#include "TFile.h"
#include "TTree.h"
#include "TH1.h"
#include "TCanvas.h"
#include <iostream>

void sumhist() {
    // List of ROOT file names
    const int nFiles = 8; // Update this to the actual number of files you have
    const char* filenames[nFiles] = {"file1.root", "file2.root", "file3.root", "file4.root", "file5.root", "file6.root", "file7.root", "file8.root"};

    TH1 *h_sum = nullptr;

    for (int i = 0; i < nFiles; i++) {
        std::cout << "Processing file: " << filenames[i] << std::endl;
        TFile *f = TFile::Open(filenames[i]);
        if (!f || f->IsZombie()) {
            std::cerr << "Error opening file: " << filenames[i] << std::endl;
            continue;
        }

        TTree *tree = (TTree*) f->Get("outTree");
        if (!tree) {
            std::cerr << "TTree 'outTree' not found in file: " << filenames[i] << std::endl;
            f->Close();
            continue;
        }

        // Create histogram from the tree data
        tree->Draw("Ener1>>h_temp(8192,0,1000)", "", "goff");
        TH1 *h_temp = (TH1*) gDirectory->Get("h_temp");
        if (!h_temp) {
            std::cerr << "Failed to create histogram in file: " << filenames[i] << std::endl;
            f->Close();
            continue;
        }

        // Debug: print entries in the temporary histogram
        std::cout << "File " << filenames[i] << ": h_temp entries = " << h_temp->GetEntries() << std::endl;

        // Clone the histogram and detach it from the file
        TH1 *h_temp_clone = (TH1*) h_temp->Clone();
        h_temp_clone->SetDirectory(0);

        // Sum the histogram with previous ones
        if (h_sum == nullptr) {
            h_sum = (TH1*) h_temp_clone->Clone("h_sum");
        } else {
            h_sum->Add(h_temp_clone);
        }

        // Clean up the temporary clone
        delete h_temp_clone;
        f->Close();
    }

    // Check and draw the summed histogram
    if (h_sum) {
        std::cout << "Final summed histogram entries: " << h_sum->GetEntries() << std::endl;
        TCanvas *c = new TCanvas("c", "Summed Histogram", 800, 600);
        h_sum->Draw();
        c->Update();
        c->SaveAs("summed_histogram.png");
    } else {
        std::cerr << "No histograms were summed." << std::endl;
    }
}