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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#ifndef ENGINES_ENGINE_H
#define ENGINES_ENGINE_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"

class OSystem;
class MetaEngineDetection;
class MetaEngine;

namespace Audio {
class Mixer;
}
namespace Common {
class Error;
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 GUIErrorMessageFormat(Common::U32String fmt, ...);
void GUIErrorMessageFormat(const char *fmt, ...) GCC_PRINTF(1, 2);


class Engine;

class PauseToken {
public:
    PauseToken();
    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:
    PauseToken(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;

private:
    int _pauseLevel;

    uint32 _pauseStartTime;

    int32 _engineStartTime;

    const int _autosaveInterval;

    int _lastAutosaveTime;

    int _saveSlotToLoad;

    GUI::Debugger *_debugger;
public:


    enum EngineFeature {
        kSupportsSubtitleOptions,

        kSupportsReturnToLauncher,

        kSupportsLoadingDuringRuntime,

        kSupportsSavingDuringRuntime,

        kSupportsChangingOptionsDuringRuntime,

        kSupportsArbitraryResolutions
    };



    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() { return _debugger; }

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

    GUI::Debugger *getOrCreateDebugger();

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

    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();

    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();

    bool saveGameDialog();

    bool loadGameDialog();

protected:
    virtual void pauseEngineIntern(bool pause);

public:

    static void quitGame();

    static bool shouldQuit();

    static MetaEngineDetection &getMetaEngineDetection();

    static MetaEngine &getMetaEngine();

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

public:

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

    void openMainMenuDialog();

    static bool warnUserAboutUnsupportedGame();

    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:
    void checkCD();


    void handleAutoSave();

    void saveAutosaveIfEnabled();

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

    virtual int getAutosaveSlot() const {
        return 0;
    }
    
    bool shouldPerformAutoSave(int lastSaveTime) {
        // TODO: Remove deprecated method once all engines are refactored
        // to no longer do autosaves directly themselves
        return false;
    }
};


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);
};

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