/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtQuick module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qquickspritesequence_p.h"
#include "qquickspritesequence_p_p.h"
#include "qquicksprite_p.h"
#include "qquickspriteengine_p.h"
#include <QtQuick/private/qsgcontext_p.h>
#include <private/qsgadaptationlayer_p.h>
#include <QtQuick/qsgnode.h>
#include <QtQuick/qsgtexturematerial.h>
#include <QtQuick/qsgtexture.h>
#include <QtQuick/qquickwindow.h>
#include <QtQml/qqmlinfo.h>
#include <QFile>
#include <cmath>
#include <qmath.h>
#include <QDebug>

QT_BEGIN_NAMESPACE

/*!
    \qmltype SpriteSequence
    \instantiates QQuickSpriteSequence
    \inqmlmodule QtQuick
    \ingroup qtquick-visual-utility
    \inherits Item
    \brief Draws a sprite animation.

    SpriteSequence renders and controls a list of animations defined
    by \l Sprite types.

    For full details, see the \l{Sprite Animations} overview.
    \sa {Sprite animations with SpriteSequence}
*/
/*!
    \qmlproperty bool QtQuick::SpriteSequence::running

    Whether the sprite is animating or not.

    Default is \c true.
*/
/*!
    \qmlproperty bool QtQuick::SpriteSequence::interpolate

    If \c true, interpolation will occur between sprite frames to make the
    animation appear smoother.

    Default is \c true.
*/
/*!
    \qmlproperty string QtQuick::SpriteSequence::currentSprite

    The name of the \l Sprite that is currently animating.
*/
/*!
    \qmlproperty string QtQuick::SpriteSequence::goalSprite

    The name of the \l Sprite that the animation should move to.

    Sprite states have defined durations and transitions between them; setting \c goalSprite
    will cause it to disregard any path weightings (including \c 0) and head down the path
    that will reach the \c goalSprite quickest (fewest animations). It will pass through
    intermediate states on that path, and animate them for their duration.

    If it is possible to return to the \c goalSprite from the starting point of the \c goalSprite,
    it will continue to do so until \c goalSprite is set to \c "" or an unreachable state.
*/
/*! \qmlmethod QtQuick::SpriteSequence::jumpTo(string sprite)

    This function causes the SpriteSequence to jump to the specified \a sprite immediately;
    intermediate sprites are not played.
*/
/*!
    \qmlproperty list<Sprite> QtQuick::SpriteSequence::sprites

    The sprite or sprites to draw. Sprites will be scaled to the size of this item.
*/

//TODO: Implicitly size element to size of first sprite?
QQuickSpriteSequence::QQuickSpriteSequence(QQuickItem *parent) :
    QQuickItem(*(new QQuickSpriteSequencePrivate), parent)
{
    setFlag(ItemHasContents);
    connect(this, SIGNAL(runningChanged(bool)),
            this, SLOT(update()));
}

void QQuickSpriteSequence::jumpTo(const QString &sprite)
{
    Q_D(QQuickSpriteSequence);
    if (!d->m_spriteEngine)
        return;
    d->m_spriteEngine->setGoal(d->m_spriteEngine->stateIndex(sprite), 0, true);
}

void QQuickSpriteSequence::setGoalSprite(const QString &sprite)
{
    Q_D(QQuickSpriteSequence);
    if (d->m_goalState != sprite){
        d->m_goalState = sprite;
        emit goalSpriteChanged(sprite);
        if (d->m_spriteEngine)
            d->m_spriteEngine->setGoal(d->m_spriteEngine->stateIndex(sprite));
    }
}

void QQuickSpriteSequence::setRunning(bool arg)
{
    Q_D(QQuickSpriteSequence);
    if (d->m_running != arg) {
        d->m_running = arg;
        Q_EMIT runningChanged(arg);
    }
}

void QQuickSpriteSequence::setInterpolate(bool arg)
{
    Q_D(QQuickSpriteSequence);
    if (d->m_interpolate != arg) {
        d->m_interpolate = arg;
        Q_EMIT interpolateChanged(arg);
    }
}

QQmlListProperty<QQuickSprite> QQuickSpriteSequence::sprites()
{
    Q_D(QQuickSpriteSequence);
    return QQmlListProperty<QQuickSprite>(this, &d->m_sprites, spriteAppend, spriteCount, spriteAt, spriteClear);
}

bool QQuickSpriteSequence::running() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_running;
}

bool QQuickSpriteSequence::interpolate() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_interpolate;
}

QString QQuickSpriteSequence::goalSprite() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_goalState;
}

QString QQuickSpriteSequence::currentSprite() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_curState;
}

void QQuickSpriteSequence::createEngine()
{
    Q_D(QQuickSpriteSequence);
    //TODO: delay until component complete
    if (d->m_spriteEngine)
        delete d->m_spriteEngine;
    if (d->m_sprites.count()) {
        d->m_spriteEngine = new QQuickSpriteEngine(d->m_sprites, this);
        if (!d->m_goalState.isEmpty())
            d->m_spriteEngine->setGoal(d->m_spriteEngine->stateIndex(d->m_goalState));
    } else {
        d->m_spriteEngine = nullptr;
    }
    reset();
}

