#include "plcdocument.h"
#include "plcitems.h"
#include <QPainter>
#include <QPen>
#include <QBrush>
#include <QMenu>
#include <QAction>
#include <QGraphicsSceneMouseEvent>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QFile>
#include <QFileInfo>
#include <QVBoxLayout>
#include <QMessageBox>
#include <QInputDialog>
#include <QDragEnterEvent>
#include <QDragMoveEvent>
#include <QCursor>
#include <QDropEvent>
#include <QMimeData>
#include <cmath>
#include <QResizeEvent>
#include <QDebug>
#include <QGraphicsItem>
#include <QSet>
#include <QMap>
#include <QPointer>
#include <QScrollArea>
#include <QKeyEvent>

PLCDocument::PLCDocument(QWidget *parent)
    : BaseDocument(PLC, parent)
    , m_rows(DEFAULT_ROWS)
    , m_columns(DEFAULT_COLUMNS)
    , m_cellSize(DEFAULT_CELL_SIZE)
{
    m_scene = new QGraphicsScene(this);
    m_scene->setSceneRect(0, 0, m_columns * m_cellSize, m_rows * m_cellSize);

    m_view = new QGraphicsView(m_scene, this);
    m_view->setRenderHint(QPainter::Antialiasing);
    m_view->setDragMode(QGraphicsView::RubberBandDrag);
    m_view->setMouseTracking(true);
    m_view->viewport()->installEventFilter(this);
    m_view->setAlignment(Qt::AlignLeft | Qt::AlignTop);

    QScrollArea *scrollArea = new QScrollArea(this);
    scrollArea->setWidget(m_view);
    scrollArea->setWidgetResizable(true);

    auto layout = new QVBoxLayout(this);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->addWidget(scrollArea);
    setLayout(layout);
    m_view->setAcceptDrops(true);
    createRealTable();

    connect(m_scene, &QGraphicsScene::selectionChanged, this, [this]()
    {
        auto items = m_scene->selectedItems();
        if (items.size() == 1 && dynamic_cast<PLCItem*>(items.first()))
        {
            clearCurrentConnection();
        }
    });

    connect(m_scene, &QGraphicsScene::changed, this, &PLCDocument::handleSceneChanged);
}

PLCDocument::~PLCDocument()
{
    qDeleteAll(m_connections);
    m_copiedItem = nullptr;
}

QString PLCDocument::title() const {
    return "PLC文档";
}

void PLCDocument::createRealTable()
{
    QRectF tableRect(0, 0, m_columns * m_cellSize, m_rows * m_cellSize);
    m_tableFrame = new QGraphicsRectItem(tableRect);
    m_tableFrame->setPen(QPen(Qt::black, 2));
    m_tableFrame->setBrush(QBrush(QColor(228, 255, 202)));
    m_tableFrame->setZValue(-10);
    m_scene->addItem(m_tableFrame);

    for (int col = 0; col <= m_columns; col++) {
        int x = col * m_cellSize;
        QGraphicsLineItem* line = new QGraphicsLineItem(x, 0, x, m_rows * m_cellSize);
        line->setPen(QPen(Qt::darkGray, 1));
        line->setZValue(-9);
        m_scene->addItem(line);
        m_verticalLines.append(line);
    }

    for (int row = 0; row <= m_rows; row++) {
        int y = row * m_cellSize;
        QGraphicsLineItem* line = new QGraphicsLineItem(0, y, m_columns * m_cellSize, y);
        line->setPen(QPen(Qt::darkGray, 1));
        line->setZValue(-9);
        m_scene->addItem(line);
        m_horizontalLines.append(line);
    }

    for (int row = 0; row < m_rows; row++)
    {
        const int terminalSize = 15;
        QPointF terminalPos(0, row * m_cellSize + m_cellSize / 2.0 - terminalSize / 2);

        QGraphicsEllipseItem* terminal = new QGraphicsEllipseItem(
            terminalPos.x(), terminalPos.y(), terminalSize, terminalSize);

        terminal->setFlag(QGraphicsItem::ItemIsSelectable, true);
        terminal->setFlag(QGraphicsItem::ItemIsFocusable, true);
        terminal->setAcceptHoverEvents(true);
        terminal->setVisible(true);

        m_scene->addItem(terminal);
        m_rowTerminals.append(terminal);
        m_rowTerminalMap[terminal] = row;
    }
}

QPointF PLCDocument::snapToCellCenter(const QPointF& pos) const
{
    int col = static_cast<int>(std::floor(pos.x() / m_cellSize));
    int row = static_cast<int>(std::floor(pos.y() / m_cellSize));

    col = qBound(0, col, m_columns - 1);
    row = qBound(0, row, m_rows - 1);

    return QPointF(col * m_cellSize + m_cellSize / 2.0,
                  row * m_cellSize + m_cellSize / 2.0);
}

QPointF PLCDocument::constrainToTable(const QPointF &pos) const
{
    int col = static_cast<int>(std::floor(pos.x() / m_cellSize));
    int row = static_cast<int>(std::floor(pos.y() / m_cellSize));

    col = qBound(0, col, m_columns - 1);
    row = qBound(0, row, m_rows - 1);

    return QPointF(col * m_cellSize + m_cellSize / 2.0,
                  row * m_cellSize + m_cellSize / 2.0);
}

bool PLCDocument::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == m_view->viewport())
    {
        if (event->type() == QEvent::DragEnter) {
            QDragEnterEvent *dragEvent = static_cast<QDragEnterEvent*>(event);
            if (dragEvent->mimeData()->hasText()) {
                dragEvent->acceptProposedAction();
                return true;
            }
        }
        else if (event->type() == QEvent::DragMove) {
            QDragMoveEvent *dragEvent = static_cast<QDragMoveEvent*>(event);
            if(dragEvent->mimeData()->hasText()) {
                dragEvent->acceptProposedAction();
                return true;
            }
        }
        else if (event->type() == QEvent::Drop) {
            QDropEvent *dropEvent = static_cast<QDropEvent*>(event);
            const QMimeData *mimeData = dropEvent->mimeData();
            if (mimeData->hasText()) {
                QPoint viewportPos = m_view->viewport()->mapFromParent(dropEvent->pos());
                QPointF scenePos = m_view->mapToScene(viewportPos);
                QPointF cellCenter = snapToCellCenter(scenePos);

