/*
  Copyright (c) 2019 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.

  Authors: Xie Han (xiehan@sogou-inc.com)
           Wu Jiaxu (wujiaxu@sogou-inc.com)
*/

#ifndef _HTTPUTIL_H_
#define _HTTPUTIL_H_

#include <string>
#include <vector>
#include <unordered_map>
#include "http_parser.h"
#include "HttpMessage.h"

/**
 * @file   HttpUtil.h
 * @brief  Http toolbox
 */

#define HttpMethodGet		"GET"
#define HttpMethodHead		"HEAD"
#define HttpMethodPost		"POST"
#define HttpMethodPut		"PUT"
#define HttpMethodPatch		"PATCH"
#define HttpMethodDelete	"DELETE"
#define HttpMethodConnect	"CONNECT"
#define HttpMethodOptions	"OPTIONS"
#define HttpMethodTrace		"TRACE"

enum
{
	HttpStatusContinue           = 100, // RFC 7231, 6.2.1
	HttpStatusSwitchingProtocols = 101, // RFC 7231, 6.2.2
	HttpStatusProcessing         = 102, // RFC 2518, 10.1

	HttpStatusOK                   = 200, // RFC 7231, 6.3.1
	HttpStatusCreated              = 201, // RFC 7231, 6.3.2
	HttpStatusAccepted             = 202, // RFC 7231, 6.3.3
	HttpStatusNonAuthoritativeInfo = 203, // RFC 7231, 6.3.4
	HttpStatusNoContent            = 204, // RFC 7231, 6.3.5
	HttpStatusResetContent         = 205, // RFC 7231, 6.3.6
	HttpStatusPartialContent       = 206, // RFC 7233, 4.1
	HttpStatusMultiStatus          = 207, // RFC 4918, 11.1
	HttpStatusAlreadyReported      = 208, // RFC 5842, 7.1
	HttpStatusIMUsed               = 226, // RFC 3229, 10.4.1

	HttpStatusMultipleChoices  = 300, // RFC 7231, 6.4.1
	HttpStatusMovedPermanently = 301, // RFC 7231, 6.4.2
	HttpStatusFound            = 302, // RFC 7231, 6.4.3
	HttpStatusSeeOther         = 303, // RFC 7231, 6.4.4
	HttpStatusNotModified      = 304, // RFC 7232, 4.1
	HttpStatusUseProxy         = 305, // RFC 7231, 6.4.5

	HttpStatusTemporaryRedirect = 307, // RFC 7231, 6.4.7
	HttpStatusPermanentRedirect = 308, // RFC 7538, 3

	HttpStatusBadRequest                   = 400, // RFC 7231, 6.5.1
	HttpStatusUnauthorized                 = 401, // RFC 7235, 3.1
	HttpStatusPaymentRequired              = 402, // RFC 7231, 6.5.2
	HttpStatusForbidden                    = 403, // RFC 7231, 6.5.3
	HttpStatusNotFound                     = 404, // RFC 7231, 6.5.4
	HttpStatusMethodNotAllowed             = 405, // RFC 7231, 6.5.5
	HttpStatusNotAcceptable                = 406, // RFC 7231, 6.5.6
	HttpStatusProxyAuthRequired            = 407, // RFC 7235, 3.2
	HttpStatusRequestTimeout               = 408, // RFC 7231, 6.5.7
	HttpStatusConflict                     = 409, // RFC 7231, 6.5.8
	HttpStatusGone                         = 410, // RFC 7231, 6.5.9
	HttpStatusLengthRequired               = 411, // RFC 7231, 6.5.10
	HttpStatusPreconditionFailed           = 412, // RFC 7232, 4.2
	HttpStatusRequestEntityTooLarge        = 413, // RFC 7231, 6.5.11
	HttpStatusRequestURITooLong            = 414, // RFC 7231, 6.5.12
	HttpStatusUnsupportedMediaType         = 415, // RFC 7231, 6.5.13
	HttpStatusRequestedRangeNotSatisfiable = 416, // RFC 7233, 4.4
	HttpStatusExpectationFailed            = 417, // RFC 7231, 6.5.14
	HttpStatusTeapot                       = 418, // RFC 7168, 2.3.3
	HttpStatusEnhanceYourCaim              = 420, // Twitter Search
	HttpStatusMisdirectedRequest           = 421, // RFC 7540, 9.1.2
	HttpStatusUnprocessableEntity          = 422, // RFC 4918, 11.2
	HttpStatusLocked                       = 423, // RFC 4918, 11.3
	HttpStatusFailedDependency             = 424, // RFC 4918, 11.4
	HttpStatusTooEarly                     = 425, // RFC 8470, 5.2.
	HttpStatusUpgradeRequired              = 426, // RFC 7231, 6.5.15
	HttpStatusPreconditionRequired         = 428, // RFC 6585, 3
	HttpStatusTooManyRequests              = 429, // RFC 6585, 4
	HttpStatusRequestHeaderFieldsTooLarge  = 431, // RFC 6585, 5
	HttpStatusNoResponse                   = 444, // Nginx
	HttpStatusBlocked                      = 450, // Windows
	HttpStatusUnavailableForLegalReasons   = 451, // RFC 7725, 3
	HttpStatusTooLargeForNginx             = 494, // Nginx

