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#include "qm3uhandler.h"
#include <qmediaresource.h>
#include <QtCore/qiodevice.h>
#include <QtCore/qfileinfo.h>
#include <QtCore/qtextstream.h>
#include <QFile>
#include <QUrl>


class QM3uPlaylistReader : public QMediaPlaylistReader
{
public:
    QM3uPlaylistReader(QIODevice *device)
        :m_ownDevice(false), m_device(device), m_textStream(new QTextStream(m_device))
    {
        readItem();
    }

    QM3uPlaylistReader(const QUrl& location)
        :m_location(location), m_ownDevice(true)
    {
        QFile *f = new QFile(location.toLocalFile());
        if (f->open(QIODevice::ReadOnly | QIODevice::Text)) {
            m_device = f;
            m_textStream = new QTextStream(m_device);
            readItem();
        } else {
            delete f;
            m_device = 0;
            m_textStream = 0;
        }
    }

    virtual ~QM3uPlaylistReader()
    {
        if (m_ownDevice) {
            delete m_device;
        }
        delete m_textStream;
    }

    bool atEnd() const override
    {
        //we can't just use m_textStream->atEnd(),
        //for files with empty lines/comments at end
        return nextResource.isNull();
    }

    QMediaContent readItem() override
    {
        QMediaContent item;
        if (!nextResource.isNull())
            item = QMediaContent(nextResource);

        nextResource = QMediaContent();

        while (m_textStream && !m_textStream->atEnd()) {
            QString line = m_textStream->readLine().trimmed();
            if (line.isEmpty() || line[0] == '#' || line.size() > 4096)
                continue;

            QUrl fileUrl = QUrl::fromLocalFile(line);
            QUrl url(line);

            //m3u may contain url encoded entries or absolute/relative file names
            //prefer existing file if any
            QList<QUrl> candidates;
            if (!m_location.isEmpty()) {
                candidates << m_location.resolved(fileUrl);
                candidates << m_location.resolved(url);
            }
            candidates << fileUrl;
            candidates << url;

            for (const QUrl &candidate : qAsConst(candidates)) {
                if (QFile::exists(candidate.toLocalFile())) {
                    nextResource = candidate;
                    break;
                }
            }

            if (nextResource.isNull()) {
                //assume the relative urls are file names, not encoded urls if m3u is local file
                if (!m_location.isEmpty() && url.isRelative()) {
                    if (m_location.scheme() == QLatin1String("file"))
                        nextResource = m_location.resolved(fileUrl);
                    else
                        nextResource = m_location.resolved(url);
                } else {
                    nextResource = QMediaContent(QUrl::fromUserInput(line));
                }
            }

            break;
        }

        return item;
    }

    void close() override
    {
    }

private:
    QUrl m_location;
    bool m_ownDevice;
    QIODevice *m_device;
    QTextStream *m_textStream;
    QMediaContent nextResource;
};

class QM3uPlaylistWriter : public QMediaPlaylistWriter
{
public:
    QM3uPlaylistWriter(QIODevice *device)
        :m_device(device), m_textStream(new QTextStream(m_device))
    {
    }

    virtual ~QM3uPlaylistWriter()
    {
        delete m_textStream;
    }

    bool writeItem(const QMediaContent& item) override
    {
        *m_textStream << item.request().url().toString() << Qt::endl;
        return true;
    }

    void close() override
    {
    }

private:
    QIODevice *m_device;
    QTextStream *m_textStream;
};


QM3uPlaylistPlugin::QM3uPlaylistPlugin(QObject *parent)
    :QMediaPlaylistIOPlugin(parent)
{
}

QM3uPlaylistPlugin::~QM3uPlaylistPlugin()
{
}

bool QM3uPlaylistPlugin::canRead(QIODevice *device, const QByteArray &format) const
{
    return device->isReadable() && (format == "m3u" || format == "m3u8" || format.isEmpty());
}

bool QM3uPlaylistPlugin::canRead(const QUrl& location, const QByteArray &format) const
{
    if (!QFileInfo(location.toLocalFile()).isReadable())
        return false;

    if (format == "m3u" || format == "m3u8")
        return true;

    if (!format.isEmpty())
        return false;
    QString localFile = location.toLocalFile().toLower();
    return localFile.endsWith(QLatin1String("m3u")) || localFile.endsWith(QLatin1String("m3u8"));
}

bool QM3uPlaylistPlugin::canWrite(QIODevice *device, const QByteArray &format) const
{
    return device->isOpen() && device->isWritable() && (format == "m3u" || format == "m3u8");
}

QMediaPlaylistReader *QM3uPlaylistPlugin::createReader(QIODevice *device, const QByteArray &format)
{
    Q_UNUSED(format);
    return new QM3uPlaylistReader(device);
}

QMediaPlaylistReader *QM3uPlaylistPlugin::createReader(const QUrl& location, const QByteArray &format)
{
    Q_UNUSED(format);
    return new QM3uPlaylistReader(location);
}

QMediaPlaylistWriter *QM3uPlaylistPlugin::createWriter(QIODevice *device, const QByteArray &format)
{
    Q_UNUSED(format);
    return new QM3uPlaylistWriter(device);
}