// plot_fft.C
// This macro opens the ROOT file "combine_injection.root", retrieves the TH2D histogram
// named "FFT_accumulated", and draws it on a canvas with a logarithmic Z-axis.
// The canvas size is set to 800 x 1000, with the top margin set to 0.05 and the right margin increased.
// Additionally, the histogram title and statistics box are removed.
// You can specify the frequency (x-axis) and time (y-axis) ranges via the function parameters.

void plot_fft(const char* canvasTitle = "FFT Accumulated",double x_min = 0, double x_max = 0, double y_min = 0, double y_max = 0) {
    // Open the ROOT file
    TFile* file = TFile::Open("combine_injection.root");
    if (!file || file->IsZombie()) {
        std::cerr << "Error: Unable to open file combine_injection.root" << std::endl;
        return;
    }
    
    // Retrieve the TH2D histogram named "FFT_accumulated"
    TH2D* hist = dynamic_cast<TH2D*>(file->Get("FFT_accumulated"));
    if (!hist) {
        std::cerr << "Error: Histogram 'FFT_accumulated' not found in the file" << std::endl;
        file->Close();
        return;
    }
    
    // Remove the histogram title
    hist->SetTitle("");
    
    // Remove the statistics box
    gStyle->SetOptStat(0);
    
    // If valid ranges are provided (non-zero and x_min < x_max, etc.), apply them to the axes
    if (x_max > x_min) {
        hist->GetXaxis()->SetRangeUser(x_min, x_max);
    }
    if (y_max > y_min) {
        hist->GetYaxis()->SetRangeUser(y_min, y_max);
    }
    
    // Create a canvas with size 800 x 1000
    TCanvas* canvas = new TCanvas("canvas", canvasTitle, 800, 1000);
    
    // Adjust canvas margins: top margin 0.05, increased right margin (e.g., 0.15)
    canvas->SetTopMargin(0.05);
    canvas->SetLeftMargin(0.12);
    canvas->SetRightMargin(0.15);
    
    // Set axis titles (if desired, you can modify these)
    hist->GetXaxis()->SetTitle("Frequency [Hz]");
    hist->GetYaxis()->SetTitle("Time [s]");
    hist->GetZaxis()->SetTitle("Amplitude (arbitrary units)");
    hist->GetZaxis()->SetTitleOffset(1.2);
    
    // Set log scale for the Z-axis (color scale)
    canvas->SetLogz();
    
    // Draw the histogram using the "COLZ" option to display a color palette
    hist->Draw("COLZ");
    
    // Update the canvas to show the plot
    canvas->Update();
    // Add the canvas title at the top using TLatex
    TLatex latex;
    latex.SetNDC();             // Use normalized coordinates
    latex.SetTextAlign(22);     // Center alignment
    latex.SetTextSize(0.04);      // Adjust text size as needed
    // Draw the title at (x=0.5, y=0.95) in normalized device coordinates
    latex.DrawLatex(0.5, 0.98, canvasTitle);
    
    // Optionally, you can save the canvas as an image file (e.g., PNG)
    // canvas->SaveAs("FFT_accumulated.png");
}