#include "graphicsItem/electricConnectLineItem.h"
#include <QGraphicsScene>
#include <QPainter>
#include <QStyleOptionGraphicsItem>

ElectricConnectLineItem::ElectricConnectLineItem(QGraphicsItem *parent)
    : GraphicsProjectModelItem(parent)
{
    initial();
}

ElectricConnectLineItem::ElectricConnectLineItem(const ElectricConnectLineItem& obj)
    : GraphicsProjectModelItem(obj)
{
    initial();
    m_lstPoints = obj.m_lstPoints;
}

ElectricConnectLineItem::~ElectricConnectLineItem()
{
}

ElectricConnectLineItem* ElectricConnectLineItem::clone() const
{
    return new ElectricConnectLineItem(*this);
}

void ElectricConnectLineItem::initial()
{
    m_boundingRect = QRectF();
    m_pen = QPen(Qt::black);
    m_brush = QBrush(Qt::NoBrush);
    setHandleVisible(false);
    setFunctionHandleIfShow(false);
    setFunctionHandleEnaable(false);
    m_lstPoints.push_back(QPointF());       //起点
    m_lstPoints.push_back(QPointF());       //终点
    _curLine = QPoint();
}


void ElectricConnectLineItem::setStartPoint(const QPointF& p)
{
    int n = m_lstPoints.size();
    if(n)
    {
        if(n >2)
        {
            if(m_lstPoints[0].x() == m_lstPoints[1].x())        //相邻点在垂直方向，水平移动,否则垂直移动
            {
                m_lstPoints[1].setX(p.x());
            }
            else
            {
                m_lstPoints[1].setY(p.y());
            }
        }
        m_lstPoints[0] = p;
    }
}
void ElectricConnectLineItem::setEndPoint(const QPointF& p)
{
    int n = m_lstPoints.size();
    if(n)
    {
        if(n >2)
        {
            if(m_lstPoints[n-1].x() == m_lstPoints[n-2].x())    //相邻点在垂直方向，水平移动,否则垂直移动
            {
                m_lstPoints[n-2].setX(p.x());
            }
            else
            {
                m_lstPoints[n-2].setY(p.y());
            }
        }
        m_lstPoints[n-1] = p;
    }
}

QPainterPath ElectricConnectLineItem::shape() const
{
    QPainterPath path;
    //path.addPath(m_points);
    path.addPath(m_pointsBoundingRect);
    return path;
}

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

void ElectricConnectLineItem::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
{
    if (option->state & QStyle::State_Selected)
    {
        painter->setPen(Qt::red);
    }
    else
    {
        if(_curMonitorStateEnable){     //当前状态被设置
            painter->setPen(QPen(_curMonitorStateColor));
        }
        else
            painter->setPen(m_pen);
    }

    painter->setBrush(m_brush);

    painter->drawPath(m_points);
}

void ElectricConnectLineItem::moveLine(QPointF pos)
{
    QPointF delta = pos - m_lastPoint;
    if(_curLine.isNull())
    {
        if(m_lstPoints.size() > 1)
        {
            int n = m_lstPoints.size();
            for(int i = 0;i < m_lstPoints.size() -1;++i)
            {
                QPointF p1 = m_lstPoints[i];
                QPointF p2 = m_lstPoints[i+1];

                if(p1.x() == p2.x() && abs(p1.x() - pos.x()) < 2)      //在相同竖线
                {
                    if(p1.y() > p2.y())
                    {
                        if(pos.y() > p2.y() && pos.y() < p1.y())     //在竖线上
                        {

                            if(i == 0 )      //起点是连接点,创建复制点
                            {
                                m_lstPoints.prepend(p1);
                                m_lstPoints.prepend(p1);

                                i+=2;
                                if(m_lstPoints.size() < 6)      //补齐后端
                                {
                                    m_lstPoints.append(m_lstPoints.last());
                                }
                            }
                            if(i+1 == n-1)  //终点是连接点，创建复制点
                            {
                                m_lstPoints.append(p2);
                                m_lstPoints.append(p2);

                                m_lstPoints[i+1] = p2;
                                if(m_lstPoints.size() < 6)      //补齐前端,移动后至少6个点
                                {
                                    m_lstPoints.prepend(m_lstPoints.first());
                                    i+=1;
                                }
                            }
                            //qDebug() << 1 <<" "<<i;
                            _curLine = QPoint(i,1);
                            break;
                        }
                    }
                    else if(p1.y() < p2.y())
                    {
                        if(pos.y() < p2.y() && pos.y() > p1.y())     //在竖线上
                        {

