/****************************************************************************
**
** Copyright (C) 2014 Digia Plc
** All rights reserved.
** For any questions to Digia, please use contact form at http://qt.digia.com
**
** This file is part of the QtDataVisualization module.
**
** Licensees holding valid Qt Enterprise licenses may use this file in
** accordance with the Qt Enterprise License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.
**
** If you have questions regarding the use of this file, please use
** contact form at http://qt.digia.com
**
****************************************************************************/

#include "abstract3drenderer_p.h"
#include "qvalue3daxis.h"
#include "texturehelper_p.h"
#include "utils_p.h"
#include "q3dscene_p.h"
#include "q3dcamera_p.h"
#include "q3dlight_p.h"
#include "qabstract3dseries_p.h"
#include "q3dtheme_p.h"
#include "objecthelper_p.h"
#include "qvalue3daxisformatter_p.h"
#include "shaderhelper_p.h"

QT_BEGIN_NAMESPACE_DATAVISUALIZATION

Abstract3DRenderer::Abstract3DRenderer(Abstract3DController *controller)
    : QObject(0),
      m_hasNegativeValues(false),
      m_cachedTheme(new Q3DTheme()),
      m_drawer(new Drawer(m_cachedTheme)),
      m_cachedShadowQuality(QAbstract3DGraph::ShadowQualityMedium),
      m_autoScaleAdjustment(1.0f),
      m_cachedSelectionMode(QAbstract3DGraph::SelectionNone),
      m_textureHelper(0),
      m_cachedScene(new Q3DScene()),
      m_selectionDirty(true),
      m_selectionState(SelectNone),
      m_devicePixelRatio(1.0f),
      m_selectionLabelDirty(true),
      m_clickPending(false),
      m_clickedSeries(0),
      m_clickedType(QAbstract3DGraph::ElementNone),
      m_selectionLabelItem(0),
      m_visibleSeriesCount(0),
      m_customItemShader(0)

{
    QObject::connect(m_drawer, &Drawer::drawerChanged, this, &Abstract3DRenderer::updateTextures);
    QObject::connect(this, &Abstract3DRenderer::needRender, controller,
                     &Abstract3DController::needRender, Qt::QueuedConnection);
    QObject::connect(this, &Abstract3DRenderer::requestShadowQuality, controller,
                     &Abstract3DController::handleRequestShadowQuality, Qt::QueuedConnection);
}

Abstract3DRenderer::~Abstract3DRenderer()
{
    delete m_drawer;
    delete m_cachedScene;
    delete m_cachedTheme;
    delete m_selectionLabelItem;
    delete m_customItemShader;

    foreach (SeriesRenderCache *cache, m_renderCacheList) {
        cache->cleanup(m_textureHelper);
        delete cache;
    }
    m_renderCacheList.clear();

    delete m_textureHelper;
}

void Abstract3DRenderer::initializeOpenGL()
{
    // Set OpenGL features
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);

#if !defined(QT_OPENGL_ES_2)
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
    glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
    glHint(GL_POLYGON_SMOOTH_HINT, GL_NICEST);
#endif

    m_textureHelper = new TextureHelper();
    m_drawer->initializeOpenGL();

    axisCacheForOrientation(QAbstract3DAxis::AxisOrientationX).setDrawer(m_drawer);
    axisCacheForOrientation(QAbstract3DAxis::AxisOrientationY).setDrawer(m_drawer);
    axisCacheForOrientation(QAbstract3DAxis::AxisOrientationZ).setDrawer(m_drawer);
}

void Abstract3DRenderer::render(const GLuint defaultFboHandle)
{
    if (defaultFboHandle) {
        glDepthMask(true);
        glEnable(GL_DEPTH_TEST);
        glDepthFunc(GL_LESS);
        glEnable(GL_CULL_FACE);
        glCullFace(GL_BACK);
        glDisable(GL_BLEND); // For QtQuick2 blending is enabled by default, but we don't want it to be
    }

