#include "mygraphicsgriditem.h"
#include <cmath>

MyGraphicsGridItem::MyGraphicsGridItem(double gridSpacing,QRectF rect)
    : m_gridSpacing(gridSpacing), m_rect(rect)
{
    m_gridSpacing = m_gridSpacing / 8.0;
    m_boundingRect = m_rect;
    double left = m_rect.left();
    double right = m_rect.right();
    double top = m_rect.top();
    double bottom = m_rect.bottom();
    // 水平网格线 Y
    for (double y = top; y <= bottom; y += m_gridSpacing)
    {
        m_listY.append(y);
    }

    // 垂直网格线
    for (double x = left; x <= right; x += m_gridSpacing)
    {
        m_listX.append(x);
    }

}

MyGraphicsGridItem::~MyGraphicsGridItem()
{
}

void MyGraphicsGridItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
    return QGraphicsItem::mousePressEvent(event);
}

void MyGraphicsGridItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
    return QGraphicsItem::mouseMoveEvent(event);
}

void MyGraphicsGridItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
    return QGraphicsItem::mouseReleaseEvent(event);
}

QRectF MyGraphicsGridItem::boundingRect() const
{
    return m_boundingRect;
}

void MyGraphicsGridItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(option);
    Q_UNUSED(widget);

    // 获取当前的变换矩阵
    QTransform transform = painter->worldTransform();
    double scaleFactor = sqrt(transform.m11() * transform.m11() +
                                   transform.m22() * transform.m22());

    QPen pen;
    pen.setWidth(1);
    double width = pen.width()/scaleFactor;
    pen.setWidthF(width);      // 线段保持原来的线宽
    painter->setPen(pen);

    // 计算网格线的数量
    double left = m_rect.left();
    double right = m_rect.right();
    double top = m_rect.top();
    double bottom = m_rect.bottom();
    int num = ((right - left) / m_gridSpacing) / 2 ;
    double middle = num * m_gridSpacing;
    const double epsilon = 1e-9;

    // 水平网格线
    for (int i = 0; i < m_listY.size(); i++)
    {
        double y = m_listY.at(i);
        int indexInt = qRound((y - top) / m_gridSpacing);

        if(fabs(y - middle) < epsilon)
        {
            pen.setColor(Qt::red);
            pen.setStyle(Qt::SolidLine);
        }
        else if(indexInt % 8 == 6)
        {
            pen.setColor(Qt::black);
            pen.setStyle(Qt::SolidLine);
        }
        else
        {
            pen.setColor(Qt::transparent);//透明色
        }
        painter->setPen(pen);
        painter->drawLine(QPointF(left, y), QPointF(right, y));//加1为笔宽
    }

    // 垂直网格线
    for (int i = 0; i < m_listX.size(); i++)
    {
        double x = m_listX.at(i);
        int indexInt = qRound((x - top) / m_gridSpacing);
        if(fabs(x - middle) < epsilon)
        {
            pen.setColor(Qt::red);
            pen.setStyle(Qt::SolidLine);
        }
        else if(indexInt % 8 == 6)
        {
            pen.setColor(Qt::black);
            pen.setStyle(Qt::SolidLine);
        }
        else
        {
            pen.setColor(Qt::transparent);//透明色
        }
        painter->setPen(pen);
        painter->drawLine(QPointF(x, top), QPointF(x, bottom));
        // 添加数字标注
//        QGraphicsTextItem *textItem = m_scene->addText(QString::number(x), font);
//        textItem->setPos(x, top-gridSpacing);
//        textItem->setDefaultTextColor(Qt::black);
    }
}

QPointF MyGraphicsGridItem::getClosestFocus(QPointF point)
{
    if (m_listX.isEmpty() || m_listY.isEmpty()) {
        return QPointF(0,0);
    }

    double minDiffX = std::numeric_limits<double>::max();
    double minDiffY = std::numeric_limits<double>::max();
    double closestX = 0.0;
    double closestY = 0.0;

    // 找离 point.x() 最近的 X 值
    for (double x : m_listX) {
        double diff = std::fabs(point.x() - x);
        if (diff < minDiffX) {
            minDiffX = diff;
            closestX = x;
        }
    }

    // 找离 point.y() 最近的 Y 值
    for (double y : m_listY) {
        double diff = std::fabs(point.y() - y);
        if (diff < minDiffY) {
            minDiffY = diff;
            closestY = y;
        }
    }

    return QPointF(closestX, closestY);
}