#include "nmPebiGridSceneController.h"

#include "nmPebiGridViewData.h"

#include "nmVTKMeshLayer.h"
#include "nmVTKPlanarScaleGridLayer.h"
#include "nmVTKScalarBarLayer.h"
#include "nmVTKScene.h"
#include "nmWxVTKRenderContainerWidget.h"

#include <QCoreApplication>

#include <vtkActor.h>
#include <vtkMath.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkUnstructuredGrid.h>

namespace {

QString controllerText(const char* pText)
{
    return QCoreApplication::translate(
                "nmPebiGridSceneController", pText);
}

bool getFiniteGridBounds(vtkUnstructuredGrid* pGrid, double dBounds[6])
{
    if(pGrid == nullptr || dBounds == nullptr) {
        return false;
    }
    pGrid->GetBounds(dBounds);
    if(!vtkMath::AreBoundsInitialized(dBounds)) {
        return false;
    }
    for(int nIndex = 0; nIndex < 6; ++nIndex) {
        if(!vtkMath::IsFinite(dBounds[nIndex])) {
            return false;
        }
    }
    return dBounds[0] <= dBounds[1] &&
            dBounds[2] <= dBounds[3] &&
            dBounds[4] <= dBounds[5];
}

}

class nmPebiGridSceneControllerPrivate
{
public:
    explicit nmPebiGridSceneControllerPrivate(
            nmWxVTKRenderContainerWidget* pRenderContainer)
        : m_pContainer(pRenderContainer),
          m_pMeshLayer(nullptr),
          m_pScalarBarLayer(nullptr),
          m_pPlanarScaleGridLayer(nullptr),
          m_bGridLinesVisible(true),
          m_bScalarBarVisible(true),
          m_bBoundsGridVisible(false),
          m_bPropertySelectionExplicit(false),
          m_bHasData(false)
    {
    }

    bool ensureBaseLayers()
    {
        nmVTKScene* pScene = m_pContainer != nullptr
                ? m_pContainer->getScene() : nullptr;
        vtkRenderer* pRenderer = m_pContainer != nullptr
                ? m_pContainer->getRenderer() : nullptr;
        if(pScene == nullptr || pRenderer == nullptr) {
            return false;
        }

        if(m_pMeshLayer == nullptr) {
            nmVTKMeshLayer* pLayer =
                    new nmVTKMeshLayer("pebi.grid.mesh");
            pLayer->setVisible(false);
            if(!pScene->addLayer(pLayer)) {
                delete pLayer;
                return false;
            }
            m_pMeshLayer = pLayer;
            // 无属性时使用稳定灰色；Material 有效时仍由 MeshLayer 的 LUT 着色。
            m_pMeshLayer->getActor()->GetProperty()->SetColor(
                        211.0 / 255.0, 211.0 / 255.0,
                        211.0 / 255.0);
            m_pMeshLayer->getActor()->GetProperty()->SetEdgeColor(
                        0.0, 0.0, 0.0);
            // 仅关闭当前 PEBI 预览 Actor 的光照，避免固定面色随视角变化。
            m_pMeshLayer->getActor()->GetProperty()->LightingOff();
        }

        if(m_pPlanarScaleGridLayer == nullptr) {
            nmVTKPlanarScaleGridLayer* pLayer =
                    new nmVTKPlanarScaleGridLayer("pebi.grid.scale_grid");
            pLayer->setVisible(false);
            if(!pScene->addLayer(pLayer)) {
                delete pLayer;
                return false;
            }
            m_pPlanarScaleGridLayer = pLayer;
        }
        return true;
    }

    bool ensureScalarBarLayer()
    {
        if(m_pScalarBarLayer != nullptr) {
            return true;
        }
        nmVTKScene* pScene = m_pContainer != nullptr
                ? m_pContainer->getScene() : nullptr;
        if(pScene == nullptr || m_pMeshLayer == nullptr) {
            return false;
        }