    // Clear the graph background to the theme color
    glViewport(m_viewport.x(),
               m_viewport.y(),
               m_viewport.width(),
               m_viewport.height());
    glScissor(m_viewport.x(),
              m_viewport.y(),
              m_viewport.width(),
              m_viewport.height());
    glEnable(GL_SCISSOR_TEST);
    QVector4D clearColor = Utils::vectorFromColor(m_cachedTheme->windowColor());
    glClearColor(clearColor.x(), clearColor.y(), clearColor.z(), 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glDisable(GL_SCISSOR_TEST);
}

void Abstract3DRenderer::updateSelectionState(SelectionState state)
{
    m_selectionState = state;
}

void Abstract3DRenderer::updateInputPosition(const QPoint &position)
{
    m_inputPosition = position;
}

void Abstract3DRenderer::initGradientShaders(const QString &vertexShader,
                                             const QString &fragmentShader)
{
    // Do nothing by default
    Q_UNUSED(vertexShader)
    Q_UNUSED(fragmentShader)
}

void Abstract3DRenderer::initCustomItemShaders(const QString &vertexShader,
                                               const QString &fragmentShader)
{
    if (m_customItemShader)
        delete m_customItemShader;
    m_customItemShader = new ShaderHelper(this, vertexShader, fragmentShader);
    m_customItemShader->initialize();
}

void Abstract3DRenderer::updateTheme(Q3DTheme *theme)
{
    // Synchronize the controller theme with renderer
    bool updateDrawer = theme->d_ptr->sync(*m_cachedTheme->d_ptr);

    if (updateDrawer)
        m_drawer->setTheme(m_cachedTheme);
}

void Abstract3DRenderer::updateScene(Q3DScene *scene)
{
    m_viewport = scene->d_ptr->glViewport();
    m_secondarySubViewport = scene->d_ptr->glSecondarySubViewport();

    if (m_primarySubViewport != scene->d_ptr->glPrimarySubViewport()) {
        // Resize of primary subviewport means resizing shadow and selection buffers
        m_primarySubViewport = scene->d_ptr->glPrimarySubViewport();
        handleResize();
    }

    if (m_devicePixelRatio != scene->devicePixelRatio()) {
        m_devicePixelRatio = scene->devicePixelRatio();
        handleResize();
    }

    scene->activeCamera()->d_ptr->updateViewMatrix(m_autoScaleAdjustment);
    // Set light position (rotate light with activeCamera, a bit above it (as set in defaultLightPos))
    scene->d_ptr->setLightPositionRelativeToCamera(defaultLightPos);

    QPoint logicalPixelPosition = scene->selectionQueryPosition();
    updateInputPosition(QPoint(logicalPixelPosition.x() * m_devicePixelRatio,
                               logicalPixelPosition.y() * m_devicePixelRatio));

    // Synchronize the renderer scene to controller scene
    scene->d_ptr->sync(*m_cachedScene->d_ptr);

    if (Q3DScene::invalidSelectionPoint() == logicalPixelPosition) {
        updateSelectionState(SelectNone);
    } else {
        // Selections are one-shot, reset selection active to false before processing
        scene->setSelectionQueryPosition(Q3DScene::invalidSelectionPoint());
        m_clickPending = true;

        if (scene->isSlicingActive()) {
            if (scene->isPointInPrimarySubView(logicalPixelPosition))
                updateSelectionState(SelectOnOverview);
            else if (scene->isPointInSecondarySubView(logicalPixelPosition))
                updateSelectionState(SelectOnSlice);
            else
                updateSelectionState(SelectNone);
        } else {
            updateSelectionState(SelectOnScene);
        }
    }
}

