//macro to add histogram files
//NOTE: This macro is kept for back compatibility only.
//Use instead the executable $ROOTSYS/bin/hadd
//
//This macro will add histograms from a list of root files and write them
//to a target root file. The target file is newly created and must not be
//identical to one of the source files.
//
//Author: Sven A. Schmidt, sven.schmidt@cern.ch
//Date:   13.2.2001

//This code is based on the hadd.C example by Rene Brun and Dirk Geppert,
//which had a problem with directories more than one level deep.
//(see macro hadd_old.C for this previous implementation).
//
//The macro from Sven has been enhanced by
//   Anne-Sylvie Nicollerat <Anne-Sylvie.Nicollerat@cern.ch>
// to automatically add Trees (via a chain of trees).
//
//To use this macro, modify the file names in function hadd.
//
//NB: This macro is provided as a tutorial.
//    Use $ROOTSYS/bin/hadd to merge many histogram files


#include <sstream>
#include <string.h>
#include "TChain.h"
#include "TFile.h"
#include "TH1.h"
#include "TTree.h"
#include "TKey.h"
#include "Riostream.h"

TList *FileList;
TFile *Target;

void MergeRootfile( TDirectory *target, TList *sourcelist );
bool CheckFile(TFile* fileAna, TFile* fileReco);


void hadd() {

    string dir = "/hera/cbm/users/slebedev/mc/dielectron/nov13/25gev/trd/1.0field/nomvd/";
    string fileArray = ".auau.25gev.centr.";
    string particleDir[5] = {"omegaepem", "phi", "omegadalitz", "rho0", "urqmd"};
    string addString = "analysis"; //analysis or litqa
    int nofFiles = 250;

	for (int iF = 0; iF < 4; iF++){
	        string fileNameAna = dir + particleDir[iF] + "/" + string("analysis") + fileArray;
	        string fileNameReco = dir + particleDir[iF] + "/" + string("reco") + fileArray;
	        string fileNameQa = dir + particleDir[iF] + "/" + string("litqa") + fileArray;

		cout << "-I- " << dir << endl;

		string outputFile = fileNameAna;
		if (addString == "litqa") outputFile = fileNameQa;
		outputFile += "all.root";
		cout << "-I- OUTPUT: " << outputFile << endl;
		TFile* Target = TFile::Open( outputFile.c_str(), "RECREATE" );

		int count = 0;
		TList* FileList = new TList();
		for (int i = 1; i < nofFiles; i++){
			stringstream ss;
			ss.fill('0');
			ss.width(5);
			ss  << i << ".root";

			TFile* fileAna = TFile::Open( (fileNameAna + ss.str() ).c_str(), "READ");
			TFile* fileReco = TFile::Open( (fileNameReco + ss.str() ).c_str(), "READ");
			TFile* fileQa = TFile::Open( (fileNameQa+ss.str() ).c_str(), "READ");

			Bool_t isGoodFile = CheckFile(fileAna, fileReco);

			if (fileReco != NULL) fileReco->Close();

			if ( isGoodFile ){
				if (addString == "analysis"){
					FileList->Add( fileAna );
					count++;
					if (fileQa != NULL) fileQa->Close();
				}
				if (addString == "litqa"){
					FileList->Add( fileQa );
					count++;
					if (fileAna != NULL) fileAna->Close();
				}
			} else {
				if ( fileAna != NULL) fileAna->Close();
				if ( fileQa != NULL) fileReco->Close();
			}
		}
		cout << endl<< "-I- number of files to merge = " << count << endl << endl;

		MergeRootfile( Target, FileList );

		Target->Close();
		int nFL = FileList->GetEntries();
		for (int iFL = 0; iFL < nFL; iFL++){
			TFile* f = (TFile*)FileList->At(iFL);
			f->Close();
			delete f;
		}
		delete Target;
		delete FileList;
	}//iF
}

bool CheckFile(TFile* fileAna, TFile* fileReco) {

    if (fileAna == NULL || fileReco == NULL)  return false;

    if (fileAna->GetEND() < 4000 || fileReco->GetEND() < 4000) return false;

    TTree* treeAna = (TTree*)fileAna->Get("cbmsim");
    TTree* treeReco = (TTree*)fileReco->Get("cbmsim");

    if (treeAna == NULL || treeReco == NULL) return false;