        // 色标只在第一次选择有效标量时创建，并共享 MeshLayer 的 LUT。
        nmVTKScalarBarLayer* pLayer =
                new nmVTKScalarBarLayer("pebi.grid.scalar_bar");
        pLayer->setLookupTable(m_pMeshLayer->getLookupTable());
        pLayer->setPosition(0.86, 0.12);
        pLayer->setSize(0.10, 0.76);
        pLayer->setVisible(false);
        if(!pScene->addLayer(pLayer)) {
            delete pLayer;
            return false;
        }
        m_pScalarBarLayer = pLayer;
        return true;
    }

    bool applyProperty(const QString& sPropertyName)
    {
        if(m_pMeshLayer == nullptr) {
            return false;
        }

        if(sPropertyName.isEmpty()) {
            m_sPropertyName.clear();
            m_pMeshLayer->setScalarVisibility(false);
            if(m_pScalarBarLayer != nullptr) {
                m_pScalarBarLayer->setVisible(false);
            }
            return true;
        }

        if(sPropertyName != "Material" || !m_oViewData.hasMaterial() ||
           !m_pMeshLayer->setScalarArray(
                sPropertyName, nmVTKMeshLayer::ScalarAssociation_CellData)) {
            // 无效属性不能沿用上一网格的标量着色或色标范围。
            m_sPropertyName.clear();
            m_pMeshLayer->setScalarVisibility(false);
            if(m_pScalarBarLayer != nullptr) {
                m_pScalarBarLayer->setVisible(false);
            }
            return false;
        }
        if(!ensureScalarBarLayer()) {
            m_sPropertyName.clear();
            m_pMeshLayer->setScalarVisibility(false);
            return false;
        }

        m_sPropertyName = sPropertyName;
        m_pMeshLayer->setScalarVisibility(true);
        m_pScalarBarLayer->setLookupTable(
                    m_pMeshLayer->getLookupTable());
        m_pScalarBarLayer->setTitle(sPropertyName);
        m_pScalarBarLayer->setVisible(m_bScalarBarVisible);
        return true;
    }

    bool bindViewData(const nmPebiGridViewData& oViewData,
                      const QString& sRequestedProperty,
                      const double dBounds[6])
    {
        if(m_pMeshLayer == nullptr || m_pPlanarScaleGridLayer == nullptr ||
           dBounds == nullptr) {
            return false;
        }

        // 本函数只提交已在外层验证过的数据，不渲染也不改变相机。
        m_oViewData = oViewData;
        if(!m_pMeshLayer->setDataSet(oViewData.getGrid())) {
            m_oViewData.clear();
            return false;
        }
        m_pMeshLayer->setEdgeVisibility(m_bGridLinesVisible);
        m_pMeshLayer->setVisible(true);

        if(!m_pPlanarScaleGridLayer->setBounds(
               dBounds[0], dBounds[1], dBounds[2],
               dBounds[3], dBounds[4])) {
            m_pMeshLayer->setDataSet(nullptr);
            m_pMeshLayer->setVisible(false);
            m_oViewData.clear();
            return false;
        }
        m_pPlanarScaleGridLayer->setVisible(m_bBoundsGridVisible);
        m_bHasData = true;

        // 属性不可用只回退固定面色，不影响已经验证成功的网格几何提交。
        applyProperty(sRequestedProperty);
        return true;
    }

    void releaseGridData()
    {
        // 先断开 Mapper 对旧网格的引用，再释放 ViewData 的共享引用。
        if(m_pMeshLayer != nullptr) {
            m_pMeshLayer->setScalarVisibility(false);
            m_pMeshLayer->setDataSet(nullptr);
            m_pMeshLayer->setVisible(false);
        }
        if(m_pScalarBarLayer != nullptr) {
            m_pScalarBarLayer->setVisible(false);
        }
        if(m_pPlanarScaleGridLayer != nullptr) {
            m_pPlanarScaleGridLayer->setVisible(false);
        }
        m_oViewData.clear();
        m_sPropertyName.clear();
        m_bHasData = false;
    }

