#include "ImageGridWidget.h"
#include <QGridLayout>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QPainter>
#include <QResizeEvent>
#include <QShowEvent>
#include <QStackedWidget>
#include <QScrollBar>
#include <QKeyEvent>
#include <QPushButton>
#include <cmath>

// ImageTileWidget 实现
ImageTileWidget::ImageTileWidget(QWidget* parent)
    : QWidget(parent)
{
    setMinimumSize(100, 100);
    setCursor(Qt::PointingHandCursor);
}

void ImageTileWidget::setImage(const QImage& image)
{
    m_image = image;
    update();
}

void ImageTileWidget::paintEvent(QPaintEvent* event)
{
    Q_UNUSED(event);
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);

    // 绘制背景
    painter.fillRect(rect(), QColor(47, 48, 52));

    if (!m_image.isNull()) {
        // 缩放图像以适应控件
        QImage scaled = m_image.scaled(size(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
        int x = (width() - scaled.width()) / 2;
        int y = (height() - scaled.height()) / 2;
        painter.drawImage(x, y, scaled);

        // 在左上角显示设备名称（无背景）
        if (!m_alias.isEmpty()) {
            QFont font("Arial", 14);
            painter.setFont(font);
            painter.setPen(Qt::white);
            painter.drawText(10, 25, m_alias);
        }
    } else {
        // 显示占位符
        QFont font("Arial", 14);
        painter.setFont(font);
        painter.setPen(Qt::white);
        painter.drawText(rect(), Qt::AlignCenter, m_alias.isEmpty() ? "无图像" : m_alias);
    }
}

void ImageTileWidget::mousePressEvent(QMouseEvent* event)
{
    if (event->button() == Qt::LeftButton) {
        emit clicked();
    } else if (event->button() == Qt::RightButton) {
        emit rightClicked();
    }
}

// ImageZoomWidget 实现
ImageZoomWidget::ImageZoomWidget(QWidget* parent)
    : QWidget(parent)
{
    setStyleSheet("background-color: rgb(25, 26, 28);");

    QVBoxLayout* mainLayout = new QVBoxLayout(this);
    mainLayout->setContentsMargins(10, 10, 10, 10);
    mainLayout->setSpacing(10);

    // 顶部标题栏
    QHBoxLayout* topLayout = new QHBoxLayout();

    m_titleLabel = new QLabel(this);
    m_titleLabel->setStyleSheet("QLabel { color: rgb(221, 225, 233); font-size: 16px; font-weight: bold; background: transparent; }");
    topLayout->addWidget(m_titleLabel);

    topLayout->addStretch();

    // 返回按钮
    QPushButton* btnBack = new QPushButton(QString::fromUtf8("返回"), this);
    btnBack->setFixedSize(80, 30);
    btnBack->setStyleSheet(
        "QPushButton { background-color: rgb(60, 62, 68); color: rgb(221, 225, 233); "
        "border: 1px solid rgb(80, 82, 88); border-radius: 5px; font-size: 14px; }"
        "QPushButton:hover { background-color: rgb(80, 82, 88); }"
        "QPushButton:pressed { background-color: rgb(50, 52, 58); }"
    );
    connect(btnBack, &QPushButton::clicked, this, &ImageZoomWidget::exitRequested);
    topLayout->addWidget(btnBack);

    mainLayout->addLayout(topLayout);

    // 滚动区域
    m_scrollArea = new QScrollArea(this);
    m_scrollArea->setWidgetResizable(false);
    m_scrollArea->setAlignment(Qt::AlignCenter);
    m_scrollArea->setStyleSheet(
        "QScrollArea { background-color: rgb(38, 40, 47); border: none; }"
        "QScrollBar:vertical { background-color: rgb(38, 40, 47); width: 12px; }"
        "QScrollBar::handle:vertical { background-color: rgb(80, 82, 88); border-radius: 6px; min-height: 20px; }"
        "QScrollBar::add-line:vertical, QScrollBar::sub-line:vertical { height: 0px; }"
        "QScrollBar:horizontal { background-color: rgb(38, 40, 47); height: 12px; }"
        "QScrollBar::handle:horizontal { background-color: rgb(80, 82, 88); border-radius: 6px; min-width: 20px; }"
        "QScrollBar::add-line:horizontal, QScrollBar::sub-line:horizontal { width: 0px; }"
    );

    m_imageLabel = new QLabel(m_scrollArea);
    m_imageLabel->setAlignment(Qt::AlignCenter);
    m_imageLabel->setStyleSheet("background-color: rgb(38, 40, 47);");
    m_imageLabel->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
    m_imageLabel->setScaledContents(false);
    m_scrollArea->setWidget(m_imageLabel);

    mainLayout->addWidget(m_scrollArea, 1);

