/****************************************************************************
**
** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt3D module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL3$
** 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
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** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
** Software Foundation and appearing in the file LICENSE.GPL included in
** the packaging of this file. Please review the following information to
** ensure the GNU General Public License version 2.0 requirements will be
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** $QT_END_LICENSE$
**
****************************************************************************/

#include "qshaderprogram.h"
#include "qshaderprogram_p.h"
#include <Qt3DCore/qscenepropertychange.h>
#include <Qt3DCore/private/qurlhelper_p.h>
#include <QDebug>
#include <QFile>
#include <QUrl>

QT_BEGIN_NAMESPACE

namespace Qt3D {

/*!
    \class Qt3D::QShaderProgramPrivate
    \internal
*/
QShaderProgramPrivate::QShaderProgramPrivate()
    : QNodePrivate()
{
}

void QShaderProgram::copy(const QNode *ref)
{
    QNode::copy(ref);
    const QShaderProgram *prog = static_cast<const QShaderProgram*>(ref);

    d_func()->m_vertexShaderCode = prog->d_func()->m_vertexShaderCode;
    d_func()->m_tessControlShaderCode = prog->d_func()->m_tessControlShaderCode;
    d_func()->m_tessEvalShaderCode = prog->d_func()->m_tessEvalShaderCode;
    d_func()->m_geometryShaderCode = prog->d_func()->m_geometryShaderCode;
    d_func()->m_fragmentShaderCode = prog->d_func()->m_fragmentShaderCode;
    d_func()->m_computeShaderCode = prog->d_func()->m_computeShaderCode;
}

QShaderProgram::QShaderProgram(QNode *parent)
    : QNode(*new QShaderProgramPrivate, parent)
{
}

/*! \internal */
QShaderProgram::QShaderProgram(QShaderProgramPrivate &dd, QNode *parent)
    : QNode(dd, parent)
{
}

/*!
 * Sets the vertexShader from raw data in \a vertexShader.
 */
void QShaderProgram::setVertexShaderCode(const QByteArray &vertexShaderCode)
{
    Q_D(QShaderProgram);
    if (vertexShaderCode != d->m_vertexShaderCode) {
        d->m_vertexShaderCode = vertexShaderCode;
        emit vertexShaderCodeChanged();
    }
}

QByteArray QShaderProgram::vertexShaderCode() const
{
    Q_D(const QShaderProgram);
    return d->m_vertexShaderCode;
}

void QShaderProgram::setTessellationControlShaderCode(const QByteArray &tessellationControlShaderCode)
{
    Q_D(QShaderProgram);
    if (tessellationControlShaderCode != d->m_tessControlShaderCode) {
        d->m_tessControlShaderCode = tessellationControlShaderCode;
        d->notifyPropertyChange(QByteArrayLiteral("tessellationControlSourceCode"),
                                tessellationControlShaderCode);
        emit tessellationControlShaderCodeChanged();
    }
}

QByteArray QShaderProgram::tessellationControlShaderCode() const
{
    Q_D(const QShaderProgram);
    return d->m_tessControlShaderCode;
}

void QShaderProgram::setTessellationEvaluationShaderCode(const QByteArray &tessellationEvaluationShaderCode)
{
    Q_D(QShaderProgram);
    if (tessellationEvaluationShaderCode != d->m_tessEvalShaderCode) {
        d->m_tessEvalShaderCode = tessellationEvaluationShaderCode;
        emit tessellationEvaluationShaderCodeChanged();
    }
}

QByteArray QShaderProgram::tessellationEvaluationShaderCode() const
{
    Q_D(const QShaderProgram);
    return d->m_tessEvalShaderCode;
}

void QShaderProgram::setGeometryShaderCode(const QByteArray &geometryShaderCode)
{
    Q_D(QShaderProgram);
    if (geometryShaderCode != d->m_geometryShaderCode) {
        d->m_geometryShaderCode = geometryShaderCode;
        emit geometryShaderCodeChanged();
    }
}

QByteArray QShaderProgram::geometryShaderCode() const
{
    Q_D(const QShaderProgram);
    return d->m_geometryShaderCode;
}

/*!
 * Sets the fragmentShader from raw data in \a fragmentShader.
 */
void QShaderProgram::setFragmentShaderCode(const QByteArray &fragmentShaderCode)
{
    Q_D(QShaderProgram);
    if (fragmentShaderCode != d->m_fragmentShaderCode) {
        d->m_fragmentShaderCode = fragmentShaderCode;
        emit fragmentShaderCodeChanged();
    }
}

QByteArray QShaderProgram::fragmentShaderCode() const
{
    Q_D(const QShaderProgram);
    return d->m_fragmentShaderCode;
}

void QShaderProgram::setComputeShaderCode(const QByteArray &computeShaderCode)
{
    Q_D(QShaderProgram);
    if (computeShaderCode != d->m_computeShaderCode) {
        d->m_computeShaderCode = computeShaderCode;
        emit computeShaderCodeChanged();
    }
}

QByteArray QShaderProgram::computeShaderCode() const
{
    Q_D(const QShaderProgram);
    return d->m_computeShaderCode;
}

void QShaderProgram::setShaderCode(ShaderType type, const QByteArray &shaderCode)
{
    switch (type) {
    case Vertex:
        setVertexShaderCode(shaderCode);
        break;
    case TessellationControl:
        setTessellationControlShaderCode(shaderCode);
        break;
    case TessellationEvaluation:
        setTessellationEvaluationShaderCode(shaderCode);
        break;
    case Geometry:
        setGeometryShaderCode(shaderCode);
        break;
    case Fragment:
        setFragmentShaderCode(shaderCode);
        break;
    case Compute:
        setComputeShaderCode(shaderCode);
        break;
    default:
        Q_UNREACHABLE();
    }
}

QByteArray QShaderProgram::shaderCode(ShaderType type) const
{
    Q_D(const QShaderProgram);
    switch (type) {
    case Vertex:
        return d->m_vertexShaderCode;
    case TessellationControl:
        return d->m_tessControlShaderCode;
    case TessellationEvaluation:
        return d->m_tessEvalShaderCode;
    case Geometry:
        return d->m_geometryShaderCode;
    case Fragment:
        return d->m_fragmentShaderCode;
    case Compute:
        return d->m_computeShaderCode;
    default:
        Q_UNREACHABLE();
    }
}

QByteArray QShaderProgram::loadSource(const QUrl &sourceUrl)
{
    // TO DO: Handle remote path
    QString filePath = QUrlHelper::urlToLocalFileOrQrc(sourceUrl);

    QFile f(filePath);
    if (!f.exists())
        qWarning() << "Couldn't read shader source file:" << sourceUrl;
    else
        f.open(QIODevice::ReadOnly | QIODevice::Text);
    return f.readAll();
}

} // of namespace Qt3D

QT_END_NAMESPACE