#include "nmVolumeSliceInteraction.h"
#include "nmWxVTKRenderContainerWidget.h"
#include <QMetaObject>
#include <vtkActor.h>
#include <vtkCallbackCommand.h>
#include <vtkCellPicker.h>
#include <vtkCommand.h>
#include <vtkImplicitPlaneRepresentation.h>
#include <vtkImplicitPlaneWidget2.h>
#include <vtkProperty.h>
#include <vtkObjectFactory.h>
#include <vtkWidgetEventTranslator.h>

namespace {
/** @brief VTK 7.1 的 DrawPlaneOff 仍拾取不可见填充面，需将拾取限定到可见轮廓和手柄。 */
class nmVolumePlaneRepresentation : public vtkImplicitPlaneRepresentation
{
public:
    /** @brief 按 VTK 引用计数规则创建本地预览表示。 */
    static nmVolumePlaneRepresentation* New();
    vtkTypeMacro(nmVolumePlaneRepresentation, vtkImplicitPlaneRepresentation);
    /** @brief 中心或轮廓沿法向移动平面，法向箭头继续使用 VTK 内建旋转。 */
    virtual int ComputeInteractionState(int nX, int nY, int nModify = 0)
    {
        const bool bMoving = this->InteractionState == Moving;
        const int nState = this->Superclass::ComputeInteractionState(nX, nY, nModify);
        if(bMoving && (nState == MovingOrigin || this->Picker->GetActor() == this->EdgesActor)) {
            this->SetInteractionState(Pushing);
            this->SetRepresentationState(Pushing);
        }
        return this->InteractionState;
    }
protected:
    /** @brief 去除填充面和固定包围盒的拾取，避免在模型空白区域抢占相机操作。 */
    nmVolumePlaneRepresentation()
    {
        this->Picker->DeletePickList(this->CutActor);
        this->Picker->DeletePickList(this->OutlineActor);
        this->Picker->AddPickList(this->EdgesActor);
    }
};
vtkStandardNewMacro(nmVolumePlaneRepresentation);

/** @brief 在隐藏、导入或退出模式时安全取消未松手的拖动，不保留 Interactor 焦点。 */
class nmVolumePlaneWidget : public vtkImplicitPlaneWidget2
{
public:
    /** @brief 创建本窗口独占的交互 Widget。 */
    static nmVolumePlaneWidget* New();
    vtkTypeMacro(nmVolumePlaneWidget, vtkImplicitPlaneWidget2);
    /** @brief 禁用时先解除主动拖动及焦点，不能发出一次伪造的松手应用。 */
    virtual void SetEnabled(int nEnabled)
    {
        if(!nEnabled && this->Enabled && this->WidgetState == Active) {
            this->ReleaseFocus();
            this->WidgetState = Start;
            this->GetImplicitPlaneRepresentation()->SetRepresentationState(vtkImplicitPlaneRepresentation::Outside);
            this->EndInteraction();
        }
        this->Superclass::SetEnabled(nEnabled);
    }
};
vtkStandardNewMacro(nmVolumePlaneWidget);
}

nmVolumeSliceInteraction::nmVolumeSliceInteraction(nmWxVTKRenderContainerWidget* pContainer, QObject* pParent)
    : QObject(pParent), m_pContainer(pContainer),
      m_pRepresentation(vtkSmartPointer<nmVolumePlaneRepresentation>::New()),
      m_pWidget(vtkSmartPointer<nmVolumePlaneWidget>::New()),
      m_pCallback(vtkSmartPointer<vtkCallbackCommand>::New()),
      m_nGeneration(0), m_nPendingGeneration(0), m_bQueued(false), m_bPendingApply(false)
{
    m_pRepresentation->SetPlaceFactor(1.0);
    m_pRepresentation->DrawPlaneOff();
    m_pRepresentation->OutlineTranslationOff();
    m_pRepresentation->ScaleEnabledOff();
    m_pRepresentation->OutsideBoundsOn();
    m_pRepresentation->ConstrainToWidgetBoundsOff();
    m_pRepresentation->GetOutlineProperty()->SetColor(0.45, 0.55, 0.65);
    m_pWidget->SetRepresentation(m_pRepresentation);
    m_pWidget->KeyPressActivationOff();
    // 中键、右键及键盘保留给现有相机和菜单；仅左键手柄用于移动或旋转平面。
    vtkWidgetEventTranslator* pTranslator = m_pWidget->GetEventTranslator();
    pTranslator->RemoveTranslation(vtkCommand::MiddleButtonPressEvent);
    pTranslator->RemoveTranslation(vtkCommand::MiddleButtonReleaseEvent);
    pTranslator->RemoveTranslation(vtkCommand::RightButtonPressEvent);
    pTranslator->RemoveTranslation(vtkCommand::RightButtonReleaseEvent);
    pTranslator->RemoveTranslation(vtkCommand::KeyPressEvent);
    pTranslator->RemoveTranslation(vtkCommand::KeyReleaseEvent);
    m_pCallback->SetClientData(this);
    m_pCallback->SetCallback(onPlaneEvent);
    m_pWidget->AddObserver(vtkCommand::InteractionEvent, m_pCallback);
    m_pWidget->AddObserver(vtkCommand::EndInteractionEvent, m_pCallback);
}

