HttpDataProc* = proc (a2: ptr THttpParser; at: cstring; length: csize): cint {.
    cdecl.}

HttpProc* = proc (a2: ptr THttpParser): cint {.cdecl.}

THttpMethod* = enum 
  HTTP_DELETE = 0, HTTP_GET, HTTP_HEAD, HTTP_POST, HTTP_PUT, HTTP_CONNECT, 
  HTTP_OPTIONS, HTTP_TRACE, HTTP_COPY, HTTP_LOCK, HTTP_MKCOL, HTTP_MOVE, 
  HTTP_PROPFIND, HTTP_PROPPATCH, HTTP_UNLOCK, HTTP_REPORT, HTTP_MKACTIVITY, 
  HTTP_CHECKOUT, HTTP_MERGE, HTTP_MSEARCH, HTTP_NOTIFY, HTTP_SUBSCRIBE, 
  HTTP_UNSUBSCRIBE, HTTP_PATCH

THttpParserType* = enum 
  HTTP_REQUEST, HTTP_RESPONSE, HTTP_BOTH

TParserFlag* = enum 
  F_CHUNKED = 1 shl 0, F_CONNECTION_KEEP_ALIVE = 1 shl 1, 
  F_CONNECTION_CLOSE = 1 shl 2, F_TRAILING = 1 shl 3, F_UPGRADE = 1 shl 4, 
  F_SKIPBODY = 1 shl 5

THttpErrNo* = enum 
  HPE_OK, HPE_CB_message_begin, HPE_CB_path, HPE_CB_query_string, HPE_CB_url, 
  HPE_CB_fragment, HPE_CB_header_field, HPE_CB_header_value, 
  HPE_CB_headers_complete, HPE_CB_body, HPE_CB_message_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_INVALID_CHUNK_SIZE, 
  HPE_INVALID_CONSTANT, HPE_INVALID_INTERNAL_STATE, HPE_STRICT, HPE_UNKNOWN

THttpParser* {.pure, final, importc: "http_parser", header: "http_parser.h".} = object 
  typ {.importc: "type".}: char
  flags {.importc: "flags".}: char
  state* {.importc: "state".}: char
  header_state* {.importc: "header_state".}: char
  index* {.importc: "index".}: char
  nread* {.importc: "nread".}: cint
  content_length* {.importc: "content_length".}: int64
  http_major* {.importc: "http_major".}: cshort
  http_minor* {.importc: "http_minor".}: cshort
  status_code* {.importc: "status_code".}: cshort
  http_method* {.importc: "method".}: cshort
  http_errno_bits {.importc: "http_errno".}: char
  upgrade {.importc: "upgrade".}: bool
  data* {.importc: "data".}: pointer

THttpParserSettings* {.pure, final, importc: "http_parser_settings", 
                       header: "http_parser.h".} = object 
  on_message_begin* {.importc: "on_message_begin".}: HttpProc
  on_url* {.importc: "on_url".}: HttpDataProc
  on_header_field* {.importc: "on_header_field".}: HttpDataProc
  on_header_value* {.importc: "on_header_value".}: HttpDataProc
  on_headers_complete* {.importc: "on_headers_complete".}: HttpProc
  on_body* {.importc: "on_body".}: HttpDataProc
  on_message_complete* {.importc: "on_message_complete".}: HttpProc

proc http_parser_init*(parser: var THttpParser; typ: THttpParserType) {.
    importc: "http_parser_init", header: "http_parser.h".}

proc http_parser_execute*(parser: var THttpParser; 
                          settings: var THttpParserSettings; data: cstring; 
                          len: csize): csize {.importc: "http_parser_execute", 
    header: "http_parser.h".}

proc http_should_keep_alive*(parser: var THttpParser): cint {.
    importc: "http_should_keep_alive", header: "http_parser.h".}

proc http_method_str*(m: THttpMethod): cstring {.importc: "http_method_str", 
    header: "http_parser.h".}

proc http_errno_name*(err: THttpErrNo): cstring {.importc: "http_errno_name", 
    header: "http_parser.h".}

proc http_errno_description*(err: THttpErrNo): cstring {.
    importc: "http_errno_description", header: "http_parser.h".}