                            if(i == 0)      //起点是连接点,创建复制点
                            {
                                m_lstPoints.prepend(p1);
                                m_lstPoints.prepend(p1);
                                i+=2;
                                if(m_lstPoints.size() < 6)      //补齐后端
                                {
                                    m_lstPoints.append(m_lstPoints.last());
                                }
                            }
                            if(i+1 == n-1)  //终点是连接点，创建复制点
                            {
                                m_lstPoints.append(p2);
                                m_lstPoints.append(p2);

                                m_lstPoints[i+1] = p2;
                                if(m_lstPoints.size() < 6)      //补齐前端
                                {
                                    m_lstPoints.prepend(m_lstPoints.first());
                                    i+=1;
                                }
                            }
                            //qDebug() << 2 <<" "<<i;
                            _curLine = QPoint(i,1);
                            break;
                        }
                    }
                }
                else if(p1.y() == p2.y() && abs(p1.y() - pos.y()) < 2)  //在相同横线
                {
                    if(p1.x() > p2.x())
                    {
                        if(pos.x() > p2.x() && pos.x() < p1.x())
                        {

                            if(i == 0)      //起点是连接点,创建复制点
                            {
                                m_lstPoints.prepend(p1);
                                m_lstPoints.prepend(p1);

                                i+=2;
                                if(m_lstPoints.size() < 6)      //补齐后端
                                {
                                    m_lstPoints.append(m_lstPoints.last());
                                }
                            }
                            if(i+1 == n-1)  //终点是连接点，创建复制点
                            {
                                m_lstPoints.append(p2);
                                m_lstPoints.append(p2);

                                if(m_lstPoints.size() < 6)      //补齐前端,移动后至少6个点
                                {
                                    m_lstPoints.prepend(m_lstPoints.first());
                                    i+=1;
                                }
                            }
                            //qDebug() << 3 <<" "<<i;
                            _curLine = QPoint(i,-1);
                            break;
                        }
                    }
                    else if(p1.x() < p2.x())
                    {
                        if(pos.x() < p2.x() && pos.x() > p1.x())
                        {

                            if(i == 0)      //起点是连接点,创建复制点
                            {
                                m_lstPoints.prepend(p1);
                                m_lstPoints.prepend(p1);

                                i+=2;
                                m_lstPoints[i] = p1;
                                if(m_lstPoints.size() < 6)      //补齐后端
                                {
                                    m_lstPoints.append(m_lstPoints.last());
                                }
                            }
                            if(i+1 == n-1)  //终点是连接点，创建复制点
                            {
                                m_lstPoints.append(p2);
                                m_lstPoints.append(p2);

                                if(m_lstPoints.size() < 6)      //补齐前端
                                {
                                    m_lstPoints.prepend(m_lstPoints.first());
                                    i+=1;
                                }
                            }
                            //qDebug() << 4 <<" "<<i;
                            _curLine = QPoint(i,-1);
                            break;
                        }
                    }
                }
            }
        }
    }
    else
    {
        int n = _curLine.x();
        //qDebug() << n <<" "<<_curLine.y();
        //if(m_lstPoints.size() > 3)
        {

