-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- 

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

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

--

if module:get_host_type() ~= "component" then

	error("Don't load mod_component manually, it should be for a component, please see http://prosody.im/doc/components", 0);

end

local hosts = _G.hosts;

local t_concat = table.concat;

local sha1 = require "util.hashes".sha1;

local st = require "util.stanza";

local log = module._log;

local main_session, send;

local function on_destroy(session, err)

	if main_session == session then

		main_session = nil;

		send = nil;

		session.on_destroy = nil;

	end

end

local function handle_stanza(event)

	local stanza = event.stanza;

	if send then

		stanza.attr.xmlns = nil;

		send(stanza);

	else

		log("warn", "Stanza being handled by default component; bouncing error for: %s", stanza:top_tag());

		if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

			event.origin.send(st.error_reply(stanza, "wait", "service-unavailable", "Component unavailable"));

		end

	end

	return true;

end

--- Handle authentication attempts by components

function handle_component_auth(event)

	local session, stanza = event.origin, event.stanza;

	if session.type ~= "component" then return; end

	if main_session == session then return; end

	if (not session.host) or #stanza.tags > 0 then

		(session.log or log)("warn", "Invalid component handshake for host: %s", session.host);

		session:close("not-authorized");

		return true;

	end

	local secret = module:get_option("component_secret");

	if not secret then

		(session.log or log)("warn", "Component attempted to identify as %s, but component_secret is not set", session.host);

		session:close("not-authorized");

		return true;

	end

	local supplied_token = t_concat(stanza);

	local calculated_token = sha1(session.streamid..secret, true);

	if supplied_token:lower() ~= calculated_token:lower() then

		log("info", "Component authentication failed for %s", session.host);

		session:close{ condition = "not-authorized", text = "Given token does not match calculated token" };

		return true;

	end

	-- If component not already created for this host, create one now

	if not main_session then

		send = session.send;

		main_session = session;

		session.on_destroy = on_destroy;

		session.component_validate_from = module:get_option_boolean("validate_from_addresses") ~= false;

		log("info", "Component successfully authenticated: %s", session.host);

		session.send(st.stanza("handshake"));

	else -- TODO: Implement stanza distribution

		log("error", "Multiple components bound to the same address, first one wins: %s", session.host);

		session:close{ condition = "conflict", text = "Component already connected" };

	end

	return true;

end

module:hook("stanza/jabber:component:accept:handshake", handle_component_auth);