#include "nmPebiResultDisplayStateBuilder.h"

#include "nmPebiResultPropertyDisplayText.h"
#include "nmPebiResultSnapshot.h"
#include "nmVTKColorMapCatalog.h"

#include <QCoreApplication>
#include <QtGlobal>

#include <vtkLookupTable.h>
#include <vtkMath.h>

#include <math.h>

namespace {

QString displayStateText(const char* pText)
{
    // 沿用原 SceneController 翻译上下文，避免迁移既有 TS 条目。
    return QCoreApplication::translate(
                "nmPebiResultSceneController", pText);
}

bool getInternalDisplayRange(const double dVisibleRange[2],
                             bool bLogarithmic,
                             bool bSingleValueMode,
                             double dInternalRange[2])
{
    if(dVisibleRange == nullptr || dInternalRange == nullptr ||
       !vtkMath::IsFinite(dVisibleRange[0]) ||
       !vtkMath::IsFinite(dVisibleRange[1]) ||
       dVisibleRange[0] > dVisibleRange[1] ||
       (bLogarithmic && dVisibleRange[0] <= 0.0)) {
        return false;
    }

    if(dVisibleRange[0] < dVisibleRange[1]) {
        dInternalRange[0] = dVisibleRange[0];
        dInternalRange[1] = dVisibleRange[1];
        return true;
    }
    if(!bSingleValueMode || dVisibleRange[0] != dVisibleRange[1]) {
        return false;
    }

    // VTK要求映射范围严格递增；微量扩展只供内部映射，不改变业务值。
    const double dValue = dVisibleRange[0];
    double dMaximum = 0.0;
    if(bLogarithmic) {
        dMaximum = dValue * (1.0 + 1.0e-6);
        if(!vtkMath::IsFinite(dMaximum) || dMaximum <= dValue) {
            dMaximum = dValue * 2.0;
        }
    } else {
        const double dEpsilon = qMax(1.0, fabs(dValue)) * 1.0e-6;
        dMaximum = dValue + dEpsilon;
    }
    if(!vtkMath::IsFinite(dMaximum) || dValue >= dMaximum ||
       (bLogarithmic && dValue <= 0.0)) {
        return false;
    }
    dInternalRange[0] = dValue;
    dInternalRange[1] = dMaximum;
    return true;
}

bool fillLookupTableWithFirstColor(vtkLookupTable* pLookupTable)
{
    if(pLookupTable == nullptr ||
       pLookupTable->GetNumberOfTableValues() <= 0) {
        return false;
    }

    double dFirstColor[4] = { 0.0, 0.0, 0.0, 1.0 };
    pLookupTable->GetTableValue(0, dFirstColor);
    for(int nComponent = 0; nComponent < 4; ++nComponent) {
        if(!vtkMath::IsFinite(dFirstColor[nComponent])) {
            return false;
        }
    }

    const int nTableValueCount = static_cast<int>(
                pLookupTable->GetNumberOfTableValues());
    for(int nIndex = 0; nIndex < nTableValueCount; ++nIndex) {
        pLookupTable->SetTableValue(nIndex, dFirstColor);
    }
    return true;
}

}

nmPebiResultDisplayState::nmPebiResultDisplayState()
    : m_pLookupTable(nullptr),
      m_bSingleValueMode(false)
{
    m_dBusinessRange[0] = m_dBusinessRange[1] = 0.0;
    m_dVisibleRange[0] = m_dVisibleRange[1] = 0.0;
    m_dInternalRange[0] = 0.0;
    m_dInternalRange[1] = 1.0;
}

bool nmPebiResultDisplayStateBuilder::build(
        const QSharedPointer<const nmPebiResultSnapshot>& pSnapshot,
        const QString& sPropertyId,
        const nmPebiResultDisplaySettings& oRequestedSettings,
        nmPebiResultDisplayState& oState,
        QString* pError)
{
    if(pError != nullptr) {
        pError->clear();
    }
    nmPebiResultDisplaySettings oSettings =
            oRequestedSettings.normalized();
    if(pSnapshot.isNull() || !pSnapshot->hasProperty(sPropertyId) ||
       !oSettings.isStructurallyValid()) {
        if(pError != nullptr) {
            *pError = displayStateText("The color settings are invalid.");
        }
        return false;
    }
    if(!nmVTKColorMapCatalog::contains(oSettings.m_sColorMapId)) {
        if(pError != nullptr) {
            *pError = displayStateText(
                        "The selected color map is unavailable.");
        }
        return false;
    }