nmVolumeSliceInteraction::~nmVolumeSliceInteraction()
{
    unbind();
    m_pWidget->RemoveObservers(vtkCommand::InteractionEvent, m_pCallback);
    m_pWidget->RemoveObservers(vtkCommand::EndInteractionEvent, m_pCallback);
    m_pCallback->SetClientData(nullptr);
}

void nmVolumeSliceInteraction::bind(const QString& sDataId, const double dBounds[6], const nmVolumeSliceSettings& oSettings)
{
    unbind();
    if(m_pContainer == nullptr || sDataId.isEmpty() || dBounds == nullptr) return;
    m_sDataId = sDataId;
    m_pWidget->SetInteractor(m_pContainer->getInteractor());
    m_pWidget->SetCurrentRenderer(m_pContainer->getRenderer());
    double dPlacement[6];
    for(int nIndex = 0; nIndex < 6; ++nIndex) dPlacement[nIndex] = dBounds[nIndex];
    m_pRepresentation->PlaceWidget(dPlacement);
    setPreview(oSettings);
}

void nmVolumeSliceInteraction::unbind()
{
    ++m_nGeneration;
    m_bPendingApply = false;
    m_pWidget->SetEnabled(0);
    m_pWidget->SetInteractor(nullptr);
    m_pWidget->SetCurrentRenderer(nullptr);
    m_sDataId.clear();
}

void nmVolumeSliceInteraction::setPreview(const nmVolumeSliceSettings& oSettings)
{
    nmVolumeSliceSettings oNormalized = oSettings;
    if(!oNormalized.normalize()) return;
    // 数值输入、重置或成功应用取代旧拖动草稿，不能再交付尚未处理的旧松手事件。
    ++m_nGeneration;
    m_bPendingApply = false;
    m_oPreview = oNormalized;
    m_pRepresentation->SetOrigin(m_oPreview.m_dOrigin);
    m_pRepresentation->SetNormal(m_oPreview.m_dNormal);
}

void nmVolumeSliceInteraction::setEnabled(bool bEnabled)
{
    bEnabled = bEnabled && !m_sDataId.isEmpty();
    if(isEnabled() == bEnabled) return;
    if(!bEnabled) { ++m_nGeneration; m_bPendingApply = false; }
    // VTK 禁用 Widget 时会清空 CurrentRenderer；恢复时不能依赖鼠标仍停留在视口内。
    if(bEnabled) m_pWidget->SetCurrentRenderer(m_pContainer->getRenderer());
    m_pWidget->SetEnabled(bEnabled ? 1 : 0);
}

bool nmVolumeSliceInteraction::isEnabled() const { return m_pWidget->GetEnabled() != 0; }

void nmVolumeSliceInteraction::onPlaneEvent(vtkObject* pCaller, unsigned long nEvent, void* pClientData, void*)
{
    nmVolumeSliceInteraction* pSelf = static_cast<nmVolumeSliceInteraction*>(pClientData);
    if(pSelf == nullptr || !pSelf->isEnabled() || pCaller != pSelf->m_pWidget.GetPointer()) return;
    pSelf->m_oPending = pSelf->m_oPreview;
    pSelf->m_pRepresentation->GetOrigin(pSelf->m_oPending.m_dOrigin);
    pSelf->m_pRepresentation->GetNormal(pSelf->m_oPending.m_dNormal);
    pSelf->m_nPendingGeneration = pSelf->m_nGeneration;
    pSelf->m_bPendingApply = pSelf->m_bPendingApply || nEvent == vtkCommand::EndInteractionEvent;
    if(!pSelf->m_bQueued) {
        pSelf->m_bQueued = true;
        QMetaObject::invokeMethod(pSelf, "deliverPendingEvent", Qt::QueuedConnection);
    }
}

void nmVolumeSliceInteraction::deliverPendingEvent()
{
    m_bQueued = false;
    const bool bApply = m_bPendingApply;
    m_bPendingApply = false;
    if(!isEnabled() || m_nPendingGeneration != m_nGeneration) return;
    const unsigned int nGeneration = m_nGeneration;
    const QString sDataId = m_sDataId;
    m_oPreview = m_oPending;
    emit previewChanged(sDataId, m_oPreview);
    // previewChanged 的接收者可能关闭窗口或切换模式，必须再次检查代次。
    if(bApply && isEnabled() && nGeneration == m_nGeneration) emit applyRequested(sDataId, m_oPreview);
}