                QSet<int> occupiedCells;
                for (QGraphicsItem* item : m_scene->items()) {
                    if (PLCItem* plcItem = dynamic_cast<PLCItem*>(item)) {
                        int col = static_cast<int>(plcItem->x() / m_cellSize);
                        int row = static_cast<int>(plcItem->y() / m_cellSize);
                        occupiedCells.insert(col * 1000 + row);
                    }
                }

                int col = static_cast<int>(cellCenter.x() / m_cellSize);
                int row = static_cast<int>(cellCenter.y() / m_cellSize);
                int cellKey = col * 1000 + row;

                if (occupiedCells.contains(cellKey)) {
                    bool found = false;
                    for (int offset = 1; offset < m_columns; offset++) {
                        int newCol = col + offset;
                        if (newCol < m_columns) {
                            int newKey = newCol * 1000 + row;
                            if (!occupiedCells.contains(newKey)) {
                                cellCenter = QPointF(newCol * m_cellSize + m_cellSize / 2.0,
                                                   row * m_cellSize + m_cellSize / 2.0);
                                found = true;
                                break;
                            }
                        }
                    }
                    if (!found) {
                        for (int offset = 1; offset < m_rows; offset++) {
                            int newRow = row + offset;
                            if (newRow < m_rows) {
                                int newKey = col * 1000 + newRow;
                                if (!occupiedCells.contains(newKey)) {
                                    cellCenter = QPointF(col * m_cellSize + m_cellSize / 2.0,
                                                       newRow * m_cellSize + m_cellSize / 2.0);
                                    found = true;
                                    break;
                                }
                            }
                        }
                    }
                }

                QString toolType = mimeData->text();
                createPLCItem(toolType, cellCenter);
                m_currentTool.clear();
                dropEvent->acceptProposedAction();
                return true;
            }
        }
    }

    if (obj != m_view->viewport()) {
        return QWidget::eventFilter(obj, event);
    }

    if (event->type() == QEvent::MouseMove && m_tempLine) {
        QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
        QPointF scenePos = m_view->mapToScene(mouseEvent->pos());
        QPointF cellCenter = snapToCellCenter(scenePos);

        if (m_connectionSourceType != ConnectionNone) {
            if (m_connectionSourceType == ConnectionFromItem && m_connectionStartItem) {
                if (m_startTerminal == LeftTerminal) {
                    QPointF startPos = m_connectionStartItem->leftTerminal();
                    QLineF line(startPos, cellCenter);
                    m_tempLine->setLine(line);
                } else if (m_startTerminal == RightTerminal) {
                    QPointF startPos = m_connectionStartItem->rightTerminal();
                    QLineF line(startPos, cellCenter);
                    m_tempLine->setLine(line);
                }
            } else if (m_connectionSourceType == ConnectionFromRowTerminal) {
                QPointF startPos(0, (m_connectionStartRow + 0.5) * m_cellSize);
                QLineF line(startPos, cellCenter);
                m_tempLine->setLine(line);
            }
        }
    }
    if (event->type() == QEvent::MouseButtonPress) {
        QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);

        if (mouseEvent->button() == Qt::RightButton) {
            createContextMenu(mouseEvent->globalPos());
            return true;
        }

        if (mouseEvent->button() == Qt::LeftButton) {
            QPointF scenePos = m_view->mapToScene(mouseEvent->pos());

            QGraphicsEllipseItem* clickedRowTerminal = nullptr;
            int rowTerminalIndex = -1;
            for (auto terminal : m_rowTerminals) {
                QPointF localPos = terminal->mapFromScene(scenePos);
                if (terminal->contains(localPos)) {
                    clickedRowTerminal = terminal;
                    rowTerminalIndex = m_rowTerminalMap[terminal];
                    break;
                }
            }

            if (clickedRowTerminal) {
                if (m_connectionSourceType != ConnectionNone) {
                    if (tryEndConnection(nullptr, RowTerminal)) {
                        return true;
                    }
                } else {
                    startConnectionFromRowTerminal(rowTerminalIndex);
                    return true;
                }
            }

            QPointF cellCenter = snapToCellCenter(scenePos);
            QGraphicsItem *clickedItem = m_scene->itemAt(cellCenter, m_view->transform());
            PLCItem *plcItem = dynamic_cast<PLCItem*>(clickedItem);

            if (!m_currentTool.isEmpty()) {
                QSet<int> occupiedCells;
                for (QGraphicsItem* item : m_scene->items()) {
                    if (PLCItem* existingItem = dynamic_cast<PLCItem*>(item)) {
                        int col = static_cast<int>(existingItem->x() / m_cellSize);
                        int row = static_cast<int>(existingItem->y() / m_cellSize);
                        occupiedCells.insert(col * 1000 + row);
                    }
                }

                int col = static_cast<int>(cellCenter.x() / m_cellSize);
                int row = static_cast<int>(cellCenter.y() / m_cellSize);
                int cellKey = col * 1000 + row;

                if (!occupiedCells.contains(cellKey)) {
                    createPLCItem(m_currentTool, cellCenter);
                    m_currentTool.clear();
                    return true;
                } else {
                    QMessageBox::warning(this, "位置被占用", "此单元格已被占用，请选择其他位置。");
                    return true;
                }
            }

            if (plcItem) {
                TerminalType clickedTerminal = whichTerminal(scenePos, plcItem);

                if (m_connectionSourceType != ConnectionNone) {
                    if (clickedTerminal != NoTerminal) {
                        if (tryEndConnection(plcItem, clickedTerminal)) {
                            return true;
                        }
                    }
                } else {
                    if (clickedTerminal != NoTerminal && !isTerminalUsed(plcItem, clickedTerminal))
                    {
                        startConnection(plcItem, clickedTerminal);
                        return true;
                    }
                }
            }
        }
    }

    return QWidget::eventFilter(obj, event);
}

void PLCDocument::startConnectionFromRowTerminal(int row)
{
    clearCurrentConnection();

    m_connectionSourceType = ConnectionFromRowTerminal;
    m_connectionStartRow = row;

    m_tempLine = new QGraphicsLineItem;
    m_tempLine->setPen(QPen(Qt::blue, 2, Qt::DashLine));

