#include "TMultiGraph.h"
#include "TCanvas.h"   
#include "TLegend.h"   
#include "TLatex.h"   
#include "TFile.h"   
#include "TROOT.h"   
#include "TStyle.h"   
#include "Riostream.h"   
#include "TAxis.h"   

//
//  This function will plot 16 TMultiGraph objects
//   into a multipane plot
//
//   Will be used for 40Ca and 48Ca plots
//  

TMultiGraph *mg_list[16];
TLegend *leg_list[16];
TLatex *label_list[16];

void ReadFromFile(TString rootfile="test.root")
{
  Int_t Zlow=5;
  Int_t Zhigh=20;

  TMultiGraph *mg = 0;
  TLegend *leg = 0;
  char name1[20], name2[20];
  Int_t count = 0;

  if (rootfile != "")
    {
      TFile *f = new TFile(rootfile, "rdnl");
      gROOT->cd();
      
      for (Int_t z=Zlow; z<=Zhigh; z++)
	{
	  sprintf(name1, "graph_Zis%d", z);
	  sprintf(name2, "legend_Zis%d", z);
	  mg = (TMultiGraph*)f->Get(name1);
	  leg = (TLegend*)f->Get(name2);

	  mg_list[count] = (TMultiGraph*)mg->Clone();
	  leg_list[count] = (TLegend*)leg->Clone();
	  count++;
	}
    }
  else
    return;
  
  return;
}

void Plot16()
{
  Int_t i;

  //  ------ changeable parameters: 
  Double_t small    = 1e-6; // small number used for setting margins of the inner pads
  Double_t dx       = 0.07; // number used for setting margins for the outer pads (where titles, labels go)
  Double_t lsize    = 16;   // label size
  Double_t tsize    = 0.03; // title size
  Double_t loffsetX = 0.02; // label offset in % of the pad height
  Double_t loffsetY = 0.02; // label offset in % of the pad height

  ReadFromFile("test.root");
    
  TCanvas *canvas = new TCanvas("canvas", "MultiPane", 800, 800);
  TString xtitle = "Neutron excess N-Z";
  TString ytitle = "Cross section (mb)";  

  Int_t font = 13;

  TLatex *label;
  for (i=0; i<16; i++) {
    mg_list[i]->GetYaxis()->SetNdivisions(503);
    mg_list[i]->GetXaxis()->SetNdivisions(505);

    mg_list[i]->GetHistogram()->GetXaxis()->SetLimits(-5,15);
    mg_list[i]->GetHistogram()->GetXaxis()->SetRange(0,0);

    mg_list[i]->GetYaxis()->SetLabelFont(font);
    mg_list[i]->GetXaxis()->SetLabelFont(font);
    mg_list[i]->GetYaxis()->SetTitleFont(font);
    mg_list[i]->GetXaxis()->SetTitleFont(font);
    mg_list[i]->GetYaxis()->SetLabelSize(lsize);
    mg_list[i]->GetXaxis()->SetLabelSize(lsize);
    mg_list[i]->GetXaxis()->SetLabelOffset(loffsetX);
    mg_list[i]->GetYaxis()->SetLabelOffset(loffsetY);

    mg_list[i]->GetXaxis()->SetTitle("");
    mg_list[i]->GetYaxis()->SetTitle("");
     
    label = new TLatex(0.3, 0.15, Form("Label %d",i));
    label->SetNDC();
    label->SetTextFont(22);
    label->SetTextSize(0.12);
    label_list[i] = label;
  }

  // Setting styles for everything in this function:
  canvas->SetFillColor(10);
  gStyle->SetPadColor(10);
  gStyle->SetPadTickX(1);
  gStyle->SetPadTickY(1);
  gStyle->SetFrameBorderMode(0);
  gStyle->SetPadBorderSize((Short_t)small);
  gStyle->SetPadLeftMargin(small);
  gStyle->SetPadTopMargin(small);
  gStyle->SetPadBottomMargin(small);
  gStyle->SetPadRightMargin(small);
  gStyle->SetOptLogy(1);

  // ------------------------------------
  Double_t x = (1-dx)/4;  // one side of the inner pad
  Double_t x1 = x+dx;     // thicker side 
  Double_t outer_margin = 3*dx/x;

  TPad *pad0 = new TPad("pad0", "", 0, 1-x, x1, 1);
  outer_margin = 1-(Double_t)pad0->VtoPixel(0)/(Double_t)pad0->UtoPixel(1);
  pad0->SetLeftMargin(outer_margin);
  TPad *pad1  = new TPad("pad1", "", x1, 1-x, x1+x, 1);
  TPad *pad2  = new TPad("pad2", "", x1+x,1-x, x1+2*x,1);
  TPad *pad3  = new TPad("pad3", "", x1+2*x,1-x, 1, 1);
  TPad *pad4  = new TPad("pad4", "", 0, 1-2*x, x1, 1-x);
  pad4->SetLeftMargin(outer_margin);
  TPad *pad5  = new TPad("pad5", "", x1, 1-2*x, x1+x, 1-x);
  TPad *pad6  = new TPad("pad6", "", x1+x, 1-2*x, x1+2*x, 1-x);
  TPad *pad7  = new TPad("pad7", "", x1+2*x, 1-2*x, 1, 1-x);
  TPad *pad8  = new TPad("pad8", "", 0, 1-3*x, x1, 1-2*x);
  pad8->SetLeftMargin(outer_margin);
  TPad *pad9  = new TPad("pad9", "", x1, 1-3*x, x1+x, 1-2*x);
  TPad *pad10 = new TPad("pad10", "", x1+x, 1-3*x, x1+2*x, 1-2*x);
  TPad *pad11 = new TPad("pad11", "", x1+2*x, 1-3*x, 1, 1-2*x);
  TPad *pad12 = new TPad("pad12", "", 0, 0, x1, 1-3*x);
  pad12->SetLeftMargin(outer_margin);
  pad12->SetBottomMargin(outer_margin);
  TPad *pad13 = new TPad("pad13", "", x1, 0, x1+x, 1-3*x);
  pad13->SetBottomMargin(outer_margin);
  TPad *pad14 = new TPad("pad14", "", x1+x, 0, x1+2*x, 1-3*x);
  pad14->SetBottomMargin(outer_margin);
  TPad *pad15 = new TPad("pad15", "", x1+2*x, 0, 1, 1-3*x);
  pad15->SetBottomMargin(outer_margin);

