/*
 * 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 OZLIBSTREAM_H_INCLUDED
#define OZLIBSTREAM_H_INCLUDED

#include "io/zlib_streambuf.h"
#include <ostream>
#include <zlib.h>

namespace zlib
{

	/**
	 * @brief Stream buffer used by zlib::ozlibstream
	 * @sa ozlibstream
	 */
	class NBT_EXPORT deflate_streambuf : public zlib_streambuf
	{
	  public:
		/**
		 * @param output the ostream to wrap
		 * @param bufsize the size of the internal buffers
		 * @param level the compression level, ranges from 0 to 9, or -1 for
		 * default
		 *
		 * Refer to the zlib documentation of deflateInit2 for details about the
		 * arguments.
		 *
		 * @throw zlib_error if zlib encounters a problem during initialization
		 */
		explicit deflate_streambuf(std::ostream& output, size_t bufsize = 32768,
								   int level = Z_DEFAULT_COMPRESSION,
								   int window_bits = 15, int mem_level = 8,
								   int strategy = Z_DEFAULT_STRATEGY);
		~deflate_streambuf() noexcept;

		///@return the wrapped ostream
		std::ostream& get_ostr() const
		{
			return os;
		}

		/// Finishes compression and writes all pending data to the output
		void close();

	  private:
		std::ostream& os;

		void deflate_chunk(int flush = Z_NO_FLUSH);

		int_type overflow(int_type ch) override;
		int sync() override;
	};

	/**
	 * @brief An ostream adapter that compresses data using zlib
	 *
	 * This ostream wraps another ostream. Data written to an ozlibstream will
	 * be deflated (compressed) with zlib and written to the wrapped ostream.
	 *
	 * @sa deflate_streambuf
	 */
	class NBT_EXPORT ozlibstream : public std::ostream
	{
	  public:
		/**
		 * @param output the ostream to wrap
		 * @param level the compression level, ranges from 0 to 9, or -1 for
		 * default
		 * @param gzip if true, the output will be in gzip format rather than
		 * zlib
		 * @param bufsize the size of the internal buffers
		 */
		explicit ozlibstream(std::ostream& output,
							 int level = Z_DEFAULT_COMPRESSION,
							 bool gzip = false, size_t bufsize = 32768)
			: std::ostream(&buf),
			  buf(output, bufsize, level, 15 + (gzip ? 16 : 0))
		{
		}

		///@return the wrapped ostream
		std::ostream& get_ostr() const
		{
			return buf.get_ostr();
		}

		/// Finishes compression and writes all pending data to the output
		void close();

	  private:
		deflate_streambuf buf;
	};

} // namespace zlib

#endif // OZLIBSTREAM_H_INCLUDED
