyManager->LoadXMLState(xmlState, loader.GetPointer());
    int mappingSize = 0;
    vtkTypeUInt32* inSituMapping = loader->GetMappingArray(mappingSize);
    // Save mapping outside that scope
    for (int i = 0; i < mappingSize; ++i)
    {
      idMappingInStateLoading.push_back(inSituMapping[i]);
    }
  }

  // Read if the simulation should be paused on INSITU side
  extractsPauseMessage >> this->SimulationPaused;
  // Process information about extracts
  int extracts_valid = 0;
  extractsPauseMessage >> extracts_valid;
  if (extracts_valid)
  {
    assert(this->ExtractsDeliveryHelper.GetPointer() != nullptr);
    this->ExtractsDeliveryHelper->ClearAllExtracts();
    int numberOfExtracts;
    extractsPauseMessage >> numberOfExtracts;
    for (int cc = 0; cc < numberOfExtracts; cc++)
    {
      std::string group, name;
      int port;
      extractsPauseMessage >> group >> name >> port;

      vtkSMProxy* proxy = this->InsituProxyManager->GetProxy(group.c_str(), name.c_str());
      if (proxy)
      {
        vtkAlgorithm* algo = vtkAlgorithm::SafeDownCast(proxy->GetClientSideObject());
        if (algo)
        {
          vtkInternals::Key key(group.c_str(), name.c_str(), port);
          this->ExtractsDeliveryHelper->AddExtractProducer(
            key.ToString().c_str(), algo->GetOutputPort(port));
        }
        else
        {
          vtkErrorMacro("No vtkAlgorithm: " << group.c_str() << ", " << name.c_str());
        }
      }
      else
      {
        vtkErrorMacro("No proxy: " << group.c_str() << ", " << name.c_str());
      }
    }
  }

  // Share the id mapping between INSITU and LIVE root node
  if (this->Proc0NodesController)
  {
    int mappingSize = static_cast<int>(idMappingInStateLoading.size());
    this->Proc0NodesController->Send(&mappingSize, 1, 1, 8013);
    if (mappingSize > 0)
    {
      this->Proc0NodesController->Send(idMappingInStateLoading.data(), mappingSize, 1, 8014);
    }
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::InsituPostProcess(double time, vtkIdType timeStep)
{
  assert(this->ProcessType == INSITU);

  if (!this->ExtractsDeliveryHelper)
  {
    // if this->ExtractsDeliveryHelper is nullptr it means we are not connected to
    // any ParaView Visualization Engine yet. Just skip.
    return;
  }

  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();

  vtkCommunicationErrorCatcher catcher(this->Proc0NodesController);
  if (myId == 0 && this->Proc0NodesController)
  {
    // notify vis root node that we are ready to ship extracts.
    ::TriggerRMI(this->Proc0NodesController, POSTPROCESS_RMI_TAG, time, timeStep);
  }

  int drop_connection = catcher.GetErrorsRaised() ? 1 : 0;
  if (pm->GetNumberOfLocalPartitions() > 1)
  {
    pm->GetGlobalController()->Broadcast(&drop_connection, 1, 0);
  }

  if (drop_connection)
  {
    // ParaView Live has disconnected. Clean up the connection.
    this->DropLiveInsituConnection();
    return;
  }

  assert(this->ExtractsDeliveryHelper);

  // We're done coprocessing. Deliver the extracts to the visualization
  // processes.
  this->ExtractsDeliveryHelper->Update();

  // Update DataInformations
  if (myId == 0 && this->Proc0NodesController)
  {
    vtkClientServerStream stream;
    vtkNew<vtkSMProxyIterator> proxyIterator;
    proxyIterator->SetSessionProxyManager(this->InsituProxyManager);
    proxyIterator->SetModeToOneGroup();
    proxyIterator->Begin("sources");

