/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** 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 Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/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 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qplatformdefs.h"

#include "qbitmap.h"
#include "qdrag.h"
#include "qpixmap.h"
#include "qevent.h"
#include "qfile.h"
#include "qtextcodec.h"
#include "qguiapplication.h"
#include "qpoint.h"
#include "qbuffer.h"
#include "qimage.h"
#include "qpainter.h"
#include "qregexp.h"
#include "qdir.h"
#include "qdnd_p.h"
#include "qimagereader.h"
#include "qimagewriter.h"
#include "qdebug.h"
#include <ctype.h>
#include <qpa/qplatformintegration.h>
#include <qpa/qplatformdrag.h>

#include <private/qguiapplication_p.h>

#ifndef QT_NO_DRAGANDDROP

QT_BEGIN_NAMESPACE

// the universe's only drag manager
QDragManager *QDragManager::m_instance = 0;


QDragManager::QDragManager()
    : QObject(qApp), m_platformDropData(0), m_currentDropTarget(0),
      m_platformDrag(QGuiApplicationPrivate::platformIntegration()->drag()),
      m_object(0)
{
    Q_ASSERT(!m_instance);

    if (m_platformDrag)
        m_platformDropData = m_platformDrag->platformDropData();
}


QDragManager::~QDragManager()
{
    m_instance = 0;
}

QDragManager *QDragManager::self()
{
    if (!m_instance && !QGuiApplication::closingDown())
        m_instance = new QDragManager;
    return m_instance;
}

QObject *QDragManager::source() const
{
    if (m_object)
        return m_object->source();
    return 0;
}

void QDragManager::setCurrentTarget(QObject *target, bool dropped)
{
    if (m_currentDropTarget == target)
        return;

    m_currentDropTarget = target;
    if (!dropped && m_object) {
        m_object->d_func()->target = target;
        emit m_object->targetChanged(target);
    }
}

QObject *QDragManager::currentTarget() const
{
    return m_currentDropTarget;
}

Qt::DropAction QDragManager::drag(QDrag *o)
{
    if (!o || m_object == o)
         return Qt::IgnoreAction;

    if (!m_platformDrag || !o->source()) {
        o->deleteLater();
        return Qt::IgnoreAction;
    }

    if (m_object) {
        qWarning("QDragManager::drag in possibly invalid state");
        return Qt::IgnoreAction;
    }

    m_object = o;

    m_object->d_func()->target = 0;

    QGuiApplicationPrivate::instance()->notifyDragStarted(o);
    const Qt::DropAction result = m_platformDrag->drag(m_object);
    m_object = 0;
    if (!m_platformDrag->ownsDragObject())
        o->deleteLater();
    return result;
}

#endif // QT_NO_DRAGANDDROP

#if !(defined(QT_NO_DRAGANDDROP) && defined(QT_NO_CLIPBOARD))

static QStringList imageReadMimeFormats()
{
    QStringList formats;
    QList<QByteArray> imageFormats = QImageReader::supportedImageFormats();
    for (int i = 0; i < imageFormats.size(); ++i) {
        QString format = QLatin1String("image/");
        format += QString::fromLatin1(imageFormats.at(i).toLower());
        formats.append(format);
    }

    //put png at the front because it is best
    int pngIndex = formats.indexOf(QLatin1String("image/png"));
    if (pngIndex != -1 && pngIndex != 0)
        formats.move(pngIndex, 0);

    return formats;
}


static QStringList imageWriteMimeFormats()
{
    QStringList formats;
    QList<QByteArray> imageFormats = QImageWriter::supportedImageFormats();
    for (int i = 0; i < imageFormats.size(); ++i) {
        QString format = QLatin1String("image/");
        format += QString::fromLatin1(imageFormats.at(i).toLower());
        formats.append(format);
    }

    //put png at the front because it is best
    int pngIndex = formats.indexOf(QLatin1String("image/png"));
    if (pngIndex != -1 && pngIndex != 0)
        formats.move(pngIndex, 0);

    return formats;
}

QInternalMimeData::QInternalMimeData()
    : QMimeData()
{
}

QInternalMimeData::~QInternalMimeData()
{
}

bool QInternalMimeData::hasFormat(const QString &mimeType) const
{
    bool foundFormat = hasFormat_sys(mimeType);
    if (!foundFormat && mimeType == QLatin1String("application/x-qt-image")) {
        QStringList imageFormats = imageReadMimeFormats();
        for (int i = 0; i < imageFormats.size(); ++i) {
            if ((foundFormat = hasFormat_sys(imageFormats.at(i))))
                break;
        }
    }
    return foundFormat;
}

QStringList QInternalMimeData::formats() const
{
    QStringList realFormats = formats_sys();
    if (!realFormats.contains(QLatin1String("application/x-qt-image"))) {
        QStringList imageFormats = imageReadMimeFormats();
        for (int i = 0; i < imageFormats.size(); ++i) {
            if (realFormats.contains(imageFormats.at(i))) {
                realFormats += QLatin1String("application/x-qt-image");
                break;
            }
        }
    }
    return realFormats;
}

