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#include "fcurve_p.h"
#include <private/bezierevaluator_p.h>

#include <QtCore/qjsonarray.h>
#include <QtCore/qjsonobject.h>
#include <QtCore/QLatin1String>

QT_BEGIN_NAMESPACE

namespace Qt3DAnimation {
namespace Animation {

FCurve::FCurve()
    : m_rangeFinder(m_localTimes)
{
}

float FCurve::evaluateAtTime(float localTime) const
{
    // TODO: Implement extrapolation beyond first/last keyframes
    if (localTime < m_localTimes.first()) {
        return m_keyframes.first().value;
    } else if (localTime > m_localTimes.last()) {
        return m_keyframes.last().value;
    } else {
        // Find keyframes that sandwich the requested localTime
        int keyframe0 = m_rangeFinder.findLowerBound(localTime);

        BezierEvaluator evaluator(m_localTimes[keyframe0], m_keyframes[keyframe0],
                                  m_localTimes[keyframe0 + 1], m_keyframes[keyframe0 + 1]);
        return evaluator.valueForTime(localTime);
    }
}

float FCurve::startTime() const
{
    if (!m_localTimes.isEmpty())
        return m_localTimes.first();
    return 0.0f;
}

float FCurve::endTime() const
{
    if (!m_localTimes.isEmpty())
        return m_localTimes.last();
    return 0.0f;
}

void FCurve::appendKeyframe(float localTime, const Keyframe &keyframe)
{
    m_localTimes.append(localTime);
    m_keyframes.append(keyframe);
}

void FCurve::read(const QJsonObject &json)
{
    clearKeyframes();

    const QJsonArray keyframeArray = json[QLatin1String("keyFrames")].toArray();
    const int keyframeCount = keyframeArray.size();

    for (int i = 0; i < keyframeCount; ++i) {
        const QJsonObject keyframeData = keyframeArray.at(i).toObject();

        // Extract the keyframe local time and value
        const QJsonArray keyframeCoords = keyframeData[QLatin1String("coords")].toArray();
        float localTime = keyframeCoords.at(0).toDouble();

        Keyframe keyframe;
        keyframe.interpolation = QKeyFrame::BezierInterpolation;
        keyframe.value = keyframeCoords.at(1).toDouble();

        const QJsonArray leftHandle = keyframeData[QLatin1String("leftHandle")].toArray();
        keyframe.leftControlPoint[0] = leftHandle.at(0).toDouble();
        keyframe.leftControlPoint[1] = leftHandle.at(1).toDouble();

        const QJsonArray rightHandle = keyframeData[QLatin1String("rightHandle")].toArray();
        keyframe.rightControlPoint[0] = rightHandle.at(0).toDouble();
        keyframe.rightControlPoint[1] = rightHandle.at(1).toDouble();

        appendKeyframe(localTime, keyframe);
    }

    // TODO: Ensure beziers have no loops or cusps by scaling the control points
    // back so they do not interset.
}

void FCurve::setFromQChannelComponent(const QChannelComponent &qcc)
{
    clearKeyframes();

    for (const auto &frontendKeyFrame : qcc) {
        // Extract the keyframe local time and value
        const float localTime = frontendKeyFrame.coordinates()[0];

        Keyframe keyFrame;
        keyFrame.interpolation = frontendKeyFrame.interpolationType();
        keyFrame.value = frontendKeyFrame.coordinates()[1];
        keyFrame.leftControlPoint = frontendKeyFrame.leftControlPoint();
        keyFrame.rightControlPoint = frontendKeyFrame.rightControlPoint();
        appendKeyframe(localTime, keyFrame);
    }

    // TODO: Ensure beziers have no loops or cusps by scaling the control points
    // back so they do not interset.
}

void ChannelComponent::read(const QJsonObject &json)
{
    name = json[QLatin1String("channelComponentName")].toString();
    fcurve.read(json);
}

void ChannelComponent::setFromQChannelComponent(const QChannelComponent &qcc)
{
    name = qcc.name();
    fcurve.setFromQChannelComponent(qcc);
}

void Channel::read(const QJsonObject &json)
{
    name = json[QLatin1String("channelName")].toString();
    const QJsonArray channelComponentsArray = json[QLatin1String("channelComponents")].toArray();
    const int channelCount = channelComponentsArray.size();
    channelComponents.resize(channelCount);

    for (int i = 0; i < channelCount; ++i) {
        const QJsonObject channel = channelComponentsArray.at(i).toObject();
        channelComponents[i].read(channel);
    }
}

void Channel::setFromQChannel(const QChannel &qch)
{
    name = qch.name();
    channelComponents.resize(qch.channelComponentCount());
    int i = 0;
    for (const auto &frontendChannelComponent : qch)
        channelComponents[i++].setFromQChannelComponent(frontendChannelComponent);
}

} // namespace Animation
} // namespace Qt3DAnimation

QT_END_NAMESPACE