    // Serialized DataInformation
    stream << vtkClientServerStream::Reply;
    while (!proxyIterator->IsAtEnd())
    {
      vtkSMSourceProxy* source = vtkSMSourceProxy::SafeDownCast(proxyIterator->GetProxy());
      if (source)
      {
        for (unsigned int port = 0; port < source->GetNumberOfOutputPorts(); ++port)
        {
          if (this->Internals->IsNew(source->GetGlobalID(), port, source->GetDataInformation(port)))
          {
            vtkClientServerStream dataStream;
            source->GetDataInformation(port)->CopyToStream(&dataStream);
            // Serialize the data
            stream << source->GetGlobalID() << port << dataStream;
          }
        }
      }
      proxyIterator->Next();
    }
    stream << vtkClientServerStream::End;

    // notify vis root node that we are ready to ship extracts.
    const unsigned char* data;
    size_t size;
    stream.GetData(&data, &size);
    vtkIdType idtype_size = static_cast<vtkIdType>(size);
    this->Proc0NodesController->Send(&idtype_size, 1, 1, 674523);
    this->Proc0NodesController->Send(&data[0], idtype_size, 1, 674524);
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::OnInsituUpdate(double time, vtkIdType timeStep)
{
  assert(this->ProcessType == LIVE);

  // this method get called on:
  // - root node when "sim" notifies the root viz node.
  // - satellizes when "root" viz node notifies the satellizes.
  vtkLiveInsituLinkDebugMacro(<< "vtkLiveInsituLink::OnInsituUpdate: " << time);

  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();
  if (myId == 0 && pm->GetNumberOfLocalPartitions() > 1)
  {
    ::TriggerRMIOnAllChildren(pm->GetGlobalController(), UPDATE_RMI_TAG, time, timeStep);
  }

  if (myId == 0)
  {
    // The steps to perform are:
    // 1. Send coprocessing pipeline state to the INSITU root, if the
    //    state has changed since the last time we sent it.
    // 2. Send information about extracts to the INSITU root, if the
    //    requested extracts has changed.

    int xml_state_size = 0;
    if (this->InsituXMLStateChanged)
    {
      xml_state_size = static_cast<int>(strlen(this->InsituXMLState));
    }
    // xml_state_size of 0 indicates that there are not updates to the state.
    // the CoProcessor simply uses the state it received most recently.
    this->Proc0NodesController->Send(&xml_state_size, 1, 1, 8010);
    if (xml_state_size > 0)
    {
      vtkLiveInsituLinkDebugMacro(<< "Sending modified state to simulation.");
      this->Proc0NodesController->Send(this->InsituXMLState, xml_state_size, 1, 8011);
    }

    vtkMultiProcessStream extractsPauseMessage;
    extractsPauseMessage << this->SimulationPaused;
    if (this->ExtractsChanged)
    {
      extractsPauseMessage << 1;
      extractsPauseMessage << static_cast<int>(this->Internals->Extracts.size());
      for (vtkInternals::ExtractsMap::iterator iter = this->Internals->Extracts.begin();
           iter != this->Internals->Extracts.end(); ++iter)
      {
        extractsPauseMessage << iter->first.Group << iter->first.Name << iter->first.Port;
      }
    }
    else
    {
      extractsPauseMessage << 0;
    }
    this->Proc0NodesController->Send(extractsPauseMessage, 1, 8012);

    // Read the server id mapping
    int numberOfIds = 0;
    this->Proc0NodesController->Receive(&numberOfIds, 1, 1, 8013);
    if (numberOfIds > 0)
    {
      vtkTypeUInt32* idMapTable = new vtkTypeUInt32[numberOfIds];
      this->Proc0NodesController->Receive(idMapTable, numberOfIds, 1, 8014);
      NotifyClientIdMapping(this->LiveSession, this->ProxyId, numberOfIds, idMapTable);
      delete[] idMapTable;
    }
  }
  else
  {
    // There's nothing to do on satellites for this call right now.
  }

  this->InsituXMLStateChanged = false;
  this->ExtractsChanged = false;
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::OnInsituPostProcess(double time, vtkIdType timeStep)
{
  assert(this->ProcessType == LIVE);

