-- Prosody IM

-- Copyright (C) 2013 Florian Zeitz

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local format, char = string.format, string.char;

local pairs, ipairs = pairs, ipairs;

local t_insert, t_concat = table.insert, table.concat;

local url_codes = {};

for i = 0, 255 do

	local c = char(i);

	local u = format("%%%02x", i);

	url_codes[c] = u;

	url_codes[u] = c;

	url_codes[u:upper()] = c;

end

local function urlencode(s)

	return s and (s:gsub("[^a-zA-Z0-9.~_-]", url_codes));

end

local function urldecode(s)

	return s and (s:gsub("%%%x%x", url_codes));

end

local function _formencodepart(s)

	return s and (urlencode(s):gsub("%%20", "+"));

end

local function formencode(form)

	local result = {};

	if form[1] then -- Array of ordered { name, value }

		for _, field in ipairs(form) do

			t_insert(result, _formencodepart(field.name).."=".._formencodepart(field.value));

		end

	else -- Unordered map of name -> value

		for name, value in pairs(form) do

			t_insert(result, _formencodepart(name).."=".._formencodepart(value));

		end

	end

	return t_concat(result, "&");

end

local function formdecode(s)

	if not s:match("=") then return urldecode(s); end

	local r = {};

	for k, v in s:gmatch("([^=&]*)=([^&]*)") do

		k, v = k:gsub("%+", "%%20"), v:gsub("%+", "%%20");

		k, v = urldecode(k), urldecode(v);

		t_insert(r, { name = k, value = v });

		r[k] = v;

	end

	return r;

end

local function contains_token(field, token)

	field = ","..field:gsub("[ \t]", ""):lower()..",";

	return field:find(","..token:lower()..",", 1, true) ~= nil;

end

local function normalize_path(path, is_dir)

	if is_dir then

		if path:sub(-1,-1) ~= "/" then path = path.."/"; end

	else

		if path:sub(-1,-1) == "/" then path = path:sub(1, -2); end

	end

	if path:sub(1,1) ~= "/" then path = "/"..path; end

	return path;

end

--- Parse the RFC 7239 Forwarded header into array of key-value pairs.

local function parse_forwarded(forwarded)

	if type(forwarded) ~= "string" then

		return nil;

	end

	local fwd = {}; -- array

	local cur = {}; -- map, to which we add the next key-value pair

	for key, quoted, value, delim in forwarded:gmatch("(%w+)%s*=%s*(\"?)([^,;\"]+)%2%s*(.?)") do

		-- FIXME quoted quotes like "foo\"bar"

		-- unlikely when only dealing with IP addresses

		if quoted == '"' then

			value = value:gsub("\\(.)", "%1");

		end

		cur[key:lower()] = value;

		if delim == "" or delim == "," then

			t_insert(fwd, cur)

			if delim == "" then

				-- end of the string

				break;

			end

			cur = {};

		elseif delim ~= ";" then

			-- misparsed

			return false;

		end

	end

	return fwd;

end

return {

	urlencode = urlencode, urldecode = urldecode;

	formencode = formencode, formdecode = formdecode;

	contains_token = contains_token;

	normalize_path = normalize_path;

	parse_forwarded = parse_forwarded;

};