/* 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 wpi_http_parser_h
#define wpi_http_parser_h

/* Also update SONAME in the Makefile whenever you change these. */
#define HTTP_PARSER_VERSION_MAJOR 2
#define HTTP_PARSER_VERSION_MINOR 8
#define HTTP_PARSER_VERSION_PATCH 1

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

/* Compile with -DHTTP_PARSER_STRICT=0 to make less checks, but run
 * faster
 */
#ifndef HTTP_PARSER_STRICT
# define HTTP_PARSER_STRICT 1
#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

namespace wpi {

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) (http_parser*, const char *at, size_t length);
typedef int (*http_cb) (http_parser*);


/* Status Codes */
#define HTTP_STATUS_MAP(XX)                                                 \
  XX(100, CONTINUE,                        Continue)                        \
  XX(101, SWITCHING_PROTOCOLS,             Switching Protocols)             \
  XX(102, PROCESSING,                      Processing)                      \
  XX(200, OK,                              OK)                              \
  XX(201, CREATED,                         Created)                         \
  XX(202, ACCEPTED,                        Accepted)                        \
  XX(203, NON_AUTHORITATIVE_INFORMATION,   Non-Authoritative Information)   \
  XX(204, NO_CONTENT,                      No Content)                      \
  XX(205, RESET_CONTENT,                   Reset Content)                   \
  XX(206, PARTIAL_CONTENT,                 Partial Content)                 \
  XX(207, MULTI_STATUS,                    Multi-Status)                    \
  XX(208, ALREADY_REPORTED,                Already Reported)                \
  XX(226, IM_USED,                         IM Used)                         \
  XX(300, MULTIPLE_CHOICES,                Multiple Choices)                \
  XX(301, MOVED_PERMANENTLY,               Moved Permanently)               \
  XX(302, FOUND,                           Found)                           \
  XX(303, SEE_OTHER,                       See Other)                       \
  XX(304, NOT_MODIFIED,                    Not Modified)                    \
  XX(305, USE_PROXY,                       Use Proxy)                       \
  XX(307, TEMPORARY_REDIRECT,              Temporary Redirect)              \
  XX(308, PERMANENT_REDIRECT,              Permanent Redirect)              \
  XX(400, BAD_REQUEST,                     Bad Request)                     \
  XX(401, UNAUTHORIZED,                    Unauthorized)                    \
  XX(402, PAYMENT_REQUIRED,                Payment Required)                \
  XX(403, FORBIDDEN,                       Forbidden)                       \
  XX(404, NOT_FOUND,                       Not Found)                       \
  XX(405, METHOD_NOT_ALLOWED,              Method Not Allowed)              \
  XX(406, NOT_ACCEPTABLE,                  Not Acceptable)                  \
  XX(407, PROXY_AUTHENTICATION_REQUIRED,   Proxy Authentication Required)   \
  XX(408, REQUEST_TIMEOUT,                 Request Timeout)                 \
  XX(409, CONFLICT,                        Conflict)                        \
  XX(410, GONE,                            Gone)                            \
  XX(411, LENGTH_REQUIRED,                 Length Required)                 \
  XX(412, PRECONDITION_FAILED,             Precondition Failed)             \
  XX(413, PAYLOAD_TOO_LARGE,               Payload Too Large)               \
  XX(414, URI_TOO_LONG,                    URI Too Long)                    \
  XX(415, UNSUPPORTED_MEDIA_TYPE,          Unsupported Media Type)          \
  XX(416, RANGE_NOT_SATISFIABLE,           Range Not Satisfiable)           \
  XX(417, EXPECTATION_FAILED,              Expectation Failed)              \
  XX(421, MISDIRECTED_REQUEST,             Misdirected Request)             \
  XX(422, UNPROCESSABLE_ENTITY,            Unprocessable Entity)            \
  XX(423, LOCKED,                          Locked)                          \
  XX(424, FAILED_DEPENDENCY,               Failed Dependency)               \
  XX(426, UPGRADE_REQUIRED,                Upgrade Required)                \
  XX(428, PRECONDITION_REQUIRED,           Precondition Required)           \
  XX(429, TOO_MANY_REQUESTS,               Too Many Requests)               \
  XX(431, REQUEST_HEADER_FIELDS_TOO_LARGE, Request Header Fields Too Large) \
  XX(451, UNAVAILABLE_FOR_LEGAL_REASONS,   Unavailable For Legal Reasons)   \
  XX(500, INTERNAL_SERVER_ERROR,           Internal Server Error)           \
  XX(501, NOT_IMPLEMENTED,                 Not Implemented)                 \
  XX(502, BAD_GATEWAY,                     Bad Gateway)                     \
  XX(503, SERVICE_UNAVAILABLE,             Service Unavailable)             \
  XX(504, GATEWAY_TIMEOUT,                 Gateway Timeout)                 \
  XX(505, HTTP_VERSION_NOT_SUPPORTED,      HTTP Version Not Supported)      \
  XX(506, VARIANT_ALSO_NEGOTIATES,         Variant Also Negotiates)         \
  XX(507, INSUFFICIENT_STORAGE,            Insufficient Storage)            \
  XX(508, LOOP_DETECTED,                   Loop Detected)                   \
  XX(510, NOT_EXTENDED,                    Not Extended)                    \
  XX(511, NETWORK_AUTHENTICATION_REQUIRED, Network Authentication Required) \

enum http_status
  {
#define XX(num, name, string) HTTP_STATUS_##name = num,
  HTTP_STATUS_MAP(XX)
#undef XX
  };