  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();
  if (myId == 0 && pm->GetNumberOfLocalPartitions() > 1)
  {
    ::TriggerRMIOnAllChildren(pm->GetGlobalController(), POSTPROCESS_RMI_TAG, time, timeStep);
  }

  vtkLiveInsituLinkDebugMacro(<< "vtkLiveInsituLink::OnInsituPostProcess: " << time);

  // Obtains extracts from the simulations processes.
  bool dataAvailable = this->ExtractsDeliveryHelper->Update();

  // Retrieve the vtkPVDataInformations
  std::map<std::pair<vtkTypeUInt32, unsigned int>, std::string> dataInformation;
  if (myId == 0 && this->Proc0NodesController)
  {
    // Convert serialized version
    vtkIdType size = 0;
    this->Proc0NodesController->Receive(&size, 1, 1, 674523);
    unsigned char* data = new unsigned char[size];
    this->Proc0NodesController->Receive((char*)data, size, 1, 674524);
    vtkClientServerStream mainStream;
    mainStream.SetData(data, size);
    delete[] data;

    int nbArgs = mainStream.GetNumberOfArguments(0);
    int arg = 0;
    vtkTypeUInt32 id;
    unsigned int port;
    vtkClientServerStream stream;
    while (arg < nbArgs)
    {
      mainStream.GetArgument(0, arg++, &id);
      mainStream.GetArgument(0, arg++, &port);
      mainStream.GetArgument(0, arg++, &stream);
      const unsigned char* oldStr;
      size_t oldStrSize;
      stream.GetData(&oldStr, &oldStrSize);
      std::string newStr((const char*)oldStr, oldStrSize);

      dataInformation[std::pair<vtkTypeUInt32, unsigned int>(id, port)] = newStr;
    }
  }
  if (myId == 0 && dataAvailable)
  {
    NotifyClientDataInformationNextTimestep(
      this->LiveSession, this->ProxyId, dataInformation, timeStep);
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::RegisterExtract(
  vtkTrivialProducer* producer, const char* groupname, const char* proxyname, int portnumber)
{
  assert(this->ProcessType == LIVE);

  if (!this->ExtractsDeliveryHelper)
  {
    vtkWarningMacro("Connection to simulation has been dropped!!!");
    return;
  }

  vtkLiveInsituLinkDebugMacro(<< "Adding Extract: " << groupname << ", " << proxyname);

  vtkInternals::Key key(groupname, proxyname, portnumber);
  this->Internals->Extracts[key] = producer;
  this->ExtractsChanged = true;
  this->ExtractsDeliveryHelper->AddExtractConsumer(key.ToString().c_str(), producer);
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::UnRegisterExtract(vtkTrivialProducer* producer)
{
  assert(this->ProcessType == LIVE);

  if (!this->ExtractsDeliveryHelper)
  {
    vtkWarningMacro("Connection to simulation has been dropped!!!");
    return;
  }

  for (vtkInternals::ExtractsMap::iterator iter = this->Internals->Extracts.begin();
       iter != this->Internals->Extracts.end(); ++iter)
  {
    if (iter->second.GetPointer() == producer)
    {
      this->ExtractsDeliveryHelper->RemoveExtractConsumer(iter->first.ToString().c_str());
      this->Internals->Extracts.erase(iter);
      this->ExtractsChanged = true;
      break;
    }
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
}
//----------------------------------------------------------------------------
bool vtkLiveInsituLink::FilterXMLState(vtkPVXMLElement* xmlState)
{
  if (xmlState == nullptr)
  {
    return false;
  }

  // Init search set if needed
  static std::set<std::string> groupSet;
  static std::set<std::string> nameSet;

