/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */
#ifndef _HTTP_PARSER_H_
#define _HTTP_PARSER_H_
#ifdef __cplusplus
extern "C" {
#endif

/* Also update SONAME in the Makefile whenever you change these. */
#define HTTP_PARSER_VERSION_MAJOR 2
#define HTTP_PARSER_VERSION_MINOR 7
#define HTTP_PARSER_VERSION_PATCH 1

#include <sys/types.h>
#if defined(_WIN32) && !defined(__MINGW32__) && \
	(!defined(_MSC_VER) || _MSC_VER < 1600) && !defined(__WINE__)
#include <BaseTsd.h>
#include <stddef.h>
typedef __int8 int8_t;
typedef unsigned __int8 uint8_t;
typedef __int16 int16_t;
typedef unsigned __int16 uint16_t;
typedef __int32 int32_t;
typedef unsigned __int32 uint32_t;
typedef __int64 int64_t;
typedef unsigned __int64 uint64_t;
#else
#include <stdint.h>
#include <stddef.h>
#endif

/* Maximium header size allowed. If the macro is not defined
 * before including this header then the default is used. To
 * change the maximum header size, define the macro in the build
 * environment (e.g. -DHTTP_MAX_HEADER_SIZE=<value>). To remove
 * the effective limit on the size of the header, define the macro
 * to a very large number (e.g. -DHTTP_MAX_HEADER_SIZE=0x7fffffff)
 */
#ifndef HTTP_MAX_HEADER_SIZE
# define HTTP_MAX_HEADER_SIZE (80 * 1024)
#endif

struct http_parser;
struct http_parser_settings;


/* Callbacks should return non-zero to indicate an error. The parser will
 * then halt execution.
 *
 * The one exception is on_headers_complete. In a HTTP_RESPONSE parser
 * returning '1' from on_headers_complete will tell the parser that it
 * should not expect a body. This is used when receiving a response to a
 * HEAD request which may contain 'Content-Length' or 'Transfer-Encoding:
 * chunked' headers that indicate the presence of a body.
 *
 * Returning `2` from on_headers_complete will tell parser that it should not
 * expect neither a body nor any futher responses on this connection. This is
 * useful for handling responses to a CONNECT request which may not contain
 * `Upgrade` or `Connection: upgrade` headers.
 *
 * http_data_cb does not return data chunks. It will be called arbitrarily
 * many times for each string. E.G. you might get 10 callbacks for "on_url"
 * each providing just a few characters more data.
 */
typedef int (*http_data_cb)(struct http_parser *, const char *at,
			    size_t length);
typedef int (*http_cb)(struct http_parser *);

enum http_method {
	HTTP_DELETE = 0,
	HTTP_GET = 1,
	HTTP_HEAD = 2,
	HTTP_POST = 3,
	HTTP_PUT = 4,
	HTTP_CONNECT = 5,
	HTTP_OPTIONS = 6,
	HTTP_TRACE = 7,
	HTTP_COPY = 8,
	HTTP_LOCK = 9,
	HTTP_MKCOL = 10,
	HTTP_MOVE = 11,
	HTTP_PROPFIND = 12,
	HTTP_PROPPATCH = 13,
	HTTP_SEARCH = 14,
	HTTP_UNLOCK = 15,
	HTTP_BIND = 16,
	HTTP_REBIND = 17,
	HTTP_UNBIND = 18,
	HTTP_ACL = 19,
	HTTP_REPORT = 20,
	HTTP_MKACTIVITY = 21,
	HTTP_CHECKOUT = 22,
	HTTP_MERGE = 23,
	HTTP_MSEARCH = 24,
	HTTP_NOTIFY = 25,
	HTTP_SUBSCRIBE = 26,
	HTTP_UNSUBSCRIBE = 27,
	HTTP_PATCH = 28,
	HTTP_PURGE = 29,
	HTTP_MKCALENDAR = 30,
	HTTP_LINK = 31,
	HTTP_UNLINK = 32
};

enum http_parser_type { HTTP_REQUEST, HTTP_RESPONSE, HTTP_BOTH };

/* Flag values for http_parser.flags field */
enum flags {
	F_CHUNKED               = 1 << 0,
	F_CONNECTION_KEEP_ALIVE = 1 << 1,
	F_CONNECTION_CLOSE      = 1 << 2,
	F_CONNECTION_UPGRADE    = 1 << 3,
	F_TRAILING              = 1 << 4,
	F_UPGRADE               = 1 << 5,
	F_SKIPBODY              = 1 << 6,
	F_CONTENTLENGTH         = 1 << 7
};

enum http_errno {
	HPE_OK,
	HPE_CB_message_begin,
	HPE_CB_url,
	HPE_CB_header_field,
	HPE_CB_header_value,
	HPE_CB_headers_complete,
	HPE_CB_body,
	HPE_CB_message_complete,
	HPE_CB_status,
	HPE_CB_chunk_header,
	HPE_CB_chunk_complete,
	HPE_INVALID_EOF_STATE,
	HPE_HEADER_OVERFLOW,
	HPE_CLOSED_CONNECTION,
	HPE_INVALID_VERSION,
	HPE_INVALID_STATUS,
	HPE_INVALID_METHOD,
	HPE_INVALID_URL,
	HPE_INVALID_HOST,
	HPE_INVALID_PORT,
	HPE_INVALID_PATH,
	HPE_INVALID_QUERY_STRING,
	HPE_INVALID_FRAGMENT,
	HPE_LF_EXPECTED,
	HPE_INVALID_HEADER_TOKEN,
	HPE_INVALID_CONTENT_LENGTH,
	HPE_UNEXPECTED_CONTENT_LENGTH,
	HPE_INVALID_CHUNK_SIZE,
	HPE_INVALID_CONSTANT,
	HPE_INVALID_INTERNAL_STATE,
	HPE_STRICT,
	HPE_PAUSED,
	HPE_UNKNOWN
};

