#include "diagramEditor/editorDiagramLayoutEngine.h"
#include "diagramEditor/editorDirectionManager.h"
#include "graphicsDataModel/diagramEditorModel.h"

// 主入口函数
QRectF DiagramLayoutEngine::executeLayout(
    QMap<QString, DiagramEditorRouteInfo>& routes,
    QMap<QString, DiagramEditorComponentInfo>& components,
    const LayoutConfig& config,
    Context& context) {

    context.initComponentsCache(components);
    context.itemCache.clear();

    QString mainRouteName = findMainRoute(routes);
    if (mainRouteName.isEmpty()) {
        qWarning() << "No main route found";
        return QRectF();
    }

    // 1. 布局主线
    layoutMainRoute(routes[mainRouteName], config, context);

    // 设置一级支线父方向
    for (auto it = routes.begin(); it != routes.end(); ++it) {
        if (it->bMainRoute) continue;
        if(it->sParentRoute == mainRouteName)       //一级支线方向
            it->preferDirection = config.subDirection();
    }

    for (auto it = routes.begin(); it != routes.end(); ++it) {
        if (it->bMainRoute) continue;
        if(it->sParentRoute == mainRouteName)
            continue;
        it->preferDirection = config.mainDirection();    //二级支线方向（与主线同向）
    }

    // 2. 布局所有支线（✅ 此时方向数据必须是最新的）
    for (auto it = routes.begin(); it != routes.end(); ++it) {
        if (it->sRouteName == mainRouteName) continue;
        layoutBranchRoute(*it, config, context);
    }

    // ✅ 3. 所有布局完成之后，才更新 components
    if (!context.saveToModel) {
        for(auto& compo:components){        //从compo缓存中读取计算过的数据
            auto mapCatch = context.componentsCache;
            compo.nUsedDirection = mapCatch[compo.sName].nUsedDirection;
            compo.nRotate = mapCatch[compo.sName].nRotate;
            compo.deltaPos = mapCatch[compo.sName].deltaPos;
        }
    }

    // 4. 计算边界
    if (!context.saveToModel) {
        return calculateBoundingRect(components);
    }

    return QRectF();
}
// 查找主线
QString DiagramLayoutEngine::findMainRoute(
    const QMap<QString, DiagramEditorRouteInfo>& routes) {

    QString mainRoute;
    bool hasMain = false;

    // 查找标记为主线
    for (auto it = routes.begin(); it != routes.end(); ++it) {
        if (it->bMainRoute) {
            mainRoute = it->sRouteName;
            hasMain = true;
            break;
        }
    }

    // 未设置主线，选择设备最多的线路
    if (!hasMain) {
        int maxCount = 0;
        for (auto it = routes.begin(); it != routes.end(); ++it) {
            int count = it->lstCompo.size();
            if (count > maxCount) {
                maxCount = count;
                mainRoute = it->sRouteName;
            }
        }

        // 标记为主线
        if (!mainRoute.isEmpty()) {
            const_cast<QMap<QString, DiagramEditorRouteInfo>&>(routes)[mainRoute].bMainRoute = true;
        }
    }

    return mainRoute;
}

// 布局主线
void DiagramLayoutEngine::layoutMainRoute(
    DiagramEditorRouteInfo& route,
    const LayoutConfig& config,
    Context& context) {

    Direction mainDir = config.mainDirection();
    auto& components = route.lstCompo;

    if (components.isEmpty()) return;

    int nSeg = components.size() / 2;
    int nSegIndex =
        (mainDir == Direction::Down || mainDir == Direction::Right)
            ? -nSeg
            : nSeg;

    for (int i = 0; i < components.size(); ++i) {
        DiagramEditorComponentInfo& compo = components[i];

        Direction dir = mainDir;
        if (i == components.size() - 1) {
            dir = DirectionManager::getOpposite(mainDir);
        }

        QPoint delta(0, 0);
        int spacing = DirectionManager::isHorizontal(mainDir)
                          ? config.horizontalSpacing()
                          : config.verticalSpacing();

        if (DirectionManager::isHorizontal(mainDir))
            delta.setX(nSegIndex * spacing);
        else
            delta.setY(nSegIndex * spacing);

        int rotate = DirectionManager::getRotationAngle(mainDir);

        // ✅ 主线方向 → 统一交给 updateComponent
        updateComponent(compo, dir, delta, rotate, context);

        nSegIndex += (mainDir == Direction::Up || mainDir == Direction::Left)
                         ? -1
                         : 1;
    }
}