    QPointF startPos(0, (row + 0.5) * m_cellSize);
    m_tempLine->setLine(QLineF(startPos, startPos));
    m_scene->addItem(m_tempLine);
}

PLCDocument::TerminalType PLCDocument::whichTerminal(const QPointF& scenePos, PLCItem* item) const
{
    const qreal terminalRadius = 20.0;

    QPointF leftTerminal = item->leftTerminal();
    qreal dxLeft = scenePos.x() - leftTerminal.x();
    qreal dyLeft = scenePos.y() - leftTerminal.y();
    qreal distLeft = std::sqrt(dxLeft*dxLeft + dyLeft*dyLeft);

    if (distLeft <= terminalRadius) {
        return LeftTerminal;
    }

    QPointF rightTerminal = item->rightTerminal();
    qreal dxRight = scenePos.x() - rightTerminal.x();
    qreal dyRight = scenePos.y() - rightTerminal.y();
    qreal distRight = std::sqrt(dxRight*dxRight + dyRight*dyRight);

    if (distRight <= terminalRadius) {
        return RightTerminal;
    }

    return NoTerminal;
}

bool PLCDocument::isTerminalUsed(PLCItem* item, TerminalType terminal) const
{
    if (item->itemType() == PLCItem::Coil && terminal == RightTerminal)
    {
            return true;
        }
    for (ConnectionLine* line : m_connections) {
        if (line->startItem() == item && line->startTerminal() == terminal) {
            return true;
        }
        if (line->endItem() == item && line->endTerminal() == terminal) {
            return true;
        }
    }

    return false;
}

void PLCDocument::startConnection(PLCItem *startItem, TerminalType startTerminal)
{
    clearCurrentConnection();

    m_connectionSourceType = ConnectionFromItem;
    m_connectionStartItem = startItem;
    m_startTerminal = startTerminal;

    m_tempLine = new QGraphicsLineItem;
    m_tempLine->setPen(QPen(Qt::blue, 2, Qt::DashLine));

    QPointF startPos;
    if (startTerminal == LeftTerminal) {
        startPos = startItem->leftTerminal();
    } else if (startTerminal == RightTerminal) {
        startPos = startItem->rightTerminal();
    }

    m_tempLine->setLine(QLineF(startPos, startPos));
    m_scene->addItem(m_tempLine);
}

bool PLCDocument::tryEndConnection(PLCItem *endItem, TerminalType endTerminal)
{
    if (m_connectionSourceType == ConnectionFromRowTerminal) {
        if (endTerminal != LeftTerminal) {
            QMessageBox::warning(this, "连线错误", "行触点只能连接到元件的左端子");
            clearCurrentConnection();
            return false;
        }

        int endRow = static_cast<int>(endItem->y() / m_cellSize);
        if (endRow != m_connectionStartRow) {
            QMessageBox::warning(this, "连线错误", "行触点只能连接到同一行元件的左端子");
            clearCurrentConnection();
            return false;
        }

        if (isTerminalUsed(endItem, LeftTerminal)) {
            QMessageBox::warning(this, "连线错误", "该元件的左端子已被使用");
            clearCurrentConnection();
            return false;
        }

        ConnectionLine *connection = new ConnectionLine(
            nullptr, RowTerminal,
            endItem, LeftTerminal
        );
        connection->setStartTerminalPoint(QPointF(0, (m_connectionStartRow + 0.5) * m_cellSize));
        connection->setRowTerminalSourceRow(m_connectionStartRow);

        m_scene->addItem(connection);
        m_connections.append(connection);

        terminalConnections[endItem][LeftTerminal] = true;

        clearCurrentConnection();
        setModified(true);
        return true;
    }

    if (endTerminal == RowTerminal) {
        if (m_startTerminal != LeftTerminal) {
            QMessageBox::warning(this, "连线错误", "行触点只能连接到元件的左端子");
            clearCurrentConnection();
            return false;
        }

        int startRow = static_cast<int>(m_connectionStartItem->y() / m_cellSize);
        ConnectionLine *connection = new ConnectionLine(
            m_connectionStartItem, m_startTerminal,
            nullptr, RowTerminal
        );
        connection->setEndTerminalPoint(QPointF(0, (startRow + 0.5) * m_cellSize));
        connection->setRowTerminalTargetRow(startRow);

        m_scene->addItem(connection);
        m_connections.append(connection);

        terminalConnections[m_connectionStartItem][m_startTerminal] = true;

        clearCurrentConnection();
        setModified(true);
        return true;
    }

    if (m_connectionSourceType == ConnectionFromItem && m_connectionStartItem) {
        if (endItem == m_connectionStartItem && endTerminal == m_startTerminal) {
            clearCurrentConnection();
            return false;
        }

        int startCol = static_cast<int>(m_connectionStartItem->pos().x() / m_cellSize);
        int endCol = static_cast<int>(endItem->pos().x() / m_cellSize);

        if (m_startTerminal == LeftTerminal)
        {
            if (endTerminal != RightTerminal)
            {
                QMessageBox::warning(this, "连线错误", "左端子只能连接到其他元件的右端子");
                clearCurrentConnection();
                return false;
            }
            if (startCol <= endCol)
            {
                QMessageBox::warning(this, "连线错误", "左端子只能连接到左边元件的右端子");
                clearCurrentConnection();
                return false;
            }
        } else if (m_startTerminal == RightTerminal)
        {
            if (endTerminal != LeftTerminal) {
                QMessageBox::warning(this, "连线错误", "右端子只能连接到其他元件的左端子");
                clearCurrentConnection();
                return false;
            }
            if (startCol >= endCol) {
                QMessageBox::warning(this, "连线错误", "右端子只能连接到右边元件的左端子");
                clearCurrentConnection();
                return false;
            }
        }

        if (isTerminalUsed(endItem, endTerminal)) {
            QMessageBox::warning(this, "连线错误", "该端子已被使用");
            clearCurrentConnection();
            return false;
        }

