#include "videoplayer_window.h"
#include "videoplayer_engine.h"
#include "../../lib/debug_config.h"

#include <QSlider>
#include <QPushButton>
#include <QLabel>
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QPainter>
#include <QKeyEvent>
#include <QMouseEvent>
#include <QCloseEvent>
#include <QResizeEvent>
#include <QApplication>
#include <QScreen>
#include <QStyle>
#include <QWindow>

/* ─── VideoRenderWidget ─── */

VideoRenderWidget::VideoRenderWidget(QWidget* parent) : QWidget(parent) {
    setMouseTracking(true);
    setAttribute(Qt::WA_OpaquePaintEvent);
}

void VideoRenderWidget::setFrame(const QImage& img) {
    m_frame = img;
    update();
}

void VideoRenderWidget::clearFrame() {
    m_frame = QImage();
    update();
}

void VideoRenderWidget::paintEvent(QPaintEvent*) {
    QPainter p(this);
    p.fillRect(rect(), Qt::black);
    if (m_frame.isNull()) return;

    QSize sz = m_frame.size();
    sz.scale(size(), Qt::KeepAspectRatio);
    QRect dst((width() - sz.width()) / 2, (height() - sz.height()) / 2, sz.width(), sz.height());
    p.drawImage(dst, m_frame);
}

/* ─── VideoPlayerWindow ─── */

static QString fmtTime(qint64 ms) {
    qint64 s = ms / 1000;
    return QString("%1:%2").arg(s / 60).arg(s % 60, 2, 10, QChar('0'));
}

/* Слайдер перемотки: клик по любому месту шкалы = прыжок к позиции (драг кружка сохраняется). */
class SeekSlider : public QSlider {
public:
    using QSlider::QSlider;

protected:
    void mousePressEvent(QMouseEvent* e) override {
        if (e->button() == Qt::LeftButton) {
            setSliderDown(true);
            int v = QStyle::sliderValueFromPosition(minimum(), maximum(),
                                                    (int)e->position().x(), width());
            setValue(v);
            emit sliderPressed();
            e->accept();
        } else {
            QSlider::mousePressEvent(e);
        }
    }
};

VideoPlayerWindow::VideoPlayerWindow(QWidget* parent)
    : QWidget(parent, Qt::Window | Qt::FramelessWindowHint)
{
    setWindowTitle(QStringLiteral("Video"));
    setFocusPolicy(Qt::StrongFocus);
    setMouseTracking(true);
    setStyleSheet("background-color: black;");

    m_engine = new VideoPlayerEngine(this);

    m_render = new VideoRenderWidget(this);
    m_render->setAttribute(Qt::WA_TransparentForMouseEvents, true);

    m_controls = new QWidget(this);
    m_controls->setObjectName("videoControls");
    m_controls->setCursor(Qt::ArrowCursor);
    m_controls->installEventFilter(this);
    m_controls->setStyleSheet(
        "#videoControls { background-color: rgba(0,0,0,0.65); }"
        "QPushButton { background: transparent; color: white; border: none; font-size: 16px; }"
        "QPushButton:hover { background: rgba(255,255,255,0.2); }"
        "QLabel { color: white; font-size: 12px; }"
        "QSlider::groove:horizontal { height: 4px; background: #444; }"
        "QSlider::sub-page:horizontal { background: #2a9; }"
        "QSlider::handle:horizontal { width: 12px; margin: -4px 0; background: white; border-radius: 6px; }");

    m_playBtn = new QPushButton(QStringLiteral("⏸"), m_controls);
    m_playBtn->setToolTip(QStringLiteral("Пауза"));
    m_slider = new SeekSlider(Qt::Horizontal, m_controls);
    m_slider->setRange(0, 0);
    m_timeLabel = new QLabel(QStringLiteral("0:00 / 0:00"), m_controls);

    auto* lay = new QHBoxLayout(m_controls);
    lay->setContentsMargins(8, 3, 8, 6);
    lay->setSpacing(6);
    lay->addWidget(m_playBtn);
    lay->addWidget(m_slider, 1);
    lay->addWidget(m_timeLabel);

