-- RFC 7230

-- Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing

local lpeg = require "lpeg"

local core = require "lpeg_patterns.core"

local uri = require "lpeg_patterns.uri"

local util = require "lpeg_patterns.util"

local C = lpeg.C

local Cc = lpeg.Cc

local Cf = lpeg.Cf

local Cg = lpeg.Cg

local Cs = lpeg.Cs

local Ct = lpeg.Ct

local P = lpeg.P

local R = lpeg.R

local S = lpeg.S

local V = lpeg.V

-- RFC 7230 Section 3.2.3

local OWS = (core.SP + core.HTAB)^0

local RWS = (core.SP + core.HTAB)^1

local BWS = OWS

-- Analogue to RFC 7230 Section 7's ABNF extension of '#'

-- Also documented as `#rule` under RFC 2616 Section 2.1

local sep = OWS * lpeg.P "," * OWS

local optional_sep = (lpeg.P"," + core.SP + core.HTAB)^0

local function comma_sep(element, min, max)

end

-- allows leading + trailing

local function comma_sep_trim(...)

return optional_sep * comma_sep(...) * optional_sep

end

-- RFC 7230 Section 2.6

local HTTP_name = P"HTTP"

local HTTP_version = HTTP_name * P"/" * (core.DIGIT * P"." * core.DIGIT / util.safe_tonumber)

-- RFC 7230 Section 2.7

local absolute_path = (P"/" * uri.segment )^1

local partial_uri = Ct(uri.relative_part * (P"?" * uri.query)^-1)

-- RFC 7230 Section 3.2.6

local tchar = S "!#$%&'*+-.^_`|~" + core.DIGIT + core.ALPHA

local token = C(tchar^1)

local obs_text = R("\128\255")

local qdtext = core.HTAB + core.SP + P"\33" + R("\35\91", "\93\126") + obs_text

local quoted_pair = Cs(P"\\" * C(core.HTAB + core.SP + core.VCHAR + obs_text) / "%1")

local quoted_string = core.DQUOTE * Cs((qdtext + quoted_pair)^0) * core.DQUOTE

local ctext = core.HTAB + core.SP + R("\33\39", "\42\91", "\93\126") + obs_text

local comment = P { P"(" * ( ctext + quoted_pair + V(1) )^0 * P")" }

-- RFC 7230 Section 3.2

local field_name = token / string.lower -- case insensitive

local field_vchar = core.VCHAR + obs_text

local field_content = field_vchar * (( core.SP + core.HTAB )^1 * field_vchar)^-1

local obs_fold = ( core.SP + core.HTAB )^0 * core.CRLF * ( core.SP + core.HTAB )^1 / " "

-- field_value is not correct, see Errata: https://www.rfc-editor.org/errata_search.php?rfc=7230&eid=4189

local field_value = Cs((field_content + obs_fold)^0)

local header_field = field_name * P":" * OWS * field_value * OWS

-- RFC 7230 Section 3.3.2

local Content_Length = core.DIGIT^1

-- RFC 7230 Section 4

-- See https://www.rfc-editor.org/errata_search.php?rfc=7230&eid=4683

local transfer_parameter = (token - S"qQ" * BWS * P"=") * BWS * P"=" * BWS * ( token + quoted_string )

local transfer_extension = Cf(Ct(token / string.lower) -- case insensitive

* ( OWS * P";" * OWS * Cg(transfer_parameter) )^0, rawset)

local transfer_coding = transfer_extension

-- RFC 7230 Section 3.3.1

local Transfer_Encoding = comma_sep_trim(transfer_coding, 1)

-- RFC 7230 Section 4.1.1

local chunk_ext_name = token

local chunk_ext_val = token + quoted_string

-- See https://www.rfc-editor.org/errata_search.php?rfc=7230&eid=4667

local chunk_ext = ( P";" * chunk_ext_name * ( P"=" * chunk_ext_val)^-1 )^0

-- RFC 7230 Section 4.3

local rank = (P"0" * ((P"." * core.DIGIT^-3) / util.safe_tonumber + Cc(0)) + P"1" * ("." * (P"0")^-3)^-1) * Cc(1)

local t_ranking = OWS * P";" * OWS * S"qQ" * P"=" * rank -- q is case insensitive

local t_codings = (transfer_coding * t_ranking^-1) / function(t, q)

if q then

t["q"] = q

end

return t

end

local TE = comma_sep_trim(t_codings)

-- RFC 7230 Section 4.4

local Trailer = comma_sep_trim(field_name, 1)

-- RFC 7230 Section 5.3

local origen_form = Cs(absolute_path * (P"?" * uri.query)^-1)

local absolute_form = util.no_rich_capture(uri.absolute_uri)

local authority_form = util.no_rich_capture(uri.authority)

local asterisk_form = C"*"

local request_target = asterisk_form + origen_form + absolute_form + authority_form

-- RFC 7230 Section 3.1.1

local method = token

local request_line = method * core.SP * request_target * core.SP * HTTP_version * core.CRLF

-- RFC 7230 Section 5.4

local Host = uri.host * (P":" * uri.port)^-1

-- RFC 7230 Section 6.7

local protocol_name = token

local protocol_version = token

local protocol = protocol_name * (P"/" * protocol_version)^-1 / "%0"

local Upgrade = comma_sep_trim(protocol)

-- RFC 7230 Section 5.7.1

local received_protocol = (protocol_name * P"/" + Cc("HTTP")) * protocol_version / "%1/%2"

local pseudonym = token

-- workaround for https://lists.w3.org/Archives/Public/ietf-http-wg/2016OctDec/0527.html

local received_by = uri.host * ((P":" * uri.port) + -lpeg.B(",")) / "%0" + pseudonym

local Via = comma_sep_trim(Ct(

Cg(received_protocol, "protocol")

* RWS * Cg(received_by, "by")

* (RWS * Cg(comment, "comment"))^-1

), 1)

-- RFC 7230 Section 6.1

local connection_option = token / string.lower -- case insensitive

local Connection = comma_sep_trim(connection_option)

return {

comma_sep = comma_sep;

comma_sep_trim = comma_sep_trim;

OWS = OWS;

RWS = RWS;

BWS = BWS;

chunk_ext = chunk_ext;

comment = comment;

field_name = field_name;

field_value = field_value;

header_field = header_field;

method = method;

obs_text = obs_text;

partial_uri = partial_uri;

pseudonym = pseudonym;

qdtext = qdtext;

quoted_string = quoted_string;

rank = rank;

request_line = request_line;

request_target = request_target;

t_ranking = t_ranking;

tchar = tchar;

token = token;

Connection = Connection;

Content_Length = Content_Length;

Host = Host;

TE = TE;

Trailer = Trailer;

Transfer_Encoding = Transfer_Encoding;

Upgrade = Upgrade;

Via = Via;

}