  // Fill search set if empty
  if (groupSet.empty())
  {
    groupSet.insert("animation");
    groupSet.insert("misc");
    groupSet.insert("representations");
    groupSet.insert("views");
    // ---
    nameSet.insert("timekeeper");
    nameSet.insert("animation");
    nameSet.insert("views");
    nameSet.insert("representations");
  }

  bool changed = false;
  if (!strcmp(xmlState->GetName(), "Proxy"))
  {
    std::string group = xmlState->GetAttribute("group");
    if (groupSet.find(group) != groupSet.end())
    {
      xmlState->GetParent()->RemoveNestedElement(xmlState);
      return true;
    }
  }
  else if (!strcmp(xmlState->GetName(), "ProxyCollection"))
  {
    std::string name = xmlState->GetAttribute("name");
    if (nameSet.find(name) != nameSet.end())
    {
      xmlState->GetParent()->RemoveNestedElement(xmlState);
      return true;
    }
  }
  else
  {
    for (unsigned int i = 0; i < xmlState->GetNumberOfNestedElements(); ++i)
    {
      if (vtkLiveInsituLink::FilterXMLState(xmlState->GetNestedElement(i)))
      {
        changed = true;
        i--;
      }
    }
  }
  return changed;
}

//----------------------------------------------------------------------------
int vtkLiveInsituLink::WaitForLiveChange()
{
  assert(this->ProcessType == INSITU);
  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();
  int numProcs = pm->GetNumberOfLocalPartitions();
  vtkLiveInsituLinkDebugMacro(<< "WaitForLiveChange " << myId);

  int error = 0;
  int processRMIError = vtkMultiProcessController::RMI_NO_ERROR;
  if (myId == 0)
  {
    vtkLiveInsituLinkDebugMacro(<< "ProcessRMIs " << myId);
    processRMIError = this->Proc0NodesController->ProcessRMIs(1, 1);
  }
  if (numProcs > 1)
  {
    // children wait for parent
    vtkLiveInsituLinkDebugMacro(<< "Broadcast" << myId);
    pm->GetGlobalController()->Broadcast(&processRMIError, 1, 0);
  }
  if (processRMIError != vtkMultiProcessController::RMI_NO_ERROR)
  {
    // catalyst paraview live connection was dropped.
    vtkLiveInsituLinkDebugMacro(<< "LIVE connection was dropped: " << processRMIError);
    this->DropLiveInsituConnection();
    error = 1;
  }
  vtkLiveInsituLinkDebugMacro(<< "Exit WaitForLiveChange " << myId);
  return error;
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::OnLiveChanged()
{
  assert(this->ProcessType == INSITU);
  vtkLiveInsituLinkDebugMacro(<< "OnLiveChanged "
                              << vtkProcessModule::GetProcessModule()->GetPartitionId());
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::LiveChanged()
{
  assert(this->ProcessType == LIVE);
  vtkProcessModule* pm = vtkProcessModule::GetProcessModule();
  int myId = pm->GetPartitionId();
  if (myId == 0 && this->Proc0NodesController != nullptr)
  {
    vtkLiveInsituLinkDebugMacro(<< "LiveChanged " << myId);
    this->Proc0NodesController->TriggerRMI(1, LIVE_CHANGED);
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::SetSimulationPaused(int paused)
{
  assert(this->ProcessType == LIVE);
  if (this->SimulationPaused != paused)
  {
    this->SimulationPaused = paused;
    this->Modified();
    vtkLiveInsituLinkDebugMacro(<< "SetSimulationPaused: " << paused);
  }
}

//----------------------------------------------------------------------------
void vtkLiveInsituLink::UpdateInsituXMLState(const char* txt)
{
  this->InsituXMLStateChanged = true;
  this->SetInsituXMLState(txt);
  vtkLiveInsituLinkDebugMacro(<< "UpdateInsituXMLState");
}
