#include "ImageView.h"
#include <QPainter>
#include <QDebug>
#include <QGraphicsPixmapItem>
#include <QScrollBar>
#include <QMenu>
#include <QFileDialog>
#include <QDateTime>
#include <QMessageBox>

#define VIEW_CENTER viewport()->rect().center()
#define VIEW_WIDTH  viewport()->rect().width()
#define VIEW_HEIGHT viewport()->rect().height()


ImageView::ImageView(QWidget* parent) :
    QGraphicsView(parent),
    m_imageOffset(0, 0),
    m_bMouseTranslate(false),
    m_isDrawing(false),
    m_curDrawing(false),
    m_currentPathItem(nullptr)
{
    m_pRuleLine = nullptr;
    setScene(new QGraphicsScene(this));
    setRenderHint(QPainter::SmoothPixmapTransform);
    setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
    this->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    this->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

}

ImageView::~ImageView()
{
}

void ImageView::setPixmap(const QPixmap& newPixmap) {
    this->m_pixmap = newPixmap;
    scene()->clear();
    m_pixmapItem = scene()->addPixmap(m_pixmap);
    m_pixmapItem->setZValue(1);
    QPointF pixmapCenter(m_pixmap.width() / 2.0, m_pixmap.height() / 2.0);
    m_pixmapItem->setPos(-pixmapCenter);
    QRectF sceneRect(-pixmapCenter.x(), -pixmapCenter.y(), m_pixmap.width(), m_pixmap.height());
    scene()->setSceneRect(sceneRect);
    setSceneRect(scene()->itemsBoundingRect());
    this->resize(m_pixmap.width(), m_pixmap.height());
    m_imageOffset = QPoint(0, 0); // 重置图片偏移量为(0, 0)
    setCursor(Qt::ArrowCursor);
    update(); // 触发重绘
}

void ImageView::setCurPixmap(const QPixmap& newPixmap) {
    this->m_pixmap = newPixmap;
    m_pixmapItem->setPixmap(m_pixmap);
}

void ImageView::startRuler()
{
    if (nullptr == m_pRuleLine) {
        m_pRuleLine = new DraggableLine(QLineF(0, 0, 50, 50));
        m_pRuleLine->setPen(QPen(Qt::red, 2));
        m_pRuleLine->setZValue(2);
        scene()->addItem(m_pRuleLine);
    }
}

void ImageView::endRuler()
{
    if (nullptr != m_pRuleLine) {
        scene()->removeItem(m_pRuleLine);
        delete m_pRuleLine;
        m_pRuleLine = nullptr;
    }
}

bool ImageView::rulerVisibale()
{
    if (nullptr == m_pRuleLine)
        return false;
    else
        return true;
}

void ImageView::paintEvent(QPaintEvent* event) {
    QGraphicsView::paintEvent(event);
}

void ImageView::mousePressEvent(QMouseEvent* event) {
    if (event->button() == Qt::LeftButton) {
        // 当光标底下没有 item 时，才能移动
        QPointF point = mapToScene(event->pos());
        if (scene()->itemAt(point, transform()) != m_pRuleLine) {
            setCursor(Qt::OpenHandCursor);
            m_bMouseTranslate = true;
            m_lastMousePos = event->pos();
        }
    }
    else if (event->button() == Qt::RightButton) {
        m_rightClickPressPos = event->pos();
        m_rightButtonPressed = true;
    }
    QGraphicsView::mousePressEvent(event);
}

void ImageView::mouseMoveEvent(QMouseEvent* event) {
    if (m_bMouseTranslate) {
        // 计算鼠标当前位置与上次位置的差值
        QPointF delta = event->pos() - m_lastMousePos;
        // 平移视图
        horizontalScrollBar()->setValue(horizontalScrollBar()->value() - delta.x());
        verticalScrollBar()->setValue(verticalScrollBar()->value() - delta.y());
        m_lastMousePos = event->pos();  // 更新鼠标位置
    }
    else if ((event->buttons() & Qt::RightButton) && m_isDrawing && m_rightButtonPressed) {
        if (!m_curDrawing && (event->pos() - m_rightClickPressPos).manhattanLength() > 5) {
            m_curDrawing = true;
            // 根据初始位置开始绘制路径
            QPointF scenePos = mapToScene(m_rightClickPressPos);
            m_currentPath = QPainterPath(scenePos);
            m_currentPathItem = new QGraphicsPathItem();
            m_currentPathItem->setPen(QPen(Qt::red, 2));
            m_currentPathItem->setPath(m_currentPath);
            m_currentPathItem->setZValue(2);
            scene()->addItem(m_currentPathItem);
            m_drawnPaths.append(m_currentPathItem);
        }
        // 如果已经处于绘制状态，则继续添加点
        if (m_curDrawing && m_currentPathItem) {
            QPointF scenePos = mapToScene(event->pos());
            m_currentPath.lineTo(scenePos);
            m_currentPathItem->setPath(m_currentPath);
        }
        event->accept();
        return;
    }
    QGraphicsView::mouseMoveEvent(event);
}

void ImageView::mouseReleaseEvent(QMouseEvent* event) {
    if (event->button() == Qt::LeftButton) {
        setCursor(Qt::ArrowCursor);  // 松开时恢复为箭头
        m_bMouseTranslate = false;
    }
    else if (event->button() == Qt::RightButton && m_rightButtonPressed) {
        if (!m_curDrawing) {
            // 右键点击（无拖动），弹出菜单
            QMenu menu(this);
            QAction* act1 = menu.addAction(tr("保存当前窗口图片"));
            QAction* act2 = menu.addAction(tr("清除"));

            connect(act1, &QAction::triggered, this, [this]() {
                saveImage();
                });
            connect(act2, &QAction::triggered, this, [this]() {
                clearDrawnLines();
                });
            menu.exec(event->globalPos());
        }
        else {
            // 绘制结束
            m_currentPathItem = nullptr;
            m_curDrawing = false;
        }
        // 恢复状态
        m_rightButtonPressed = false;
        event->accept();
        return;
    }
    QGraphicsView::mouseReleaseEvent(event);
}

void ImageView::wheelEvent(QWheelEvent* event)
{
    if (event->orientation() == Qt::Vertical) {
        event->ignore(); // 忽略竖直滚轮事件（即禁用滚动条滑动）
        return;
    }
    event->accept();
}

void ImageView::saveImage()
{
    // 使用当前时间生成默认文件名
    QString defaultFileName = QDateTime::currentDateTime().toString("yyyy-MM-dd_HH-mm-ss") + ".png";

    QString fileName = QFileDialog::getSaveFileName(
        this,
        tr("保存图片"),
        QDir::homePath() + "/" + defaultFileName, // 默认路径为用户目录，文件名为当前时间
        tr("PNG 文件 (*.png);;JPEG 文件 (*.jpg);;所有文件 (*)")
    );
    if (!fileName.isEmpty()) {
        QImage image(viewport()->size(), QImage::Format_ARGB32);
        image.fill(Qt::white);
        QPainter painter(&image);
        this->render(&painter);
        if (!image.save(fileName)) {
            QMessageBox::warning(this, tr("保存失败"), tr("无法保存图片到指定路径。"));
        }
        else {
            QMessageBox::information(this, tr("保存成功"), tr("图片已成功保存到：") + fileName);
        }
        painter.end();
    }
}


void ImageView::clearDrawnLines()
{
    qDeleteAll(m_drawnPaths);
    m_drawnPaths.clear();
}