    nmWxVTKRenderContainerWidget* m_pContainer; ///< 非所有权指针。
    nmVTKMeshLayer* m_pMeshLayer; ///< Scene 所有，控制器只观察。
    nmVTKScalarBarLayer* m_pScalarBarLayer; ///< Scene 所有，按需创建。
    nmVTKPlanarScaleGridLayer* m_pPlanarScaleGridLayer; ///< Scene 所有。
    nmPebiGridViewData m_oViewData;
    bool m_bGridLinesVisible;
    bool m_bScalarBarVisible; ///< 用户偏好，无属性时仍保留。
    bool m_bBoundsGridVisible;
    bool m_bPropertySelectionExplicit; ///< 是否已由业务界面明确选择属性。
    bool m_bHasData;
    QString m_sRequestedPropertyName; ///< 显式选择偏好，可暂时不可用。
    QString m_sPropertyName;
};

nmPebiGridSceneController::nmPebiGridSceneController(
        nmWxVTKRenderContainerWidget* pContainer)
    : m_pPrivate(new nmPebiGridSceneControllerPrivate(pContainer))
{
}

nmPebiGridSceneController::~nmPebiGridSceneController()
{
    if(m_pPrivate != nullptr) {
        // Layer 已归 Scene 所有；这里只解除数据和非所有权指针。
        m_pPrivate->releaseGridData();
        m_pPrivate->m_pContainer = nullptr;
        m_pPrivate->m_pMeshLayer = nullptr;
        m_pPrivate->m_pScalarBarLayer = nullptr;
        m_pPrivate->m_pPlanarScaleGridLayer = nullptr;
        delete m_pPrivate;
        m_pPrivate = nullptr;
    }
}

bool nmPebiGridSceneController::setViewData(
        const nmPebiGridViewData& oViewData,
        QString* pError)
{
    if(pError != nullptr) {
        pError->clear();
    }
    if(m_pPrivate == nullptr || m_pPrivate->m_pContainer == nullptr ||
       !oViewData.isValid()) {
        if(pError != nullptr) {
            *pError = controllerText("The grid preview data is invalid.");
        }
        return false;
    }

    double dBounds[6];
    if(!getFiniteGridBounds(oViewData.getGrid(), dBounds)) {
        if(pError != nullptr) {
            *pError = controllerText("The grid bounds are invalid.");
        }
        return false;
    }
    if(!m_pPrivate->ensureBaseLayers()) {
        if(pError != nullptr) {
            *pError = controllerText("Unable to create the grid render layers.");
        }
        return false;
    }

    QString sRequestedProperty;
    if(m_pPrivate->m_bPropertySelectionExplicit) {
        // 用户明确选择优先；即使属性暂时缺失，也保留偏好供后续网格恢复。
        sRequestedProperty = m_pPrivate->m_sRequestedPropertyName;
    } else if(oViewData.hasMaterial()) {
        // 默认选择与“是否首次装入网格”无关，首次出现 Material 时同样生效。
        sRequestedProperty = "Material";
    }

    // 强引用保留上一份成功数据，提交任一步失败时可以完整恢复旧画面。
    const bool bHadPreviousData = m_pPrivate->m_bHasData;
    const nmPebiGridViewData oPreviousViewData = m_pPrivate->m_oViewData;
    const QString sPreviousProperty = m_pPrivate->m_sPropertyName;
    double dPreviousBounds[6];
    const bool bHasPreviousBounds = bHadPreviousData &&
            getFiniteGridBounds(oPreviousViewData.getGrid(), dPreviousBounds);

    // 几何替换先解除旧输入，再共享新网格；Renderer 和图层对象保持不变。
    m_pPrivate->releaseGridData();
    if(!m_pPrivate->bindViewData(oViewData, sRequestedProperty, dBounds)) {
        // 回滚同样不渲染；外层失败状态会决定恢复旧画面还是显示错误页。
        m_pPrivate->releaseGridData();
        if(bHadPreviousData && bHasPreviousBounds) {
            m_pPrivate->bindViewData(
                        oPreviousViewData,
                        sPreviousProperty,
                        dPreviousBounds);
        }
        if(pError != nullptr) {
            *pError = controllerText("Unable to bind the grid render data.");
        }
        return false;
    }

