/*
  Copyright (c) 2021 Sogou, Inc.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

  Author: Li Yingxin (liyingxin@sogou-inc.com)
*/

#ifndef _WEBSOCKET_PARSER_H_
#define _WEBSOCKET_PARSER_H_

#define WS_HEADER_LENGTH_MAX	14
#define WS_SERVER_LENGTH_MIN	2
#define WS_CLIENT_LENGTH_MIN	6
#define WS_MASKING_KEY_LENGTH	4

#include <stddef.h>
#include <stdint.h>

enum
{
	WebSocketFrameContinuation		= 0,
	WebSocketFrameText				= 1,
	WebSocketFrameBinary			= 2,
	WebSocketFrameConnectionClose	= 8,
	WebSocketFramePing				= 9,
	WebSocketFramePong				= 10,
};

enum
{
	WSStatusCodeUndefined			= 0,

	WSStatusCodeNormal				= 1000,
	WSStatusCodeGoingAway			= 1001,
	WSStatusCodeProtocolError		= 1002,
	WSStatusCodeUnsupported			= 1003,
	WSStatusCodeReserved			= 1004, // reserved
	WSStatusCodeNoStatus			= 1005, // reserved
	WSStatusCodeAbnomal				= 1006, // reserved
	WSStatusCodeUnsupportedData		= 1007,
	WSStatusCodePolicyViolation		= 1008,
	WSStatusCodeTooLarge			= 1009,
	WSStatusCodeMissExtention		= 1010,
	WSStatusCodeInternalError		= 1011,
//	WSStatusCodeServiceRestart		= 1012,
//	WSStatusCodeTryAgainLater		= 1013,
	WSStatusCodeTLSHandshake		= 1015, // reserved

	WSStatusCodeProtocolMax			= 2999,

	WSStatusCodeIANAMin				= 3000,
	WSStatusCodeIANAMax				= 3999,

	WSStatusCodeUserMin				= 4000,
	WSStatusCodeUserMax				= 4999,
};

typedef struct __websocket_parser
{
	char fin;
	char mask;
	int opcode;
	unsigned char masking_key[WS_MASKING_KEY_LENGTH];
	unsigned long long payload_length;
	unsigned char header_buf[WS_HEADER_LENGTH_MAX];
	void *payload_data;
	unsigned long long nreceived;
	int masking_key_offset;
	int nleft;
	int is_server;
	int status_code;
} websocket_parser_t;

#ifdef __cplusplus
extern "C"
{
#endif

void websocket_parser_init(websocket_parser_t *parser);
void websocket_parser_deinit(websocket_parser_t *parser);
int websocket_parser_append_message(const void *buf, size_t *n,
									websocket_parser_t *parser);

int websocket_parser_decode_payload_length(websocket_parser_t *parser);

void websocket_parser_encode_payload_length(websocket_parser_t *parser);

int websocket_parser_parse(websocket_parser_t *parser);

void websocket_parser_mask_data(websocket_parser_t *parser);

unsigned char *utf8_check(unsigned char *s, size_t len);

#ifdef __cplusplus
}
#endif

static inline void websocket_set_mask_key(unsigned int masking_key,
										  websocket_parser_t *parser)
{
	uint32_t *key = (uint32_t *)parser->masking_key;
	*key = masking_key;
	parser->mask = 1;
}

static inline void websocket_set_opcode(int opcode, websocket_parser_t *parser)
{
	parser->opcode = opcode;
}

#endif