#include "compress.h"
#include "cpps_gzip.h"

namespace cpps {


	/* Compress gzip data */
	/* data 原数据 ndata 原数据长度 zdata 压缩后数据 nzdata 压缩后长度 */
	int gzcompress(Bytef* zdata, uLong* nzdata, Bytef* data, uLong ndata,cpps_integer level)
	{
		z_stream c_stream;
		int err = 0;

		if (data && ndata > 0) {
			c_stream.zalloc = NULL;
			c_stream.zfree = NULL;
			c_stream.opaque = NULL;
			//只有设置为MAX_WBITS + 16才能在在压缩文本中带header和trailer
			if (deflateInit2(&c_stream, (int)level, Z_DEFLATED,
				MAX_WBITS + 16, 8, Z_DEFAULT_STRATEGY) != Z_OK) return -1;
			c_stream.next_in = data;
			c_stream.avail_in = ndata;
			c_stream.next_out = zdata;
			c_stream.avail_out = *nzdata;
			while (c_stream.avail_in != 0 && c_stream.total_out < *nzdata) {
				if (deflate(&c_stream, Z_NO_FLUSH) != Z_OK) return -1;
			}
			if (c_stream.avail_in != 0) return c_stream.avail_in;
			for (;;) {
				if ((err = deflate(&c_stream, Z_FINISH)) == Z_STREAM_END) break;
				if (err != Z_OK) return -1;
			}
			if (deflateEnd(&c_stream) != Z_OK) return -1;
			*nzdata = c_stream.total_out;
			return 0;
		}
		return -1;
	}

	/* Uncompress gzip data */
	/* zdata 数据 nzdata 原数据长度 data 解压后数据 ndata 解压后长度 */
	int gzdecompress(
		Byte* data, uLong* ndata,
		Byte* zdata, uLong nzdata)
	{
		int err = 0;
		z_stream d_stream = { 0 }; /* decompression stream */
		static char dummy_head[2] = {
			0x8 + 0x7 * 0x10,
			(((0x8 + 0x7 * 0x10) * 0x100 + 30) / 31 * 31) & 0xFF,
		};
		d_stream.zalloc = NULL;
		d_stream.zfree = NULL;
		d_stream.opaque = NULL;
		d_stream.next_in = zdata;
		d_stream.avail_in = 0;
		d_stream.next_out = data;
		//只有设置为MAX_WBITS + 16才能在解压带header和trailer的文本
		if (inflateInit2(&d_stream, MAX_WBITS + 16) != Z_OK) return -1;
		//if(inflateInit2(&d_stream, 47) != Z_OK) return -1;
		while (d_stream.total_out < *ndata && d_stream.total_in < nzdata) {
			d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
			if ((err = inflate(&d_stream, Z_NO_FLUSH)) == Z_STREAM_END) break;
			if (err != Z_OK) {
				if (err == Z_DATA_ERROR) {
					d_stream.next_in = (Bytef*)dummy_head;
					d_stream.avail_in = sizeof(dummy_head);
					if ((err = inflate(&d_stream, Z_NO_FLUSH)) != Z_OK) {
						return -1;
					}
				}
				else return -1;
			}
		}
		if (inflateEnd(&d_stream) != Z_OK) return -1;
		*ndata = d_stream.total_out;
		return 0;
	}

	cpps::cpps_value cpps_compress_gzip_compress(C* c, cpps_value data, cpps_value level)
	{
		cpps_integer nlevel = cpps_isint(level) ? level.value.integer : Z_DEFAULT_COMPRESSION;
		Bytef* buf = NULL;
		uLong len = 0;

		if (data.tt == CPPS_TSTRING) {
			std::string* str = cpps_get_string(data);
			buf = (Bytef*)str->c_str();
			len = (uLong)str->size();
		}
		else if (data.isdomain() && data.is_kindof<Buffer>())
		{
			cpps_cppsclassvar* cppsclassvar = (cpps_cppsclassvar*)data.value.domain;
			Buffer* buffer = (Buffer*)cppsclassvar->getclsptr();
			buf = (Bytef*)buffer->getbuffer();
			len = (uLong)buffer->length();
		}
		else {
			throw(cpps_error("", 0, cpps_error_normalerror, "compress data just support Buffer or string."));
		}
		
		uLongf destlen = (uLongf)len + 20; /*不知道这个协议头到底是多大*/
		Bytef* dest = new Bytef[destlen];

		int32 err = gzcompress(dest, &destlen, buf, len , nlevel);
		if (err != Z_OK) {
			delete[] dest;
			dest = NULL;
			return nil;
		}

		std::string* rets;
		cpps_value ret;
		newclass<std::string>(c, &rets ,&ret);
		ret.tt = CPPS_TSTRING;
		rets->append((const char*)dest, destlen);
		delete[] dest;
		dest = NULL;

		return ret;
	}

	cpps::cpps_value cpps_compress_gzip_decompress(C* c, cpps_value data, cpps_value bufsize)
	{
		cpps_uinteger nbufsize = cpps_isint(bufsize) ? bufsize.value.uinteger : DEF_BUF_SIZE;

		Bytef* buf = NULL;
		uLong len = 0;

		if (data.tt == CPPS_TSTRING) {
			std::string* str = cpps_get_string(data);
			buf = (Bytef*)str->c_str();
			len = (uLong)str->size();
		}
		else if (data.isdomain() && data.is_kindof<Buffer>())
		{
			cpps_cppsclassvar* cppsclassvar = (cpps_cppsclassvar*)data.value.domain;
			Buffer* buffer = (Buffer*)cppsclassvar->getclsptr();
			buf = (Bytef*)buffer->getbuffer();
			len = (uLong)buffer->length();
		}
		else {
			throw(cpps_error("", 0, cpps_error_normalerror, "decompress data just support Buffer or string."));
		}

		Bytef* dest = new Bytef[size_t(nbufsize)];
		uLong destlen = (uLong)nbufsize;

		int32 err = gzdecompress(dest, &destlen, buf, len);
		if (err != Z_OK) {
			return nil;
		}

		std::string* rets;
		cpps_value ret;
		newclass<std::string>(c, &rets,&ret);
		ret.tt = CPPS_TSTRING;
		rets->append((const char*)dest, destlen);
		delete[] dest;
		dest = NULL;

		return ret;
	}

}