            if(_curLine.y() == 1)       //竖线
            {
                if(n == 0)          //起点是原点
                {
                    QPointF p(0,delta.y());                         //原点不动
                    m_lstPoints[n +1] = m_lstPoints[n +1] + p;      //第二个点只竖直移动
                    m_lstPoints[n +2] = m_lstPoints[n +2] + p;      //第三个点只竖直移动
                }
                else if(n == 1)
                {
                    QPointF p(delta.x(),0);
                    m_lstPoints[n] += p;                //第一个点只水平移动
                    m_lstPoints[n +1] +=  p;            //第二个点只水平移动
                }
                else if(n == m_lstPoints.size()-2)      //起点是倒数第二个点
                {
                    QPointF p(0,delta.y());
                    m_lstPoints[n] += p;                //起点只上下移动
                    m_lstPoints[n-1] += p;              //上个点只竖直移动
                }
                else if(n == m_lstPoints.size()-3)      //起点是倒数第三个点
                {
                    QPointF py(0,delta.y());
                    QPointF px(delta.x(),0);
                    m_lstPoints[n-1] += py;                            //上个点只垂直移动
                    m_lstPoints[n] += delta;                          //起点任意动
                    m_lstPoints[n+1] += px;                           //第二个点只水平移动
                }
                else
                {
                    m_lstPoints[n -1].setY(m_lstPoints[n ].y());
                    m_lstPoints[n] += delta;
                    m_lstPoints[n +1] += delta;
                    m_lstPoints[n +2].setY(m_lstPoints[n +1].y());
                }
            }
            else                        //横线
            {
                if(n == 0)          //起点是原点
                {
                    QPointF p(delta.x(),0);                         //原点不动
                    m_lstPoints[n +1] = m_lstPoints[n +1] + p;      //第二个点只水平移动
                    m_lstPoints[n +2] = m_lstPoints[n +2] + p;      //第三个点只水平移动
                }
                else if(n == 1)
                {
                    QPointF p(0,delta.y());
                    m_lstPoints[n] = m_lstPoints[n] + p;            //第一个点只竖直移动
                    m_lstPoints[n +1] = m_lstPoints[n +1] + p;      //第二个点只竖直移动
                }
                else if(n == m_lstPoints.size()-2)      //起点是倒数第二个点
                {
                    QPointF p(delta.x(),0);
                    m_lstPoints[n] += p;                //起点水平移动
                    m_lstPoints[n-1] += p;              //上个点只水平移动
                }
                else if(n == m_lstPoints.size()-3)      //起点是倒数第三个点
                {
                    QPointF py(0,delta.y());
                    QPointF px(delta.x(),0);
                    m_lstPoints[n-1] += px;                            //上个点只水平移动
                    m_lstPoints[n] += delta;                          //起点任意动
                    m_lstPoints[n+1] += py;                           //第二个点只上下移动
                }
                else
                {
                    m_lstPoints[n -1].setX(m_lstPoints[n].x());
                    m_lstPoints[n] += delta;
                    m_lstPoints[n +1] += delta;
                    m_lstPoints[n +2].setX(m_lstPoints[n +1].x());
                }
            }
        }

        calculatePath();
    }

    m_lastPoint = pos;
}

void ElectricConnectLineItem::calculatePath()
{
    if (m_lstPoints.size() < 2) return;

    QPointF start = m_lstPoints.first();
    QPointF end = m_lstPoints.last();

    qDebug() << "\n=== calculatePath ===";
    qDebug() << "Start:" << start << "End:" << end;

    // 创建新路径
    m_points = QPainterPath();
    m_points.moveTo(start);
    qDebug() << "Initialized path, current position:" << m_points.currentPosition();

    // 获取元件
    QList<QRectF> components = getComponentCollisionRects();
    qDebug() << "Found" << components.size() << "components";

    // 检查起点终点距离
    qDebug() << "Distance:" << QLineF(start, end).length();

    // 如果距离很近，直接连接
    if (QLineF(start, end).length() < 10) {
        qDebug() << "Points are very close, direct connection";
        m_points.lineTo(end);
    } else {
        // 生成路径
        generateAvoidancePath(start, end, components);
    }

    // 验证路径
    qDebug() << "After generation - Path element count:" << m_points.elementCount();
    qDebug() << "After generation - Current position:" << m_points.currentPosition();

    if (m_points.elementCount() <= 1) {
        qWarning() << "Path has only" << m_points.elementCount() << "elements! Adding direct line";
        m_points.lineTo(end);
    }

    // 确保路径结束于终点
    if (m_points.currentPosition() != end) {
        qWarning() << "Path does not end at destination! Adding final segment";
        qDebug() << "Expected end:" << end << "Actual end:" << m_points.currentPosition();
        m_points.lineTo(end);
    }

    update();
    m_boundingRect = m_points.boundingRect();
    prepareGeometryChange();

    qDebug() << "Final path bounds:" << m_boundingRect;
    qDebug() << "=== calculatePath end ===\n";
}

// 使用形状进行避障
void ElectricConnectLineItem::generateAvoidancePath(const QPointF& start, const QPointF& end,
                                                              const QList<QRectF>& components)
{
    qDebug() << "=== generateAvoidancePath (rectilinear) ===";

    m_points = QPainterPath();
    m_points.moveTo(start);