// 拆分支线
void DiagramLayoutEngine::splitBranchRoute(
    DiagramEditorRouteInfo& route,
    Context& context) {

    route.lstOrder.clear();
    route.lstReverse.clear();

    if (route.lstCompo.isEmpty()) {
        return;
    }

    // 检查首尾元件
    int firstDir = getComponentDirection(route.lstCompo.first().sName, context);
    int lastDir = getComponentDirection(route.lstCompo.last().sName, context);

    if (firstDir != 0) {
        // 情况1: 首元件是节点
        route.lstOrder = route.lstCompo;
    } else if (lastDir != 0) {
        // 情况2: 末元件是节点
        for (auto it = route.lstCompo.rbegin(); it != route.lstCompo.rend(); ++it) {
            route.lstReverse.append(*it);
        }
    } else {
        // 情况3: 查找中间节点
        int nodeIndex = -1;
        for (int i = 0; i < route.lstCompo.size(); ++i) {
            int dir = getComponentDirection(route.lstCompo[i].sName, context);
            if (dir != 0) {
                nodeIndex = i;
                break;
            }
        }

        if (nodeIndex == -1) {
            // 没有节点，默认为正序
            route.lstOrder = route.lstCompo;
            return;
        }

        // 反向序列: 从节点到开头
        for (int i = nodeIndex; i >= 0; --i) {
            route.lstReverse.append(route.lstCompo[i]);
        }

        // 正序序列: 从节点到结尾
        for (int i = nodeIndex; i < route.lstCompo.size(); ++i) {
            route.lstOrder.append(route.lstCompo[i]);
        }
    }
}

// 布局支线
void DiagramLayoutEngine::layoutBranchRoute(
    DiagramEditorRouteInfo& route,
    const LayoutConfig& config,
    Context& context) {

    splitBranchRoute(route, context);

    if (route.lstOrder.size() > 1) {
        // ✅ 第一个元件的真实方向，由 determineBranchDirection 决定
        Direction startDir =
            determineBranchDirection(route.lstOrder[0],
                                     route.preferDirection,
                                     context);

        int polarity = 1;
        layoutBranchSequence(route.lstOrder,
                             startDir,
                             config,
                             context,
                             true,
                             polarity);
    }

    if (route.lstReverse.size() > 1) {
        Direction startDir =
            determineBranchDirection(route.lstReverse[0],
                                     route.preferDirection,
                                     context);
        int polarity = -1;
        layoutBranchSequence(route.lstReverse,
                             startDir,
                             config,
                             context,
                             false,
                             polarity);
    }
}

// 布局分支序列
void DiagramLayoutEngine::layoutBranchSequence(
    QList<DiagramEditorComponentInfo>& sequence,
    Direction branchDir,
    const LayoutConfig& config,
    Context& context,
    bool isOrder,
    int polarity) {

    if (sequence.size() < 2) return;

    bool isVertical =
        DirectionManager::isVertical(branchDir);

    // ✅ 2. 间距由主线方向决定
    int spacing = isVertical
                      ? config.verticalSpacing()
                      : config.horizontalSpacing();


    for (int i = 0; i < sequence.size(); ++i) {

        // ✅ 当前元件作为“起点”
        QPoint basePos = getComponentPosition(sequence[i].sName, context);
        Direction dir =
            determineBranchDirection(sequence[i], branchDir, context);

        // ✅ 如果后面还有元件，才计算偏移
        if (i + 1 < sequence.size()) {

            DiagramEditorComponentInfo& next = sequence[i + 1];
            int offset = (i + 1) * polarity * spacing;
            QPoint nextPos = basePos;

            if (isVertical) {
                nextPos.setY(basePos.y() + offset);
            } else {
                nextPos.setX(basePos.x() + offset);
            }

            QPoint deltaPos = nextPos - basePos;
            Direction nextConnectionDir =
                DirectionManager::getOpposite(dir);
            int rotate =
                DirectionManager::getRotationAngle(dir);

            updateComponent(next, nextConnectionDir,
                            nextPos, rotate, context);
        }
    }
}

void DiagramLayoutEngine::markDirectionUsed(
    const QString& compoName,
    Direction dir,
    Context& context)
{
    if (context.saveToModel) {
        QStandardItem* item = getNameItem(compoName, context);
        if (!item) return;

        int old = item->data().toInt();
        int updated = old | static_cast<int>(dir);
        item->setData(updated);
    } else {
        context.componentsCache[compoName].nUsedDirection |=
            static_cast<int>(dir);
    }
}

