#include "COMETSpectrumFactory.hh"
#include "COMETVSpectrum.hh"
#include <TH1.h>
#include <TFile.h>
#include <ICOMETLog.hxx>
#include <cstdlib>
#include <string>
#include <sstream>

using std::cout;
using std::endl;

void Usage(const char* prog){
    cout<<"Usage: "<<prog<<" [options]\n"
        <<"\n"
        <<" -s <spectrum>   Name of the spectrum to sample. \n"
        <<"                 Should be one of: "<<COMETSpectrumFactory::Instance().ListTypes()<<"\n"
        <<" -n <n_samples>  Specify the number of times to sample the spectrum  \n"
        <<" -f <out_file>   Set the name of the output file  \n"
        <<" -b <n_bins>     Set the number of bins in the output histogram  \n"
        <<" -u <max>        Set the upper limit of the output histogram  \n"
        <<" -l <min>        Set the lower limit of the output histogram  \n"
        <<endl;
}

int main(int argc,char** argv) {
    COMET::ICOMETLog::Configure();

    std::string outfilename="spectrum.root";
    std::string requested_spectrum;
    long int n_samples=1000;
    int n_bins=1000;
    double max=0;
    double min=0;
    for (;;) {
        char c = getopt(argc, argv, "h?f:u:l:n:s:b:");
        std::stringstream stream;
        if(optarg) stream.str(optarg);
        if (c<0) break;
        switch (c) {
            case 'u':
                {
                    stream>>max;
                    break;
                }
            case 'l':
                {
                    stream>>min;
                    break;
                }
            case 'n':
                {
                    stream>>n_samples;
                    break;
                }
            case 'b':
                {
                    stream>>n_bins;
                    break;
                }
            case 'f':
                {
                    outfilename=optarg;
                    continue;
                }
            case 's':
                {
                    requested_spectrum=optarg;
                    continue;
                }
            case 'h':case '?':
                Usage(argv[0]);
                return 0;
            default:
                cout<<"Error: Unknown option: "<<c<<endl<<endl;
                Usage(argv[0]);
                return 1;
        }
        if(stream.fail() || ! stream.eof()){
            cout<<"Error: Bad option value: '"<<optarg<<"' for option '"<<c <<"'"<<endl<<endl;
            Usage(argv[0]);
            return 1;
        }
    }

    if (requested_spectrum.empty()){
        COMETError("I need the name of a spectrum to plot");
        return 1;
    }
    COMETVSpectrum* spectrum=COMETSpectrumFactory::Make(requested_spectrum);
    if(!spectrum){
        COMETError("Invalid spectrum requested");
        return 2;
    }
    TFile* out_file=TFile::Open(outfilename.c_str(),"recreate");
    if(!out_file || out_file->IsZombie()){
        COMETError("Cannot open output file for spectrum histogram");
        return 3;
    }
    std::string title="Sampling of spectrum: ";
    title+=spectrum->GetName();
    TH1* hist=new TH1F(spectrum->GetName().c_str(),title.c_str(),n_bins,min,max);

    for(int i=0;i<n_samples;++i){
        double energy=spectrum->GenerateOne();
        hist->Fill(energy);
    }
    out_file->Write();
    out_file->Close();

    return 0;
}