#include "emojipanel.h"
#include "emoji.h"
#include "emojitabbar.h"
#include "animtimer.h"
#include "lottieicon.h"
#include <QPushButton>
#include <QScrollArea>
#include <QTabWidget>
#include <QGridLayout>
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QPainter>
#include <QTimer>

namespace {

class EmojiTabWidget : public QTabWidget {
public:
    using QTabWidget::setTabBar;
};

class EmojiButton : public QPushButton {
public:
    EmojiButton(const EmojiData &data, QWidget *parent = nullptr)
        : QPushButton(data.unicode, parent)
        , m_data(data)
    {
        setFixedSize(32, 32);
        setCursor(Qt::PointingHandCursor);
        setStyleSheet(
            "QPushButton { border: none; border-radius: 4px; font-size: 18px; background: transparent; }"
            "QPushButton:hover { background: rgba(0,0,0,0.08); }"
        );
        if (data.type == EmojiType::Animation) {
            setMouseTracking(true);
            m_icon = AnimTimer::instance()->icon(data.animPath);
            m_timer.setInterval(33);
            connect(&m_timer, &QTimer::timeout, this, [this]() {
                if (m_icon && m_icon->isValid()) {
                    m_frame = (m_frame + 1) % m_icon->frameCount();
                    update();
                }
            });
        }
    }
    const QString &unicode() const { return m_data.unicode; }

protected:
#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
    void enterEvent(QEnterEvent *e) override {
#else
    void enterEvent(QEvent *e) override {
#endif
        QPushButton::enterEvent(e);
        if (m_icon && m_icon->isValid()) {
            m_hovered = true;
            m_frame = 0;
            m_timer.start();
        }
    }
    void leaveEvent(QEvent *e) override {
        QPushButton::leaveEvent(e);
        m_hovered = false;
        m_timer.stop();
        update();
    }
    void paintEvent(QPaintEvent *e) override {
        if (m_hovered && m_icon && m_icon->isValid()) {
            QPainter p(this);
            p.setRenderHint(QPainter::SmoothPixmapTransform);
            int sz = qMin(width(), height()) - 4;
            QImage frame = m_icon->renderFrame(m_frame, QSize(sz, sz));
            int x = (width() - sz) / 2, y = (height() - sz) / 2;
            p.drawImage(x, y, frame);
        } else {
            QPushButton::paintEvent(e);
        }
    }

private:
    EmojiData m_data;
    LottieIcon *m_icon = nullptr;
    QTimer m_timer;
    int m_frame = 0;
    bool m_hovered = false;
};

} // namespace

EmojiPanel::EmojiPanel(QWidget *parent)
    : QWidget(parent)
{
    setStyleSheet("EmojiPanel { background: palette(window); }");
    buildPanel(builtinEmojiSet());
    hide();
}

void EmojiPanel::showEvent(QShowEvent *event) {
    if (parentWidget()) {
        setFixedHeight(qBound(200, parentWidget()->height() * 3 / 10, 800));
    }
    QWidget::showEvent(event);
}

void EmojiPanel::buildPanel(const QVector<EmojiCategory> &categories) {
    auto *tabs = new EmojiTabWidget();
    tabs->setDocumentMode(true);
    tabs->setTabBar(new EmojiTabBar(tabs));
    tabs->setStyleSheet("QTabWidget::pane { border: none; background: rgba(255,255,255,0.6); }");

    for (const auto &cat : categories) {
        tabs->addTab(buildCategoryPage(cat), cat.name);
    }

    auto *layout = new QVBoxLayout(this);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->setSpacing(0);
    layout->addWidget(tabs);
}

QWidget *EmojiPanel::buildCategoryPage(const EmojiCategory &cat) {
    auto *scroll = new QScrollArea();
    scroll->setWidgetResizable(true);
    scroll->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    scroll->setStyleSheet("QScrollArea { border: none; }");

    auto *container = new QWidget();
    auto *grid = new QGridLayout(container);
    grid->setContentsMargins(4, 4, 4, 4);
    grid->setSpacing(2);

    int cols = 9;
    for (int i = 0; i < cat.items.size(); ++i) {
        const auto &e = cat.items[i];
        QPushButton *btn;
        if (e.type == EmojiType::Animation)
            btn = new EmojiButton(e, container);
        else {
            btn = new QPushButton(e.unicode, container);
            btn->setFixedSize(32, 32);
            btn->setCursor(Qt::PointingHandCursor);
            btn->setStyleSheet(
                "QPushButton { border: none; border-radius: 4px; font-size: 18px; background: transparent; }"
                "QPushButton:hover { background: rgba(0,0,0,0.08); }"
            );
        }
        btn->setToolTip(e.shortcode);
        connect(btn, &QPushButton::clicked, this, &EmojiPanel::onEmojiClicked);
        grid->addWidget(btn, i / cols, i % cols);
    }
    grid->setRowStretch(grid->rowCount(), 1);

    scroll->setWidget(container);
    return scroll;
}

void EmojiPanel::onEmojiClicked() {
    auto *btn = qobject_cast<QPushButton *>(sender());
    if (!btn) return;
    auto *eb = dynamic_cast<EmojiButton *>(btn);
    emit emojiSelected(eb ? eb->unicode() : btn->text());
}