engine.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef ENGINES_ENGINE_H
#define ENGINES_ENGINE_H

#include "common/error.h"
#include "common/scummsys.h"
#include "common/str.h"
#include "common/language.h"
#include "common/platform.h"
#include "common/queue.h"
#include "common/singleton.h"
#include "engines/enhancements.h"

class OSystem;
class MetaEngineDetection;
class MetaEngine;

namespace Audio {
class Mixer;
}
namespace Common {
class Error;
class FSDirectory;
class EventManager;
class SaveFileManager;
class TimerManager;
class FSNode;
class SeekableReadStream;
class WriteStream;
}
namespace GUI {
class Debugger;
class Dialog;
}

void GUIErrorMessage(const Common::U32String &msg, const char *url = nullptr);
void GUIErrorMessage(const Common::String &msg, const char *url = nullptr);
void GUIErrorMessageWithURL(const Common::U32String &msg, const char *url);
void GUIErrorMessageWithURL(const Common::String &msg, const char *url);
void GUIErrorMessageFormatU32StringPtr(const Common::U32String *fmt, ...);
template<class... TParam>
inline void GUIErrorMessageFormat(const Common::U32String &fmt, TParam... param) {
    GUIErrorMessageFormatU32StringPtr(&fmt, Common::forward<TParam>(param)...);
}
void GUIErrorMessageFormat(MSVC_PRINTF const char *fmt, ...) GCC_PRINTF(1, 2);


class Engine;

class PauseToken {
public:
    constexpr PauseToken() : _engine(nullptr) {}
    PauseToken(const PauseToken &);
#if __cplusplus >= 201103L
    PauseToken(PauseToken &&);
#endif
    ~PauseToken();
    void operator=(const PauseToken &);
#if __cplusplus >= 201103L
    void operator=(PauseToken &&);
#endif

    void clear();

    bool isActive() const { return _engine != nullptr; }

private:
    constexpr PauseToken(Engine *engine) : _engine(engine) {}

    Engine *_engine;
    friend class Engine;
};

class Engine {
public:
    OSystem *_system;
    Audio::Mixer *_mixer;

protected:
    Common::TimerManager *_timer;
    Common::EventManager *_eventMan;
    Common::SaveFileManager *_saveFileMan;

    GUI::Dialog *_mainMenuDialog;
    virtual int runDialog(GUI::Dialog &dialog);

    const Common::String _targetName;

    int32 _activeEnhancements = kEnhGameBreakingBugFixes;

private:
    MetaEngine *_metaEngine;

    int _pauseLevel;

    uint32 _pauseStartTime;

    int _pauseScreenChangeID;

    int32 _engineStartTime;

    int _autosaveInterval;

    int _lastAutosaveTime;

    int _saveSlotToLoad;

    bool _autoSaving;

    GUI::Debugger *_debugger;

    static bool _quitRequested;

public:
    enum EngineFeature {
        kSupportsSubtitleOptions,

        kSupportsReturnToLauncher,

        kSupportsLoadingDuringRuntime,

        kSupportsSavingDuringRuntime,

        kSupportsChangingOptionsDuringRuntime,

        kSupportsArbitraryResolutions,

         kSupportsHelp,

        kSupportsQuitDialogOverride,
    };



    Engine(OSystem *syst);
    virtual ~Engine();

    virtual void initializePath(const Common::FSNode &gamePath);

    virtual Common::Error run() = 0;

    virtual void errorString(const char *buf_input, char *buf_output, int buf_output_size);

    virtual GUI::Debugger *getDebugger() final { return _debugger; }

    void setDebugger(GUI::Debugger *debugger) {
        assert(!_debugger);
        _debugger = debugger;
    }

    GUI::Debugger *getOrCreateDebugger();

    virtual bool hasFeature(EngineFeature f) const { return false; }

    bool enhancementEnabled(int32 cls);

    virtual void syncSoundSettings();

    virtual void applyGameSettings() {}

    virtual void flipMute();

    virtual Common::String getSaveStateName(int slot) const {
        return Common::String::format("%s.%03d", _targetName.c_str(), slot);
    }

    virtual Common::Error loadGameState(int slot);

    virtual Common::Error loadGameStream(Common::SeekableReadStream *stream);

    void setGameToLoadSlot(int slot);

    virtual bool canLoadGameStateCurrently(Common::U32String *msg = nullptr);

    virtual Common::Error saveGameState(int slot, const Common::String &desc, bool isAutosave = false);

    virtual Common::Error saveGameStream(Common::WriteStream *stream, bool isAutosave = false);

    virtual bool canSaveGameStateCurrently(Common::U32String *msg = nullptr);

    bool saveGameDialog();

    bool loadGameDialog();

protected:
    virtual void pauseEngineIntern(bool pause);

public:

    static void quitGame();

    static bool shouldQuit();

    inline MetaEngine *getMetaEngine() const { return _metaEngine; }

    inline void setMetaEngine(MetaEngine *metaEngine) { _metaEngine = metaEngine; }

    PauseToken pauseEngine();
private:
    void resumeEngine();
    friend class PauseToken;

    bool warnBeforeOverwritingAutosave();

public:

    bool isPaused() const { return _pauseLevel != 0; }

    void openMainMenuDialog();

    static bool warnUserAboutUnsupportedGame(Common::String msg = Common::String());

    static bool warnUserAboutUnsupportedAddOn(Common::String addOnName);

    static void errorAddingAddOnWithoutBaseGame(Common::String addOnName, Common::String gameId);

    static void errorUnsupportedGame(Common::String extraMsg);

    uint32 getTotalPlayTime() const;

    void setTotalPlayTime(uint32 time = 0);

    inline Common::TimerManager *getTimerManager() { return _timer; }
    inline Common::EventManager *getEventManager() { return _eventMan; }
    inline Common::SaveFileManager *getSaveFileManager() { return _saveFileMan; }

public:
    bool existExtractedCDAudioFiles(uint track = 1);
    bool isDataAndCDAudioReadFromSameCD();
    void warnMissingExtractedCDAudio();

    void handleAutoSave();

    void saveAutosaveIfEnabled();

    virtual bool canSaveAutosaveCurrently() {
        return canSaveGameStateCurrently();
    }

    virtual int getAutosaveSlot() const {
        return 0;
    }

    virtual bool gameTypeHasAddOns() const;

    virtual bool dirCanBeGameAddOn(const Common::FSDirectory &dir) const;

    virtual bool dirMustBeGameAddOn(const Common::FSDirectory &dir) const;

    Common::ErrorCode updateAddOns(const MetaEngine *metaEngine) const;


protected:
    void defaultSyncSoundSettings();
};


class ChainedGamesManager : public Common::Singleton<ChainedGamesManager> {
private:
    struct Game {
        Common::String target;
        int slot;
    };

    Common::Queue<Game> _chainedGames;

public:
    ChainedGamesManager();
    void clear();
    void push(const Common::String &target, const int slot = -1);
    bool pop(Common::String &target, int &slot);
    bool empty() { return _chainedGames.empty(); }
};

#define ChainedGamesMan ChainedGamesManager::instance()
 //FIXME
extern Engine *g_engine;
#endif