    // 生成候选路径列表，按长度排序
    QMultiMap<double, QList<QPointF>> candidatePaths;

    // 1. 收集所有可能的直角路径
    collectRectilinearPaths(start, end, components, candidatePaths);

    // 2. 选择最短的安全路径
    for (auto it = candidatePaths.begin(); it != candidatePaths.end(); ++it) {
        const QList<QPointF>& path = it.value();

        if (isPathSafe(path, components)) {
            qDebug() << "  Selected path with length" << it.key() << ":" << path;

            // 绘制路径
            for (int i = 1; i < path.size(); i++) {
                m_points.lineTo(path[i]);
            }
            return;
        }
    }

    // 3. 所有路径都失败，使用强制绕行
    qDebug() << "  All rectilinear paths failed, using forced bypass";
    generateForcedRectilinearBypass(start, end, components);
}

// 计算路径长度
double ElectricConnectLineItem::calculatePathLength(const QList<QPointF>& path)
{
    double length = 0;
    for (int i = 0; i < path.size() - 1; i++) {
        length += QLineF(path[i], path[i+1]).length();
    }
    return length;
}


// 单一线段与矩形相交检测
bool ElectricConnectLineItem::lineIntersectsRect(const QLineF& line, const QRectF& rect)
{
    // 检查端点是否在矩形内
    if (rect.contains(line.p1()) || rect.contains(line.p2())) {
        return true;
    }

    // 检查是否与矩形的边相交
    QLineF edges[4] = {
        QLineF(rect.topLeft(), rect.topRight()),
        QLineF(rect.topRight(), rect.bottomRight()),
        QLineF(rect.bottomRight(), rect.bottomLeft()),
        QLineF(rect.bottomLeft(), rect.topLeft())
    };

    QPointF intersection;
    for (int i = 0; i < 4; i++) {
        if (line.intersects(edges[i], &intersection) == QLineF::BoundedIntersection) {
            return true;
        }
    }

    return false;
}

// 辅助方法实现
bool ElectricConnectLineItem::isSegmentSafe(const QPointF& p1, const QPointF& p2,
                                            const QList<QRectF>& components)
{
    QLineF segment(p1, p2);

    for (const QRectF& component : components) {
        if (segmentPenetratesComponent(segment, component)) {
            return false;
        }
    }

    return true;
}

bool ElectricConnectLineItem::isPathSafe(const QList<QPointF>& path,
                                         const QList<QRectF>& components)
{
    for (int i = 0; i < path.size() - 1; i++) {
        if (!isSegmentSafe(path[i], path[i+1], components)) {
            return false;
        }
    }
    return true;
}

// 检查线段是否穿透元件
bool ElectricConnectLineItem::segmentPenetratesComponent(const QLineF& segment,
                                                         const QRectF& component)
{
    // 检查线段端点是否在元件内
    bool p1Inside = component.contains(segment.p1());
    bool p2Inside = component.contains(segment.p2());

    if (p1Inside && p2Inside) {
        // 线段完全在元件内
        return true;
    }

    // 获取与元件的交点
    int intersectionCount = 0;
    QLineF edges[4] = {
        QLineF(component.topLeft(), component.topRight()),
        QLineF(component.topRight(), component.bottomRight()),
        QLineF(component.bottomRight(), component.bottomLeft()),
        QLineF(component.bottomLeft(), component.topLeft())
    };

    QPointF intersection;
    for (int i = 0; i < 4; i++) {
        if (segment.intersects(edges[i], &intersection) == QLineF::BoundedIntersection) {
            intersectionCount++;
        }
    }

    // 如果线段与元件有2个或更多交点，说明穿透了元件
    return intersectionCount >= 2;
}

// 获取所有元件的总边界
QRectF ElectricConnectLineItem::getTotalComponentsBounds(const QList<QRectF>& components)
{
    if (components.isEmpty()) {
        return QRectF();
    }

    QRectF total = components.first();
    for (int i = 1; i < components.size(); i++) {
        total = total.united(components[i]);
    }

    return total;
}

// 收集所有可能的直角路径
void ElectricConnectLineItem::collectRectilinearPaths(const QPointF& start, const QPointF& end,
                                                      const QList<QRectF>& components,
                                                      QMultiMap<double, QList<QPointF>>& paths)
{
    // 2段路径
    QPointF turn1(start.x(), end.y());  // 水平-垂直
    QPointF turn2(end.x(), start.y());  // 垂直-水平

    addPathIfRectilinear({start, turn1, end}, paths);
    addPathIfRectilinear({start, turn2, end}, paths);