        ConnectionLine *connection = new ConnectionLine(
            m_connectionStartItem, m_startTerminal,
            endItem, endTerminal
        );

        m_scene->addItem(connection);
        m_connections.append(connection);

        terminalConnections[m_connectionStartItem][m_startTerminal] = true;
        terminalConnections[endItem][endTerminal] = true;

        clearCurrentConnection();
        setModified(true);
        return true;
    }

    return false;
}

void PLCDocument::clearCurrentConnection()
{
    if (m_tempLine) {
        m_scene->removeItem(m_tempLine);
        delete m_tempLine;
        m_tempLine = nullptr;
    }
    m_connectionSourceType = ConnectionNone;
    m_connectionStartItem = nullptr;
    m_startTerminal = NoTerminal;
    m_connectionStartRow = -1;
}

void PLCDocument::createPLCItem(const QString &type, const QPointF &pos)
{
    PLCItem *item = nullptr;

    if (type == "常开") {
        item = new NormallyOpenItem;
    } else if (type == "常闭") {
        item = new NormallyClosedItem;
    } else if (type == "大于") {
        item = new GreaterThanItem;
    } else if (type == "大于等于") {
        item = new GreaterEqualItem;
    } else if (type == "小于") {
        item = new LessThanItem;
    } else if (type == "小于等于") {
        item = new LessEqualItem;
    } else if (type == "等于") {
        item = new EqualItem;
    } else if (type == "线圈") {
        item = new CoilItem;
    }

    if (item) {
        QPointF constrainedPos = constrainToTable(pos);
        item->setPos(constrainedPos);
        m_scene->addItem(item);
        setModified(true);

        terminalConnections[item][LeftTerminal] = false;
        terminalConnections[item][RightTerminal] = false;

        m_lastValidPositions[item] = constrainedPos;

        connect(item, &PLCItem::stateChanged, this, [this, item](bool active) {
            if (m_simulationRunning) {
                if (active) {
                    m_activeItems.insert(item);
                } else {
                    m_activeItems.remove(item);
                }
                updateConnections();
            }
        });
    }
}

void PLCDocument::handleSceneChanged()
{
    for (auto* connection : qAsConst(m_connections))
    {
        connection->updatePosition();
    }

    if (m_tempLine && m_connectionSourceType != ConnectionNone)
    {
        QPointF cursorPos = m_view->mapFromGlobal(QCursor::pos());
        QPointF scenePos = m_view->mapToScene(cursorPos.toPoint());
        QLineF line = m_tempLine->line();
        line.setP2(scenePos);
        m_tempLine->setLine(line);
    }

    for (QGraphicsItem *item : m_scene->items())
    {
        if (PLCItem *plcItem = dynamic_cast<PLCItem*>(item))
        {
            handleItemPositionChange(plcItem);
        }
    }
}

QList<PLCItem*> PLCDocument::allPLCItems() const
{
    QList<PLCItem*> items;
    for (QGraphicsItem *item : m_scene->items()) {
        if (PLCItem *plcItem = dynamic_cast<PLCItem*>(item)) {
            items.append(plcItem);
        }
    }
    return items;
}

bool PLCDocument::isCellOccupied(int col, int row, PLCItem* excludeItem) const
{
    for (PLCItem* item : allPLCItems()) {
        if (item == excludeItem) continue;

        int itemCol = static_cast<int>(item->x() / m_cellSize);
        int itemRow = static_cast<int>(item->y() / m_cellSize);

        if (itemCol == col && itemRow == row) {
            return true;
        }
    }
    return false;
}

// 计算元件在连线上的位置比例（0-1）
qreal PLCDocument::getPositionRatioOnLine(PLCItem* item, ConnectionLine* line) const
{
    if (!item || !line) return -1;

    QLineF lineSeg = line->line();
    QPointF itemPos = item->pos();

    // 计算投影比例
    qreal dx = lineSeg.dx();
    qreal dy = lineSeg.dy();
    qreal lengthSquared = dx*dx + dy*dy;

    if (lengthSquared == 0) return 0;

    qreal t = ((itemPos.x() - lineSeg.p1().x()) * dx +
               (itemPos.y() - lineSeg.p1().y()) * dy) / lengthSquared;

    return qBound(0.0, t, 1.0);
}

void PLCDocument::handleItemPositionChange(PLCItem *item)
{
    if (!item) return;

    if (m_loadingFile) {
        QPointF newPos = constrainToTable(item->pos());
        item->setPos(newPos);
        m_lastValidPositions[item] = newPos;
        return;
    }

    if (m_processingItems.contains(item)) {
        return;
    }
    m_processingItems.insert(item);

    QPointF newPos = constrainToTable(item->pos());
    int newCol = static_cast<int>(newPos.x() / m_cellSize);
    int newRow = static_cast<int>(newPos.y() / m_cellSize);

    if (isCellOccupied(newCol, newRow, item))
    {
        if (m_lastValidPositions.contains(item))
        {
            item->setPos(m_lastValidPositions[item]);
            QMessageBox::warning(this, "移动失败", "无法移动，该单元格已被占用");
        }
    }
    else
    {
        int oldCol = static_cast<int>(m_lastValidPositions[item].x() / m_cellSize);
        item->setPos(newPos);
        m_lastValidPositions[item] = newPos;

        if (newCol != oldCol) {
            removeInvalidConnectionsForItem(item);
        }

        // 获取要拆分的连线并排序
        QList<ConnectionLine*> connectionsToSplit = findConnectionsUnderItem(item);

        // 按元件在连线上的位置排序，确保从左到右处理
        std::sort(connectionsToSplit.begin(), connectionsToSplit.end(),
                  [this, item](ConnectionLine* a, ConnectionLine* b) {
                      return getPositionRatioOnLine(item, a) < getPositionRatioOnLine(item, b);
                  });

        // 处理每条连线
        for (ConnectionLine* line : connectionsToSplit) {
            if (m_connections.contains(line) && !line->isProcessing()) {
                splitConnection(line, item);
            }
        }

        // 更新所有连接位置
        for (ConnectionLine *line : m_connections) {
            if (line) {
                line->updatePosition();
            }
        }
    }

    m_processingItems.remove(item);
}

//QList<ConnectionLine*> PLCDocument::findConnectionsUnderItem(PLCItem* item) const
//{
//    QList<ConnectionLine*> result;
//    if (!item) return result;

//    QRectF itemRect = item->boundingRect();
//    itemRect.adjust(-2, -2, 2, 2);
//    QPolygonF itemPolygon = QPolygonF(itemRect).translated(item->pos());