/* Request Methods */
#define HTTP_METHOD_MAP(XX)         \
  XX(0,  DELETE,      DELETE)       \
  XX(1,  GET,         GET)          \
  XX(2,  HEAD,        HEAD)         \
  XX(3,  POST,        POST)         \
  XX(4,  PUT,         PUT)          \
  /* pathological */                \
  XX(5,  CONNECT,     CONNECT)      \
  XX(6,  OPTIONS,     OPTIONS)      \
  XX(7,  TRACE,       TRACE)        \
  /* WebDAV */                      \
  XX(8,  COPY,        COPY)         \
  XX(9,  LOCK,        LOCK)         \
  XX(10, MKCOL,       MKCOL)        \
  XX(11, MOVE,        MOVE)         \
  XX(12, PROPFIND,    PROPFIND)     \
  XX(13, PROPPATCH,   PROPPATCH)    \
  XX(14, SEARCH,      SEARCH)       \
  XX(15, UNLOCK,      UNLOCK)       \
  XX(16, BIND,        BIND)         \
  XX(17, REBIND,      REBIND)       \
  XX(18, UNBIND,      UNBIND)       \
  XX(19, ACL,         ACL)          \
  /* subversion */                  \
  XX(20, REPORT,      REPORT)       \
  XX(21, MKACTIVITY,  MKACTIVITY)   \
  XX(22, CHECKOUT,    CHECKOUT)     \
  XX(23, MERGE,       MERGE)        \
  /* upnp */                        \
  XX(24, MSEARCH,     M-SEARCH)     \
  XX(25, NOTIFY,      NOTIFY)       \
  XX(26, SUBSCRIBE,   SUBSCRIBE)    \
  XX(27, UNSUBSCRIBE, UNSUBSCRIBE)  \
  /* RFC-5789 */                    \
  XX(28, PATCH,       PATCH)        \
  XX(29, PURGE,       PURGE)        \
  /* CalDAV */                      \
  XX(30, MKCALENDAR,  MKCALENDAR)   \
  /* RFC-2068, section 19.6.1.2 */  \
  XX(31, LINK,        LINK)         \
  XX(32, UNLINK,      UNLINK)       \
  /* icecast */                     \
  XX(33, SOURCE,      SOURCE)       \

enum http_method
  {
#define XX(num, name, string) HTTP_##name = num,
  HTTP_METHOD_MAP(XX)
#undef XX
  };


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
  };


/* Map for errno-related constants
 *
 * The provided argument should be a macro that takes 2 arguments.
 */
#define HTTP_ERRNO_MAP(XX)                                           \
  /* No error */                                                     \
  XX(OK, "success")                                                  \
                                                                     \
  /* Callback-related errors */                                      \
  XX(CB_message_begin, "the on_message_begin callback failed")       \
  XX(CB_url, "the on_url callback failed")                           \
  XX(CB_header_field, "the on_header_field callback failed")         \
  XX(CB_header_value, "the on_header_value callback failed")         \
  XX(CB_headers_complete, "the on_headers_complete callback failed") \
  XX(CB_body, "the on_body callback failed")                         \
  XX(CB_message_complete, "the on_message_complete callback failed") \
  XX(CB_status, "the on_status callback failed")                     \
  XX(CB_chunk_header, "the on_chunk_header callback failed")         \
  XX(CB_chunk_complete, "the on_chunk_complete callback failed")     \
                                                                     \
  /* Parsing-related errors */                                       \
  XX(INVALID_EOF_STATE, "stream ended at an unexpected time")        \
  XX(HEADER_OVERFLOW,                                                \
     "too many header bytes seen; overflow detected")                \
  XX(CLOSED_CONNECTION,                                              \
     "data received after completed connection: close message")      \
  XX(INVALID_VERSION, "invalid HTTP version")                        \
  XX(INVALID_STATUS, "invalid HTTP status code")                     \
  XX(INVALID_METHOD, "invalid HTTP method")                          \
  XX(INVALID_URL, "invalid URL")                                     \
  XX(INVALID_HOST, "invalid host")                                   \
  XX(INVALID_PORT, "invalid port")                                   \
  XX(INVALID_PATH, "invalid path")                                   \
  XX(INVALID_QUERY_STRING, "invalid query string")                   \
  XX(INVALID_FRAGMENT, "invalid fragment")                           \
  XX(LF_EXPECTED, "LF character expected")                           \
  XX(INVALID_HEADER_TOKEN, "invalid character in header")            \
  XX(INVALID_CONTENT_LENGTH,                                         \
     "invalid character in content-length header")                   \
  XX(UNEXPECTED_CONTENT_LENGTH,                                      \
     "unexpected content-length header")                             \
  XX(INVALID_CHUNK_SIZE,                                             \
     "invalid character in chunk size header")                       \
  XX(INVALID_CONSTANT, "invalid constant string")                    \
  XX(INVALID_INTERNAL_STATE, "encountered unexpected internal state")\
  XX(STRICT, "strict mode assertion failed")                         \
  XX(PAUSED, "parser is paused")                                     \
  XX(UNKNOWN, "an unknown error occurred")


/* Define HPE_* values for each errno value above */
#define HTTP_ERRNO_GEN(n, s) HPE_##n,
enum http_errno {
  HTTP_ERRNO_MAP(HTTP_ERRNO_GEN)
};
#undef HTTP_ERRNO_GEN


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


struct http_parser {
  /** PRIVATE **/
  unsigned int type : 2;         /* enum http_parser_type */
  unsigned int flags : 8;        /* F_* 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(http_parser *parser, enum http_parser_type type);


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


/* Executes the parser. Returns number of parsed bytes. Sets
 * `parser->http_errno` on error. */
size_t http_parser_execute(http_parser *parser,
                           const 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 http_parser *parser);

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

/* Returns a string version of the HTTP status code. */
const char *http_status_str(enum http_status s);

/* 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(http_parser *parser, int paused);

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

}  // namespace wpi

#endif