void Abstract3DRenderer::reInitShaders()
{
#if !defined(QT_OPENGL_ES_2)
    if (m_cachedShadowQuality > QAbstract3DGraph::ShadowQualityNone) {
        initGradientShaders(QStringLiteral(":/shaders/vertexShadow"),
                            QStringLiteral(":/shaders/fragmentShadowNoTexColorOnY"));
        initShaders(QStringLiteral(":/shaders/vertexShadow"),
                    QStringLiteral(":/shaders/fragmentShadowNoTex"));
        initBackgroundShaders(QStringLiteral(":/shaders/vertexShadow"),
                              QStringLiteral(":/shaders/fragmentShadowNoTex"));
        initCustomItemShaders(QStringLiteral(":/shaders/vertexShadow"),
                              QStringLiteral(":/shaders/fragmentShadow"));
    } else {
        initGradientShaders(QStringLiteral(":/shaders/vertex"),
                            QStringLiteral(":/shaders/fragmentColorOnY"));
        initShaders(QStringLiteral(":/shaders/vertex"),
                    QStringLiteral(":/shaders/fragment"));
        initBackgroundShaders(QStringLiteral(":/shaders/vertex"),
                              QStringLiteral(":/shaders/fragment"));
        initCustomItemShaders(QStringLiteral(":/shaders/vertexTexture"),
                              QStringLiteral(":/shaders/fragmentTexture"));
    }
#else
    initGradientShaders(QStringLiteral(":/shaders/vertex"),
                        QStringLiteral(":/shaders/fragmentColorOnYES2"));
    initShaders(QStringLiteral(":/shaders/vertex"),
                QStringLiteral(":/shaders/fragmentES2"));
    initBackgroundShaders(QStringLiteral(":/shaders/vertex"),
                          QStringLiteral(":/shaders/fragmentES2"));
    initCustomItemShaders(QStringLiteral(":/shaders/vertexTexture"),
                          QStringLiteral(":/shaders/fragmentTextureES2"));
#endif
}

void Abstract3DRenderer::handleShadowQualityChange()
{
    reInitShaders();

#if defined(QT_OPENGL_ES_2)
    if (m_cachedShadowQuality != QAbstract3DGraph::ShadowQualityNone) {
        emit requestShadowQuality(QAbstract3DGraph::ShadowQualityNone);
        qWarning("Shadows are not yet supported for OpenGL ES2");
        m_cachedShadowQuality = QAbstract3DGraph::ShadowQualityNone;
    }
#endif
}

void Abstract3DRenderer::updateSelectionMode(QAbstract3DGraph::SelectionFlags mode)
{
    m_cachedSelectionMode = mode;
    m_selectionDirty = true;
}

void Abstract3DRenderer::handleResize()
{
    if (m_primarySubViewport.width() == 0 || m_primarySubViewport.height() == 0)
        return;

    // Calculate zoom level based on aspect ratio
    GLfloat div;
    GLfloat zoomAdjustment;
    div = qMin(m_primarySubViewport.width(), m_primarySubViewport.height());
    zoomAdjustment = defaultRatio * ((m_primarySubViewport.width() / div)
                                     / (m_primarySubViewport.height() / div));
    m_autoScaleAdjustment = qMin(zoomAdjustment, 1.0f); // clamp to 1.0f

    // Re-init selection buffer
    initSelectionBuffer();

#if !defined(QT_OPENGL_ES_2)
    // Re-init depth buffer
    updateDepthBuffer();
#endif
}

void Abstract3DRenderer::updateAxisType(QAbstract3DAxis::AxisOrientation orientation,
                                        QAbstract3DAxis::AxisType type)
{
    axisCacheForOrientation(orientation).setType(type);
}

void Abstract3DRenderer::updateAxisTitle(QAbstract3DAxis::AxisOrientation orientation,
                                         const QString &title)
{
    axisCacheForOrientation(orientation).setTitle(title);
}

void Abstract3DRenderer::updateAxisLabels(QAbstract3DAxis::AxisOrientation orientation,
                                          const QStringList &labels)
{
    axisCacheForOrientation(orientation).setLabels(labels);
}