//    foreach (ConnectionLine* line, m_connections) {
//        if (!line || line->isProcessing()) continue;

//        QLineF lineGeometry = line->line();
//        QRectF lineRect(lineGeometry.p1(), lineGeometry.p2());
//        lineRect.adjust(-10, -10, 10, 10);

//        if (itemPolygon.intersects(lineRect)) {
//            result.append(line);
//        }
//    }
//    return result;
//}

// 在PLCDocument类的splitConnection函数中，修改逻辑以支持行触点连线的插入
bool PLCDocument::splitConnection(ConnectionLine* originalLine, PLCItem* insertItem)
{
    if (!originalLine || !insertItem || originalLine->isProcessing()) {
        return false;
    }

    originalLine->setProcessing(true);

    PLCItem* originalStart = originalLine->startItem();
    TerminalType originalStartTerminal = originalLine->startTerminal();
    PLCItem* originalEnd = originalLine->endItem();
    TerminalType originalEndTerminal = originalLine->endTerminal();

    // 保存原始行触点信息
    int sourceRow = originalLine->rowTerminalSourceRow();
    int targetRow = originalLine->rowTerminalTargetRow();

    PLCItem* logicalInput = originalStart;
    TerminalType inputTerminal = originalStartTerminal;
    PLCItem* logicalOutput = originalEnd;
    TerminalType outputTerminal = originalEndTerminal;

    // 标准化方向时同步交换行触点信息
    if ((originalStartTerminal == LeftTerminal && originalEndTerminal == RightTerminal) ||
        (originalStartTerminal == LeftTerminal && originalEndTerminal == RowTerminal))
    {
        std::swap(logicalInput, logicalOutput);
        std::swap(inputTerminal, outputTerminal);
        std::swap(sourceRow, targetRow); // 同步交换行号
    }

    // 位置有效性校验
    int inputCol = (inputTerminal == RowTerminal) ? 0 :
                   static_cast<int>(logicalInput->x() / m_cellSize);

    int outputCol = (outputTerminal == RowTerminal) ? 0 :
                    static_cast<int>(logicalOutput->x() / m_cellSize);

    int insertCol = static_cast<int>(insertItem->x() / m_cellSize);

    // 统一位置验证逻辑
    bool isBetween = (insertCol > qMin(inputCol, outputCol)) &&
                   (insertCol < qMax(inputCol, outputCol));

    if (!isBetween) {
        originalLine->setProcessing(false);
        return false;
    }

    // 检查端子可用性
    if (isTerminalUsed(insertItem, LeftTerminal) ||
        isTerminalUsed(insertItem, RightTerminal))
    {
        originalLine->setProcessing(false);
        return false;
    }

    // 创建新连线
    ConnectionLine* line1 = new ConnectionLine(
        logicalInput, inputTerminal,
        insertItem, LeftTerminal
    );

    // 保留行触点源信息
    if (inputTerminal == RowTerminal) {
        line1->setStartTerminalPoint(QPointF(0, (sourceRow + 0.5) * m_cellSize));
        line1->setRowTerminalSourceRow(sourceRow);
    }

    ConnectionLine* line2 = new ConnectionLine(
        insertItem, RightTerminal,
        logicalOutput, outputTerminal
    );

    // 保留行触点目标信息
    if (outputTerminal == RowTerminal) {
        line2->setEndTerminalPoint(QPointF(0, (targetRow + 0.5) * m_cellSize));
        line2->setRowTerminalTargetRow(targetRow);
    }

    // 添加新连线
    m_scene->addItem(line1);
    m_scene->addItem(line2);
    m_connections.append(line1);
    m_connections.append(line2);

    // 更新端子状态
    terminalConnections[insertItem][LeftTerminal] = true;
    terminalConnections[insertItem][RightTerminal] = true;

    // 移除原连线
    m_connections.removeAll(originalLine);
    m_scene->removeItem(originalLine);
    delete originalLine;

    setModified(true);
    originalLine->setProcessing(false);
    return true;
}


// 补充：确保行触点连线能被检测为"需要拆分的连线"（扩展findConnectionsUnderItem）
QList<ConnectionLine*> PLCDocument::findConnectionsUnderItem(PLCItem* item) const
{
    QList<ConnectionLine*> result;
    if (!item) return result;

    // 元件的边界框（扩大检测范围，确保行触点连线也能被检测）
    QRectF itemRect = item->boundingRect();
    itemRect.adjust(-5, -5, 5, 5);  // 扩大边界框，提高检测灵敏度
    QPolygonF itemPolygon = QPolygonF(itemRect).translated(item->pos());

    foreach (ConnectionLine* line, m_connections) {
        if (!line || line->isProcessing()) continue;

        // 行触点连线的特殊处理：起点是(0, row)，终点是元件左端子
        QLineF lineGeometry = line->line();
        QRectF lineRect = QRectF(lineGeometry.p1(), lineGeometry.p2()).normalized();
        lineRect.adjust(-10, -10, 10, 10);  // 扩大连线的检测范围

        // 检查元件是否与连线相交（包括行触点连线）
        if (itemPolygon.intersects(lineRect)) {
            result.append(line);
        }
    }
    return result;
}

void PLCDocument::removeInvalidConnectionsForItem(PLCItem* movedItem)
{
    if (!movedItem || m_connections.isEmpty()) return;
    if (m_cellSize <= 0) {
        qWarning() << "Invalid cell size!";
        return;
    }

    int movedCol = static_cast<int>(movedItem->x() / m_cellSize);
    QSet<ConnectionLine*> connectionsToRemove;
    bool shouldRemoveAll = false;

    for (ConnectionLine* line : m_connections) {
        if (!line) continue;