QSGSpriteNode *QQuickSpriteSequence::initNode()
{
    Q_D(QQuickSpriteSequence);

    if (!d->m_spriteEngine) {
        qmlWarning(this) << "No sprite engine...";
        return nullptr;
    } else if (d->m_spriteEngine->status() == QQuickPixmap::Null) {
        d->m_spriteEngine->startAssemblingImage();
        update();//Schedule another update, where we will check again
        return nullptr;
    } else if (d->m_spriteEngine->status() == QQuickPixmap::Loading) {
        update();//Schedule another update, where we will check again
        return nullptr;
    }

    QImage image = d->m_spriteEngine->assembledImage(d->sceneGraphRenderContext()->maxTextureSize());
    if (image.isNull())
        return nullptr;

    QSGSpriteNode *node = d->sceneGraphContext()->createSpriteNode();

    d->m_sheetSize = QSize(image.size() / image.devicePixelRatioF());
    node->setTexture(window()->createTextureFromImage(image));
    d->m_spriteEngine->start(0);
    node->setTime(0.0f);
    node->setSourceA(QPoint(d->m_spriteEngine->spriteX(), d->m_spriteEngine->spriteY()));
    node->setSourceB(QPoint(d->m_spriteEngine->spriteX(), d->m_spriteEngine->spriteY()));
    node->setSpriteSize(QSize(d->m_spriteEngine->spriteWidth(), d->m_spriteEngine->spriteHeight()));
    node->setSheetSize(d->m_sheetSize);
    node->setSize(QSizeF(width(), height()));

    d->m_curState = d->m_spriteEngine->state(d->m_spriteEngine->curState())->name();
    emit currentSpriteChanged(d->m_curState);
    d->m_timestamp.start();
    return node;
}

void QQuickSpriteSequence::reset()
{
    Q_D(QQuickSpriteSequence);
    d->m_pleaseReset = true;
}

QSGNode *QQuickSpriteSequence::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
{
    Q_D(QQuickSpriteSequence);

    if (d->m_pleaseReset) {
        delete oldNode;

        oldNode = nullptr;
        d->m_pleaseReset = false;
    }

    QSGSpriteNode *node = static_cast<QSGSpriteNode *>(oldNode);
    if (!node)
        node = initNode();

    if (node)
        prepareNextFrame(node);

    if (d->m_running) {
        update();
    }

    return node;
}

void QQuickSpriteSequence::prepareNextFrame(QSGSpriteNode *node)
{
    Q_D(QQuickSpriteSequence);

    uint timeInt = d->m_timestamp.elapsed();
    qreal time =  timeInt / 1000.;

    //Advance State
    d->m_spriteEngine->updateSprites(timeInt);
    if (d->m_curStateIdx != d->m_spriteEngine->curState()) {
        d->m_curStateIdx = d->m_spriteEngine->curState();
        d->m_curState = d->m_spriteEngine->state(d->m_spriteEngine->curState())->name();
        emit currentSpriteChanged(d->m_curState);
        d->m_curFrame= -1;
    }

    //Advance Sprite
    qreal animT = d->m_spriteEngine->spriteStart()/1000.0;
    qreal frameCount = d->m_spriteEngine->spriteFrames();
    qreal frameDuration = d->m_spriteEngine->spriteDuration()/frameCount;
    double frameAt;
    qreal progress;
    if (frameDuration > 0) {
        qreal frame = (time - animT)/(frameDuration / 1000.0);
        frame = qBound(qreal(0.0), frame, frameCount - qreal(1.0));//Stop at count-1 frames until we have between anim interpolation
        progress = std::modf(frame,&frameAt);
    } else {
        d->m_curFrame++;
        if (d->m_curFrame >= frameCount){
            d->m_curFrame = 0;
            d->m_spriteEngine->advance();
        }
        frameAt = d->m_curFrame;
        progress = 0;
    }
    if (d->m_spriteEngine->sprite()->reverse())
        frameAt = (d->m_spriteEngine->spriteFrames() - 1) - frameAt;
    int y = d->m_spriteEngine->spriteY();
    int w = d->m_spriteEngine->spriteWidth();
    int h = d->m_spriteEngine->spriteHeight();
    int x1 = d->m_spriteEngine->spriteX();
    x1 += frameAt * w;
    int x2 = x1;
    if (frameAt < (frameCount-1))
        x2 += w;

    node->setSourceA(QPoint(x1, y));
    node->setSourceB(QPoint(x2, y));
    node->setSpriteSize(QSize(w, h));
    node->setTime(d->m_interpolate ? progress : 0.0);
    node->setSize(QSizeF(width(), height()));
    node->setFiltering(smooth() ? QSGTexture::Linear : QSGTexture::Nearest);
    node->update();
}

QT_END_NAMESPACE

#include "moc_qquickspritesequence_p.cpp"