    // 底部信息栏
    m_infoLabel = new QLabel(this);
    m_infoLabel->setStyleSheet("QLabel { color: rgb(180, 180, 180); font-size: 12px; background: transparent; }");
    m_infoLabel->setText(QString::fromUtf8("滚轮缩放 | 拖拽平移 | 双击还原 | 点击返回按钮退出"));
    mainLayout->addWidget(m_infoLabel);

    setFocusPolicy(Qt::StrongFocus);
}

void ImageZoomWidget::setImage(const QImage& image, const QString& title)
{
    m_originalImage = image;
    m_titleLabel->setText(title);
    m_needResetZoom = true;

    // 先显示图像，showEvent 中会重新计算缩放
    updateImageDisplay();
}

void ImageZoomWidget::showEvent(QShowEvent* event)
{
    QWidget::showEvent(event);
    if (m_needResetZoom && !m_originalImage.isNull()) {
        m_needResetZoom = false;
        // 延迟一帧执行，确保布局完成
        QMetaObject::invokeMethod(this, &ImageZoomWidget::resetZoom, Qt::QueuedConnection);
    }
}

void ImageZoomWidget::updateImageDisplay()
{
    if (m_originalImage.isNull()) {
        m_imageLabel->setText(QString::fromUtf8("无图像"));
        return;
    }

    int newWidth = static_cast<int>(m_originalImage.width() * m_scaleFactor);
    int newHeight = static_cast<int>(m_originalImage.height() * m_scaleFactor);

    QImage scaledImage = m_originalImage.scaled(newWidth, newHeight,
                                                 Qt::KeepAspectRatio,
                                                 Qt::SmoothTransformation);
    m_imageLabel->setPixmap(QPixmap::fromImage(scaledImage));
    m_imageLabel->resize(scaledImage.size());

    QString info = QString::fromUtf8("缩放: %1% | 尺寸: %2x%3 | 滚轮缩放 | 拖拽平移 | 双击还原")
        .arg(static_cast<int>(m_scaleFactor * 100))
        .arg(m_originalImage.width())
        .arg(m_originalImage.height());
    m_infoLabel->setText(info);
}

void ImageZoomWidget::resetZoom()
{
    if (m_originalImage.isNull()) return;

    QSize viewSize = m_scrollArea->viewport()->size();
    double scaleX = static_cast<double>(viewSize.width() - 20) / m_originalImage.width();
    double scaleY = static_cast<double>(viewSize.height() - 20) / m_originalImage.height();
    m_scaleFactor = qMin(scaleX, scaleY);
    m_scaleFactor = qMax(m_scaleFactor, MIN_SCALE);

    updateImageDisplay();

    m_scrollArea->horizontalScrollBar()->setValue(
        (m_imageLabel->width() - m_scrollArea->viewport()->width()) / 2);
    m_scrollArea->verticalScrollBar()->setValue(
        (m_imageLabel->height() - m_scrollArea->viewport()->height()) / 2);
}

void ImageZoomWidget::wheelEvent(QWheelEvent* event)
{
    if (m_originalImage.isNull()) return;

    double delta = event->angleDelta().y() > 0 ? SCALE_STEP : -SCALE_STEP;

    double newScale = m_scaleFactor + delta;
    newScale = qMax(newScale, MIN_SCALE);
    newScale = qMin(newScale, MAX_SCALE);

    if (qAbs(newScale - m_scaleFactor) > 0.001) {
        QScrollBar* hBar = m_scrollArea->horizontalScrollBar();
        QScrollBar* vBar = m_scrollArea->verticalScrollBar();

        double hRatio = hBar->maximum() > 0 ? static_cast<double>(hBar->value()) / hBar->maximum() : 0.5;
        double vRatio = vBar->maximum() > 0 ? static_cast<double>(vBar->value()) / vBar->maximum() : 0.5;

