#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QApplication>
#include <QShortcut>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_clock.start();
    m_refreshTimer.setInterval(100);
    connect(&m_refreshTimer, &QTimer::timeout, this, &MainWindow::refreshDisplay);
    for (QSpinBox *spin : {ui->hoursSpin, ui->minutesSpin, ui->secondsSpin})
        connect(spin, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged),
                this, &MainWindow::durationChanged);
    connect(ui->startButton, &QPushButton::clicked, this, [this] {
        m_countdown.start(m_clock.elapsed());
        refreshDisplay();
    });
    connect(ui->pauseButton, &QPushButton::clicked, this, [this] {
        const auto previousState = m_countdown.state();
        m_countdown.pause(m_clock.elapsed());
        if (previousState == Countdown::State::Running
                && m_countdown.state() == Countdown::State::Finished
                && ui->soundCheck->isChecked())
            QApplication::beep();
        refreshDisplay();
    });
    connect(ui->resetButton, &QPushButton::clicked, this, [this] {
        m_countdown.reset();
        refreshDisplay();
    });
    connect(ui->fullscreenButton, &QPushButton::clicked, this, [this] {
        if (isFullScreen()) showNormal(); else showFullScreen();
        ui->fullscreenButton->setText(isFullScreen() ? tr("退出全屏") : tr("全屏显示"));
    });
    auto *escape = new QShortcut(QKeySequence(Qt::Key_Escape), this);
    connect(escape, &QShortcut::activated, this, [this] {
        if (isFullScreen()) {
            showNormal();
            ui->fullscreenButton->setText(tr("全屏显示"));
        }
    });
    durationChanged();
}

MainWindow::~MainWindow() { delete ui; }

void MainWindow::durationChanged()
{
    const qint64 seconds = ui->hoursSpin->value() * 3600
        + ui->minutesSpin->value() * 60 + ui->secondsSpin->value();
    m_countdown.setDuration(seconds * 1000);
    refreshDisplay();
}

void MainWindow::refreshDisplay()
{
    const qint64 now = m_clock.elapsed();
    const auto previousState = m_countdown.state();
    m_countdown.update(now);
    const auto state = m_countdown.state();
    const bool running = state == Countdown::State::Running;
    const bool paused = state == Countdown::State::Paused;
    if (running && !m_refreshTimer.isActive()) m_refreshTimer.start();
    if (!running) m_refreshTimer.stop();
    const qint64 remaining = m_countdown.remaining(now);
    // 向上取整：还剩 1 毫秒时显示 1 秒，真正到时才显示零。
    const qint64 seconds = (remaining + 999) / 1000;
    ui->timeLabel->setText(QStringLiteral("%1:%2:%3")
        .arg(seconds / 3600, 2, 10, QLatin1Char('0'))
        .arg((seconds / 60) % 60, 2, 10, QLatin1Char('0'))
        .arg(seconds % 60, 2, 10, QLatin1Char('0')));
    ui->progressBar->setValue(m_countdown.duration() == 0 ? 0
        : static_cast<int>(remaining * 1000 / m_countdown.duration()));
    ui->durationGroup->setEnabled(!running && !paused);
    ui->startButton->setEnabled(!running && m_countdown.duration() > 0);
    ui->pauseButton->setEnabled(running);
    ui->startButton->setText(paused ? tr("继续") :
        state == Countdown::State::Finished ? tr("重新开始") : tr("开始"));
    if (running) ui->statusLabel->setText(tr("正在计时"));
    else if (paused) ui->statusLabel->setText(tr("已暂停 · 点击“继续”接着计时"));
    else if (state == Countdown::State::Finished)
        ui->statusLabel->setText(tr("时间到！本轮计时已结束。"));
    else ui->statusLabel->setText(m_countdown.duration() > 0
        ? tr("准备就绪 · 点击“开始”") : tr("请先设置大于 0 的时长。"));
    if (previousState == Countdown::State::Running && state == Countdown::State::Finished
            && ui->soundCheck->isChecked())
        QApplication::beep();
}