void Abstract3DRenderer::updateAxisRange(QAbstract3DAxis::AxisOrientation orientation,
                                         float min, float max)
{
    AxisRenderCache &cache = axisCacheForOrientation(orientation);
    cache.setMin(min);
    cache.setMax(max);

    foreach (SeriesRenderCache *cache, m_renderCacheList)
        cache->setDataDirty(true);
}

void Abstract3DRenderer::updateAxisSegmentCount(QAbstract3DAxis::AxisOrientation orientation,
                                                int count)
{
    AxisRenderCache &cache = axisCacheForOrientation(orientation);
    cache.setSegmentCount(count);
}

void Abstract3DRenderer::updateAxisSubSegmentCount(QAbstract3DAxis::AxisOrientation orientation,
                                                   int count)
{
    AxisRenderCache &cache = axisCacheForOrientation(orientation);
    cache.setSubSegmentCount(count);
}

void Abstract3DRenderer::updateAxisLabelFormat(QAbstract3DAxis::AxisOrientation orientation,
                                               const QString &format)
{
    axisCacheForOrientation(orientation).setLabelFormat(format);
}

void Abstract3DRenderer::updateAxisFormatter(QAbstract3DAxis::AxisOrientation orientation,
                                             QValue3DAxisFormatter *formatter)
{
    AxisRenderCache &cache = axisCacheForOrientation(orientation);
    if (cache.ctrlFormatter() != formatter) {
        delete cache.formatter();
        cache.setFormatter(formatter->createNewInstance());
        cache.setCtrlFormatter(formatter);
    }
    formatter->d_ptr->populateCopy(*(cache.formatter()));
    cache.markPositionsDirty();

    foreach (SeriesRenderCache *cache, m_renderCacheList)
        cache->setDataDirty(true);
}

void Abstract3DRenderer::modifiedSeriesList(const QVector<QAbstract3DSeries *> &seriesList)
{
    foreach (QAbstract3DSeries *series, seriesList) {
        SeriesRenderCache *cache = m_renderCacheList.value(series, 0);
        if (cache)
            cache->setDataDirty(true);
    }
}

void Abstract3DRenderer::fixMeshFileName(QString &fileName, QAbstract3DSeries::Mesh mesh)
{
    // Default implementation does nothing.
    Q_UNUSED(fileName)
    Q_UNUSED(mesh)
}

void Abstract3DRenderer::updateSeries(const QList<QAbstract3DSeries *> &seriesList)
{
    foreach (SeriesRenderCache *cache, m_renderCacheList)
        cache->setValid(false);

    m_visibleSeriesCount = 0;
    int seriesCount = seriesList.size();
    for (int i = 0; i < seriesCount; i++) {
        QAbstract3DSeries *series = seriesList.at(i);
        SeriesRenderCache *cache = m_renderCacheList.value(series);
        bool newSeries = false;
        if (!cache) {
            cache = createNewCache(series);
            m_renderCacheList[series] = cache;
            newSeries = true;
        }
        cache->setValid(true);
        cache->populate(newSeries);
        if (cache->isVisible())
            m_visibleSeriesCount++;
    }

    // Remove non-valid objects from the cache list
    foreach (SeriesRenderCache *cache, m_renderCacheList) {
        if (!cache->isValid())
            cleanCache(cache);
    }
}

void Abstract3DRenderer::updateCustomData(const QList<CustomDataItem *> &customItems)
{
    if (customItems.isEmpty() && m_customRenderCache.isEmpty())
        return;

    // There are probably not too many custom items, just recreate the array if something changes
    foreach (CustomRenderItem *item, m_customRenderCache)
        delete item;
    m_customRenderCache.clear();
    foreach (CustomDataItem *item, customItems)
        addCustomItem(item);
}

SeriesRenderCache *Abstract3DRenderer::createNewCache(QAbstract3DSeries *series)
{
    return new SeriesRenderCache(series, this);
}

void Abstract3DRenderer::cleanCache(SeriesRenderCache *cache)
{
    m_renderCacheList.remove(cache->series());
    cache->cleanup(m_textureHelper);
    delete cache;
}