        m_scaleFactor = newScale;
        updateImageDisplay();

        hBar->setValue(static_cast<int>(hRatio * hBar->maximum()));
        vBar->setValue(static_cast<int>(vRatio * vBar->maximum()));
    }

    event->accept();
}

void ImageZoomWidget::mousePressEvent(QMouseEvent* event)
{
    if (event->button() == Qt::LeftButton) {
        m_dragging = true;
        m_lastPos = event->pos();
        setCursor(Qt::ClosedHandCursor);
    }
    QWidget::mousePressEvent(event);
}

void ImageZoomWidget::mouseMoveEvent(QMouseEvent* event)
{
    if (m_dragging) {
        QPoint delta = event->pos() - m_lastPos;
        m_lastPos = event->pos();

        QScrollBar* hBar = m_scrollArea->horizontalScrollBar();
        QScrollBar* vBar = m_scrollArea->verticalScrollBar();

        hBar->setValue(hBar->value() - delta.x());
        vBar->setValue(vBar->value() - delta.y());
    }
    QWidget::mouseMoveEvent(event);
}

void ImageZoomWidget::mouseReleaseEvent(QMouseEvent* event)
{
    if (event->button() == Qt::LeftButton) {
        m_dragging = false;
        setCursor(Qt::ArrowCursor);
    }
    QWidget::mouseReleaseEvent(event);
}

void ImageZoomWidget::mouseDoubleClickEvent(QMouseEvent* event)
{
    if (event->button() == Qt::LeftButton) {
        resetZoom();
    }
    QWidget::mouseDoubleClickEvent(event);
}

void ImageZoomWidget::keyPressEvent(QKeyEvent* event)
{
    switch (event->key()) {
    case Qt::Key_Escape:
        emit exitRequested();
        break;
    case Qt::Key_Plus:
    case Qt::Key_Equal:
        m_scaleFactor = qMin(m_scaleFactor + SCALE_STEP, MAX_SCALE);
        updateImageDisplay();
        break;
    case Qt::Key_Minus:
        m_scaleFactor = qMax(m_scaleFactor - SCALE_STEP, MIN_SCALE);
        updateImageDisplay();
        break;
    case Qt::Key_0:
        m_scaleFactor = 1.0;
        updateImageDisplay();
        break;
    case Qt::Key_F:
        resetZoom();
        break;
    default:
        QWidget::keyPressEvent(event);
    }
}

void ImageZoomWidget::resizeEvent(QResizeEvent* event)
{
    QWidget::resizeEvent(event);
    if (!m_originalImage.isNull()) {
        resetZoom();
    }
}

// ImageGridWidget 实现
ImageGridWidget::ImageGridWidget(QWidget* parent)
    : QWidget(parent)
{
    // 使用 QStackedWidget 切换网格视图和放大视图
    m_stackedWidget = new QStackedWidget(this);

    QVBoxLayout* mainLayout = new QVBoxLayout(this);
    mainLayout->setContentsMargins(0, 0, 0, 0);
    mainLayout->addWidget(m_stackedWidget);

    // 网格容器
    m_gridContainer = new QWidget(this);
    m_layout = new QGridLayout(m_gridContainer);
    m_layout->setSpacing(5);
    m_layout->setContentsMargins(5, 5, 5, 5);

    // 创建无图像提示标签
    m_noImageLabel = new QLabel("暂无图像", m_gridContainer);
    m_noImageLabel->setAlignment(Qt::AlignCenter);
    m_noImageLabel->setStyleSheet("color: rgb(150, 150, 150); font-size: 24px;");
    m_noImageLabel->hide();

    m_stackedWidget->addWidget(m_gridContainer);

    // 放大视图
    m_zoomWidget = new ImageZoomWidget(this);
    connect(m_zoomWidget, &ImageZoomWidget::exitRequested, this, &ImageGridWidget::showGridView);
    m_stackedWidget->addWidget(m_zoomWidget);

