/*
    Copyright (C) 2007 Matthias Kretz <kretz@kde.org>
    Copyright (C) 2011 Harald Sitter <sitter@kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) version 3, or any
    later version accepted by the membership of KDE e.V. (or its
    successor approved by the membership of KDE e.V.), Nokia Corporation
    (or its successors, if any) and the KDE Free Qt Foundation, which shall
    act as a proxy defined in Section 6 of version 3 of the license.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library.  If not, see <http://www.gnu.org/licenses/>.

*/

#ifndef PHONON_MEDIACONTROLLER_H
#define PHONON_MEDIACONTROLLER_H

#include "phonon_export.h"
#include "objectdescription.h"

#include <QObject>
#include <QtGlobal>


#ifndef QT_NO_PHONON_MEDIACONTROLLER

namespace Phonon
{
class MediaControllerPrivate;
class MediaObject;

/** \class MediaController mediacontroller.h phonon/MediaController
 * \brief Controls optional features of a media file/device like title, chapter, angle.
 *
 * \ingroup Playback
 * \author Matthias Kretz <kretz@kde.org>
 */
class PHONON_EXPORT MediaController : public QObject
{
    Q_OBJECT
    Q_FLAGS(Features)
    public:
        enum Feature {
            /**
             * In the VOB (DVD) format, it is possible to give several video streams
             * of the same scene, each of which displays the scene from a different
             * angle. The DVD viewer can then change between these angles.
             */
            Angles = 1,
            /**
             * In the VOB format, chapters are points in a single video stream
             * that can be played and seeked to separately.
             */
            Chapters = 2,
            /**
             * In the VOB format, navigations are menus to quickly navigate
             * to content.
             */
            Navigations = 3,
            /**
             * On a CD, a title is a separate sound track. On DVD, a title is a
             * separate VOB file (i.e. usually a different video entity).
             */
            Titles = 4,
            /**
             * Subtitles for videos.
             */
            Subtitles = 5,
            /**
             * Audio channel/track setting for sources with multiple tracks.
             * This can be a DVD or a regular file based container such as MKV or MP4.
             */
            AudioChannels = 6
        };
        Q_DECLARE_FLAGS(Features, Feature)

        enum NavigationMenu {
            RootMenu,     /** < Root/main menu. */
            TitleMenu,    /** < Title Menu to access different titles on the media source.
                                The title menu is usually where one would select
                                the episode of a TV series DVD. It can be equal to
                                the main menu but does not need to be. */
            AudioMenu,    /** < Audio menu for language (and sometimes also subtitle)
                                settings etc. */
            SubtitleMenu, /** < Subtitle menu. Usually this represents the same menu
                                as AudioMenu or is not present at all (in which case
                                subtitle settings are probably also in the AudioMenu). */
            ChapterMenu,  /** < Chapter menu for chapter selection. */
            AngleMenu     /** < Angle menu. Rarely supported on any media source. */
        };

        MediaController(MediaObject *parent);
        ~MediaController() override;

        Features supportedFeatures() const;

        int availableAngles() const;
        int currentAngle() const;

        int availableChapters() const;
        int currentChapter() const;

        /**
         * Translates a NavigationMenu enum to a string you can use in your GUI.
         * Please note that keyboard shortucts will not be present in the returned
         * String, therefore it is probably not a good idea to use this function
         * if you are providing keyboard shortcuts for every other clickable.
         *
         * Please note that RootMenu has the string representation "Main Menu" as
         * root is a rather technical term when talking about menus.
         *
         * Example:
         * \code
         * QString s = Phonon::MediaController::navigationMenuToString(MenuMain);
         * // s now contains "Main Menu"
         * \endcode
         *
         * \returns the QString representation of the menu
         */
        static QString navigationMenuToString(NavigationMenu menu);

        /**
         * Get the list of currently available menus for the present media source.
         *
         * The list is always ordered by occurrence in the NavgiationMenu enum.
         * Should you wish to use a different order in your application you will
         * have to make appropriate changes.
         *
         * \returns list of available menus (supported by backend and media source).
         *
         * \see navigationMenuToString()
         */
        QList<NavigationMenu> availableMenus() const;

        int availableTitles() const;
        int currentTitle() const;

        bool autoplayTitles() const;

        /**
         * Returns the selected audio stream.
         *
         * \see availableAudioChannels
         * \see setCurrentAudioChannel
         */
        AudioChannelDescription currentAudioChannel() const;

        /**
         * Returns the selected subtitle stream.
         *
         * \see availableSubtitles
         * \see setCurrentSubtitle
         */
        SubtitleDescription currentSubtitle() const;

        /**
         * Subtitle auto-detection transparently tries to find a subtitle file
         * for the current MediaSource and will automatically select a possible
         * match. Detected subtitles are added to the regular subtitle
         * descriptions, allowing the user to deactivate it manually or switch
         * to another detected file.
         *
         * Matching method depends on the backend in use and may either be
         * driven by a backend or even subsystem implementation. Consequently
         * different backends may not give the same results. At any rate all
         * algorithms are supposed to give as accurate as possible matches.
         * Should you require reproducible matching across backends you should
         * deactivate auto-detection entirely and instead do the lookup yourself
         * and set the desired file using setCurrentSubtitle(QUrl); the file
         * will still be added to the subtitledescriptions model.
         *
         * \note Auto-detection is always activate so long as the backend supports it.
         *
         * \returns \c true if subtitles are autodetected, otherwise \c false is
         * returned.
         *
         * \see setSubtitleAutodetect
         * \since 4.7.0
         */
        bool subtitleAutodetect() const;

