#include "SpectrumWidget.h"
#include <QPainter>
#include <QLinearGradient>

SpectrumWidget::SpectrumWidget(int barCount, QWidget* parent)
    : QWidget(parent), _barCount(barCount), _current(barCount, 0), _peak(barCount, 0)
{
    setFixedSize(100, 26);
    _decayTimer = new QTimer(this);
    _decayTimer->setInterval(33);
    connect(_decayTimer, &QTimer::timeout, this, [this]() {
        bool anyActive = false;
        for (int i = 0; i < _barCount; ++i) {
            _peak[i] *= 0.88f;
            if (_peak[i] < 0.01f) _peak[i] = 0;
            else anyActive = true;
        }
        if (!anyActive) _decayTimer->stop();
        update();
    });
}

void SpectrumWidget::updateLevels(const QVector<float>& levels) {
    for (int i = 0; i < _barCount && i < levels.size(); ++i) {
        _current[i] = levels[i];
        if (levels[i] > _peak[i]) _peak[i] = levels[i];
    }
    if (!_decayTimer->isActive()) _decayTimer->start();
    update();
}

void SpectrumWidget::reset() {
    _current.fill(0);
    _peak.fill(0);
    _decayTimer->stop();
    update();
}

void SpectrumWidget::paintEvent(QPaintEvent*) {
    QPainter p(this);
    p.setRenderHint(QPainter::Antialiasing);

    int w = width(), h = height();
    qreal gap = 1.5;
    qreal barW = (w - (_barCount - 1) * gap) / _barCount;

    for (int i = 0; i < _barCount; ++i) {
        qreal x = i * (barW + gap);
        qreal level = qMin(1.0f, _peak[i]);
        qreal barH = qMax(2.0, level * h);

        QLinearGradient grad(0, h, 0, h - barH);
        if (level > 0.01) {
            grad.setColorAt(0, QColor(94, 179, 230, 200));
            grad.setColorAt(1, QColor(92, 184, 92, 240));
        } else {
            grad.setColorAt(0, QColor(42, 48, 64, 100));
            grad.setColorAt(1, QColor(42, 48, 64, 60));
        }

        p.setPen(Qt::NoPen);
        p.setBrush(grad);
        p.drawRoundedRect(QRectF(x, h - barH, barW, barH), 1.5, 1.5);
    }
}