#include <TCanvas.h>
#include <TH1.h>
#include <TRandom3.h>

void scale() {
    
    TH1F* hist1 = new TH1F("hist1", "Histogram 1", 100, -5, 5);
    TH1F* hist2 = new TH1F("hist2", "Histogram 2", 100, -5, 5);
    TH1F* hist3 = new TH1F("hist3", "Histogram 3", 100, -5, 5);

    TRandom3 randGen;
    
    for (int i = 0; i < 50000; i++) {
        double value1 = randGen.Gaus(0.0, 1.0);
        hist1->Fill(value1);
    }

    for (int i = 0; i < 20000; i++) {
        double value2 = randGen.Gaus(0.0, 1.0);
        hist2->Fill(value2);
    }

    for (int i = 0; i < 5000; i++) {
        double value3 = randGen.Gaus(0.0, 1.0);
        hist3->Fill(value3);
    }

    //Distribution without Normalization
    TCanvas* can1 = new TCanvas("can1", "Histogram", 800, 600);

    hist1->SetTitle("");
    hist1->SetStats(0);

    hist1->SetLineColor(kBlue); 
    hist1->Draw();
    hist2->SetLineColor(kRed);
    hist2->Draw("same");
    hist3->SetLineColor(kGreen);
    hist3->Draw("same");

    TLegend* legend = new TLegend(0.7, 0.7, 0.8, 0.8);
    legend->SetBorderSize(0);
    legend->AddEntry(hist1, "Histogram 1", "l");
    legend->AddEntry(hist2, "Histogram 2", "l");
    legend->AddEntry(hist3, "Histogram 3", "l");
    legend->Draw();

    can1->Update();
    can1->SaveAs("scale_v1.pdf");

    //Normalization with respect to Area
    TCanvas* can2 = new TCanvas("can2", "Histogram", 800, 600);

    TH1F* hist1_cp = (TH1F*)hist1->Clone();
    hist1_cp->Scale(1/hist1_cp->Integral());

    TH1F* hist2_cp = (TH1F*)hist2->Clone();
    hist2_cp->Scale(1/hist2_cp->Integral());

    TH1F* hist3_cp = (TH1F*)hist3->Clone();
    hist3_cp->Scale(1/hist3_cp->Integral());

    hist1_cp->SetTitle("");
    hist1_cp->SetStats(0);
    hist1_cp->GetYaxis()->SetRangeUser(0, 1.2 * hist1_cp->GetMaximum());

    hist1_cp->SetLineColor(kBlue);
    hist1_cp->Draw("hist");
    hist2_cp->SetLineColor(kRed);
    hist2_cp->Draw("same hist");
    hist3_cp->SetLineColor(kGreen);
    hist3_cp->Draw("same hist");

    TLegend* legend2 = new TLegend(0.7, 0.7, 0.8, 0.8);
    legend2->SetBorderSize(0);
    legend2->AddEntry(hist1_cp, "Histogram 1", "l");
    legend2->AddEntry(hist2_cp, "Histogram 2", "l");
    legend2->AddEntry(hist3_cp, "Histogram 3", "l");
    legend2->Draw();

    can2->Update();
    can2->SaveAs("scale_v2.pdf");

    //Normalization with respect to Maximum
    TCanvas* can3 = new TCanvas("can3", "Histogram", 800, 600);

    TH1F* hist1_cp2 = (TH1F*)hist1->Clone();

    TH1F* hist2_cp2 = (TH1F*)hist2->Clone();
    hist2_cp2->Scale(hist1_cp2->GetMaximum()/hist2_cp2->GetMaximum());

    TH1F* hist3_cp2 = (TH1F*)hist3->Clone();
    hist3_cp2->Scale(hist2->GetMaximum()/hist3_cp2->GetMaximum());
    //hist3_cp2->Scale(hist2->Integral()/hist3_cp2->Integral());

    hist1_cp2->SetTitle("");
    hist1_cp2->SetStats(0);
    hist1_cp2->GetYaxis()->SetRangeUser(0, 1.2 * hist1_cp2->GetMaximum());

    hist1_cp2->SetLineColor(kBlue);
    hist1_cp2->Draw("hist");
    hist2_cp2->SetLineColor(kRed);
    hist2_cp2->Draw("same hist");
    hist3_cp2->SetLineColor(kGreen);
    hist3_cp2->Draw("same hist");

    TLegend* legend3 = new TLegend(0.7, 0.7, 0.8, 0.8);
    legend3->SetBorderSize(0);
    legend3->AddEntry(hist2_cp2, "Histogram 1", "l");
    legend3->AddEntry(hist2_cp2, "Histogram 2", "l");
    legend3->AddEntry(hist3_cp2, "Histogram 3", "l");
    legend3->Draw();

    can3->Update();
    can3->SaveAs("scale_v3.pdf");
}