/**
 *  \brief A timer class to time function calls
 *
 *  Copyright 2007-2013 IMP Inventors. All rights reserved.
 *
 */

#ifndef IMPISD_INTERNAL_TIMER_H
#define IMPISD_INTERNAL_TIMER_H

#include <IMP/isd/isd_config.h>

#include <boost/date_time/posix_time/posix_time.hpp>

IMPISD_BEGIN_INTERNAL_NAMESPACE

using boost::posix_time::microsec_clock;
using boost::posix_time::ptime;
using boost::posix_time::time_duration;

//struct for call statistics
struct func_stats
{
    ptime start;
    ptime stop;
    time_duration total, firstcall, lastcall;
    unsigned ncalls;
};


/** Simple class to monitor runtime duration of some functions
 * */
template <unsigned nfuncs> class CallTimer {

private:
    func_stats stats_[nfuncs];

private:
    void start_helper(int name) {
        stats_[name].start = microsec_clock::local_time();
    }

    void stop_helper(int name) {
        stats_[name].stop = microsec_clock::local_time();
        stats_[name].lastcall = stats_[name].stop - stats_[name].start;
        stats_[name].total += stats_[name].lastcall;
        if (stats_[name].ncalls == 0)
            stats_[name].firstcall = stats_[name].lastcall;
        stats_[name].ncalls += 1;
    }


public:

    CallTimer()
    {
        for (unsigned i=0; i<nfuncs; i++)
        {
            stats_[i].ncalls = 0;
            stats_[i].total = time_duration(0,0,0);
        }
    }

    void start(int name) const
    {
        const_cast<CallTimer *>(this)->start_helper(name);
    }

    void stop(int name) const
    {
        const_cast<CallTimer *>(this)->stop_helper(name);
    }

    void stats(int name, std::string dispname) const
    {
        std::cout << dispname
            << "\t" << stats_[name].total.total_milliseconds();
        if (stats_[name].ncalls > 0)
        {
            std::cout << "\t"
                << stats_[name].total.total_microseconds()/stats_[name].ncalls;
        } else {
            std::cout << "\t---";
        }
        std::cout << "\t" << stats_[name].firstcall.total_microseconds()
            << "\t" << stats_[name].lastcall.total_microseconds()
            << "\t" << stats_[name].ncalls
            << std::endl;
    }

    void stats(std::string dispnames[]) const
    {
        std::cout <<
            "Function\tTotal(ms)\tMean(mus)\tFirst(mus)\tLast(mus)\tNumber\n";
        for (unsigned i=0; i<nfuncs; i++) stats(i,dispnames[i]);
    }

    func_stats stats_data(int name)
    {
        return stats_[name];
    }

};

IMPISD_END_INTERNAL_NAMESPACE


#endif /* IMPISD_INTERNAL_TIMER_H */