// Time.cxx

#include "dataset_util/Time.h"
#include <iostream>
#include <sstream>
#include <iomanip>
#include <time.h>

using std::string;
using std::ostream;
using std::ostringstream;
using std::setw;
using std::setfill;

//**********************************************************************
// Static methods for Time.
//**********************************************************************

// Now.

Time Time::now() {
  return Time(time(0));
}

//**********************************************************************
// Methods for Time.
//**********************************************************************

// Constructor from unix time.

Time::Time(unsigned long time) : m_time(time) { }

//**********************************************************************

// Set time.

Time& Time::set() {
  m_time = time(0);
  return *this;
}

//**********************************************************************

// Add time interval.

Time& Time::operator+=(TimeInterval dtim) {
  if ( is_valid() ) {
    m_time += dtim.seconds();
  }
  return *this;
}

//**********************************************************************

// Subtract time interval.

Time& Time::operator-=(TimeInterval dtim) {
  if ( is_valid() ) {
    m_time -= dtim.seconds();
  }
  return *this;
}

//**********************************************************************

// Validity.

bool Time::is_valid() const {
  return m_time != 0;
}

//**********************************************************************

// Time in seconds.

unsigned long Time::unix_time() const {
  return m_time;
}

//**********************************************************************

// Formatted UTC.

string Time::to_string() const {
  if ( ! is_valid() ) {
    return "invalid time";
  }
  time_t utim = m_time;
  const tm* ptm = gmtime(&utim);
  char ctim[128];
  const char* fmt = "%Y %b %d %H:%M:%S";
  size_t nchar = strftime(ctim, 128, fmt, ptm);
  string stim(ctim);
  return stim;
}

//**********************************************************************
// Methods for TimeInterval.
//**********************************************************************

// Constructor from interval.

TimeInterval::TimeInterval(long dtime) : m_dtime(dtime) { }

//**********************************************************************

// Constructor from start and stop.

TimeInterval::TimeInterval(Time start, Time stop)
: m_dtime(stop.unix_time() - start.unix_time()) { }

//**********************************************************************

// Add time interval.

TimeInterval& TimeInterval::operator+=(TimeInterval dtim) {
  m_dtime += dtim.seconds();
  return *this;
}

//**********************************************************************

// Subtract time interval.

TimeInterval& TimeInterval::operator-=(TimeInterval dtim) {
  m_dtime -= dtim.seconds();
  return *this;
}

//**********************************************************************

// Interval in seconds.

long TimeInterval::seconds() const {
  return m_dtime;
}

//**********************************************************************

// Formatted interval.

string TimeInterval::to_string() const {
  long rem = m_dtime;
  long sign = 1;
  if ( rem < 0 ) {
    sign = -1;
    rem = -rem;
  }
  long days = rem/(24*3600);
  rem -= 24*3600*days;
  long hours = rem/3600;
  rem -= 3600*hours;
  long mins = rem/60;
  rem -= 60*mins;
  long secs = rem;
  ostringstream ssint;
  if ( sign < 0 ) {
    ssint << "-";
  }
  if ( days > 0 ) {
    ssint << days << ":" << setw(2) << setfill('0');
  }
  ssint << hours << ":";
  ssint << setw(2) << setfill('0') << mins << ":";
  ssint << setw(2) << setfill('0') << secs;
  return ssint.str();
}

//**********************************************************************
// Free functions.
//**********************************************************************

// Time output stream.

ostream& operator<<(std::ostream& lhs, const Time& rhs) {
  lhs << rhs.to_string();
  return lhs;
}

//**********************************************************************

// TimeInterval output stream.

ostream& operator<<(std::ostream& lhs, const TimeInterval& rhs) {
  lhs << rhs.to_string();
  return lhs;
}

//**********************************************************************