        PLCItem* otherItem = nullptr;
        TerminalType movedTerminal = NoTerminal;
        TerminalType otherTerminal = NoTerminal;

        if (line->startItem() == movedItem) {
            otherItem = line->endItem();
            movedTerminal = line->startTerminal();
            otherTerminal = line->endTerminal();
        } else if (line->endItem() == movedItem) {
            otherItem = line->startItem();
            movedTerminal = line->endTerminal();
            otherTerminal = line->startTerminal();
        } else {
            continue;
        }

        if (!otherItem) continue;

        int otherCol = static_cast<int>(otherItem->x() / m_cellSize);

        if (movedTerminal == LeftTerminal && otherTerminal == RightTerminal) {
            if (movedCol <= otherCol) {
                shouldRemoveAll = true;
                break;
            }
        } else if (movedTerminal == RightTerminal && otherTerminal == LeftTerminal) {
            if (movedCol >= otherCol) {
                shouldRemoveAll = true;
                break;
            }
        }
    }

    if (shouldRemoveAll) {
        for (ConnectionLine* line : m_connections) {
            if (!line) continue;
            if (line->startItem() == movedItem || line->endItem() == movedItem) {
                connectionsToRemove.insert(line);
            }
        }
    }

    for (ConnectionLine* line : connectionsToRemove) {
        if (!line) continue;

        if (line->startItem()) {
            terminalConnections[line->startItem()].remove(line->startTerminal());
        }
        if (line->endItem()) {
            terminalConnections[line->endItem()].remove(line->endTerminal());
        }

        if (m_scene && line->scene() == m_scene) {
            m_scene->removeItem(line);
        }

        if (m_connections.contains(line)) {
            m_connections.removeAll(line);
        }
        delete line;
    }

    if (!connectionsToRemove.isEmpty()) {
        setModified(true);
    }
}

void PLCDocument::setSimulationRunning(bool running)
{
    m_simulationRunning = running;
    if (!running) {
        resetSimulation();
    }
}

void PLCDocument::resetSimulation()
{
    m_activeItems.clear();
    for (QGraphicsItem *item : m_scene->items()) {
        if (PLCItem *plcItem = dynamic_cast<PLCItem*>(item)) {
            plcItem->setState(false);
        }
    }
    terminalConnections.clear();
    updateConnections();
}

void PLCDocument::updateConnections()
{
    for (ConnectionLine *line : m_connections) {
        PLCItem *start = line->startItem();
        PLCItem *end = line->endItem();

        if (line->endTerminal() == RowTerminal || line->startTerminal() == RowTerminal) {
            line->setPen(QPen(Qt::green, 2));
            continue;
        }

        if (m_activeItems.contains(start) && m_activeItems.contains(end)) {
            line->setPen(QPen(Qt::green, 2));
        } else {
            line->setPen(QPen(Qt::black, 1));
        }
    }
}

void PLCDocument::deleteSelectedItems()
{
    QList<QGraphicsItem*> selected = m_scene->selectedItems();
    if (selected.isEmpty()) return;

    QList<PLCItem*> itemsToDelete;
    QList<ConnectionLine*> linesToDelete;
    QSet<ConnectionLine*> connectionsToDelete;

    for (QGraphicsItem* item : selected) {
        if (PLCItem* plcItem = dynamic_cast<PLCItem*>(item)) {
            itemsToDelete.append(plcItem);
        } else if (ConnectionLine* line = dynamic_cast<ConnectionLine*>(item)) {
            linesToDelete.append(line);
        }
    }

    for (ConnectionLine* line : m_connections) {
        if (line->startItem() && itemsToDelete.contains(line->startItem())) {
            connectionsToDelete.insert(line);
        }
        if (line->endItem() && itemsToDelete.contains(line->endItem())) {
            connectionsToDelete.insert(line);
        }
    }

    for (ConnectionLine* line : linesToDelete) {
        connectionsToDelete.insert(line);
    }

    for (ConnectionLine* line : connectionsToDelete) {
        if (!line) continue;

        if (line->startItem()) {
            terminalConnections[line->startItem()].remove(line->startTerminal());
        }
        if (line->endItem()) {
            terminalConnections[line->endItem()].remove(line->endTerminal());
        }

        if (m_scene && m_scene->items().contains(line)) {
            m_scene->removeItem(line);
        }

        m_connections.removeAll(line);
        delete line;
    }

    for (PLCItem* item : itemsToDelete) {
        terminalConnections.remove(item);
        m_lastValidPositions.remove(item);
        m_scene->removeItem(item);
        delete item;
    }

    setModified(true);
}

void PLCDocument::copySelectedItem()
{
    QList<QGraphicsItem*> selected = m_scene->selectedItems();
    if (selected.size() != 1) return;

    if (PLCItem* item = dynamic_cast<PLCItem*>(selected.first())) {
        m_copiedItem = item;
    }
}

void PLCDocument::pasteItem()
{
    if (!m_copiedItem) return;
    QPointF pastePos = snapToCellCenter(m_view->mapToScene(m_view->viewport()->mapFromGlobal(QCursor::pos())));
    pastePos.setX(pastePos.x() - 70);
    pastePos.setY(pastePos.y() - 70);

    int col = static_cast<int>(pastePos.x() / m_cellSize);
    int row = static_cast<int>(pastePos.y() / m_cellSize);
    if (isCellOccupied(col, row, nullptr))
    {
        QMessageBox::warning(this, "粘贴失败", "目标单元格已被占用");
        return;
    }

    PLCItem* newItem = createItemByType(m_copiedItem->itemType());
    if (!newItem) return;
    newItem->setPos(pastePos);
    newItem->setName(m_copiedItem->name() + "_副本");
    m_scene->addItem(newItem);

    terminalConnections[newItem][LeftTerminal] = false;
    terminalConnections[newItem][RightTerminal] = false;
    m_lastValidPositions[newItem] = pastePos;
    setModified(true);
}

void PLCDocument::keyPressEvent(QKeyEvent* event)
{
    if (event->key() == Qt::Key_Delete)
    {
        deleteSelectedItems();
        event->accept();
        return;
    }
    BaseDocument::keyPressEvent(event);
}

void PLCDocument::createContextMenu(QPoint globalPos)
{
    QMenu menu(this);

    QAction* deleteAction = menu.addAction("删除");
    QAction* copyAction = menu.addAction("复制");
    QAction* pasteAction = menu.addAction("粘贴");

    QList<QGraphicsItem*> selected = m_scene->selectedItems();
    deleteAction->setEnabled(!selected.isEmpty());
    copyAction->setEnabled(selected.size() == 1&&dynamic_cast<PLCItem*>(selected.first()));
    pasteAction->setEnabled(m_copiedItem != nullptr);

    connect(deleteAction, &QAction::triggered, this, &PLCDocument::deleteSelectedItems);
    connect(copyAction, &QAction::triggered, this, &PLCDocument::copySelectedItem);
    connect(pasteAction, &QAction::triggered, this, &PLCDocument::pasteItem);

    menu.addSeparator();

