////////////////////////////////////////////////////////////////////
//
// This processor outputs the events into a T tree containing
// DS::Entry instances and a runT tree containing DS::Run instances.
// The name of the file can be specified at the command line, in
// the ratdb and in the macro.
//
// Author: Stan Seibert <volsung@physics.utexas.edu>
//         P G Jones <p.g.jones@qmul.ac.uk> - contact person
//
// REVISION HISTORY:
//     2014-04-26 : P Jones - refactor, add doxygen.
//     2016-10-19 : M Stringer - Changes to how MCTracks are accessed (PR #1508).
//     2017-04-26:  J Dunger - add end of job meta informatio
//     2018-01-11: N Barros - Change file opening logic to allow to specify a file suffix
//     2018-01-12: N Barros - Moved file creation to BeginOfRun to make sure that
//                           a file is always created, even if it is empty
//
////////////////////////////////////////////////////////////////////
#ifndef __RATOutROOTProc___
#define __RATOutROOTProc___

#include <RAT/Processor.hh>
#include <RAT/MetaHelper.hh>
#include <string>

class TFile;
class TTree;

namespace RAT
{

class OutROOTProc : public Processor
{
public:
  // Constructor, initialises pointers to NULL
  OutROOTProc();

  // Destructor, close file and finalise
  ~OutROOTProc();

  // Called when a procset string is set on the command line
  //
  // The options are,
  // `file name` which sets the name of a file to create and write to
  // `updatefile name` which sets the name of a file to update to
  //
  // param: parameter or command
  // value: value to set
  // Throws ParamUnknown if the param is not file or updatefile
  void SetS( const std::string& param, const std::string& value );

  // Called when a procset int is set on the command line
  //
  // The options are,
  // `autosave value` which sets the maximum interval between points in run at which all
  //  the baskets are closed and written to disk individually.
  // `autoflush value` which sets the maximum interval between points in run at which
  //  a new key is written in the output root file and all data are output.
  // See comments in the ROOT routine TTree.cxx
  //
  // param: parameter or command
  // value: value to set
  // Throws ParamUnknown if the param is not autosave or autoflush
  // Throws ParamInvalid if the autosave value is negative
  void SetI( const std::string& param, const int value );

  // Begin of run, load from the database
  //
  // run: Data structure for the run
  void BeginOfRun( DS::Run& run );

  // New event, write it out
  //
  // run: Data structure for the run
  // ds: Data structure for the event
  Processor::Result DSEvent( DS::Run& run, DS::Entry& ds );

  // End of run, write out the run
  //
  // run: Data structure for the run
  void EndOfRun( DS::Run& run );

private:
  // Opens the file ready to write to
  void OpenFile();

  std::string fDBFileName; // The file name as loaded from the ratdb, the default
  std::string fOverrideFileName; // The file name as set from the macro
  std::string fFileNameSuffix; // suffix to be applied between the file name and the extension

  TFile* fFile; // The file to write to
  TTree* fDSTree; // The dsTree to write DS::Entry instances to
  TTree* fRunTree; // The runTree to write DS::Run instances to
  DS::Entry* fDSBranch; // The branch in the dsTree
  DS::Run* fRunBranch; // The branch in the runTree

  int fAutoSave; // Number to pass to ROOT to indicate when to autosave
  int fAutoFlush; // Number to pass to ROOT to indicate when to autoflush

  bool fUpdate; // Update the file if true, overwrite if false

  MetaHelper fMetaHelper; // to count the events going by each run, written to meta data at the end
};

} // namespace RAT

#endif