#include "DialogImageViewer.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QPushButton>
#include <QScrollBar>
#include <QKeyEvent>
#include <QApplication>
#include <QScreen>

DialogImageViewer::DialogImageViewer(QWidget* parent)
    : QDialog(parent)
{
    setupUI();
}

DialogImageViewer::~DialogImageViewer()
{
}

void DialogImageViewer::setupUI()
{
    // 设置窗口属性
    setWindowTitle(QString::fromUtf8("图像查看"));
    setWindowFlags(Qt::Dialog | Qt::WindowMaximizeButtonHint | Qt::WindowCloseButtonHint);
    setStyleSheet("background-color: rgb(25, 26, 28);");

    // 获取屏幕大小，设置窗口为屏幕的80%
    QScreen* screen = QApplication::primaryScreen();
    QRect screenGeometry = screen->availableGeometry();
    int width = screenGeometry.width() * 0.8;
    int height = screenGeometry.height() * 0.8;
    resize(width, height);

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

    // 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; }"
    );

    // 图像标签
    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
    QHBoxLayout* bottomLayout = new QHBoxLayout();
    bottomLayout->setSpacing(20);

    m_infoLabel = new QLabel(this);
    m_infoLabel->setStyleSheet("QLabel { color: rgb(180, 180, 180); font-size: 14px; }");
    m_infoLabel->setText(QString::fromUtf8("滚轮缩放 | 拖拽平移 | 双击还原 | ESC退出"));
    bottomLayout->addWidget(m_infoLabel);

    bottomLayout->addStretch();

    // 关闭按钮
    QPushButton* btnClose = new QPushButton(QString::fromUtf8("关闭"), this);
    btnClose->setFixedSize(100, 35);
    btnClose->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(btnClose, &QPushButton::clicked, this, &QDialog::close);
    bottomLayout->addWidget(btnClose);

    mainLayout->addLayout(bottomLayout);

    // 设置焦点策略以接收键盘事件
    setFocusPolicy(Qt::StrongFocus);
}

void DialogImageViewer::setImage(const QImage& image, const QString& title)
{
    m_originalImage = image;
    m_scaleFactor = 1.0;

    if (!title.isEmpty()) {
        setWindowTitle(QString::fromUtf8("图像查看 - %1").arg(title));
    }

    // 计算初始缩放比例，使图像适应窗口
    if (!m_originalImage.isNull()) {
        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);
        m_scaleFactor = qMin(m_scaleFactor, 1.0);  // 初始不放大超过100%
    }

    updateImageDisplay();
}

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

    // 计算缩放后的尺寸
    int newWidth = static_cast<int>(m_originalImage.width() * m_scaleFactor);
    int newHeight = static_cast<int>(m_originalImage.height() * m_scaleFactor);

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

    // 更新信息标签
    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 DialogImageViewer::resetZoom()
{
    if (m_originalImage.isNull()) return;

    // 重置为适应窗口的缩放比例
    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();

    // 居中显示
    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 DialogImageViewer::wheelEvent(QWheelEvent* event)
{
    if (m_originalImage.isNull()) return;

    // 获取滚轮方向
    double delta = event->angleDelta().y() > 0 ? SCALE_STEP : -SCALE_STEP;

    // 计算新的缩放比例
    double newScale = m_scaleFactor + delta;
    newScale = qMax(newScale, MIN_SCALE);
    newScale = qMin(newScale, MAX_SCALE);

    if (qAbs(newScale - m_scaleFactor) > 0.001) {
        // 保存当前滚动位置比例
        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();

        // 恢复滚动位置比例
        hBar->setValue(static_cast<int>(hRatio * hBar->maximum()));
        vBar->setValue(static_cast<int>(vRatio * vBar->maximum()));
    }

    event->accept();
}

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

void DialogImageViewer::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());
    }
    QDialog::mouseMoveEvent(event);
}

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

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

void DialogImageViewer::keyPressEvent(QKeyEvent* event)
{
    switch (event->key()) {
    case Qt::Key_Escape:
        close();
        break;
    case Qt::Key_Plus:
    case Qt::Key_Equal:
        // 放大
        m_scaleFactor = qMin(m_scaleFactor + SCALE_STEP, MAX_SCALE);
        updateImageDisplay();
        break;
    case Qt::Key_Minus:
        // 缩小
        m_scaleFactor = qMax(m_scaleFactor - SCALE_STEP, MIN_SCALE);
        updateImageDisplay();
        break;
    case Qt::Key_0:
        // 原始大小
        m_scaleFactor = 1.0;
        updateImageDisplay();
        break;
    case Qt::Key_F:
        // 适应窗口
        resetZoom();
        break;
    default:
        QDialog::keyPressEvent(event);
    }
}