/*
 * SPDX-FileCopyrightText: 2013, 2015 ljfa-ag <ljfa-ag@web.de>
 *
 * SPDX-License-Identifier: LGPL-3.0-or-later
 */

/*
 * libnbt++ - A library for the Minecraft Named Binary Tag format.
 * Copyright (C) 2013, 2015  ljfa-ag
 *
 * This file is part of libnbt++.
 *
 * libnbt++ is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * libnbt++ 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libnbt++.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef IZLIBSTREAM_H_INCLUDED
#define IZLIBSTREAM_H_INCLUDED

#include "io/zlib_streambuf.h"
#include <istream>
#include <neozip.h>

namespace zlib
{

	/**
	 * @brief Stream buffer used by zlib::izlibstream
	 * @sa izlibstream
	 */
	class NBT_EXPORT inflate_streambuf : public zlib_streambuf
	{
	  public:
		/**
		 * @param input the istream to wrap
		 * @param bufsize the size of the internal buffers
		 * @param window_bits the base two logarithm of the maximum window size
		 * that zlib will use. This parameter also determines which type of
		 * input to expect. The default argument will autodetect between zlib
		 * and gzip data. Refer to the zlib documentation of inflateInit2 for
		 * more details.
		 *
		 * @throw zlib_error if zlib encounters a problem during initialization
		 */
		explicit inflate_streambuf(std::istream& input, size_t bufsize = 32768,
								   int window_bits = 32 + 15);
		~inflate_streambuf() noexcept;

		///@return the wrapped istream
		std::istream& get_istr() const
		{
			return is;
		}

	  private:
		std::istream& is;
		bool stream_end;

		int_type underflow() override;
	};

	/**
	 * @brief An istream adapter that decompresses data using zlib
	 *
	 * This istream wraps another istream. The izlibstream will read compressed
	 * data from the wrapped istream and inflate (decompress) it with zlib.
	 *
	 * @note If you want to read more data from the wrapped istream after the
	 * end of the compressed data, then it must allow seeking. It is unavoidable
	 * for the izlibstream to consume more data after the compressed data. It
	 * will automatically attempt to seek the wrapped istream back to the point
	 * after the end of the compressed data.
	 * @sa inflate_streambuf
	 */
	class NBT_EXPORT izlibstream : public std::istream
	{
	  public:
		/**
		 * @param input the istream to wrap
		 * @param bufsize the size of the internal buffers
		 */
		explicit izlibstream(std::istream& input, size_t bufsize = 32768)
			: std::istream(&buf), buf(input, bufsize)
		{
		}
		///@return the wrapped istream
		std::istream& get_istr() const
		{
			return buf.get_istr();
		}

	  private:
		inflate_streambuf buf;
	};

} // namespace zlib

#endif // IZLIBSTREAM_H_INCLUDED