    /* крестик закрытия — отдельно, справа вверху */
    m_closeBtn = new QPushButton(QStringLiteral("✕"), this);
    m_closeBtn->setToolTip(QStringLiteral("Закрыть"));
    m_closeBtn->setCursor(Qt::ArrowCursor);
    m_closeBtn->setStyleSheet(
        "QPushButton { background: rgba(0,0,0,0.5); color: white; border: none; "
        "border-radius: 4px; font-size: 14px; }"
        "QPushButton:hover { background: rgba(255,255,255,0.25); }");

    m_hideTimer = new QTimer(this);
    m_hideTimer->setSingleShot(true);
    m_hideTimer->setInterval(2500);
    connect(m_hideTimer, &QTimer::timeout, this, &VideoPlayerWindow::hideControls);

    m_snapTimer = new QTimer(this);
    m_snapTimer->setSingleShot(true);
    m_snapTimer->setInterval(150);
    connect(m_snapTimer, &QTimer::timeout, this, &VideoPlayerWindow::snapToAspect);

    connect(m_playBtn, &QPushButton::clicked, this, &VideoPlayerWindow::onPlayPause);
    connect(m_closeBtn, &QPushButton::clicked, this, &VideoPlayerWindow::onClose);
    connect(m_slider, &QSlider::sliderPressed, this, &VideoPlayerWindow::onSliderPressed);
    connect(m_slider, &QSlider::sliderReleased, this, &VideoPlayerWindow::onSliderReleased);

    connect(m_engine, &VideoPlayerEngine::opened, this, &VideoPlayerWindow::onEngineOpened);
    connect(m_engine, &VideoPlayerEngine::positionChanged, this, &VideoPlayerWindow::onPositionChanged);
    connect(m_engine, &VideoPlayerEngine::stateChanged, this, &VideoPlayerWindow::onStateChanged);
    connect(m_engine, &VideoPlayerEngine::error, this, &VideoPlayerWindow::onError);
    connect(m_engine, &VideoPlayerEngine::framePresented, this, &VideoPlayerWindow::onFramePresented);

    resize(640, 360);
}

VideoPlayerWindow::~VideoPlayerWindow() = default;

void VideoPlayerWindow::playFile(const QString& path) {
    m_render->clearFrame();
    m_slider->setRange(0, 0);
    m_timeLabel->setText(QStringLiteral("0:00 / 0:00"));
    if (m_fullscreen) { showNormal(); m_fullscreen = false; setControlsVisible(true); unsetCursor(); }
    show();
    raise();
    activateWindow();
    m_engine->open(path);
}

void VideoPlayerWindow::onEngineOpened(int width, int height, qint64 durationMs, bool hasAudio) {
    Q_UNUSED(hasAudio);
    m_slider->setRange(0, (int)durationMs);
    updateTimeLabels(0);
    m_videoAspect = (height > 0) ? (double)width / height : 0.0;

    QScreen* scr = QApplication::primaryScreen();
    QRect ag = scr ? scr->availableGeometry() : QRect(0, 0, 1280, 720);
    QSize s = fitWindowSize(width, height);

    if (width <= ag.width() && height <= ag.height()) {
        /* видео помещается — натуральный размер по центру */
        resize(s);
        move(ag.center().x() - s.width() / 2, ag.center().y() - s.height() / 2);
    } else {
        /* видео больше экрана — fullscreen (нормальная геометрия для выхода уже задана) */
        resize(s);
        move(ag.center().x() - s.width() / 2, ag.center().y() - s.height() / 2);
        showFullScreen();
        m_fullscreen = true;
        m_hideTimer->start();
    }
    DEBUG_INFO(DEBUG_CATEGORY_VIDEO, "VideoWindow: %dx%d dur=%lldms size=%dx%d fullscreen=%d",
               width, height, (long long)durationMs, s.width(), s.height(), m_fullscreen ? 1 : 0);
}

void VideoPlayerWindow::onPositionChanged(qint64 ms) {
    if (!m_sliderDragging) {
        m_slider->blockSignals(true);
        m_slider->setValue((int)ms);
        m_slider->blockSignals(false);
    }
    updateTimeLabels(ms);
}

void VideoPlayerWindow::onStateChanged(int state) {
    VideoPlayerEngine::State s = (VideoPlayerEngine::State)state;
    if (s == VideoPlayerEngine::Playing) {
        m_playBtn->setText(QStringLiteral("⏸"));
        m_playBtn->setToolTip(QStringLiteral("Пауза"));
    } else if (s == VideoPlayerEngine::Paused || s == VideoPlayerEngine::Finished) {
        m_playBtn->setText(QStringLiteral("▶"));
        m_playBtn->setToolTip(QStringLiteral("Играть"));
        showControls();
    }
}

