/*]  Copyright (c) 2009-2011, Charles McGarvey  [*****************************
**]  All rights reserved.
*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
*****************************************************************************/

#include <iostream>
#include <stdexcept>
#include <zlib.h>

#include "compression.hh"

#define ZLIB_BUF_SIZE		262114


namespace moof {


void inflate(std::istream& in, std::ostream& out)
{
	char inbuf[ZLIB_BUF_SIZE];
	char outbuf[ZLIB_BUF_SIZE];

	z_stream zstream;

	zstream.zalloc		= Z_NULL;
	zstream.zfree		= Z_NULL;
	zstream.opaque		= Z_NULL;
	zstream.avail_in	= 0;
	zstream.next_in		= Z_NULL;
	
	int result = inflateInit2(&zstream, 32 + MAX_WBITS);
	if (result != Z_OK) throw std::runtime_error("zlib init error");

	do {
		in.read(inbuf, sizeof(inbuf));
		zstream.next_in = (Bytef*)inbuf;
		zstream.avail_in = in.gcount();

		if (zstream.avail_in == 0) break;

		do {
			zstream.next_out = (Bytef*)outbuf;
			zstream.avail_out = sizeof(outbuf);

			result = inflate(&zstream, Z_NO_FLUSH);
			switch (result)
			{
			case Z_NEED_DICT:
			case Z_DATA_ERROR:
			case Z_MEM_ERROR:
				inflateEnd(&zstream);
				throw std::runtime_error("zlib inflate error");
			case Z_STREAM_ERROR:
				throw std::runtime_error("zlib stream error");
			}

			int inflated = sizeof(outbuf) - zstream.avail_out;
			out.write(outbuf, inflated);
		}
		while (zstream.avail_out == 0);
	}
	while(result != Z_STREAM_END);

	inflateEnd(&zstream);
}

void inflate(const char* in, size_t size, std::ostream& out)
{
	char buf[ZLIB_BUF_SIZE];

	z_stream zstream;
	zstream.zalloc		= Z_NULL;
	zstream.zfree		= Z_NULL;
	zstream.opaque		= Z_NULL;
	zstream.avail_in	= size;
	zstream.next_in		= (Bytef*)in;
	
	int result = inflateInit2(&zstream, 32 + MAX_WBITS);
	if (result != Z_OK) throw std::runtime_error("zlib init error");

	do {
		zstream.next_out = (Bytef*)buf;
		zstream.avail_out = sizeof(buf);

		result = inflate(&zstream, Z_NO_FLUSH);
		switch (result)
		{
		case Z_NEED_DICT:
		case Z_DATA_ERROR:
		case Z_MEM_ERROR:
			inflateEnd(&zstream);
			throw std::runtime_error("zlib inflate error");
		case Z_STREAM_ERROR:
			throw std::runtime_error("zlib stream error");
		}

		size_t inflated = sizeof(buf) - zstream.avail_out;
		out.write(buf, inflated);
	}
	while (zstream.avail_out == 0);

	inflateEnd(&zstream);
}


} // namespace moof