/* Get an http_errno value from an http_parser */
#define HTTP_PARSER_ERRNO(p)            ((enum http_errno) (p)->http_errno)


struct http_parser {
	/** PRIVATE **/
	unsigned int type : 2;         /* enum http_parser_type */
	unsigned int flags : 8;		/* F_xxx values from 'flags' enum;
					 * semi-public
					 */
	unsigned int state : 7;        /* enum state from http_parser.c */
	unsigned int header_state : 7; /* enum header_state from http_parser.c
					*/
	unsigned int index : 7;        /* index into current matcher */
	unsigned int lenient_http_headers : 1;

	uint32_t nread;          /* # bytes read in various scenarios */
	uint64_t content_length; /* # bytes in body (0 if no Content-Length
				  * header)
				  */
	/** READ-ONLY **/
	unsigned short http_major;
	unsigned short http_minor;
	unsigned int status_code : 16; /* responses only */
	unsigned int method : 8;       /* requests only */
	unsigned int http_errno : 7;

	/* 1 = Upgrade header was present and the parser has exited because of
	 * that.
	 * 0 = No upgrade header present.
	 * Should be checked when http_parser_execute() returns in addition to
	 * error checking.
	 */
	unsigned int upgrade : 1;

	/** PUBLIC **/
	void *data; /* A pointer to get hook to the "connection" or "socket"
		     * object
		     */
};


struct http_parser_settings {
	http_cb      on_message_begin;
	http_data_cb on_url;
	http_data_cb on_status;
	http_data_cb on_header_field;
	http_data_cb on_header_value;
	http_cb      on_headers_complete;
	http_data_cb on_body;
	http_cb      on_message_complete;
	/* When on_chunk_header is called, the current chunk length is stored
	 * in parser->content_length.
	 */
	http_cb      on_chunk_header;
	http_cb      on_chunk_complete;
};


enum http_parser_url_fields {
	  UF_SCHEMA           = 0
	, UF_HOST             = 1
	, UF_PORT             = 2
	, UF_PATH             = 3
	, UF_QUERY            = 4
	, UF_FRAGMENT         = 5
	, UF_USERINFO         = 6
	, UF_MAX              = 7
};


/* Result structure for http_parser_parse_url().
 *
 * Callers should index into field_data[] with UF_* values iff field_set
 * has the relevant (1 << UF_*) bit set. As a courtesy to clients (and
 * because we probably have padding left over), we convert any port to
 * a uint16_t.
 */
struct http_parser_url {
	uint16_t field_set;           /* Bitmask of (1 << UF_*) values */
	uint16_t port;                /* Converted UF_PORT string */

	struct {
		uint16_t off;               /* Offset into buffer in which field
					     * starts
					     */
		uint16_t len;               /* Length of run in buffer */
	} field_data[UF_MAX];
};


/* Returns the library version. Bits 16-23 contain the major version number,
 * bits 8-15 the minor version number and bits 0-7 the patch level.
 * Usage example:
 *
 *   unsigned long version = http_parser_version();
 *   unsigned major = (version >> 16) & 255;
 *   unsigned minor = (version >> 8) & 255;
 *   unsigned patch = version & 255;
 *   printf("http_parser v%u.%u.%u\n", major, minor, patch);
 */
unsigned long http_parser_version(void);

void http_parser_init(struct http_parser *parser, enum http_parser_type type);


/* Initialize http_parser_settings members to 0
 */
void http_parser_settings_init(struct http_parser_settings *settings);


/* Executes the parser. Returns number of parsed bytes. Sets
 * `parser->http_errno` on error.
 */

int http_parser_execute(struct http_parser *parser,
			const struct http_parser_settings *settings,
			const char *data, size_t len);

/* If http_should_keep_alive() in the on_headers_complete or
 * on_message_complete callback returns 0, then this should be
 * the last message on the connection.
 * If you are the server, respond with the "Connection: close" header.
 * If you are the client, close the connection.
 */
int http_should_keep_alive(const struct http_parser *parser);

/* Returns a string version of the HTTP method. */
const char *http_method_str(enum http_method m);

/* Return a string name of the given error */
const char *http_errno_name(enum http_errno err);

/* Return a string description of the given error */
const char *http_errno_description(enum http_errno err);

/* Initialize all http_parser_url members to 0 */
void http_parser_url_init(struct http_parser_url *u);

/* Parse a URL; return nonzero on failure */
int http_parser_parse_url(const char *buf, size_t buflen,
			  int is_connect, struct http_parser_url *u);

/* Pause or un-pause the parser; a nonzero value pauses */
void http_parser_pause(struct http_parser *parser, int paused);

/* Checks if this is the final chunk of the body. */
int http_body_is_final(const struct http_parser *parser);

#ifdef __cplusplus
}
#endif
#endif