#include <string>
#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>

#include "TROOT.h"
#include "TFile.h"
#include "TKey.h"
#include "TH1.h"
#include "TProfile.h"
#include "TString.h"
#include "TRegexp.h"

#include "JGizmo/JRootObjectID.hh"
#include "JGizmo/JGizmoToolkit.hh"

#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


/**
 * \file
 * Auxiliary program to determine standard deviation of a set of 1D histograms.
 * The option <tt>-f</tt> corresponds to <tt>\<file name\>:\<object name\></tt>.
 * \author mdejong
 */
int main(int argc, char **argv)
{
  using namespace std;
  using namespace JPP;
  
  vector<JRootObjectID> inputFile;
  string                outputFile;
  int                   debug;

  try {

    JParser<> zap("Auxiliary program to determine standard deviation of a set of 1D histograms.");

    zap['f'] = make_field(inputFile,  "<input file>:<object name>");
    zap['o'] = make_field(outputFile, "ROOT file with histogram") = "stdev.root";
    zap['d'] = make_field(debug)      = 1;

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }


  TH1* h3 = NULL;
  
  vector<TH1*> listOfHistograms;

  for (vector<JRootObjectID>::const_iterator input = inputFile.begin(); input != inputFile.end(); ++input) {

    DEBUG("Input: " << *input << endl);

    TDirectory* dir = getDirectory(*input);

    if (dir == NULL) {
      ERROR("File: " << input->getFullFilename() << " not opened." << endl);
      continue;
    }

    const TRegexp regexp(input->getObjectName());

    TIter iter(dir->GetListOfKeys());

    for (TKey* key; (key = (TKey*) iter.Next()) != NULL; ) {

      const TString tag(key->GetName());

      DEBUG("Key: " << tag << " match = " << tag.Contains(regexp) << endl);

      // option match

      if (tag.Contains(regexp) && isTObject(key)) {

	TObject* p  = key->ReadObj();

	if (!p->InheritsFrom("TH1")) {
	  FATAL("Object " << p->GetName() << " not compatible with histogram operations." << endl);
	}

	if (h3 == NULL) {

	  h3 = (TH1*) p->Clone("stdev");
	  
	} else {

	  TH1* h1 = (TH1*) p;
	  
	  if (h3->GetXaxis()->GetNbins() != h1->GetXaxis()->GetNbins() ||
	      h3->GetXaxis()->GetXmin () != h1->GetXaxis()->GetXmin () ||
	      h3->GetXaxis()->GetXmax () != h1->GetXaxis()->GetXmax ()) {
	    FATAL("Objects " << h3->GetName() << " and " << p->GetName() << " have different binning." << endl);
	  }
	}

	listOfHistograms.push_back((TH1*) p);
      }
    }
  }

  if (listOfHistograms.size() <= 1) {
    FATAL("Not enough histograms " << listOfHistograms.size() << endl);
  }

  for (Int_t i = 1; i <= h3->GetNbinsX(); ++i) {

    Double_t Y = 0.0;
    Double_t Z = 0.0;

    for (vector<TH1*>::const_iterator p = listOfHistograms.begin(); p != listOfHistograms.end(); ++p) {
      Y += (*p)->GetBinContent(i);
      Z += (*p)->GetBinError(i) * (*p)->GetBinError(i);
    }

    Z  = sqrt(Z);
    Y /= listOfHistograms.size();
    Z /= listOfHistograms.size();

    Double_t y = 0.0;
    
    for (vector<TH1*>::const_iterator p = listOfHistograms.begin(); p != listOfHistograms.end(); ++p) {
      y += ((*p)->GetBinContent(i) - Y)*((*p)->GetBinContent(i) - Y) / ((*p)->GetBinError(i)*(*p)->GetBinError(i) + Z*Z);
    }

    y  = sqrt(y / listOfHistograms.size());

    h3->SetBinContent(i, y);
    h3->SetBinError  (i, 0.0);
  }

  if (h3 != NULL) {

    TFile out(outputFile.c_str(), "recreate");
    
    h3->Write();
    
    out.Write();
    out.Close();
  }
}