/*
 * Copyright (C) 2001-2019 Jacek Sieka, arnetheduck on gmail point com
 *
 * 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, see <https://www.gnu.org/licenses/>.
 */

#pragma once

#include <cstddef>
#include <cstdint>
#include <string>
#include <zlib.h>

namespace dcpp {

using std::string;

class ZFilter {
public:
    /** Compression will automatically be turned off if below this... */
    static const double MIN_COMPRESSION_LEVEL;

    ZFilter();
    ~ZFilter();
    /**
     * Compress data.
     * @param in Input data
     * @param insize Input size (Set to 0 to indicate that no more data will follow)
     * @param out Output buffer
     * @param outsize Output size, set to compressed size on return.
     * @return True if there's more processing to be done
     */
    bool operator()(const void* in, size_t& insize, void* out, size_t& outsize);
private:
    z_stream zs;
    int64_t totalIn;
    int64_t totalOut;
    bool compressing;
};

class UnZFilter {
public:
    UnZFilter();
    ~UnZFilter();
    /**
     * Decompress data.
     * @param in Input data
     * @param insize Input size (Set to 0 to indicate that no more data will follow)
     * @param out Output buffer
     * @param outsize Output size, set to decompressed size on return.
     * @return True if there's more processing to be done
     */
    bool operator()(const void* in, size_t& insize, void* out, size_t& outsize);
private:
    z_stream zs;
};

class GZ {
public:
    static void decompress(const string& source, const string& target);
};

class CRC32Filter {
public:
    CRC32Filter() : crc(crc32(0, NULL, 0)) { }
    // TODO 64-bits?
    void operator()(const void* buf, size_t len) { crc = crc32(crc, (const Bytef*)buf, (uInt)len); }
    uint32_t getValue() const { return crc; }
private:
    uint32_t crc;
};

} // namespace dcpp