// 确定支线方向
Direction DiagramLayoutEngine::determineBranchDirection(
    const DiagramEditorComponentInfo& currentNode,
    Direction preferredDir,
    Context& context) {

    int usedDirections = getComponentDirection(currentNode.sName, context);
    bool horizontal = DirectionManager::isHorizontal(preferredDir);

    if (horizontal) {
        bool left  = DirectionManager::isDirectionOccupied(usedDirections, Direction::Left);
        bool right = DirectionManager::isDirectionOccupied(usedDirections, Direction::Right);

        if (!left && right) return Direction::Left;
        if (left && !right) return Direction::Right;
    } else {
        bool up    = DirectionManager::isDirectionOccupied(usedDirections, Direction::Up);
        bool down  = DirectionManager::isDirectionOccupied(usedDirections, Direction::Down);

        if (!up && down) return Direction::Up;
        if (up && !down) return Direction::Down;
    }

    return preferredDir;
}

// 获取组件位置
QPoint DiagramLayoutEngine::getComponentPosition(
    const QString& componentName,
    Context& context) {

    if (context.saveToModel) {
        QStandardItem* item = getNameItem(componentName, context);
        if (item) {
            QVariant posData = item->data(Qt::UserRole + 2);
            if (posData.isValid() && posData.canConvert<QPoint>()) {
                return posData.toPoint();
            }
        }
        return QPoint(0, 0);
    } else {
        // ✅ 核心修复：优先使用 componentsCache
        if (context.componentsCache.contains(componentName)) {
            return context.componentsCache[componentName].deltaPos;
        }

        // ✅ 终极兜底：如果 cache 里也没有，从原始 components 取
        QStandardItem* item = getNameItem(componentName, context);
        if (item) {
            QVariant posData = item->data(Qt::UserRole + 2);
            if (posData.isValid() && posData.canConvert<QPoint>()) {
                return posData.toPoint(); // ✅ 返回真实的 deltaPos
            }
        }

        return QPoint(0, 0);
    }
}

// 获取组件方向
int DiagramLayoutEngine::getComponentDirection(
    const QString& compoName,
    Context& context) {

    if (context.saveToModel) {
        QStandardItem* item = getNameItem(compoName, context);
        return item ? item->data().toInt() : 0;
    } else {
        if (context.componentsCache.contains(compoName)) {
            return context.componentsCache[compoName].nUsedDirection;
        }
        return 0;
    }
}

// 获取名称项
QStandardItem* DiagramLayoutEngine::getNameItem(
    const QString& name,
    Context& context) {

    if (!m_model)
        return nullptr;

    return m_model->getNameItem(name, context.sourceId);
}

// 更新组件
void DiagramLayoutEngine::updateComponent(
    DiagramEditorComponentInfo& compo,
    Direction dir,
    const QPoint& position,
    int rotate,
    Context& context) {

    if (context.saveToModel) {
        QStandardItem* item = getNameItem(compo.sName, context);
        if (item) {
            int currentDir = item->data().toInt();
            int newDir = DirectionManager::markDirectionOccupied(currentDir, dir);
            item->setData(QString::number(newDir));
            item->setData(position, Qt::UserRole + 2);
            item->setData(rotate, Qt::UserRole + 5);
        }
    } else {
        compo.nUsedDirection = DirectionManager::markDirectionOccupied(compo.nUsedDirection, dir);
        compo.deltaPos = position;
        compo.nRotate = rotate;

        // 更新缓存
        context.componentsCache[compo.sName].nUsedDirection = compo.nUsedDirection;
        context.componentsCache[compo.sName].deltaPos = compo.deltaPos;
        context.componentsCache[compo.sName].nRotate = compo.nRotate;
    }
}

// 计算边界矩形
QRectF DiagramLayoutEngine::calculateBoundingRect(
    const QMap<QString, DiagramEditorComponentInfo>& components) {

    if (components.isEmpty()) {
        return QRectF();
    }

    qreal minX = 0, maxX = 0, minY = 0, maxY = 0;
    bool first = true;

    for (auto it = components.begin(); it != components.end(); ++it) {
        if (it->nUsedDirection == 0) continue;  // 未使用的组件

        QPointF pos = it->deltaPos;

        if (first) {
            minX = pos.x();
            maxX = pos.x() + m_compoWidth;
            minY = pos.y();
            maxY = pos.y() + m_compoHeight;
            first = false;
        } else {
            minX = qMin(minX, pos.x());
            maxX = qMax(maxX, pos.x() + m_compoWidth);
            minY = qMin(minY, pos.y());
            maxY = qMax(maxY, pos.y() + m_compoHeight);
        }
    }

    if (first) {
        return QRectF();  // 没有使用的组件
    }

    return QRectF(minX, minY, maxX - minX, maxY - minY);
}

Direction DiagramLayoutEngine::getRouteDirection(
    const QString& routeName,
    const QMap<QString, DiagramEditorRouteInfo>& routes)
{
    if (!routes.contains(routeName))
        return Direction::Invalid;

    const auto& route = routes[routeName];

    if (route.bMainRoute)
        return Direction::Invalid; // 主线没有父方向

    // ✅ 主线 → 支线
    if (route.preferDirection == Direction::Invalid)
        return Direction::Invalid; // 等待填充

    return route.preferDirection;
}