AxisRenderCache &Abstract3DRenderer::axisCacheForOrientation(
        QAbstract3DAxis::AxisOrientation orientation)
{
    switch (orientation) {
    case QAbstract3DAxis::AxisOrientationX:
        return m_axisCacheX;
    case QAbstract3DAxis::AxisOrientationY:
        return m_axisCacheY;
    case QAbstract3DAxis::AxisOrientationZ:
        return m_axisCacheZ;
    default:
        qFatal("Abstract3DRenderer::axisCacheForOrientation");
        return m_axisCacheX;
    }
}

void Abstract3DRenderer::lowerShadowQuality()
{
    QAbstract3DGraph::ShadowQuality newQuality = QAbstract3DGraph::ShadowQualityNone;

    switch (m_cachedShadowQuality) {
    case QAbstract3DGraph::ShadowQualityHigh:
        qWarning("Creating high quality shadows failed. Changing to medium quality.");
        newQuality = QAbstract3DGraph::ShadowQualityMedium;
        break;
    case QAbstract3DGraph::ShadowQualityMedium:
        qWarning("Creating medium quality shadows failed. Changing to low quality.");
        newQuality = QAbstract3DGraph::ShadowQualityLow;
        break;
    case QAbstract3DGraph::ShadowQualityLow:
        qWarning("Creating low quality shadows failed. Switching shadows off.");
        newQuality = QAbstract3DGraph::ShadowQualityNone;
        break;
    case QAbstract3DGraph::ShadowQualitySoftHigh:
        qWarning("Creating soft high quality shadows failed. Changing to soft medium quality.");
        newQuality = QAbstract3DGraph::ShadowQualitySoftMedium;
        break;
    case QAbstract3DGraph::ShadowQualitySoftMedium:
        qWarning("Creating soft medium quality shadows failed. Changing to soft low quality.");
        newQuality = QAbstract3DGraph::ShadowQualitySoftLow;
        break;
    case QAbstract3DGraph::ShadowQualitySoftLow:
        qWarning("Creating soft low quality shadows failed. Switching shadows off.");
        newQuality = QAbstract3DGraph::ShadowQualityNone;
        break;
    default:
        // You'll never get here
        break;
    }

    emit requestShadowQuality(newQuality);
    updateShadowQuality(newQuality);
}

void Abstract3DRenderer::generateBaseColorTexture(const QColor &color, GLuint *texture)
{
    m_textureHelper->deleteTexture(texture);
    *texture = m_textureHelper->createUniformTexture(color);
}

void Abstract3DRenderer::fixGradientAndGenerateTexture(QLinearGradient *gradient, GLuint *gradientTexture)
{
    // Readjust start/stop to match gradient texture size
    gradient->setStart(qreal(gradientTextureWidth), qreal(gradientTextureHeight));
    gradient->setFinalStop(0.0, 0.0);

    m_textureHelper->deleteTexture(gradientTexture);

    *gradientTexture = m_textureHelper->createGradientTexture(*gradient);
}

LabelItem &Abstract3DRenderer::selectionLabelItem()
{
    if (!m_selectionLabelItem)
        m_selectionLabelItem = new LabelItem;
    return *m_selectionLabelItem;
}

void Abstract3DRenderer::setSelectionLabel(const QString &label)
{
    if (m_selectionLabelItem)
        m_selectionLabelItem->clear();
    m_selectionLabel = label;
}

