// card_meta — pure implementation. See card_meta.h.

#include "core/ui/card_meta.h"

#include <cmath>
#include <cstdio>

namespace reasampler::ui {

Rect cardNameStrip(const Rect& cell) {
    // Both strips plus a waveform band at least as tall as one strip; below that the card
    // is a text block, not a thumbnail.
    const int minHeight = 3 * kCardStripHeight;
    if (cell.width <= 2 * kCardStripPad || cell.height < minHeight) return Rect{};
    // Inset by 1px from the top edge so the name never sits on the selection border.
    return Rect{cell.x + kCardStripPad, cell.y + 1,
                cell.width - 2 * kCardStripPad, kCardStripHeight};
}

std::string formatBarsBeats(const MusicalLength& m) {
    if (m.tempoBpm <= 0.0 || m.timeSigNum <= 0 || m.timeSigDenom <= 0) return {};

    const double len = m.lengthSeconds > 0.0 ? m.lengthSeconds : 0.0;

    // A quarter-note is 60/tempo s; a beat is (4/denom) quarter-notes.
    const double secondsPerBeat = (60.0 / m.tempoBpm) * (4.0 / m.timeSigDenom);
    double totalBeats = len / secondsPerBeat;

    // Snap to an exact beat within epsilon so a bar-aligned capture reads "2.1.00" rather than
    // "1.4.99" from FP error just under the boundary.
    const double snapped = std::floor(totalBeats + 0.5);
    if (std::fabs(totalBeats - snapped) < 1e-6) totalBeats = snapped;

    double wholeBeats = std::floor(totalBeats);
    double frac = totalBeats - wholeBeats;

    const long wb = static_cast<long>(wholeBeats);
    const long bar  = wb / m.timeSigNum + 1;
    const long beat = wb % m.timeSigNum + 1;

    int sub = static_cast<int>(std::floor(frac * 100.0));
    if (sub < 0) sub = 0;
    if (sub > 99) sub = 99;

    char buf[48];
    std::snprintf(buf, sizeof(buf), "%ld.%ld.%02d", bar, beat, sub);
    return buf;
}

std::string formatSecondsMs(double lengthSeconds) {
    double len = lengthSeconds > 0.0 ? lengthSeconds : 0.0;

    long secs = static_cast<long>(std::floor(len));
    // Round to nearest ms, not floor: FP storage error would otherwise render e.g. "62.036"
    // for a value that should read "62.037".
    int ms = static_cast<int>((len - static_cast<double>(secs)) * 1000.0 + 0.5);
    if (ms >= 1000) { ms -= 1000; ++secs; }  // rounding can carry into the next second
    if (ms < 0) ms = 0;

    char buf[48];
    std::snprintf(buf, sizeof(buf), "%ld.%03d", secs, ms);
    return buf;
}

} // namespace reasampler::ui