#include <vector>
#include <string>
#include <map>
#include <iostream>
#include "TCanvas.h"
#include "TSystem.h"
#include "TH1F.h"
#include "TTree.h"
#include "TString.h"

using namespace std;

void makeHists(int flag = 0x3,
               const char *outname = "chi2.root")
{
   TH1::AddDirectory(false);
   vector< TH1F* > hvec;
   vector< string > varVec, histNameVec, histRangeVec, cutVec;
   map < string, void* > histMap;
   TH1F *hptr;
   // your tree name
   const char *treename = "candFCNC";
   const int kNumFiles = 2;
   // the prefixes the histograms will have
   string prefix[kNumFiles] = {"fcnc", "znjet"};
   // The three filenames I can find the trees
   string filenames[kNumFiles] = { "fcnc.list", "zjets.list" };
   bool saveHistFile = false;
   bool writeEpsFiles = true;
   bool unitArea = true;
   string epsPrefix = "images/";

   ///////////////////////////////////////////////////////////////////
   //
   //
   //

   // Note: In order for this to work, anytime you push something on
   // to one of the vectores (varVec, histNameVec, histRangeVec, and
   // cutVec), you need to push something on to all of the vectors.
   

   // old chi2 10
   varVec.push_back       ("sqrt(m_permTcaPtr.m_chi2)");
   histNameVec.push_back  ("old_10_chi2");
   histRangeVec.push_back ("(100, 0, 10)");
   cutVec.push_back       ("10==m_permTcaPtr.m_type");
     
   // old chi2 21
   varVec.push_back       ("sqrt(m_permTcaPtr.m_chi2)");
   histNameVec.push_back  ("old_21_chi2");
   histRangeVec.push_back ("(100, 0, 10)");
   cutVec.push_back       ("21==m_permTcaPtr.m_type");

   //
   //
   //
   ///////////////////////////////////////////////////////////////////


   int size = (int) varVec.size();
   for (int outer = 0; outer < kNumFiles; ++outer)
   {
      cout << endl << "Making " << prefix[outer] << " histograms now." << endl;
      TChain *candFCNC = CLPFunctions::chainFromList (filenames[outer],
                                                      treename);
      for (int inner = 0; inner < size; ++inner)
      {
         string histname = prefix[outer] + "_" + histNameVec[inner];
         string drawstring = varVec[inner] + ">>" + histname
            + histRangeVec[inner];
         // now do cuts
         string cuts = cutVec[inner];
         cout << "  draw: " << drawstring << endl
              << "  cuts: " << cuts << endl;
         candFCNC->Draw(drawstring.c_str(), cuts.c_str());
         TH1F  *origPtr   = (TH1F*) gROOT->FindObject(histname.c_str());
         string clonename = histname + "C";
         TH1F  *clonePtr  = (TH1F*) origPtr->Clone(clonename.c_str());
         hvec.push_back( clonePtr );
         histMap [clonename] = (void*) clonePtr;
      } // for inner
   } // for outer

   if (flag & 0x1)
   {
      cout << "Writing to file " << outname << endl;
      TFile output (outname, "recreate");
      size = (int) hvec.size();
      for (int loop = 0; loop < size; ++loop)
      {
         hptr = hvec[loop];
         hptr->Write();
      } // for loop
      output.Close();
   };

   if (flag & 0x2)
   {
      gROOT->SetStyle("Plain");
      const int kNumColors = 3;
      const int kColors[kNumColors] = {1, 4, 2};
      const int kNumStyles = 4;
      const int kStyles[kNumStyles] = {1, 2, 3, 4};
      for (int hIndex = 0; hIndex < size; ++hIndex)
      {
         // get max size first
         float max = 0;
         for (int fIndex = 0; fIndex < kNumFiles; ++fIndex)
         {
            string histname = prefix[fIndex]  + "_"+ histNameVec[hIndex] + "C";
            //TH1F *hPtr = (TH1F*) gROOT->FindObject (histname.c_str());
            //cout << "Trying to get " << histname.c_str() << endl;
            TH1F *hPtr = (TH1F*) histMap[histname];
            if (unitArea)
            {
               // get the integral WITH overflow
               int numBins = hPtr->GetNbinsX();
               double integral = hPtr->Integral(0, numBins + 1);
               if (integral > 0)
               {
                  hPtr->Scale (1. / integral);
               }
            }
            float localmax = hPtr->GetMaximum();
            if (localmax > max)
            {
               max = localmax;
            } // localmax
         } // for fIndex
         
         // Draw everything
         TCanvas *c1 = new TCanvas();
         TLegend legend (0.7, 0.6, 0.9, 0.8); // x1, y1, x2, y2
         legend.SetFillStyle(4000); // transparent
         for (int fIndex = 0; fIndex < kNumFiles; ++fIndex)
         {
            string histname = prefix[fIndex] +"_" + histNameVec[hIndex] + "C";
            TH1F *hPtr = (TH1F*) histMap[histname];
            legend.AddEntry (hPtr, prefix[fIndex].c_str(), "l");
            hPtr->SetLineColor (kColors [fIndex % kNumColors] );
            hPtr->SetLineStyle (kStyles [fIndex % kNumStyles] );
            if (0 == fIndex) 
            {
               hPtr->SetMaximum (1.1 * max);
               hPtr->Draw();
            } else {
               hPtr->Draw("same");
            }
         } // for fIndex
         legend.Draw("same");

         // save eps file
         string epsname = epsPrefix + histNameVec[hIndex] + ".eps";
         c1->Print (epsname.c_str());
         delete c1;
      } // for hIndex
   } // writeEpsFile
} // makeHists()