#include "transition_overlay.h"

#include <QEvent>
#include <QFont>
#include <QGuiApplication>
#include <QLabel>
#include <QPalette>
#include <QScreen>
#include <QTimer>
#include <QVBoxLayout>
#include <QVariant>

namespace vdi {
namespace {

constexpr int kTickMs = 400;     // 省略号/旋轮动画周期
constexpr int kFadeStepMs = 40;  // 淡出步进周期
constexpr int kFadeSteps = 25;   // 全程约 1 秒淡出

const char* kSpinnerFrames[] = {"◐", "◓", "◑", "◒"};

}  // namespace

TransitionOverlay::TransitionOverlay(QWidget* parent) : QWidget(parent) {
    // 独立置顶无边框窗口只在启动时映射一次，后续不再与 Moonlight 抢焦点。
    setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint |
                   Qt::WindowDoesNotAcceptFocus
#ifdef Q_OS_UNIX
                   | Qt::X11BypassWindowManagerHint
#endif
    );
    setAttribute(Qt::WA_ShowWithoutActivating);
    // A plain QWidget subclass needs an explicit opaque palette; a type-name
    // stylesheet alone may leave the native window using its default white.
    setAutoFillBackground(true);
    QPalette background = palette();
    background.setColor(QPalette::Window, QColor(QStringLiteral("#0f1420")));
    setPalette(background);

    auto* layout = new QVBoxLayout(this);
    layout->setSpacing(28);

    labelSpinner_ = new QLabel(this);
    QFont spinFont = labelSpinner_->font();
    spinFont.setPointSize(44);
    labelSpinner_->setFont(spinFont);
    labelSpinner_->setAlignment(Qt::AlignCenter);
    labelSpinner_->setStyleSheet(QStringLiteral("color: #2f6feb; background: transparent;"));
    layout->addStretch(1);
    layout->addWidget(labelSpinner_);

    labelTitle_ = new QLabel(this);
    QFont titleFont = labelTitle_->font();
    titleFont.setPointSize(20);
    labelTitle_->setFont(titleFont);
    labelTitle_->setAlignment(Qt::AlignCenter);
    labelTitle_->setStyleSheet(QStringLiteral("color: #e6e9ef; background: transparent;"));
    layout->addWidget(labelTitle_);
    layout->addStretch(2);

    tickTimer_ = new QTimer(this);
    connect(tickTimer_, &QTimer::timeout, this, &TransitionOverlay::onTick);
    fadeTimer_ = new QTimer(this);
    connect(fadeTimer_, &QTimer::timeout, this, &TransitionOverlay::onFadeStep);

    // 活动期间吞掉本窗口的键盘/鼠标事件，避免误触下层页面
    installEventFilter(this);
}

void TransitionOverlay::start(const QString& title) {
    tickTimer_->stop();
    fadeTimer_->stop();
    dots_ = 0;
    setWindowOpacity(1.0);
    setProperty("baseTitle", title);
    labelTitle_->setText(title);
    labelSpinner_->setText(QString::fromUtf8(kSpinnerFrames[0]));

    if (QScreen* targetScreen = QGuiApplication::primaryScreen()) {
        setGeometry(targetScreen->geometry());
    }
    show();
    raise();
    tickTimer_->start(kTickMs);
}

void TransitionOverlay::finish() {
    tickTimer_->stop();
    fadeTimer_->stop();
    hide();
    setWindowOpacity(1.0);
}

void TransitionOverlay::onFirstFrame() {
    // The exclusive X11 kiosk has no compositor to apply window opacity.
    // Once the full-screen stream is ready, unmap the opaque cover directly.
#ifdef Q_OS_UNIX
    if (QGuiApplication::platformName() == QStringLiteral("xcb")) {
        finish();
        return;
    }
#endif
    // 首帧已出画：停止动画并淡出；若尚未显示/已在淡出则忽略
    if (!isVisible() || fadeTimer_->isActive()) {
        return;
    }
    tickTimer_->stop();
    fadeTimer_->start(kFadeStepMs);
}

void TransitionOverlay::onTick() {
    dots_ = (dots_ + 1) % 4;
    const QString base = property("baseTitle").toString();
    if (!base.isEmpty()) {
        labelTitle_->setText(base + QString(dots_, QLatin1Char('.')));
    }
    labelSpinner_->setText(QString::fromUtf8(kSpinnerFrames[dots_]));
}

void TransitionOverlay::onFadeStep() {
    const double opacity = windowOpacity() - 1.0 / kFadeSteps;
    if (opacity <= 0.0) {
        finish();
        return;
    }
    setWindowOpacity(opacity);
}

bool TransitionOverlay::eventFilter(QObject* watched, QEvent* event) {
    if (watched == this && isVisible()) {
        switch (event->type()) {
            case QEvent::KeyPress:
            case QEvent::KeyRelease:
            case QEvent::MouseButtonPress:
            case QEvent::MouseButtonRelease:
            case QEvent::MouseMove:
            case QEvent::Wheel:
                return true;
            default:
                break;
        }
    }
    return QWidget::eventFilter(watched, event);
}

}  // namespace vdi