    // 几何变化始终恢复正交顶视图并适配；整批更新最终只在就绪入口渲染一次。
    m_pPrivate->m_pContainer->fitTopViewWithoutRender();
    m_pPrivate->m_pContainer->showReadyState();
    return true;
}

void nmPebiGridSceneController::clear()
{
    if(m_pPrivate == nullptr) {
        return;
    }
    m_pPrivate->releaseGridData();
    m_pPrivate->m_sPropertyName.clear();
    m_pPrivate->m_sRequestedPropertyName.clear();
    m_pPrivate->m_bGridLinesVisible = true;
    m_pPrivate->m_bScalarBarVisible = true;
    m_pPrivate->m_bBoundsGridVisible = false;
    m_pPrivate->m_bPropertySelectionExplicit = false;
}

void nmPebiGridSceneController::setGridLinesVisible(bool bVisible)
{
    if(m_pPrivate == nullptr) {
        return;
    }
    m_pPrivate->m_bGridLinesVisible = bVisible;
    if(m_pPrivate->m_pMeshLayer != nullptr) {
        m_pPrivate->m_pMeshLayer->setEdgeVisibility(bVisible);
    }
    if(m_pPrivate->m_bHasData && m_pPrivate->m_pContainer != nullptr) {
        m_pPrivate->m_pContainer->renderView();
    }
}

bool nmPebiGridSceneController::setProperty(const QString& sPropertyName)
{
    if(m_pPrivate == nullptr || !m_pPrivate->m_bHasData) {
        return false;
    }
    const bool bSucceeded = m_pPrivate->applyProperty(sPropertyName);
    // 只有公开入口代表用户/业务明确选择，内部默认绑定不会污染该状态。
    m_pPrivate->m_bPropertySelectionExplicit = true;
    m_pPrivate->m_sRequestedPropertyName = bSucceeded
            ? sPropertyName : QString();
    if(m_pPrivate->m_pContainer != nullptr) {
        m_pPrivate->m_pContainer->renderView();
    }
    return bSucceeded;
}

void nmPebiGridSceneController::setScalarBarVisible(bool bVisible)
{
    if(m_pPrivate == nullptr) {
        return;
    }
    // 无属性时只保存偏好；重新选择 Material 后按该偏好恢复色标。
    m_pPrivate->m_bScalarBarVisible = bVisible;
    if(m_pPrivate->m_pScalarBarLayer != nullptr) {
        m_pPrivate->m_pScalarBarLayer->setVisible(
                    bVisible && m_pPrivate->m_bHasData &&
                    !m_pPrivate->m_sPropertyName.isEmpty());
    }
    if(m_pPrivate->m_bHasData && m_pPrivate->m_pContainer != nullptr) {
        m_pPrivate->m_pContainer->renderView();
    }
}

void nmPebiGridSceneController::setBoundsGridVisible(bool bVisible)
{
    if(m_pPrivate == nullptr) {
        return;
    }
    m_pPrivate->m_bBoundsGridVisible = bVisible;
    if(m_pPrivate->m_pPlanarScaleGridLayer != nullptr) {
        m_pPrivate->m_pPlanarScaleGridLayer->setVisible(
                    bVisible && m_pPrivate->m_bHasData);
    }
    if(m_pPrivate->m_bHasData && m_pPrivate->m_pContainer != nullptr) {
        m_pPrivate->m_pContainer->renderView();
    }
}

bool nmPebiGridSceneController::hasViewData() const
{
    return m_pPrivate != nullptr && m_pPrivate->m_bHasData;
}

QString nmPebiGridSceneController::getProperty() const
{
    return m_pPrivate != nullptr
            ? m_pPrivate->m_sPropertyName : QString();
}

bool nmPebiGridSceneController::isGridLinesVisible() const
{
    return m_pPrivate != nullptr && m_pPrivate->m_bGridLinesVisible;
}

bool nmPebiGridSceneController::isScalarBarVisible() const
{
    return m_pPrivate != nullptr && m_pPrivate->m_bScalarBarVisible;
}

bool nmPebiGridSceneController::isBoundsGridVisible() const
{
    return m_pPrivate != nullptr && m_pPrivate->m_bBoundsGridVisible;
}