file.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 SCI_ENGINE_FILE_H
#define SCI_ENGINE_FILE_H

#include "common/memstream.h"
#include "common/str-array.h"
#include "common/stream.h"

namespace Sci {

enum kFileOpenMode {
    kFileOpenModeOpenOrCreate = 0,
    kFileOpenModeOpenOrFail = 1,
    kFileOpenModeCreate = 2
};

enum {
    kMaxSaveNameLength = 36, 
    kMaxNumSaveGames = 20 
};

enum {
    kAutoSaveId = 0,  
    kNewGameId = 999, 

    // SCI engine expects game IDs to start at 0, but slot 0 in ScummVM is
    // reserved for autosave, so non-autosave games get their IDs shifted up
    // when saving or restoring, and shifted down when enumerating save games.
    // ScummVM slot 0 can't be shifted down as -1 is an illegal SCI save ID
    // so it is instead wrapped around to 99 and then back to 0 when shifting up.
    kSaveIdShift = 1,
    kMaxShiftedSaveId = 99
};

enum {
    kVirtualFileHandleStart = 32000,
    kVirtualFileHandleSci32Save = 32100,
    kVirtualFileHandleSciAudio = 32300,
    kVirtualFileHandleEnd = 32300
};

struct SavegameDesc {
    int16 id;
    int date;
    int time;
    int version;
    // name is a null-terminated 36 character array in SCI16,
    // but in SCI32 the 36th character can be used for text.
    // At least Phant2 makes use of this. We add an element
    // so that this string is always terminated internally.
    char name[kMaxSaveNameLength + 1];
    Common::String gameVersion;
    uint32 script0Size;
    uint32 gameObjectOffset;
#ifdef ENABLE_SCI32
    // Used by Shivers 1
    uint16 lowScore;
    uint16 highScore;
    // Used by MGDX
    uint8 avatarId;
#endif
};

class FileHandle {
public:
    Common::String _name;
    Common::SeekableReadStream *_in;
    Common::WriteStream *_out;

public:
    FileHandle();
    ~FileHandle();

    void close();
    bool isOpen() const;
};


class DirSeeker {
protected:
    reg_t _outbuffer;
    Common::StringArray _files;
    Common::StringArray _virtualFiles;
    Common::StringArray::const_iterator _iter;

public:
    DirSeeker() {
        _outbuffer = NULL_REG;
        _iter = _files.begin();
    }

    reg_t firstFile(const Common::String &mask, reg_t buffer, SegManager *segMan);
    reg_t nextFile(SegManager *segMan);

    Common::String getVirtualFilename(uint fileNumber);

private:
    void addAsVirtualFiles(Common::String title, Common::String fileMask);
};

#ifdef ENABLE_SCI32

class MemoryDynamicRWStream : public Common::MemoryWriteStreamDynamic, public Common::SeekableReadStream {
public:
    MemoryDynamicRWStream(DisposeAfterUse::Flag disposeMemory = DisposeAfterUse::NO) : MemoryWriteStreamDynamic(disposeMemory), _eos(false) { }

    uint32 read(void *dataPtr, uint32 dataSize) override;

    bool eos() const override { return _eos; }
    int64 pos() const override { return _pos; }
    int64 size() const override { return _size; }
    void clearErr() override { _eos = false; Common::MemoryWriteStreamDynamic::clearErr(); }
    bool seek(int64 offs, int whence = SEEK_SET) override { return Common::MemoryWriteStreamDynamic::seek(offs, whence); }

protected:
    bool _eos;
};

class SaveFileRewriteStream : public MemoryDynamicRWStream {
public:
    SaveFileRewriteStream(const Common::String &fileName,
                          Common::SeekableReadStream *inFile,
                          kFileOpenMode mode, bool compress);
    ~SaveFileRewriteStream() override;

    uint32 write(const void *dataPtr, uint32 dataSize) override { _changed = true; return MemoryDynamicRWStream::write(dataPtr, dataSize); }

    void commit(); //< Save back to disk

protected:
    Common::String _fileName;
    bool _compress;
    bool _changed;
};

#endif

uint findFreeFileHandle(EngineState *s);
reg_t file_open(EngineState *s, const Common::String &filename, kFileOpenMode mode, bool unwrapFilename);
FileHandle *getFileFromHandle(EngineState *s, uint handle);
int fgets_wrapper(EngineState *s, char *dest, int maxsize, int handle);
void listSavegames(Common::Array<SavegameDesc> &saves);
int findSavegame(Common::Array<SavegameDesc> &saves, int16 savegameId);
bool fillSavegameDesc(const Common::String &filename, SavegameDesc &desc);

#ifdef ENABLE_SCI32

Common::MemoryReadStream *makeCatalogue(const uint maxNumSaves, const uint gameNameSize, const Common::String &fileNamePattern, const bool ramaFormat);

int shiftSciToScummVMSaveId(int saveId);
int shiftScummVMToSciSaveId(int saveId);
#endif

} // End of namespace Sci

#endif // SCI_ENGINE_FILE_H