    Long64_t treeSizeAna = treeAna->GetEntriesFast();
    Long64_t treeSizeReco = treeReco->GetEntriesFast();

    if (treeSizeAna == 1000 && treeSizeReco == 1000) return true;

    return false;
}

void MergeRootfile( TDirectory *target, TList *sourcelist ) {

   //  cout << "Target path: " << target->GetPath() << endl;
   TString path( (char*)strstr( target->GetPath(), ":" ) );
   path.Remove( 0, 2 );

   TFile *first_source = (TFile*)sourcelist->First();
   first_source->cd( path );
   TDirectory *current_sourcedir = gDirectory;
   //gain time, do not add the objects in the list in memory
   Bool_t status = TH1::AddDirectoryStatus();
   TH1::AddDirectory(kFALSE);

   // loop over all keys in this directory
   TChain *globChain = 0;
   TIter nextkey( current_sourcedir->GetListOfKeys() );
   TKey *key, *oldkey=0;
   while ( (key = (TKey*)nextkey())) {
      //keep only the highest cycle number for each key
      if (oldkey && !strcmp(oldkey->GetName(),key->GetName())) continue;

      // read object from first source file
      first_source->cd( path );
      TObject *obj = key->ReadObj();

      if ( obj->IsA()->InheritsFrom( TH1::Class() ) ) {
         // descendant of TH1 -> merge it

         //      cout << "Merging histogram " << obj->GetName() << endl;
         TH1 *h1 = (TH1*)obj;

         // loop over all source files and add the content of the
         // correspondant histogram to the one pointed to by "h1"
         TFile *nextsource = (TFile*)sourcelist->After( first_source );
         while ( nextsource ) {
            // make sure we are at the correct directory level by cd'ing to path
            nextsource->cd( path );
            TKey *key2 = (TKey*)gDirectory->GetListOfKeys()->FindObject(h1->GetName());
            if (key2) {
               TH1 *h2 = (TH1*)key2->ReadObj();
               h1->Add( h2 );
               delete h2;
            }
           // cout << nextsource->GetPath() << endl;
            nextsource = (TFile*)sourcelist->After( nextsource );
         }
      }
//      else if ( obj->IsA()->InheritsFrom( TTree::Class() ) ) {
//
//         // loop over all source files create a chain of Trees "globChain"
//         const char* obj_name= obj->GetName();
//
//         globChain = new TChain(obj_name);
//         globChain->Add(first_source->GetName());
//         TFile *nextsource = (TFile*)sourcelist->After( first_source );
//         //      const char* file_name = nextsource->GetName();
//         // cout << "file name  " << file_name << endl;
//         while ( nextsource ) {
//
//            globChain->Add(nextsource->GetName());
//            nextsource = (TFile*)sourcelist->After( nextsource );
//         }
//
//      } else if ( obj->IsA()->InheritsFrom( TDirectory::Class() ) ) {
//         // it's a subdirectory
//
//         cout << "Found subdirectory " << obj->GetName() << endl;
//
//         // create a new subdir of same name and title in the target file
//         target->cd();
//         TDirectory *newdir = target->mkdir( obj->GetName(), obj->GetTitle() );
//
//         // newdir is now the starting point of another round of merging
//         // newdir still knows its depth within the target file via
//         // GetPath(), so we can still figure out where we are in the recursion
//         MergeRootfile( newdir, sourcelist );
//
//      } else {
//
//         // object is of no type that we know or can handle
//         cout << "Unknown object type, name: "
//         << obj->GetName() << " title: " << obj->GetTitle() << endl;
//      }

      // now write the merged histogram (which is "in" obj) to the target file
      // note that this will just store obj in the current directory level,
      // which is not persistent until the complete directory itself is stored
      // by "target->Write()" below
      if ( obj ) {
         target->cd();

         //!!if the object is a tree, it is stored in globChain...
//         if(obj->IsA()->InheritsFrom( TTree::Class() ))
//            globChain->Merge(target->GetFile(),0,"keep");
//         else
            obj->Write( key->GetName() );
      }

   } // while ( ( TKey *key = (TKey*)nextkey() ) )

   // save modifications to target file
   target->SaveSelf(kTRUE);
   TH1::AddDirectory(status);
}