// 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/>.
 */
#include "io/ozlibstream.h"
#include "io/zlib_streambuf.h"

namespace zlib
{

	deflate_streambuf::deflate_streambuf(std::ostream& output, size_t bufsize,
										 int level, int window_bits,
										 int mem_level, int strategy)
		: zlib_streambuf(bufsize), os(output)
	{
		int ret = deflateInit2(&zstr, level, Z_DEFLATED, window_bits, mem_level,
							   strategy);
		if (ret != Z_OK)
			throw zlib_error(zstr.msg, ret);

		setp(in.data(), in.data() + in.size());
	}

	deflate_streambuf::~deflate_streambuf() noexcept
	{
		try {
			close();
		} catch (...) {
			// ignore as we can't do anything about it
		}
		deflateEnd(&zstr);
	}

	void deflate_streambuf::close()
	{
		deflate_chunk(Z_FINISH);
	}

	void deflate_streambuf::deflate_chunk(int flush)
	{
		zstr.next_in = reinterpret_cast<Bytef*>(pbase());
		zstr.avail_in = pptr() - pbase();
		do {
			zstr.next_out = reinterpret_cast<Bytef*>(out.data());
			zstr.avail_out = out.size();
			int ret = deflate(&zstr, flush);
			if (ret != Z_OK && ret != Z_STREAM_END) {
				os.setstate(std::ios_base::failbit);
				throw zlib_error(zstr.msg, ret);
			}
			int have = out.size() - zstr.avail_out;
			if (!os.write(out.data(), have))
				throw std::ios_base::failure(
					"Could not write to the output stream");
		} while (zstr.avail_out == 0);
		setp(in.data(), in.data() + in.size());
	}

	deflate_streambuf::int_type deflate_streambuf::overflow(int_type ch)
	{
		deflate_chunk();
		if (ch != traits_type::eof()) {
			*pptr() = ch;
			pbump(1);
		}
		return ch;
	}

	int deflate_streambuf::sync()
	{
		deflate_chunk();
		return 0;
	}

	void ozlibstream::close()
	{
		// Capture the exception mask so we can restore it if close() fails.
		std::ios_base::iostate old_ex = exceptions();
		try {
			buf.close();
			return;
		} catch (...) {
			// fall through to mark the stream as bad
		}

		// Setting the stream state while exceptions are enabled may cause
		// `setstate` to throw an `ios_base::failure` which would replace
		// the original exception. Temporarily disable exceptions on this
		// stream, set the `badbit`, then restore the exception mask.
		exceptions(std::ios_base::goodbit);
		setstate(std::ios_base::badbit);
		exceptions(old_ex);
	}

} // namespace zlib