//pad0->SetGridx();
//pad1->SetGridx();
//pad2->SetGridx();
//pad3->SetGridx();
//pad4->SetGridx();
//pad5->SetGridx();
//pad6->SetGridx();
//pad7->SetGridx();
//pad8->SetGridx();
//pad9->SetGridx();

  Double_t factorY = (Double_t)pad9->VtoPixel(0)/(Double_t)pad12->VtoPixel(0);
  Double_t factorX = (Double_t)pad9->UtoPixel(1)/(Double_t)pad12->UtoPixel(1);
  
  cout << "FactorX: "<<factorX<<"  and factorY: "<<factorY<<endl;

  // now a pad for global axis titles
  TPad *pad = new TPad("pad", "", 0, 0, 1, 1);   // transparent pad
  pad->SetFillStyle(4000);
  pad->SetFillColor(10);
  
  TLatex *titleX = new TLatex(0.5, 0.025, xtitle.Data());
  titleX->SetNDC();
  titleX->SetTextFont(font);
  titleX->SetTextSize(tsize);
  titleX->SetTextAlign(22);
  TLatex *titleY = new TLatex(0.016, 0.5, ytitle.Data());
  titleY->SetNDC();
  titleY->SetTextAngle(90);
  titleY->SetTextFont(font);
  titleY->SetTextSize(tsize);
  titleY->SetTextAlign(22);

  canvas->Clear();
  pad0->Draw();
  pad1->Draw();
  pad2->Draw();
  pad3->Draw();
  pad4->Draw();
  pad5->Draw();
  pad6->Draw();
  pad7->Draw();
  pad8->Draw();
  pad9->Draw();
  pad10->Draw();
  pad11->Draw();
  pad12->Draw();
  pad13->Draw();
  pad14->Draw();
  pad15->Draw();
  // now drawing:
  pad0->cd();
  mg_list[0]->Draw("ap");
  label_list[0]->SetX(label_list[0]->GetX()*factorX+1-factorX);
  label_list[0]->Draw();
  pad1->cd();
  mg_list[1]->Draw("ap");
  label_list[1]->Draw();
  pad2->cd();
  mg_list[2]->Draw("ap");
  label_list[2]->Draw();
  pad3->cd();
  mg_list[3]->Draw("ap");
  label_list[3]->Draw();
  pad4->cd();
  mg_list[4]->Draw("ap");
  label_list[4]->SetX(label_list[4]->GetX()*factorX+1-factorX);
  label_list[4]->Draw();
  pad5->cd();
  mg_list[5]->Draw("ap");
  label_list[5]->Draw();
  pad6->cd();
  mg_list[6]->Draw("ap");
  label_list[6]->Draw();
  pad7->cd();
  mg_list[7]->Draw("ap");
  label_list[7]->Draw();
  pad8->cd();
  mg_list[8]->Draw("ap");
  label_list[8]->SetX(label_list[8]->GetX()*factorX+1-factorX);
  label_list[8]->Draw();
  pad9->cd();
  mg_list[9]->Draw("ap");
  label_list[9]->Draw();
  pad10->cd();
  mg_list[10]->Draw("ap");
  label_list[10]->Draw();
  pad11->cd();
  mg_list[11]->Draw("ap");
  label_list[11]->Draw();
  pad12->cd();
  label_list[12]->SetX(label_list[12]->GetX()*factorX+1-factorX);
  label_list[12]->SetY(label_list[12]->GetY()*factorY+1-factorY);
  label_list[12]->SetTextSize(label_list[12]->GetTextSize()*factorX);
  mg_list[12]->GetXaxis()->SetLabelSize(lsize*factorX);
  mg_list[12]->GetYaxis()->SetLabelSize(lsize*factorY);
  mg_list[12]->GetXaxis()->SetLabelOffset(loffsetX/factorX);
  mg_list[12]->GetYaxis()->SetLabelOffset(loffsetY/factorY);
  mg_list[12]->Draw("ap");
  label_list[12]->Draw();
  pad13->cd();
  mg_list[13]->Draw("ap");
  label_list[13]->SetY(label_list[13]->GetY()*factorY+1-factorY);
  label_list[13]->Draw();
  pad14->cd();
  mg_list[14]->Draw("ap");
  label_list[14]->SetY(label_list[14]->GetY()*factorY+1-factorY);
  label_list[14]->Draw();
  pad15->cd();
  mg_list[15]->Draw("ap");
  label_list[15]->SetY(label_list[15]->GetY()*factorY+1-factorY);
  label_list[15]->Draw();
  canvas->cd();
  pad->Draw();
  pad->cd();
  titleX->Draw();
  titleY->Draw();

  canvas->Update();

}