linux-wallpaperengine-kde/src/WallpaperEngine/Media/MediaSource.h

#pragma once

#include <chrono>
#include <functional>
#include <map>
#include <string>

namespace WallpaperEngine::Media {
class MediaSource {
public:
    enum PlaybackState {
	Stopped = 0,
	Playing = 1,
	Paused = 2,
    };

    struct MediaInfo {
	PlaybackState playbackState;
	std::string title;
	std::string artist;
	std::string album;
	std::optional<std::string> url;
	double duration;
	double position;
	bool available;
    };

    explicit MediaSource (std::chrono::milliseconds updateInterval);
    virtual ~MediaSource ();

    virtual void update ();

    /**
     * @param listener The callback to call when media info changes
     *
     * @return A function that can be called to remove the listener
     */
    std::function<void ()> addMetadataListener (std::function<void (const MediaInfo&)> listener);
    /**
     * @param listener The callback to call when media info changes
     *
     * @return A function that can be called to remove the listener
     */
    std::function<void ()> addAlbumArtListener (std::function<void (const MediaInfo&)> listener);

    [[nodiscard]] const MediaInfo& getMediaInfo () const { return m_mediaInfo; }

protected:
    void fireMetadataListeners ();
    void fireAlbumArtListeners ();
    virtual void performUpdate () = 0;

    std::shared_ptr<bool> m_aliveFlag;
    uint32_t m_metadataListenerId = 0;
    std::map<uint32_t, std::function<void (MediaInfo&)>> m_metadataListeners;
    uint32_t m_albumArtListenerId = 0;
    std::map<uint32_t, std::function<void (MediaInfo&)>> m_albumArtListeners;
    MediaInfo m_mediaInfo;
    std::chrono::milliseconds m_updateInterval;
    std::chrono::time_point<std::chrono::steady_clock> m_nextUpdate;
};
}