scummvm/engines/twp/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