// M Hentz, 2017

// This class reads in the input phase space file in a buffered manner.

#include "FileReader.hh"

#include "G4ThreeVector.hh"

FileReader::FileReader( G4String filename )
    :fBufferSize(10000)
{
  fInputFile.open( filename.data(), std::ios::in );
  
  G4cout << "----------------- Input ----------------" << G4endl;
  G4cout << "Generating primaries from \"" << filename << "\"" << G4endl;

  // Skipping first line
  G4String commentLine = "";
  getline(fInputFile, commentLine); // uncomment to skip first line
  G4cout << "  Skipped line:" << G4endl;
  G4cout << "      " << commentLine << G4endl;
  G4cout << "----------------------------------------" << G4endl;
  G4cout << G4endl;
}

FileReader::~FileReader()
{
  fInputFile.close();
}

// Primary class constructor
FileReader::Primary::Primary()
{;}

// Primary class destructor
FileReader::Primary::~Primary()
{;}

FileReader::Primary* FileReader::GetPrimary()
{
  // Read in primaries if the primary list is empty
  if( fPrimaryList.size() == 0 ){

    // Read 100 primaries at a time
    for( int i = 0; i < fBufferSize; i++ ){

      // getline() requires strings to fill
      G4String blank;
      G4String name;
      G4String _x, _y, _z;
      G4String _momx, _momy, _momz;
      G4String _energy;

      getline( fInputFile, blank, ',' );
      getline( fInputFile, name, ',' );
      getline( fInputFile, _x, ',' );
      getline( fInputFile, _y, ',' );
      getline( fInputFile, _z, ',' );
      getline( fInputFile, _momx, ',' );
      getline( fInputFile, _momy, ',' );
      getline( fInputFile, _momz, ',' );
      getline( fInputFile, _energy, '\n' );

      // Parse strings to doubles
      G4double x, y, z;
      G4double momx, momy, momz;
      G4double energy;

      x      = stod( _x );
      y      = stod( _y );
      z      = stod( _z );
      momx   = stod( _momx );
      momy   = stod( _momy );
      momz   = stod( _momz );
      energy = stod( _energy );

      // Define position and momentum direction vectors
      G4ThreeVector pos = G4ThreeVector( x, y, z );
      G4ThreeVector mom = G4ThreeVector( momx, momy, momz );

      // Generate primary particle
      FileReader::Primary* primary = new Primary();
      primary->SetName( name );
      primary->SetPosition( pos );
      primary->SetMomentum( mom );
      primary->SetEnergy( energy );

      // Populate the primaries list
      fPrimaryList.push_back( primary );
    }
  }

  // Get first element and delete it so it's not reused
  FileReader::Primary* primary = fPrimaryList.front();
  fPrimaryList.pop_front();

  return primary;
}