    double dBusinessRange[2] = { 0.0, 0.0 };
    if(!pSnapshot->getPropertyRange(sPropertyId, dBusinessRange) ||
       !vtkMath::IsFinite(dBusinessRange[0]) ||
       !vtkMath::IsFinite(dBusinessRange[1]) ||
       dBusinessRange[0] > dBusinessRange[1]) {
        if(pError != nullptr) {
            *pError = displayStateText(
                        "The result property range is invalid.");
        }
        return false;
    }

    double dVisibleRange[2] = {
        dBusinessRange[0], dBusinessRange[1]
    };
    if(oSettings.m_bHasManualRange) {
        if(!vtkMath::IsFinite(oSettings.m_dManualMinimum) ||
           !vtkMath::IsFinite(oSettings.m_dManualMaximum) ||
           oSettings.m_dManualMinimum >= oSettings.m_dManualMaximum) {
            if(pError != nullptr) {
                *pError = displayStateText(
                    "The manual range must contain two finite increasing values.");
            }
            return false;
        }
        dVisibleRange[0] = oSettings.m_dManualMinimum;
        dVisibleRange[1] = oSettings.m_dManualMaximum;
    }

    const bool bSingleValueMode =
            !oSettings.m_bHasManualRange &&
            dBusinessRange[0] == dBusinessRange[1];
    const bool bLogarithmic =
            oSettings.m_eScaleMode == NM_PebiColorScale_Logarithmic;
    if(bLogarithmic &&
       (dBusinessRange[0] <= 0.0 || dVisibleRange[0] <= 0.0)) {
        if(pError != nullptr) {
            *pError = displayStateText(
                "Logarithmic scale requires positive property and display ranges.");
        }
        return false;
    }

    double dInternalRange[2] = { 0.0, 1.0 };
    vtkSmartPointer<vtkLookupTable> pLookupTable =
            nmVTKColorMapCatalog::createLookupTable(
                oSettings.m_sColorMapId);
    if(pLookupTable == nullptr ||
       !getInternalDisplayRange(dVisibleRange, bLogarithmic,
                                bSingleValueMode, dInternalRange)) {
        if(pError != nullptr) {
            *pError = displayStateText(
                        "Unable to construct the color mapping.");
        }
        return false;
    }

    pLookupTable->SetTableRange(dInternalRange);
    if(bLogarithmic) {
        pLookupTable->SetScaleToLog10();
    } else {
        pLookupTable->SetScaleToLinear();
    }
    // 单值自动范围固定到色带第0色，特殊越界色随后单独构造。
    if(bSingleValueMode &&
       !fillLookupTableWithFirstColor(pLookupTable)) {
        if(pError != nullptr) {
            *pError = displayStateText(
                        "Unable to construct the color mapping.");
        }
        return false;
    }

    const QColor oBelowColor = oSettings.m_oBelowRangeColor;
    const QColor oAboveColor = oSettings.m_oAboveRangeColor;
    pLookupTable->SetBelowRangeColor(
                oBelowColor.redF(), oBelowColor.greenF(),
                oBelowColor.blueF(), 1.0);
    pLookupTable->SetAboveRangeColor(
                oAboveColor.redF(), oAboveColor.greenF(),
                oAboveColor.blueF(), 1.0);
    pLookupTable->SetUseBelowRangeColor(
                oSettings.m_bUseBelowRangeColor ? 1 : 0);
    pLookupTable->SetUseAboveRangeColor(
                oSettings.m_bUseAboveRangeColor ? 1 : 0);
    pLookupTable->BuildSpecialColors();
    pLookupTable->IndexedLookupOff();
    pLookupTable->ResetAnnotations();

    oState.m_oSettings = oSettings;
    oState.m_dBusinessRange[0] = dBusinessRange[0];
    oState.m_dBusinessRange[1] = dBusinessRange[1];
    oState.m_dVisibleRange[0] = dVisibleRange[0];
    oState.m_dVisibleRange[1] = dVisibleRange[1];
    oState.m_dInternalRange[0] = dInternalRange[0];
    oState.m_dInternalRange[1] = dInternalRange[1];
    oState.m_pLookupTable = pLookupTable;
    oState.m_sScalarBarTitle =
            nmPebiResultPropertyDisplayText::getScalarBarTitle(
                sPropertyId, bLogarithmic);
    oState.m_bSingleValueMode = bSingleValueMode;
    return true;
}