QString &Abstract3DRenderer::selectionLabel()
{
    return m_selectionLabel;
}

QVector4D Abstract3DRenderer::indexToSelectionColor(GLint index)
{
    GLubyte idxRed = index & 0xff;
    GLubyte idxGreen = (index & 0xff00) >> 8;
    GLubyte idxBlue = (index & 0xff0000) >> 16;

    return QVector4D(idxRed, idxGreen, idxBlue, 0);
}

void Abstract3DRenderer::addCustomItem(CustomDataItem *item) {
    CustomRenderItem *newItem = new CustomRenderItem();
    newItem->setMesh(item->meshFile());
    newItem->setScaling(item->scaling());
    newItem->setRotation(item->rotation());
    newItem->setTexture(item->texture());
    QVector3D translation = convertPositionToTranslation(item->position());
    newItem->setTranslation(translation);
    m_customRenderCache.append(newItem);
}

void Abstract3DRenderer::drawCustomItems(RenderingState state,
                                         ShaderHelper *shader,
                                         const QMatrix4x4 &viewMatrix,
                                         const QMatrix4x4 &projectionViewMatrix,
                                         const QMatrix4x4 &depthProjectionViewMatrix,
                                         GLuint depthTexture,
                                         GLfloat shadowQuality)
{
    if (m_customRenderCache.isEmpty())
        return;

    int itemIndex = 0;

    if (RenderingNormal == state) {
        shader->bind();
        shader->setUniformValue(shader->lightP(), m_cachedScene->activeLight()->position());
        shader->setUniformValue(shader->ambientS(), m_cachedTheme->ambientLightStrength());
        shader->setUniformValue(shader->lightColor(),
                                Utils::vectorFromColor(m_cachedTheme->lightColor()));
        shader->setUniformValue(shader->view(), viewMatrix);

        glEnable(GL_TEXTURE_2D);
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    }

    // Draw custom items
    foreach (CustomRenderItem *item, m_customRenderCache) {
        QMatrix4x4 modelMatrix;
        QMatrix4x4 itModelMatrix;
        QMatrix4x4 MVPMatrix;

        modelMatrix.translate(item->translation());
        modelMatrix.rotate(item->rotation());
        modelMatrix.scale(item->scaling());
        itModelMatrix.rotate(item->rotation());
        itModelMatrix.scale(item->scaling());
        MVPMatrix = projectionViewMatrix * modelMatrix;

        if (RenderingNormal == state) {
            // Normal render
            shader->setUniformValue(shader->model(), modelMatrix);
            shader->setUniformValue(shader->MVP(), MVPMatrix);
            shader->setUniformValue(shader->nModel(), itModelMatrix.inverted().transposed());

#if !defined(QT_OPENGL_ES_2)
            if (m_cachedShadowQuality > QAbstract3DGraph::ShadowQualityNone) {
                // Set shadow shader bindings
                shader->setUniformValue(shader->shadowQ(), shadowQuality);
                shader->setUniformValue(shader->depth(), depthProjectionViewMatrix * modelMatrix);
                shader->setUniformValue(shader->lightS(), m_cachedTheme->lightStrength() / 10.0f);
                m_drawer->drawObject(shader, item->mesh(), item->texture(), depthTexture);
            } else
#else
            Q_UNUSED(depthTexture)
            Q_UNUSED(shadowQuality)
#endif
            {
                // Set shadowless shader bindings
                shader->setUniformValue(shader->lightS(), m_cachedTheme->lightStrength());
                m_drawer->drawObject(shader, item->mesh(), item->texture());
            }
        } else if (RenderingSelection == state) {
            // Selection render
            shader->setUniformValue(shader->MVP(), MVPMatrix);
            QVector4D itemColor = indexToSelectionColor(itemIndex++);
            itemColor.setW(customItemAlpha);
            itemColor /= 255.0f;
            shader->setUniformValue(shader->color(), itemColor);
            m_drawer->drawObject(shader, item->mesh());
        } else {
            // Depth render
            shader->setUniformValue(shader->MVP(), depthProjectionViewMatrix * modelMatrix);
            m_drawer->drawObject(shader, item->mesh());
        }
    }

    if (RenderingNormal == state) {
        glDisable(GL_TEXTURE_2D);
        glDisable(GL_BLEND);
    }
}

QT_END_NAMESPACE_DATAVISUALIZATION