	HttpStatusInternalServerError           = 500, // RFC 7231, 6.6.1
	HttpStatusNotImplemented                = 501, // RFC 7231, 6.6.2
	HttpStatusBadGateway                    = 502, // RFC 7231, 6.6.3
	HttpStatusServiceUnavailable            = 503, // RFC 7231, 6.6.4
	HttpStatusGatewayTimeout                = 504, // RFC 7231, 6.6.5
	HttpStatusHTTPVersionNotSupported       = 505, // RFC 7231, 6.6.6
	HttpStatusVariantAlsoNegotiates         = 506, // RFC 2295, 8.1
	HttpStatusInsufficientStorage           = 507, // RFC 4918, 11.5
	HttpStatusLoopDetected                  = 508, // RFC 5842, 7.2
	HttpStatusNotExtended                   = 510, // RFC 2774, 7
	HttpStatusNetworkAuthenticationRequired = 511, // RFC 6585, 6
};

namespace protocol
{

// static class
class HttpUtil
{
public:
	static void set_response_status(HttpResponse *resp, int status_code);
	static std::string decode_chunked_body(const HttpMessage *msg);
};

class HttpHeaderMap
{
public:
	HttpHeaderMap(const HttpMessage *message);

	bool key_exists(std::string key);
	std::string get(std::string key);
	bool get(std::string key, std::string& value);
	std::vector<std::string> get_strict(std::string key);
	bool get_strict(std::string key, std::vector<std::string>& values);

private:
	std::unordered_map<std::string, std::vector<std::string>> header_map_;
};

class HttpHeaderCursor
{
public:
	HttpHeaderCursor(const HttpMessage *message);
	virtual ~HttpHeaderCursor();

public:
	bool next(struct HttpMessageHeader *header);
	bool find(struct HttpMessageHeader *header);
	bool erase();
	bool find_and_erase(struct HttpMessageHeader *header);
	void rewind();

	/* std::string interface */
public:
	bool next(std::string& name, std::string& value);
	bool find(const std::string& name, std::string& value);
	bool find_and_erase(const std::string& name);

protected:
	http_header_cursor_t cursor;
};

class HttpChunkCursor
{
public:
	HttpChunkCursor(const HttpMessage *message);
	virtual ~HttpChunkCursor() { }

public:
	bool next(const void **chunk, size_t *size);
	void rewind();

protected:
	const void *body;
	size_t body_len;
	const void *pos;
	bool chunked;
	bool end;
};

////////////////////

inline HttpHeaderCursor::HttpHeaderCursor(const HttpMessage *message)
{
	http_header_cursor_init(&this->cursor, message->get_parser());
}

inline HttpHeaderCursor::~HttpHeaderCursor()
{
	http_header_cursor_deinit(&this->cursor);
}

inline bool HttpHeaderCursor::next(struct HttpMessageHeader *header)
{
	return http_header_cursor_next(&header->name, &header->name_len,
								   &header->value, &header->value_len,
								   &this->cursor) == 0;
}

inline bool HttpHeaderCursor::find(struct HttpMessageHeader *header)
{
	return http_header_cursor_find(header->name, header->name_len,
								   &header->value, &header->value_len,
								   &this->cursor) == 0;
}

inline bool HttpHeaderCursor::erase()
{
	return http_header_cursor_erase(&this->cursor) == 0;
}

inline bool HttpHeaderCursor::find_and_erase(struct HttpMessageHeader *header)
{
	if (this->find(header))
		return this->erase();

	return false;
}

inline void HttpHeaderCursor::rewind()
{
	http_header_cursor_rewind(&this->cursor);
}

}

#endif