//*-- Author : Manuel Sanchez
//*-- Modified : 13/05/99 by Manuel Sanchez
//*-- Modified : 5/05/98 by Manuel Sanchez
//*-- Copyright : GENP (Univ. Santiago de Compostela)

//////////////////////////////////////////////////////
// HRootSource
//
//  This data source can read data from a ROOT file generated by
//HYDRA, this includes both the reconstruction and simulation software.
//
//  The data source takes care of instantiating the appropiate classes even
//if they are non-standard. That is, if you have an input file with 
//HMdcHitSim instead of HMdcHit; HRootSource will take care of using
//HMdcHitSim during the analysis.
//
//////////////////////////////////////////////////////

#include "hrootsource.h"
#include "hades.h"
#include "hevent.h"
#include <iostream.h>

ClassImp(HRootSource)

  HRootSource::HRootSource(void) {
  //Class' constructor.
    fInputTree=NULL;
    fInputFile=NULL;
    fEventInFile=0;
    fCursor=0;
}

HRootSource::~HRootSource(void) {
  //Class destructor, it clears the data source.
  Clear();
}

Bool_t HRootSource::init(void) {
  //Initializes the data source connecting the parts of the input tree in
  //the input ROOT file to the event structure used for the analysis. If
  //no event structure has been set by the user, HRootSource::init() will
  //set one taken from the input file.
  Bool_t r=kTRUE;

  if (fEventInFile!=0 && fInputFile!=0) {
    //If there is an active event structure
    if (gHades->getCurrentEvent()!=0) { 
      Warning("init","Using user defined event structure");
    } else  gHades->setEvent(fEventInFile); 
    
    if ( fInputTree!=NULL) {
      Char_t sl=*(strchr(fInputTree->GetTitle(),'.')+1);
      switch (sl) {
      case '0' : fSplitLevel=0; break;
      case '1' : fSplitLevel=1; break;
      case '2' : fSplitLevel=2; break;
      default : fSplitLevel=0;
      }
      fInputTree->SetBranchStatus("*",kFALSE);
      gHades->activateTree(fInputTree);
      r=kTRUE;
    } else {
      Clear();
      r=kFALSE;
    }
  } else {
    r=kFALSE;
  }
  return r;
}

EDsState HRootSource::getNextEvent(void) {
  //Retrieves next event in the input file.
  if (fInputTree) {
    if (fInputTree->GetEvent(fCursor)>0) {
      fCursor++;
    } else return kDsEndData;
  } else return kDsError;
  return kDsOk;
}

Bool_t HRootSource::getEvent(Int_t eventN) {
  //Retrieves event in position eventN in the input file, copying the 
  //information to the event structure.
  if (fInputTree) {
    if (fInputTree->GetEvent(eventN)>0) return kTRUE;
    else return kFALSE;
  }
  return kFALSE;
}

void HRootSource::Clear(void) {
  //Closes the input file.
  if (fInputTree) delete fInputTree;
  if (fInputFile) delete fInputFile;
}

Bool_t HRootSource::setInput(Text_t *fileName,Text_t *treeName) {
  //Sets the input file and tree. Opening the corresponding files, it also
  //loads in memory the input event description so the disableCategory() 
  //method can be used.
  fInputFile=new TFile(fileName);
  if (!fInputFile) return kFALSE;
  fInputTree=(TTree *)fInputFile->Get(treeName);
  if (!fInputTree) return kFALSE;
  fEventInFile=(HEvent *)fInputFile->Get("Event");
  if (!fEventInFile) return kFALSE;
 
  return kTRUE;
}

Bool_t HRootSource::disableCategory(Cat_t aCat) {
  //Disables the category aCat so it is not read event if it is stored in
  //the input file. This method shouldn't be called after init()
  //Returns kTRUE if the aCat was stored in the input file and has succesfully
  //been disabled, otherwise the return value is kFALSE.
  if (!fEventInFile) return kFALSE;
  return fEventInFile->removeCategory(aCat);
}

inline Int_t HRootSource::getSplitLevel(void) {
  //Returns the split level of the input tree.
  return fSplitLevel;
}

void HRootSource::deactivateBranch(Text_t *branchName) {
  //Deactivates a branch so it is not read. 
  //This method is deprecated, use disableCategory() instead.
  if (fInputTree) {
    fInputTree->SetBranchStatus(branchName,kFALSE);
  }
}

TTree *HRootSource::getTree(void) {
  //Returns the input tree.
  return fInputTree;
}