// Copyright 2019-2020 CERN and copyright holders of ALICE O2.

// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.

// All rights not expressly granted are reserved.

//

// This software is distributed under the terms of the GNU General Public

// License v3 (GPL Version 3), copied verbatim in the file "COPYING".

//

// In applying this license CERN does not waive the privileges and immunities

// granted to it by virtue of its status as an Intergovernmental Organization

// or submit itself to any jurisdiction.

#include <SimulationDataFormat/ConstMCTruthContainer.h>

#include <SimulationDataFormat/MCTruthContainer.h>

#include <SimulationDataFormat/IOMCTruthContainerView.h>

#include <SimulationDataFormat/MCCompLabel.h>

#include <TFile.h>

#include <TTree.h>

#include <iostream>

using namespace o2::dataformats;

ConstMCTruthContainer<o2::MCCompLabel>* MCLabelIOHelper::loadFromTTree(TTree* tree, std::string const& brname, int entry)

{

o2::dataformats::MCTruthContainer<o2::MCCompLabel>* labels = nullptr;

o2::dataformats::IOMCTruthContainerView* labelROOTbuffer = nullptr;

o2::dataformats::ConstMCTruthContainer<o2::MCCompLabel>* constlabels = new ConstMCTruthContainer<o2::MCCompLabel>();

auto branch = tree->GetBranch(brname.c_str());

if (!branch) {

return nullptr;

}

auto labelClass = branch->GetClassName();

bool oldlabelformat = false;

// we check how the labels are persisted and react accordingly

if (TString(labelClass).Contains("IOMCTruthContainer")) {

branch->SetAddress(&labelROOTbuffer);

branch->GetEntry(entry);

if (labelROOTbuffer) {

labelROOTbuffer->copyandflatten(*constlabels);

delete labelROOTbuffer;

}

} else {

// case when we directly streamed MCTruthContainer

// TODO: support more cases such as ConstMCTruthContainer etc

std::string serializedtype("o2::dataformats::MCTruthContainer<o2::MCCompLabel>");

if (!TString(labelClass).EqualTo(serializedtype.c_str())) {

std::cerr << "Error: expected serialized type " << serializedtype << " but found " << labelClass;

return nullptr;

}

branch->SetAddress(&labels);

branch->GetEntry(entry);

if (labels) {

labels->flatten_to(*constlabels);

delete labels;

}

}

return constlabels;

}