local base64 = require "base64"

local log = require "util.logger".init("sasl");

local tostring = tostring;

local st = require "util.stanza";

local s_match = string.match;

module "sasl"

local function new_plain(onAuth, onSuccess, onFail, onWrite)

	local object = { mechanism = "PLAIN", onAuth = onAuth, onSuccess = onSuccess, onFail = onFail,

	 				onWrite = onWrite}

	--local challenge = base64.encode("");

	--onWrite(st.stanza("challenge", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):text(challenge))

	object.feed = 	function(self, stanza)

						if stanza.name ~= "response" and stanza.name ~= "auth" then self.onFail("invalid-stanza-tag") end

						if stanza.attr.xmlns ~= "urn:ietf:params:xml:ns:xmpp-sasl" then self.onFail("invalid-stanza-namespace") end

						local response = base64.decode(stanza[1])

						local authorization = s_match(response, "([^&%z]+)")

						local authentication = s_match(response, "%z([^&%z]+)%z")

						local password = s_match(response, "%z[^&%z]+%z([^&%z]+)")

						if self.onAuth(authentication, password) == true then

							self.onWrite(st.stanza("success", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}))

							self.onSuccess(authentication)

						else

							self.onWrite(st.stanza("failure", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):tag("temporary-auth-failure"));

						end

					end

	return object

end

function new(mechanism, onAuth, onSuccess, onFail, onWrite)

	local object

	if mechanism == "PLAIN" then object = new_plain(onAuth, onSuccess, onFail, onWrite)

	else

		log("debug", "Unsupported SASL mechanism: "..tostring(mechanism));

		onFail("unsupported-mechanism")

	end

	return object

end

return _M;