ggpack.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 TWP_GGPACK_H
#define TWP_GGPACK_H

#include "common/hash-str.h"
#include "common/stream.h"
#include "common/list.h"
#include "common/path.h"
#include "common/stablemap.h"
#include "common/formats/json.h"

namespace Twp {

struct XorKey {
    XorKey() {}
    XorKey(const Common::Array<int> &mb, int m) : magicBytes(mb), multiplier(m) {}

    Common::Array<int> magicBytes;
    int multiplier = 0;
};

class MemStream : public Common::SeekableReadStream {
public:
    MemStream();

    bool open(const byte *buf, int64 bufSize);
    uint32 read(void *dataPtr, uint32 dataSize);
    bool eos() const;

    int64 pos() const;
    int64 size() const;
    bool seek(int64 offset, int whence = SEEK_SET);

private:
    const byte *_buf = nullptr;
    int64 _bufSize = 0;
    int64 _pos = 0;
};

class OutMemStream : public Common::SeekableWriteStream {
public:
    OutMemStream();

    bool open(byte *buf, int64 bufSize);
    uint32 write(const void *dataPtr, uint32 dataSize) override;

    int64 pos() const override;
    int64 size() const override;
    bool seek(int64 offset, int whence = SEEK_SET) override;

private:
    byte *_buf = nullptr;
    int64 _bufSize = 0;
    int64 _pos = 0;
};

class XorStream : public Common::SeekableReadStream {
public:
    XorStream();

    bool open(Common::SeekableReadStream *stream, int len, const XorKey &key);
    uint32 read(void *dataPtr, uint32 dataSize);
    bool eos() const;

    int64 pos() const;
    int64 size() const;
    bool seek(int64 offset, int whence = SEEK_SET);

private:
    Common::SeekableReadStream *_s = nullptr;
    int _previous = 0;
    int _start = 0;
    int _size = 0;
    XorKey _key;
};

class RangeStream : public Common::SeekableReadStream {
public:
    RangeStream();

    bool open(Common::SeekableReadStream *stream, int64 size);
    uint32 read(void *dataPtr, uint32 dataSize);
    bool eos() const;

    int64 pos() const;
    int64 size() const;
    bool seek(int64 offset, int whence = SEEK_SET);

private:
    Common::SeekableReadStream *_s = nullptr;
    int64 _start = 0;
    int64 _size = 0;
};

class GGHashMapDecoder {
public:
    GGHashMapDecoder();

    Common::JSONValue *open(Common::SeekableReadStream *stream);

private:
    Common::JSONValue *readHash();
    Common::String readString(uint32 i);
    Common::JSONValue *readValue();
    Common::JSONValue *readArray();

private:
    Common::SeekableReadStream *_stream = nullptr;
    Common::Array<int> _offsets;
};

class GGHashMapEncoder {
public:
    GGHashMapEncoder();

    void open(Common::SeekableWriteStream *stream);
    void write(const Common::JSONObject &obj);

private:
    void writeMarker(byte marker);
    void writeString(const Common::String &s);
    void writeRawString(const Common::String &s);
    void writeNull();
    void writeInt(int value);
    void writeFloat(float value);
    void writeArray(const Common::JSONArray &arr);
    void writeValue(const Common::JSONValue *obj);
    void writeMap(const Common::JSONObject &obj);
    void writeKeys();
    void writeKey(const Common::String &key);

private:
    Common::SeekableWriteStream *_s = nullptr;
    Common::StableMap<Common::String, uint32> _strings;
};

struct GGPackEntry {
    int offset, size;
};

typedef Common::HashMap<Common::String, GGPackEntry, Common::IgnoreCase_Hash> GGPackEntries;

class GGPackDecoder {
public:
    friend class GGPackEntryReader;

public:
    GGPackDecoder();

    bool open(Common::SeekableReadStream *s, const XorKey &key);

    bool assetExists(const char *asset) { return _entries.contains(asset); }

private:
    XorKey _key;
    GGPackEntries _entries;
    Common::SeekableReadStream *_s = nullptr;
};

class GGPackSet {
public:
    void init(const XorKey &key);
    bool assetExists(const char *asset);

    bool containsDLC() const;

public:
    Common::StableMap<long, GGPackDecoder, Common::Greater<long> > _packs;
};

class GGBnutReader : public Common::ReadStream {
public:
    GGBnutReader();

    bool open(Common::SeekableReadStream *s);

    uint32 read(void *dataPtr, uint32 dataSize) override;
    bool eos() const override;

private:
    Common::SeekableReadStream *_s = nullptr;
    int _cursor = 0;
};

class GGPackEntryReader : public Common::SeekableReadStream {
public:
    GGPackEntryReader();

    bool open(GGPackDecoder &pack, const Common::String &entry);
    bool open(GGPackSet &packs, const Common::String &entry);

    uint32 read(void *dataPtr, uint32 dataSize) override;
    bool eos() const override;

    int64 pos() const override;
    int64 size() const override;
    bool seek(int64 offset, int whence = SEEK_SET) override;

private:
    Common::Array<byte> _buf;
    MemStream _ms;
};

} // namespace Twp

#endif