//Author: C. Delaere
//Original version: 31/05/2007

#include "TObject.h"
#include "TKey.h"
#include "TFile.h"
#include "TString.h"
#include "TH1.h"
#include "TProfile.h"
#include "TObjArray.h"
#include "TObjString.h"
#include "TDirectory.h"
#include <iostream>

class mergeInfo {
 public:
  mergeInfo(TString basename, unsigned int n);
  virtual ~mergeInfo() { }
  virtual void merge();
 private:
  virtual void scanDirectory();
  virtual void copyProfile(TString path, TProfile* profile);
  virtual void createPath(TString path);
  TFile* input_;
  TFile* output_;
  TString basename_;
  unsigned int nInput_;
};

mergeInfo::mergeInfo(TString basename, unsigned int n):basename_(basename),nInput_(n)
{
  output_ = new TFile(basename+"_merged.root","RECREATE");
}

void mergeInfo::merge() 
{
  if(!output_) return;
  TString num;
  for(unsigned int i=0; i<nInput_; ++i) {
    if(i<10) num = "00"; else if(i<100) num = "0"; else num = "";
    num += i;
    input_ = new TFile(basename_+"_"+num+".root");
    input_->cd();
    input_->cd("DQMData");
    std::cout << "Merging data from file " << input_->GetName() << std::endl;
    scanDirectory();
    input_->Close();
    delete input_;
  }
  std::cout << "Saving..." << std::endl;
  output_->Write(output_->GetName(),TObject::kWriteDelete);
  output_->Close(); 
  delete output_;
  output_ = NULL;
}

void mergeInfo::scanDirectory() 
{
  TIter next(gDirectory->GetListOfKeys());
  TString filename = input_->GetName();
  int offset = filename.Sizeof()+15;
  while (TKey *obj = (TKey*)next()) {
    TObject* o = obj->ReadObj();
    // if it's a directory, enter
    if (strcmp(o->IsA()->GetName(),"TDirectory")==0) {
       gDirectory->cd(o->GetName());
       scanDirectory();
       gDirectory->cd("..");
    }
    // if it's a TProfile, handle it
    if( strcmp(o->IsA()->GetName(),"TProfile")==0) {
      TProfile* p = (TProfile*) o;
      TString path = gDirectory->GetPath()+offset;
      copyProfile(path, p);
    }
    // else, ignore
    delete o;
  }
}

void mergeInfo::copyProfile(TString path, TProfile* profile)
{
  TDirectory* sourceDir = gDirectory;
  // first check that the directory exist. If not, create it.
  if(!output_->GetDirectory(path)) createPath(path);
  output_->cd(path);
  // then look if there is a TProfile there.
  TProfile* p = (TProfile*)gDirectory->Get(profile->GetName());
  if(p) {
    // then add the profile to the existing one
    p->Add(profile);
  } else {
    // then copy the profile here
    gDirectory->WriteTObject(profile);
  }
  sourceDir->cd();
}

void mergeInfo::createPath(TString path)
{
  TDirectory* startDir = gDirectory;
  // first split the path
  TObjArray* tokens = path.Tokenize("/");
  output_->cd();
  // start at the first level, and create if needed
  for(int i=0;i<tokens->GetEntriesFast();++i) {
    TString subpath = ((TObjString*)tokens->At(i))->GetString();
    if(!gDirectory->GetDirectory(subpath)) {
      gDirectory->mkdir(subpath);
    }
    gDirectory->cd(subpath);
  }
  delete tokens;
  startDir->cd();
}