        /**
         * Returns the encoding used to render subtitles
         *
         * \see setSubtitleEncoding
         * \since 4.7.0
         */
        QString subtitleEncoding() const;

        /**
         * Returns the font used to render subtitles
         *
         * \see setSubtitleFont
         * \see QApplication::setFont
         * \since 4.7.0
         */
        QFont subtitleFont() const;

        /**
         * Returns the audio streams that can be selected by the user. The
         * strings can directly be used in the user interface.
         *
         * \see selectedAudioChannel
         * \see setCurrentAudioChannel
         */
        QList<Phonon::AudioChannelDescription> availableAudioChannels() const;

        /**
         * Returns the subtitle streams that can be selected by the user. The
         * strings can directly be used in the user interface.
         *
         * \see selectedSubtitle
         * \see setCurrentSubtitle
         */
        QList<SubtitleDescription> availableSubtitles() const;

        /**
         * Selects an audio stream from the media.
         *
         * Some media formats allow multiple audio streams to be stored in
         * the same file. Normally only one should be played back.
         *
         * \param stream Description of an audio stream
         *
         * \see availableAudioChannels()
         * \see currentAudioChannel()
         */
        void setCurrentAudioChannel(const Phonon::AudioChannelDescription &stream);

        /**
         * Switches to a menu (e.g. on a DVD).
         *
         * \see availableMenus()
         */
        void setCurrentMenu(NavigationMenu menu);

        /**
         * Selects a subtitle stream from the media.
         *
         * Some media formats allow multiple subtitle streams to be stored in
         * the same file. Normally only one should be displayed.
         *
         * \param stream description of a subtitle stream
         *
         * \see availableSubtitles()
         * \see currentSubtitle()
         */
        void setCurrentSubtitle(const Phonon::SubtitleDescription &stream);

        /**
         * \brief Selects a subtitle file as subtitle source for the media.
         *
         * \note The file will also be added to the model of SubtitleDescriptions,
         *       so you do not need special handling in the UI.
         *
         * \see setCurrentSubtitle(const Phonon::SubtitleDescription &stream)
         */
        void setCurrentSubtitle(const QUrl &url);

        /**
         * Sets/Unsets subtitles autodetection.
         *
         * Detection is attempted when moving the MediaObject into Playing state.
         * In order to enable/disable autodetection it must be set before play()
         * is called. Whether a MediaSource is set on the MediaObject does not
         * matter, and once detection is set it will remain set that way for
         * this exact combination of MediaController and MediaObject.
         *
         * \note The subtitle autodetection may only be changed in states other
         *       than Playing | Buffering | Paused.
         *
         * \see subtitleAutodetect
         * \since 4.7.0
         */
        void setSubtitleAutodetect(bool enable);

        /**
         * Selects the current encoding used to render subtitles.
         *
         * The encoding name must respect the
         * @link http://www.iana.org/assignments/character-sets
         * Link text IANA character-sets encoding file @endlink
         * If no encoding is explicitly set, it defaults to UTF-8.
         *
         * \note The subtitle encoding may only be changed in states other
         *       than Playing | Buffering | Paused.
         * \note Decoding support may vary between backends.
         *
         * \see subtitleEncoding
         * \since 4.7.0
         */
        void setSubtitleEncoding(const QString &encoding);

        /**
         * Selects the current font used to render subtitles.
         *
         * If no font is explicitly set, the system default font is used.
         *
         * \note The subtitle font may only be changed in states other
         *       than Playing | Buffering | Paused.
         * \note Non-system fonts can not be used. In particular adding
         *       fonts manually to the QFontDatabase will not make them
         *       available as render fonts.
         *
         * \see subtitleFont
         * \since 4.7.0
         */
        void setSubtitleFont(const QFont &font);

    public Q_SLOTS:
        void setCurrentAngle(int angleNumber);
        void setCurrentChapter(int chapterNumber);

        /**
         * Skips to the given title \p titleNumber.
         *
         * If it was playing before the title change it will start playback on the new title if
         * autoplayTitles is enabled.
         */
        void setCurrentTitle(int titleNumber);
        void setAutoplayTitles(bool);

        /**
         * Skips to the next title.
         *
         * If it was playing before the title change it will start playback on the next title if
         * autoplayTitles is enabled.
         */
        void nextTitle();

        /**
         * Skips to the previous title.
         *
         * If it was playing before the title change it will start playback on the previous title if
         * autoplayTitles is enabled.
         */
        void previousTitle();

    Q_SIGNALS:
        void availableAnglesChanged(int availableAngles);
        void availableAudioChannelsChanged();
        void availableChaptersChanged(int availableChapters);

        /**
         * The available menus changed, this for example emitted when Phonon switches
         * from a media source without menus to one with menus (e.g. a DVD).
         *
         * \param menus is a list of all currently available menus, you should update
         * GUI representations of the available menus with the new set.
         *
         * \see availableMenus()
         * \see navigationMenuToString()
         */
        void availableMenusChanged(QList<NavigationMenu> menus);
        void availableSubtitlesChanged();
        void availableTitlesChanged(int availableTitles);

        void angleChanged(int angleNumber);
        void chapterChanged(int chapterNumber);
        void titleChanged(int titleNumber);

    protected:
        MediaControllerPrivate *const d;
};

Q_DECLARE_OPERATORS_FOR_FLAGS(MediaController::Features)

} // namespace Phonon

Q_DECLARE_METATYPE(Phonon::MediaController::NavigationMenu)
Q_DECLARE_METATYPE(QList<Phonon::MediaController::NavigationMenu>)

#endif //QT_NO_PHONON_MEDIACONTROLLER


#endif // PHONON_MEDIACONTROLLER_H
