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#include "avfmediaplayermetadatacontrol.h"
#include "avfmediaplayersession.h"

#include <QtMultimedia/qmediametadata.h>

#import <AVFoundation/AVFoundation.h>

QT_USE_NAMESPACE

AVFMediaPlayerMetaDataControl::AVFMediaPlayerMetaDataControl(AVFMediaPlayerSession *session, QObject *parent)
    : QMetaDataReaderControl(parent)
    , m_session(session)
    , m_asset(nullptr)
{
    QObject::connect(m_session, SIGNAL(mediaStatusChanged(QMediaPlayer::MediaStatus)), this, SLOT(updateTags()));
}

AVFMediaPlayerMetaDataControl::~AVFMediaPlayerMetaDataControl()
{
#ifdef QT_DEBUG_AVF
    qDebug() << Q_FUNC_INFO;
#endif
}

bool AVFMediaPlayerMetaDataControl::isMetaDataAvailable() const
{
    return !m_tags.isEmpty();
}

bool AVFMediaPlayerMetaDataControl::isWritable() const
{
    return false;
}

QVariant AVFMediaPlayerMetaDataControl::metaData(const QString &key) const
{
    return m_tags.value(key);
}

QStringList AVFMediaPlayerMetaDataControl::availableMetaData() const
{
    return m_tags.keys();
}

static QString itemKey(AVMetadataItem *item)
{
    NSString *keyString = [item commonKey];

    if (keyString.length != 0) {
        if ([keyString isEqualToString:AVMetadataCommonKeyTitle]) {
            return QMediaMetaData::Title;
        } else if ([keyString isEqualToString: AVMetadataCommonKeySubject]) {
            return QMediaMetaData::SubTitle;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyDescription]) {
            return QMediaMetaData::Description;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyPublisher]) {
            return QMediaMetaData::Publisher;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyCreationDate]) {
            return QMediaMetaData::Date;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyType]) {
            return QMediaMetaData::MediaType;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyLanguage]) {
            return QMediaMetaData::Language;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyCopyrights]) {
            return QMediaMetaData::Copyright;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyAlbumName]) {
            return QMediaMetaData::AlbumTitle;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyAuthor]) {
            return QMediaMetaData::Author;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyArtist]) {
            return QMediaMetaData::ContributingArtist;
        } else if ([keyString isEqualToString: AVMetadataCommonKeyArtwork]) {
            return QMediaMetaData::PosterUrl;
        }
    }

    return QString();
}

void AVFMediaPlayerMetaDataControl::updateTags()
{
#ifdef QT_DEBUG_AVF
    qDebug() << Q_FUNC_INFO;
#endif
    AVAsset *currentAsset = static_cast<AVAsset*>(m_session->currentAssetHandle());

    //Don't read the tags from the same asset more than once
    if (currentAsset == m_asset)
        return;

    m_asset = currentAsset;

    QVariantMap oldTags = m_tags;
    //Since we've changed assets, clear old tags
    m_tags.clear();
    bool changed = false;

    // TODO: also process ID3, iTunes and QuickTime metadata

    NSArray *metadataItems = [currentAsset commonMetadata];
    for (AVMetadataItem* item in metadataItems) {
        const QString key = itemKey(item);
        if (!key.isEmpty()) {
            const QString value = QString::fromNSString([item stringValue]);
            if (!value.isNull()) {
                m_tags.insert(key, value);
                if (value != oldTags.value(key)) {
                    changed = true;
                    Q_EMIT metaDataChanged(key, value);
                }
            }
        }
    }

    if (oldTags.isEmpty() != m_tags.isEmpty()) {
        Q_EMIT metaDataAvailableChanged(!m_tags.isEmpty());
        changed = true;
    }

    if (changed)
        Q_EMIT metaDataChanged();
}