#include "openmc/progress_bar.h"

#include <iomanip>
#include <iostream>
#include <sstream>

#if defined(__unix__) || defined(__unix) ||                                    \
  (defined(__APPLE__) && defined(__MACH__))
#include <unistd.h>
#endif

#define BAR_WIDTH 72

bool is_terminal()
{
#ifdef _POSIX_VERSION
  return isatty(STDOUT_FILENO) != 0;
#else
  return false;
#endif
}

ProgressBar::ProgressBar()
{
  // initialize bar
  set_value(0.0);
}

void ProgressBar::set_value(double val)
{

  if (!is_terminal())
    return;

  // set the bar percentage
  if (val >= 100.0) {
    bar.append("100");
  } else if (val <= 0.0) {
    bar.append("  0");
  } else {
    std::stringstream ss;
    ss << std::setfill(' ') << std::setw(3) << (int)val;
    bar.append(ss.str());
  }

  bar.append("% |");
  // remaining width of the bar
  int remaining_width = BAR_WIDTH - bar.size() - 2;

  // set the bar width
  if (val >= 100.0) {
    bar.append(remaining_width, '=');
  } else if (val < 0.0) {
    bar.append(remaining_width, ' ');
  } else {
    int width = (int)((double)remaining_width * val / 100);
    bar.append(width, '=');
    bar.append(1, '>');
    bar.append(remaining_width - width - 1, ' ');
  }

  bar.append("|+");

  // write the bar
  std::cout << '\r' << bar << std::flush;
  if (val >= 100.0) {
    std::cout << "\n";
  }

  // reset the bar value
  bar = "";
}