// SPDX-License-Identifier: MIT
#include "status_text.hpp"

#include <cmath>
#include <cstdio>

namespace udpscope {

/// `12 s`, `3m 07s`, `2h 14m` -- one unit coarser as soon as the finer one would need
/// three digits, so the field never grows past six characters and the status line's shape
/// does not depend on how long the wait has been.
std::string format_elapsed(double seconds) {
  if (!(seconds >= 0.0)) return "--";
  char buf[32];
  if (seconds < 60.0) {
    std::snprintf(buf, sizeof(buf), "%.0f s", std::floor(seconds));
  } else if (seconds < 3600.0) {
    const int m = static_cast<int>(seconds) / 60;
    std::snprintf(buf, sizeof(buf), "%dm %02ds", m, static_cast<int>(seconds) % 60);
  } else {
    const int h = static_cast<int>(seconds) / 3600;
    std::snprintf(buf, sizeof(buf), "%dh %02dm", h, (static_cast<int>(seconds) / 60) % 60);
  }
  return buf;
}

/// A sample rate in the unit it reads shortest in. Rates here span six decades (a 1 Hz
/// housekeeping signal next to a 1 MS/s acquisition), so a fixed unit makes one of the
/// two unreadable.
std::string format_rate(double per_s) {
  char buf[32];
  if (!(per_s > 0.0)) {
    return "0 S/s";
  } else if (per_s >= 1.0e6) {
    std::snprintf(buf, sizeof(buf), "%.3g MS/s", per_s / 1.0e6);
  } else if (per_s >= 1.0e3) {
    std::snprintf(buf, sizeof(buf), "%.3g kS/s", per_s / 1.0e3);
  } else {
    std::snprintf(buf, sizeof(buf), "%.3g S/s", per_s);
  }
  return buf;
}

std::string format_glance(const StatusSnapshot& s) {
  std::string out = s.state_word;
  out += " · ";
  out += s.rate_text.empty() ? "no data" : s.rate_text;
  out += " · ";
  out += s.window_text;
  out += " window";
  if (s.trigger_on) {
    out += " · ";
    if (s.have_event) {
      out += "event " + format_elapsed(s.since_event_s) + " ago";
    } else {
      out += "no event yet";
    }
  }
  return out;
}

std::string format_detail(const StatusSnapshot& s) {
  char buf[1024];
  std::snprintf(buf, sizeof(buf),
                "[%s] %s  %s | rate %s | packets %llu  frames %llu  gaps %llu | %zu signals, "
                "%zu channels | plot 1: %d trace(s), %zu samples | buffer %.1f MB, %.2f s "
                "span, time x%llu",
                s.state_detail.c_str(), s.connected ? "connected" : "waiting",
                s.have_config ? "configured" : "-",
                s.rate_text.empty() ? "--" : s.rate_text.c_str(),
                static_cast<unsigned long long>(s.packets),
                static_cast<unsigned long long>(s.frames),
                static_cast<unsigned long long>(s.gaps), s.signals, s.channels,
                s.plot1_traces, s.plot1_samples, s.buffer_mb, s.span_s,
                static_cast<unsigned long long>(s.time_stride));
  std::string out = buf;
  if (s.trigger_on) {
    out += s.have_event ? " | last event " + format_elapsed(s.since_event_s) + " ago"
                        : " | no event yet";
  }
  if (s.reconnects > 0) {
    char note[48];
    std::snprintf(note, sizeof(note), " | %d reconnects", s.reconnects);
    out += note;
  }
  return out;
}

}  // namespace udpscope