    // 默认显示网格视图
    m_stackedWidget->setCurrentIndex(0);
}

void ImageGridWidget::initImages(int count)
{
    // 清除现有的tiles
    for (auto tile : m_tiles) {
        m_layout->removeWidget(tile);
        delete tile;
    }
    m_tiles.clear();
    m_aliasMap.clear();

    if (count <= 0) {
        m_noImageLabel->show();
        m_columns = 0;
        m_rows = 0;
        return;
    }

    m_noImageLabel->hide();

    // 计算行列数
    m_columns = static_cast<int>(std::ceil(std::sqrt(count)));
    m_rows = static_cast<int>(std::ceil(static_cast<double>(count) / m_columns));

    // 创建新的tiles
    for (int i = 0; i < count; ++i) {
        auto tile = new ImageTileWidget(m_gridContainer);
        m_tiles.append(tile);

        int row = i / m_columns;
        int col = i % m_columns;
        m_layout->addWidget(tile, row, col);

        connect(tile, &ImageTileWidget::clicked, [this, i]() {
            // 点击时显示放大视图
            showZoomView(i);
            emit tileClicked(i);
        });

        connect(tile, &ImageTileWidget::rightClicked, [this, i]() {
            // 右键点击时发射信号，携带索引和别名
            QString alias = m_tiles[i]->alias();
            emit tileRightClicked(i, alias);
        });
    }

    updateTileSizes();
}

void ImageGridWidget::setImages(int index, const QImage& image)
{
    if (index >= 0 && index < m_tiles.size()) {
        m_tiles[index]->setImage(image);
    }
}

void ImageGridWidget::setImages(const QString& alias, const QImage& image)
{
    if (m_aliasMap.contains(alias)) {
        int index = m_aliasMap[alias];
        setImages(index, image);
    }
}

void ImageGridWidget::setTileAlias(int index, const QString& alias)
{
    if (index >= 0 && index < m_tiles.size()) {
        m_tiles[index]->setAlias(alias);
        m_aliasMap[alias] = index;
    }
}

void ImageGridWidget::setSelectedIndex(int index)
{
    m_selectedIndex = index;
}

void ImageGridWidget::setExpandedIndex(int index)
{
    m_expandedIndex = index;
    updateTileSizes();
}

void ImageGridWidget::rebuildGrid()
{
    // 重新构建网格布局
    for (int i = 0; i < m_tiles.size(); ++i) {
        int row = i / m_columns;
        int col = i % m_columns;
        m_layout->addWidget(m_tiles[i], row, col);
    }
}

void ImageGridWidget::updateTileSizes()
{
    if (m_tiles.isEmpty() || m_columns == 0 || m_rows == 0) {
        return;
    }

    // 使用 stackedWidget 的尺寸，因为 gridContainer 在 stackedWidget 内
    int containerWidth = m_stackedWidget->width();
    int containerHeight = m_stackedWidget->height();

    int availableWidth = containerWidth - m_layout->contentsMargins().left() - m_layout->contentsMargins().right()
                         - (m_columns - 1) * m_layout->spacing();
    int availableHeight = containerHeight - m_layout->contentsMargins().top() - m_layout->contentsMargins().bottom()
                          - (m_rows - 1) * m_layout->spacing();

    int tileWidth = availableWidth / m_columns;
    int tileHeight = availableHeight / m_rows;

    for (auto tile : m_tiles) {
        tile->setFixedSize(tileWidth, tileHeight);
    }
}

void ImageGridWidget::resizeEvent(QResizeEvent* event)
{
    QWidget::resizeEvent(event);
    updateTileSizes();
}

QImage ImageGridWidget::getImage(int index) const
{
    if (index >= 0 && index < m_tiles.size()) {
        return m_tiles[index]->image();
    }
    return QImage();
}

QString ImageGridWidget::getAlias(int index) const
{
    if (index >= 0 && index < m_tiles.size()) {
        return m_tiles[index]->alias();
    }
    return QString();
}

void ImageGridWidget::showZoomView(int index)
{
    if (index < 0 || index >= m_tiles.size()) {
        return;
    }

    QImage image = m_tiles[index]->image();
    if (image.isNull()) {
        return;
    }

    QString alias = m_tiles[index]->alias();
    m_zoomWidget->setImage(image, alias);
    m_stackedWidget->setCurrentIndex(1);
    m_zoomWidget->setFocus();
}

void ImageGridWidget::showGridView()
{
    m_stackedWidget->setCurrentIndex(0);
}