void VideoPlayerWindow::onError(const QString& msg) {
    DEBUG_ERROR(DEBUG_CATEGORY_VIDEO, "VideoWindow: %s", qPrintable(msg));
    m_timeLabel->setText(msg);
    showControls();
}

void VideoPlayerWindow::onFramePresented() {
    m_render->setFrame(m_engine->currentFrame());
}

void VideoPlayerWindow::onSliderPressed() {
    m_sliderDragging = true;
}

void VideoPlayerWindow::onSliderReleased() {
    m_sliderDragging = false;
    m_engine->seekMs(m_slider->value());
    if (m_engine->state() == VideoPlayerEngine::Paused ||
        m_engine->state() == VideoPlayerEngine::Finished) {
        m_engine->play();
    }
}

void VideoPlayerWindow::onPlayPause() {
    if (m_engine->state() == VideoPlayerEngine::Playing) m_engine->pause();
    else m_engine->togglePlayPause();
}

void VideoPlayerWindow::onClose() {
    m_engine->close();
    close();
}

void VideoPlayerWindow::toggleFullscreen() {
    if (m_fullscreen) {
        showNormal();
        m_fullscreen = false;
        setControlsVisible(true);
        unsetCursor();
    } else {
        showFullScreen();
        m_fullscreen = true;
        m_hideTimer->start();
    }
}

void VideoPlayerWindow::setControlsVisible(bool visible) {
    m_controls->setVisible(visible);
    m_closeBtn->setVisible(visible);
}

void VideoPlayerWindow::showControls() {
    setControlsVisible(true);
    unsetCursor();
    if (m_fullscreen) m_hideTimer->start();
}

void VideoPlayerWindow::hideControls() {
    if (!m_fullscreen) return;
    if (m_engine && (m_engine->state() == VideoPlayerEngine::Paused ||
                     m_engine->state() == VideoPlayerEngine::Finished)) return;
    setControlsVisible(false);
    setCursor(Qt::BlankCursor);
}

void VideoPlayerWindow::updateTimeLabels(qint64 posMs) {
    qint64 dur = m_engine ? m_engine->durationMs() : 0;
    m_timeLabel->setText(QString("%1 / %2").arg(fmtTime(posMs), fmtTime(dur)));
}

QSize VideoPlayerWindow::fitWindowSize(int vw, int vh) const {
    if (vw <= 0 || vh <= 0) return QSize(640, 360);
    QScreen* scr = QApplication::primaryScreen();
    QSize avail(1280, 720);
    if (scr) avail = scr->availableGeometry().size();
    QSize s(vw, vh);
    if (s.width() > avail.width() || s.height() > avail.height())
        s.scale(avail, Qt::KeepAspectRatio);
    return s;
}

void VideoPlayerWindow::keyPressEvent(QKeyEvent* e) {
    if (e->key() == Qt::Key_Escape) {
        if (m_fullscreen) { toggleFullscreen(); return; }
        onClose();
        return;
    }
    if (e->key() == Qt::Key_Return && (e->modifiers() & Qt::AltModifier)) {
        toggleFullscreen();
        return;
    }
    if (e->key() == Qt::Key_Space) {
        onPlayPause();
        return;
    }
    QWidget::keyPressEvent(e);
}

void VideoPlayerWindow::mousePressEvent(QMouseEvent* e) {
    if (e->button() == Qt::LeftButton) {
        if (m_fullscreen) {
            /* клик в fullscreen — показать/скрыть контролы */
            if (m_controls->isVisible()) hideControls();
            else showControls();
            return;
        }
        ResizeMode m = hitTestResize(e->pos());
        if (m != ResizeNone) {
            m_resizeEdges = edgesForMode(m);
            if (windowHandle()) windowHandle()->startSystemResize(m_resizeEdges);
        } else {
            if (windowHandle()) windowHandle()->startSystemMove();
        }
    }
}

void VideoPlayerWindow::mouseMoveEvent(QMouseEvent* e) {
    if (m_fullscreen) {
        showControls();
        return;
    }
    if (!(e->buttons() & Qt::LeftButton))
        updateResizeCursor(e->pos());
}

void VideoPlayerWindow::mouseDoubleClickEvent(QMouseEvent* e) {
    if (e->button() == Qt::LeftButton) toggleFullscreen();
}