    // 3段路径
    double midX = (start.x() + end.x()) / 2;
    double midY = (start.y() + end.y()) / 2;

    // 水平-垂直-水平
    addPathIfRectilinear({start,
                          QPointF(start.x(), midY),
                          QPointF(end.x(), midY),
                          end}, paths);

    // 垂直-水平-垂直
    addPathIfRectilinear({start,
                          QPointF(midX, start.y()),
                          QPointF(midX, end.y()),
                          end}, paths);

    // 4段路径（绕行）
    collectBypassPaths(start, end, components, paths);
}

// 添加路径（如果是直角）
void ElectricConnectLineItem::addPathIfRectilinear(const QList<QPointF>& path,
                                                   QMultiMap<double, QList<QPointF>>& paths)
{
    // 检查是否所有线段都是水平或垂直
    for (int i = 0; i < path.size() - 1; i++) {
        if (path[i].x() != path[i+1].x() && path[i].y() != path[i+1].y()) {
            return; // 不是直角
        }
    }

    double length = calculatePathLength(path);
    paths.insert(length, path);
}

// 收集绕行路径
void ElectricConnectLineItem::collectBypassPaths(const QPointF& start, const QPointF& end,
                                                 const QList<QRectF>& components,
                                                 QMultiMap<double, QList<QPointF>>& paths)
{
    if (components.isEmpty()) return;

    // 获取所有元件的总边界
    QRectF totalBounds = getTotalComponentsBounds(components);
    if (!totalBounds.isValid()) return;

    const double clearance = 20.0;
    QRectF expanded = totalBounds.adjusted(-clearance, -clearance, clearance, clearance);

    // 从上方绕行
    addPathIfRectilinear({start,
                          QPointF(start.x(), expanded.top()),
                          QPointF(end.x(), expanded.top()),
                          end}, paths);

    // 从下方绕行
    addPathIfRectilinear({start,
                          QPointF(start.x(), expanded.bottom()),
                          QPointF(end.x(), expanded.bottom()),
                          end}, paths);

    // 从左方绕行
    addPathIfRectilinear({start,
                          QPointF(expanded.left(), start.y()),
                          QPointF(expanded.left(), end.y()),
                          end}, paths);

    // 从右方绕行
    addPathIfRectilinear({start,
                          QPointF(expanded.right(), start.y()),
                          QPointF(expanded.right(), end.y()),
                          end}, paths);
}

// 强制直角绕行
void ElectricConnectLineItem::generateForcedRectilinearBypass(const QPointF& start, const QPointF& end,
                                                              const QList<QRectF>& components)
{
    qDebug() << "  In generateForcedRectilinearBypass";

    // 找到阻挡的元件
    QRectF blocking = findFirstBlockingComponent(start, end, components);

    if (blocking.isValid()) {
        qDebug() << "  Blocking component:" << blocking;

        // 从上方或下方绕过
        const double clearance = 15.0;
        double bypassY = (start.y() < blocking.center().y()) ?
                             blocking.top() - clearance : blocking.bottom() + clearance;

        QList<QPointF> path = {start,
                               QPointF(start.x(), bypassY),
                               QPointF(end.x(), bypassY),
                               end};

        qDebug() << "  Forced bypass path:" << path;

        for (int i = 1; i < path.size(); i++) {
            m_points.lineTo(path[i]);
        }
    } else {
        // 没有阻挡，使用简单的直角路径
        qDebug() << "  No blocking component, using simple orthogonal path";
        QPointF turnPoint = (qAbs(start.x() - end.x()) < qAbs(start.y() - end.y())) ?
                                QPointF(end.x(), start.y()) : QPointF(start.x(), end.y());

        m_points.lineTo(turnPoint);
        m_points.lineTo(end);
    }
}

// 找到第一个阻挡的元件
QRectF ElectricConnectLineItem::findFirstBlockingComponent(const QPointF& start, const QPointF& end,
                                                           const QList<QRectF>& components)
{
    QLineF line(start, end);

    for (const QRectF& rect : components) {
        if (lineIntersectsRect(line, rect)) {
            return rect;
        }
    }

    return QRectF();
}