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//
// Author: Ivana Hrivnacova, 26/08/2021 (ivana@ipno.in2p3.fr)

#include "G4AnalysisUtilities.hh"
#include "G4RootRFileDef.hh"

#include "tools/rroot/file"
#include "tools/rroot/rall"
#include "tools/rroot/streamers"

//_____________________________________________________________________________
template <typename HT>
inline
tools::rroot::buffer* G4RootHnRFileManager<HT>::GetBuffer(
  const G4String& fileName, const G4String& dirName, const G4String& objectName)
{
// Get buffer for reading histogram or profile specified by objectNmae
// for a file specified by fileName;
// Open the file if it was not yet open

  // Histograms and profiles are not saved per thread
  G4bool isPerThread = false;

  // Get or open a file
  auto rfileTuple = fRFileManager->GetRFile(fileName, isPerThread);
  if (rfileTuple == nullptr) {
    if ( ! fRFileManager->OpenRFile(fileName, isPerThread) ) {
      return nullptr;
    }
    rfileTuple = fRFileManager->GetRFile(fileName, isPerThread);
  }
  auto rfile = std::get<0>(*rfileTuple);

  // Get or open a directory if dirName is defined
  tools::rroot::TDirectory* histoDirectory = nullptr;
  if ( histoDirectory == nullptr ) {
    // Retrieve directory only once as analysis manager supports only
    // 1 histo directory par file)
    if ( ! dirName.empty() ) {
      histoDirectory = tools::rroot::find_dir(rfile->dir(), dirName);
      if ( histoDirectory != nullptr ) {
        std::get<1>(*rfileTuple) = histoDirectory;
      }
      else {
        G4Analysis::Warn(
          "Directory " + dirName + " not found in file " + fileName + ".",
          fkClass, "ReadNtupleImpl");
        return nullptr;
      }
    }
  }

  // Get key
  tools::rroot::key* key = nullptr;
  if ( histoDirectory != nullptr ) {
    key = histoDirectory->find_key(objectName);
  }
  else {
    key = rfile->dir().find_key(objectName);
  }
  if (key == nullptr) {
    G4Analysis::Warn(
      "Key " + objectName + " for Histogram/Profile not found in file " +
      fileName + ", directory " + dirName, fkClass, "GetBuffer");
    return nullptr;
  }

  unsigned int size;
  char* charBuffer = key->get_object_buffer(*rfile, size);

  if (charBuffer == nullptr) {
    G4Analysis::Warn(
      "Cannot get " + objectName + " in file " + fileName,
      fkClass, "GetBuffer");
    return nullptr;
  }

  auto verbose = false;
  return new tools::rroot::buffer(G4cout, rfile->byte_swap(), size, charBuffer,
                                  key->key_length(), verbose);
}

//_____________________________________________________________________________
template <>
inline
tools::histo::h1d* G4RootHnRFileManager<tools::histo::h1d>::ReadT(
  tools::rroot::buffer* buffer)
{
  return tools::rroot::TH1D_stream(*buffer);
}

//_____________________________________________________________________________
template <>
inline
tools::histo::h2d* G4RootHnRFileManager<tools::histo::h2d>::ReadT(
  tools::rroot::buffer* buffer)
{
  return tools::rroot::TH2D_stream(*buffer);
}

//_____________________________________________________________________________
template <>
inline
tools::histo::h3d* G4RootHnRFileManager<tools::histo::h3d>::ReadT(
  tools::rroot::buffer* buffer)
{
  return tools::rroot::TH3D_stream(*buffer);
}

//_____________________________________________________________________________
template <>
inline
tools::histo::p1d* G4RootHnRFileManager<tools::histo::p1d>::ReadT(
  tools::rroot::buffer* buffer)
{
  return tools::rroot::TProfile_stream(*buffer);
}

//_____________________________________________________________________________
template <>
inline
tools::histo::p2d* G4RootHnRFileManager<tools::histo::p2d>::ReadT(
  tools::rroot::buffer* buffer)
{
  return tools::rroot::TProfile2D_stream(*buffer);
}

//_____________________________________________________________________________
template <typename HT>
inline
HT* G4RootHnRFileManager<HT>::Read(
  const G4String& htName, const G4String& fileName, const G4String& dirName,
  G4bool /*isUserFileName*/)
{
  auto buffer = GetBuffer(fileName, dirName, htName);
  if ( ! buffer ) {
    return nullptr;
  }

  auto ht = ReadT(buffer);
  delete buffer;

  if ( ! ht ) {
    G4Analysis::Warn(
      "Streaming " + htName + " in file " + fileName + " failed.",
      fkClass, "Read");
    return nullptr;
  }

  return ht;
}