bool VideoPlayerWindow::eventFilter(QObject* obj, QEvent* ev) {
    /* Резрез за нижний край: панель контролов перекрывает нижнюю кромку окна,
     * поэтому маршрутизируем press из её пустых полей в нативный resize. */
    if (obj == m_controls && !m_fullscreen && ev->type() == QEvent::MouseButtonPress) {
        QMouseEvent* me = static_cast<QMouseEvent*>(ev);
        if (me->button() == Qt::LeftButton) {
            QPoint winPos = m_controls->mapTo(this, me->pos());
            ResizeMode m = hitTestResize(winPos);
            if (m != ResizeNone) {
                m_resizeEdges = edgesForMode(m);
                if (windowHandle()) windowHandle()->startSystemResize(m_resizeEdges);
                return true;
            }
        }
    }
    return QWidget::eventFilter(obj, ev);
}

void VideoPlayerWindow::closeEvent(QCloseEvent* e) {
    m_engine->close();
    emit closed();
    QWidget::closeEvent(e);
}

void VideoPlayerWindow::resizeEvent(QResizeEvent* e) {
    QWidget::resizeEvent(e);
    m_render->setGeometry(rect());
    int ch = 48;
    m_controls->setGeometry(0, height() - ch, width(), ch);
    m_controls->raise();
    m_closeBtn->setGeometry(width() - 40, 8, 32, 32);
    m_closeBtn->raise();
    /* во время нативного resize снэпаем пропорцию после окончания жеста */
    if (m_resizeEdges != 0) m_snapTimer->start();
}

VideoPlayerWindow::ResizeMode VideoPlayerWindow::hitTestResize(const QPoint& pos) const {
    const int M = 6;
    int w = width(), h = height();
    bool l = pos.x() <= M;
    bool r = pos.x() >= w - M - 1;
    bool t = pos.y() <= M;
    bool b = pos.y() >= h - M - 1;
    if (t && l) return ResizeTopLeft;
    if (t && r) return ResizeTopRight;
    if (b && l) return ResizeBottomLeft;
    if (b && r) return ResizeBottomRight;
    if (l) return ResizeLeft;
    if (r) return ResizeRight;
    if (t) return ResizeTop;
    if (b) return ResizeBottom;
    return ResizeNone;
}

void VideoPlayerWindow::updateResizeCursor(const QPoint& pos) {
    switch (hitTestResize(pos)) {
        case ResizeTopLeft: case ResizeBottomRight: setCursor(Qt::SizeFDiagCursor); break;
        case ResizeTopRight: case ResizeBottomLeft: setCursor(Qt::SizeBDiagCursor); break;
        case ResizeLeft: case ResizeRight:          setCursor(Qt::SizeHorCursor);   break;
        case ResizeTop: case ResizeBottom:          setCursor(Qt::SizeVerCursor);   break;
        default:                                    unsetCursor();                  break;
    }
}

Qt::Edges VideoPlayerWindow::edgesForMode(ResizeMode m) {
    switch (m) {
        case ResizeLeft:        return Qt::LeftEdge;
        case ResizeRight:       return Qt::RightEdge;
        case ResizeTop:         return Qt::TopEdge;
        case ResizeBottom:      return Qt::BottomEdge;
        case ResizeTopLeft:     return Qt::TopEdge | Qt::LeftEdge;
        case ResizeTopRight:    return Qt::TopEdge | Qt::RightEdge;
        case ResizeBottomLeft:  return Qt::BottomEdge | Qt::LeftEdge;
        case ResizeBottomRight: return Qt::BottomEdge | Qt::RightEdge;
        default:                return {};
    }
}

void VideoPlayerWindow::snapToAspect() {
    if (m_videoAspect <= 0.0 || m_resizeEdges == 0) return;
    Qt::Edges edges = m_resizeEdges;
    m_resizeEdges = {};   /* сброс до resize(), чтобы снэп не ре-триггерил сам себя */
    int w = width(), h = height();
    if (w <= 0 || h <= 0) return;

    bool verticalOnly = !(edges & (Qt::LeftEdge | Qt::RightEdge));
    if (verticalOnly) {
        int newW = qRound(h * m_videoAspect);
        if (qAbs(newW - w) > 1) resize(newW, h);
    } else {
        int newH = qRound(w / m_videoAspect);
        if (qAbs(newH - h) > 1) resize(w, newH);
    }
}