    QAction *tableGridAction = menu.addAction("隐藏/显示网格");
    connect(tableGridAction, &QAction::triggered, this, [this]() {
        for (auto line : m_horizontalLines)
        {
            line->setVisible(!line->isVisible());
        }
        for (auto line : m_verticalLines)
        {
            line->setVisible(!line->isVisible());
        }
    });

    menu.exec(globalPos + QPoint(10, 10));
}

void PLCDocument::onRowTerminalConnection()
{
    QList<QGraphicsItem*> selected = m_scene->selectedItems();
    if (selected.size() != 1) return;

    PLCItem* item = dynamic_cast<PLCItem*>(selected.first());
    if (!item) return;

    int itemRow = static_cast<int>(item->y() / m_cellSize);
    int itemCol = static_cast<int>(item->x() / m_cellSize);
    if (itemCol != 0) {
        QMessageBox::warning(this, "连接错误", "只有最左侧列的元件可以连接到行触点");
        return;
    }

    if (isTerminalUsed(item, LeftTerminal)) {
        QMessageBox::warning(this, "连接失败", "该元件的左端子已被使用");
        return;
    }

    ConnectionLine* connection = new ConnectionLine(
        item, LeftTerminal,
        nullptr, RowTerminal
    );

    connection->setRowTerminalTargetRow(itemRow);
    connection->setEndTerminalPoint(QPointF(0, (itemRow + 0.5) * m_cellSize));
    connection->updatePosition();

    m_scene->addItem(connection);
    m_connections.append(connection);

    terminalConnections[item][LeftTerminal] = true;

    setModified(true);
}

PLCItem* PLCDocument::createItemByType(PLCItem::ItemType type)
{
    switch (type) {
    case PLCItem::NormallyOpen:    return new NormallyOpenItem;
    case PLCItem::NormallyClosed:  return new NormallyClosedItem;
    case PLCItem::GreaterThan:     return new GreaterThanItem;
    case PLCItem::GreaterEqual:    return new GreaterEqualItem;
    case PLCItem::LessThan:        return new LessThanItem;
    case PLCItem::LessEqual:       return new LessEqualItem;
    case PLCItem::Equal:           return new EqualItem;
    case PLCItem::Coil:            return new CoilItem;
    default:
        qWarning() << "未知的PLC元件类型:" << type;
        return nullptr;
    }
}

bool PLCDocument::saveToFile(const QString &filePath)
{
    QFile file(filePath);
    if (!file.open(QIODevice::WriteOnly)) {
        QMessageBox::warning(this, "保存失败", "无法打开文件进行写入：" + filePath);
        return false;
    }

    QJsonObject docObject;
    docObject["type"] = "PLCDocument";

    docObject["table_rows"] = m_rows;
    docObject["table_columns"] = m_columns;
    docObject["table_cell_size"] = m_cellSize;

    QJsonArray itemsArray;
    for (QGraphicsItem *item : m_scene->items()) {
        if (PLCItem *plcItem = dynamic_cast<PLCItem*>(item)) {
            QJsonObject itemObj;
            itemObj["type"] = static_cast<int>(plcItem->itemType());
            int col = static_cast<int>(plcItem->x() / m_cellSize);
            int row = static_cast<int>(plcItem->y() / m_cellSize);
            itemObj["col"] = col;
            itemObj["row"] = row;
            itemObj["name"] = plcItem->name();
            itemObj["active"] = plcItem->isActive();
            itemsArray.append(itemObj);
        }
    }
    docObject["items"] = itemsArray;

    QJsonArray connectionsArray;
    for (ConnectionLine *line : m_connections) {
        QJsonObject connObj;

        if (line->startItem()) {
            int startCol = static_cast<int>(line->startItem()->pos().x() / m_cellSize);
            int startRow = static_cast<int>(line->startItem()->pos().y() / m_cellSize);
            connObj["startCol"] = startCol;
            connObj["startRow"] = startRow;
        } else if (line->startTerminal() == RowTerminal) {
            connObj["startRowTerminal"] = line->rowTerminalSourceRow();
        }
        connObj["startTerminal"] = static_cast<int>(line->startTerminal());

        connObj["endTerminal"] = static_cast<int>(line->endTerminal());
        if (line->endTerminal() == RowTerminal) {
            connObj["endRowTerminal"] = line->rowTerminalTargetRow();
        } else if (line->endItem()) {
            int endCol = static_cast<int>(line->endItem()->pos().x() / m_cellSize);
            int endRow = static_cast<int>(line->endItem()->pos().y() / m_cellSize);
            connObj["endCol"] = endCol;
            connObj["endRow"] = endRow;
        }

        connectionsArray.append(connObj);
    }
    docObject["connections"] = connectionsArray;

    QJsonDocument doc(docObject);
    file.write(doc.toJson());
    file.close();

    setFilePath(filePath);
    setModified(false);
    return true;
}

bool PLCDocument::loadFromFile(const QString &filePath)
{
    QFile file(filePath);
    if (!file.open(QIODevice::ReadOnly)) {
        QMessageBox::warning(this, "打开失败", "无法打开文件：" + filePath);
        return false;
    }

    QByteArray data = file.readAll();
    file.close();

    QJsonParseError parseError;
    QJsonDocument doc = QJsonDocument::fromJson(data, &parseError);
    if (parseError.error != QJsonParseError::NoError) {
        QMessageBox::warning(this, "文件格式错误", "JSON解析错误: " + parseError.errorString());
        return false;
    }

    if (doc.isNull() || !doc.isObject()) {
        QMessageBox::warning(this, "文件格式错误", "不是有效的PLC文档");
        return false;
    }

    QJsonObject docObject = doc.object();
    if (docObject["type"].toString() != "PLCDocument") {
        QMessageBox::warning(this, "文件类型错误", "不是有效的PLC文档");
        return false;
    }

    m_rows = docObject["table_rows"].toInt(DEFAULT_ROWS);
    m_columns = docObject["table_columns"].toInt(DEFAULT_COLUMNS);
    m_cellSize = docObject["table_cell_size"].toInt(DEFAULT_CELL_SIZE);

    setSimulationRunning(false);

    m_scene->blockSignals(true);

    for (auto conn : m_connections) {
        m_scene->removeItem(conn);
        delete conn;
    }
    m_connections.clear();

