#include <iostream>
#include <iomanip>
#include <string>
#include <vector>
#include <deque>
#include <queue>
#include <algorithm>

#include "km3net-dataformat/offline/Head.hh"
#include "km3net-dataformat/offline/MultiHead.hh"
#include "km3net-dataformat/offline/Evt.hh"

#include "JLang/JException.hh"

#include "JSupport/JMeta.hh"
#include "JSupport/JSupport.hh"
#include "JSupport/JFileRecorder.hh"
#include "JSupport/JSingleFileScanner.hh"
#include "JSupport/JTreeScanner.hh"
#include "JSupport/JMonteCarloFileSupportkit.hh"

#include "Jeep/JeepToolkit.hh"
#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


namespace {

  /**
   * Auxiliary data structure for sorting of Monte Carlo events.
   */
  struct JCompare_t {
    /**
     * Compare two events.
     *
     * \param  first           first  event
     * \param  second          second event
     * \return                 true if first event earlier than second; else false
     */
    inline bool operator()(const Evt& first, const Evt& second) const
    {
      return first.mc_event_time.AsDouble() < second.mc_event_time.AsDouble();
    }
  };
}


/**
 * \file
 * Auxiliary program for time sorting of Monte-Carlo events.
 *
 * \author mdejong
 */
int main(int argc, char **argv)
{
  using namespace std;
  using namespace JPP;

  typedef typename JTYPELIST<Head, MultiHead, Evt, JMeta>::typelist  typelist;

  string    inputFile;
  string    outputFile;
  size_t    numberOfFiles;
  Long64_t  autoflush;
  bool      option;
  int       debug;

  try {
    
    JParser<> zap("Auxiliary program for time sorting of Monte-Carlo events.");
    
    zap['f'] = make_field(inputFile);
    zap['o'] = make_field(outputFile, "If number of files > " << 1 
			  << ", file name should contain wild card \'" << FILENAME_WILDCARD << "\'");
    zap['N'] = make_field(numberOfFiles)       = 1;
    zap['R'] = make_field(autoflush)           = 1000;
    zap['O'] = make_field(option,     "Write [multi] header to each output file");
    zap['d'] = make_field(debug)               = 2;

    zap(argc, argv);
  }
  catch(const exception& error) {
    FATAL(error.what() << endl);
  }


  if (numberOfFiles == 0) {
    numberOfFiles = 1;
  }

  if (numberOfFiles > 1 && !hasWildCard(outputFile)) {
    FATAL("Output file name should contain wildcard \'" << FILENAME_WILDCARD << "\'" << endl);
  }

  JTreeScanner<Evt> in(inputFile);
  
  counter_type number_of_events = in.getEntries();

  counter_type ns = (number_of_events + numberOfFiles - 1) / numberOfFiles;
  counter_type ni = 0;

  vector<Evt> buffer;

  for (size_t i = 0; i != numberOfFiles; ++i, ni += ns) {

    const JLimit limit(ni, min(ni + ns, number_of_events));

    const string filename(hasWildCard(outputFile) ? setWildCard(outputFile, to_string(i)) : outputFile);

    STATUS("Processing " << filename << ' ' << limit << "." << flush);

    buffer.clear();

    for (in.setLimit(limit); in.hasNext(); ) {
      buffer.push_back(*in.next());
    }

    STATUS("." << flush);

    sort(buffer.begin(), buffer.end(), JCompare_t());

    STATUS("." << flush);

    JFileRecorder<typelist> out(filename.c_str());

    out.open();
    
    dynamic_cast<JTreeWriterObjectOutput<Evt>&>(*out).getTreeWriter().SetAutoFlush(autoflush);

    out.put(JMeta(argc, argv));

    for (const auto& evt : buffer) {
      out.put(evt);
    }

    if (i == 0 || option) {

      JSingleFileScanner<JRemove<typelist, Evt>::typelist> io(inputFile);
 
      io >> out;
    }

    out.close();

    STATUS("OK" << endl);
  }

  return 0;
}