// SPDX-License-Identifier: BSD-3-Clause
/**
 * Copyright (c) MapBox
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice, this
 *   list of conditions and the following disclaimer in the documentation and/or
 *   other materials provided with the distribution.
 * - Neither the name "MapBox" nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "vector_tile_compression.hpp"

// zlib
#include <zlib.h>

// std
#include <stdexcept>

// decodes both zlib and gzip
// http://stackoverflow.com/a/1838702/2333354
void mapnik::vector_tile_impl::zlib_decompress(const char * data, std::size_t size, std::string & output)
{
    z_stream inflate_s;
    inflate_s.zalloc = Z_NULL;
    inflate_s.zfree = Z_NULL;
    inflate_s.opaque = Z_NULL;
    inflate_s.avail_in = 0;
    inflate_s.next_in = Z_NULL;
    inflateInit2(&inflate_s, 32 + 15);
    inflate_s.next_in = (Bytef *)data;
    inflate_s.avail_in = size;
    size_t length = 0;
    do {
        output.resize(length + 2 * size);
        inflate_s.avail_out = 2 * size;
        inflate_s.next_out = (Bytef *)(output.data() + length);
        int ret = inflate(&inflate_s, Z_FINISH);
        if (ret != Z_STREAM_END && ret != Z_OK && ret != Z_BUF_ERROR)
        {
            std::string error_msg = inflate_s.msg;
            inflateEnd(&inflate_s);
            throw std::runtime_error(error_msg);
        }

        length += (2 * size - inflate_s.avail_out);
    } while (inflate_s.avail_out == 0);
    inflateEnd(&inflate_s);
    output.resize(length);
}