    QList<QGraphicsItem*> allItems = m_scene->items();
    for (QGraphicsItem* item : allItems) {
        if (dynamic_cast<PLCItem*>(item) || dynamic_cast<ConnectionLine*>(item)) {
            m_scene->removeItem(item);
            delete item;
        }
    }

    m_activeItems.clear();
    terminalConnections.clear();
    clearCurrentConnection();

    createRealTable();

    QMap<QPair<int, int>, PLCItem*> itemMap;
    QJsonArray itemsArray = docObject["items"].toArray();
    for (const QJsonValue &itemValue : itemsArray) {
        QJsonObject itemObj = itemValue.toObject();
        PLCItem::ItemType type = static_cast<PLCItem::ItemType>(itemObj["type"].toInt());
        int col = itemObj["col"].toInt();
        int row = itemObj["row"].toInt();
        QString name = itemObj["name"].toString();
        bool active = itemObj["active"].toBool();

        col = qBound(0, col, m_columns - 1);
        row = qBound(0, row, m_rows - 1);

        PLCItem *item = createItemByType(type);
        if (item) {
            QPointF pos(col * m_cellSize + m_cellSize / 2.0,
                        row * m_cellSize + m_cellSize / 2.0);
            item->setPos(pos);
            item->setName(name);
            item->setState(active);
            m_scene->addItem(item);

            itemMap.insert(qMakePair(col, row), item);

            if (active) {
                m_activeItems.insert(item);
            }

            terminalConnections[item][LeftTerminal] = false;
            terminalConnections[item][RightTerminal] = false;

            connect(item, &PLCItem::stateChanged, this, [this, item](bool active) {
                if (m_simulationRunning) {
                    if (active) m_activeItems.insert(item);
                    else m_activeItems.remove(item);
                    updateConnections();
                }
            });
        }
    }

    QJsonArray connectionsArray = docObject["connections"].toArray();
    for (const QJsonValue &connValue : connectionsArray) {
        QJsonObject connObj = connValue.toObject();

        TerminalType startTerminal = static_cast<TerminalType>(connObj["startTerminal"].toInt());
        TerminalType endTerminal = static_cast<TerminalType>(connObj["endTerminal"].toInt());

        PLCItem *startItem = nullptr;
        PLCItem *endItem = nullptr;

        if (connObj.contains("startRowTerminal")) {
            int startRow = connObj["startRowTerminal"].toInt();
            ConnectionLine *line = new ConnectionLine(
                nullptr, RowTerminal,
                endItem, endTerminal
            );
            line->setStartTerminalPoint(QPointF(0, (startRow + 0.5) * m_cellSize));
            line->setRowTerminalSourceRow(startRow);
            m_scene->addItem(line);
            m_connections.append(line);
        }
        else if (connObj.contains("startCol") && connObj.contains("startRow")) {
            int startCol = connObj["startCol"].toInt();
            int startRow = connObj["startRow"].toInt();
            startItem = itemMap.value(qMakePair(startCol, startRow));

            if (endTerminal == RowTerminal && connObj.contains("endRowTerminal")) {
                int endRow = connObj["endRowTerminal"].toInt();
                ConnectionLine *line = new ConnectionLine(
                    startItem, startTerminal,
                    nullptr, RowTerminal
                );
                line->setEndTerminalPoint(QPointF(0, (endRow + 0.5) * m_cellSize));
                line->setRowTerminalTargetRow(endRow);
                m_scene->addItem(line);
                m_connections.append(line);
            }
            else if (connObj.contains("endCol") && connObj.contains("endRow")) {
                int endCol = connObj["endCol"].toInt();
                int endRow = connObj["endRow"].toInt();
                endItem = itemMap.value(qMakePair(endCol, endRow));

                if (startItem && endItem) {
                    ConnectionLine *line = new ConnectionLine(
                        startItem, startTerminal,
                        endItem, endTerminal
                    );
                    m_scene->addItem(line);

                    m_connections.append(line);
                }
            }
        }
    }

    for (ConnectionLine* line : m_connections) {
        if (line->startItem()) {
            terminalConnections[line->startItem()][line->startTerminal()] = true;
        }
        if (line->endItem()) {
            terminalConnections[line->endItem()][line->endTerminal()] = true;
        }
    }

    m_scene->blockSignals(false);
    handleSceneChanged();

    setFilePath(filePath);
    setModified(false);

    return true;
}

ConnectionLine::ConnectionLine(
    PLCItem *startItem, PLCDocument::TerminalType startTerminal,
    PLCItem *endItem, PLCDocument::TerminalType endTerminal,
    QGraphicsItem *parent
) : QGraphicsLineItem(parent)
  , m_startItem(startItem)
  , m_startTerminal(startTerminal)
  , m_endItem(endItem)
  , m_endTerminal(endTerminal)
  , m_rowTerminalTargetRow(-1)
  , m_rowTerminalSourceRow(-1)
  , m_processing(false)
{
    setFlag(QGraphicsItem::ItemIsSelectable, true);
    setPen(QPen(Qt::black, 1));
    setZValue(-1);
    updatePosition();
}

void ConnectionLine::updatePosition()
{
    QPointF startPoint;
    if (m_startItem) {
        if (m_startTerminal == PLCDocument::LeftTerminal) {
            startPoint = m_startItem->leftTerminal();
        } else if (m_startTerminal == PLCDocument::RightTerminal) {
            startPoint = m_startItem->rightTerminal();
        }
    } else if (!m_startTerminalPoint.isNull()) {
        startPoint = m_startTerminalPoint;
    }

    QPointF endPoint;
    if (m_endItem) {
        if (m_endTerminal == PLCDocument::LeftTerminal) {
            endPoint = m_endItem->leftTerminal();
        } else if (m_endTerminal == PLCDocument::RightTerminal) {
            endPoint = m_endItem->rightTerminal();
        }
    } else if (!m_endTerminalPoint.isNull()) {
        endPoint = m_endTerminalPoint;
    }

    if (!startPoint.isNull() && !endPoint.isNull()) {
        setLine(QLineF(startPoint, endPoint));
    }
}