QVariant QInternalMimeData::retrieveData(const QString &mimeType, QVariant::Type type) const
{
    QVariant data = retrieveData_sys(mimeType, type);
    if (mimeType == QLatin1String("application/x-qt-image")) {
        if (data.isNull() || (data.type() == QVariant::ByteArray && data.toByteArray().isEmpty())) {
            // try to find an image
            QStringList imageFormats = imageReadMimeFormats();
            for (int i = 0; i < imageFormats.size(); ++i) {
                data = retrieveData_sys(imageFormats.at(i), type);
                if (data.isNull() || (data.type() == QVariant::ByteArray && data.toByteArray().isEmpty()))
                    continue;
                break;
            }
        }
        // we wanted some image type, but all we got was a byte array. Convert it to an image.
        if (data.type() == QVariant::ByteArray
            && (type == QVariant::Image || type == QVariant::Pixmap || type == QVariant::Bitmap))
            data = QImage::fromData(data.toByteArray());

    } else if (mimeType == QLatin1String("application/x-color") && data.type() == QVariant::ByteArray) {
        QColor c;
        QByteArray ba = data.toByteArray();
        if (ba.size() == 8) {
            ushort * colBuf = (ushort *)ba.data();
            c.setRgbF(qreal(colBuf[0]) / qreal(0xFFFF),
                      qreal(colBuf[1]) / qreal(0xFFFF),
                      qreal(colBuf[2]) / qreal(0xFFFF),
                      qreal(colBuf[3]) / qreal(0xFFFF));
            data = c;
        } else {
            qWarning("Qt: Invalid color format");
        }
    } else if (data.type() != type && data.type() == QVariant::ByteArray) {
        // try to use mime data's internal conversion stuf.
        QInternalMimeData *that = const_cast<QInternalMimeData *>(this);
        that->setData(mimeType, data.toByteArray());
        data = QMimeData::retrieveData(mimeType, type);
        that->clear();
    }
    return data;
}

bool QInternalMimeData::canReadData(const QString &mimeType)
{
    return imageReadMimeFormats().contains(mimeType);
}

// helper functions for rendering mimedata to the system, this is needed because QMimeData is in core.
QStringList QInternalMimeData::formatsHelper(const QMimeData *data)
{
    QStringList realFormats = data->formats();
    if (realFormats.contains(QLatin1String("application/x-qt-image"))) {
        // add all supported image formats
        QStringList imageFormats = imageWriteMimeFormats();
        for (int i = 0; i < imageFormats.size(); ++i) {
            if (!realFormats.contains(imageFormats.at(i)))
                realFormats.append(imageFormats.at(i));
        }
    }
    return realFormats;
}

bool QInternalMimeData::hasFormatHelper(const QString &mimeType, const QMimeData *data)
{

    bool foundFormat = data->hasFormat(mimeType);
    if (!foundFormat) {
        if (mimeType == QLatin1String("application/x-qt-image")) {
            // check all supported image formats
            QStringList imageFormats = imageWriteMimeFormats();
            for (int i = 0; i < imageFormats.size(); ++i) {
                if ((foundFormat = data->hasFormat(imageFormats.at(i))))
                    break;
            }
        } else if (mimeType.startsWith(QLatin1String("image/"))) {
            return data->hasImage() && imageWriteMimeFormats().contains(mimeType);
        }
    }
    return foundFormat;
}

QByteArray QInternalMimeData::renderDataHelper(const QString &mimeType, const QMimeData *data)
{
    QByteArray ba;
    if (mimeType == QLatin1String("application/x-color")) {
        /* QMimeData can only provide colors as QColor or the name
           of a color as a QByteArray or a QString. So we need to do
           the conversion to application/x-color here.
           The application/x-color format is :
           type: application/x-color
           format: 16
           data[0]: red
           data[1]: green
           data[2]: blue
           data[3]: opacity
        */
        ba.resize(8);
        ushort * colBuf = (ushort *)ba.data();
        QColor c = qvariant_cast<QColor>(data->colorData());
        colBuf[0] = ushort(c.redF() * 0xFFFF);
        colBuf[1] = ushort(c.greenF() * 0xFFFF);
        colBuf[2] = ushort(c.blueF() * 0xFFFF);
        colBuf[3] = ushort(c.alphaF() * 0xFFFF);
    } else {
        ba = data->data(mimeType);
        if (ba.isEmpty()) {
            if (mimeType == QLatin1String("application/x-qt-image") && data->hasImage()) {
                QImage image = qvariant_cast<QImage>(data->imageData());
                QBuffer buf(&ba);
                buf.open(QBuffer::WriteOnly);
                // would there not be PNG ??
                image.save(&buf, "PNG");
            } else if (mimeType.startsWith(QLatin1String("image/")) && data->hasImage()) {
                QImage image = qvariant_cast<QImage>(data->imageData());
                QBuffer buf(&ba);
                buf.open(QBuffer::WriteOnly);
                image.save(&buf, mimeType.mid(mimeType.indexOf(QLatin1Char('/')) + 1).toLatin1().toUpper());
            }
        }
    }
    return ba;
}

#endif // QT_NO_DRAGANDDROP && QT_NO_CLIPBOARD

QT_END_NAMESPACE
