--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_carbons/mod_carbons.lua	Sat Oct 29 19:59:48 2011 +0200
@@ -0,0 +1,129 @@
+local st = require "util.stanza";
+local jid_bare = require "util.jid".bare;
+local jid_split = require "util.jid".split;
+local xmlns_carbons = "urn:xmpp:carbons:1";
+local xmlns_forward = "urn:xmpp:forward:0";
+local host_sessions = hosts[module.host].sessions;
+
+-- TODO merge message handlers into one somehow
+
+module:hook("iq/self/"..xmlns_carbons..":enable", function(event)
+	local origin, stanza = event.origin, event.stanza;
+	if stanza.attr.type == "set" then
+		module:log("debug", "%s enabled carbons", origin.full_jid);
+		origin.want_carbons = true;
+		origin.send(st.reply(stanza));
+		return true
+	end
+end);
+
+module:hook("iq/self/"..xmlns_carbons..":disable", function(event)
+	local origin, stanza = event.origin, event.stanza;
+	if stanza.attr.type == "set" then
+		module:log("debug", "%s disabled carbons", origin.full_jid);
+		origin.want_carbons = nil;
+		origin.send(st.reply(stanza));
+		return true
+	end
+end);
+
+function c2s_message_handler(event)
+	local origin, stanza = event.origin, event.stanza;
+	local orig_type = stanza.attr.type;
+	local orig_to = stanza.attr.to;
+	
+	if not (orig_type == nil
+			or orig_type == "normal"
+			or orig_type == "chat") then
+		return
+	end
+
+	local bare_jid, user_sessions;
+	if origin.type == "s2s" then
+		bare_jid = jid_bare(stanza.attr.from);
+		user_sessions = host_sessions[jid_split(orig_to)];
+	else
+		bare_jid = (origin.username.."@"..origin.host)
+		user_sessions = host_sessions[origin.username];
+	end
+
+	if not stanza:get_child("private", xmlns_carbons)
+			and not stanza:get_child("forwarded", xmlns_forward) then
+		user_sessions = user_sessions and user_sessions.sessions;
+		for resource, session in pairs(user_sessions) do
+			local full_jid = bare_jid .. "/" .. resource;
+			if session ~= origin and session.want_carbons then
+				local msg = st.clone(stanza);
+				msg.attr.xmlns = msg.attr.xmlns or "jabber:client";
+				local fwd = st.message{
+							from = bare_jid,
+							to = full_jid,
+							type = orig_type,
+						}
+					:tag("forwarded", { xmlns = xmlns_forward })
+						:tag("received", { xmlns = xmlns_carbons }):up()
+							:add_child(msg);
+				core_route_stanza(origin, fwd);
+			end
+		end
+	end
+end
+
+function s2c_message_handler(event)
+	local origin, stanza = event.origin, event.stanza;
+	local orig_type = stanza.attr.type;
+	local orig_to = stanza.attr.to;
+	
+	if not (orig_type == nil
+			or orig_type == "normal"
+			or orig_type == "chat") then
+		return
+	end
+
+	local full_jid, bare_jid = orig_to, jid_bare(orig_to);
+	local username, hostname, resource = jid_split(full_jid);
+	local user_sessions = username and host_sessions[username];
+	if not user_sessions or hostname ~= module.host then
+		return
+	end
+
+	local no_carbon_to = {};
+	if resource then
+		no_carbon_to[resource] = true;
+	else
+		local top_resources = user_sessions.top_resources;
+		for i=1,top_resources do
+			no_carbon_to[top_resources[i]] = true;
+		end
+	end
+
+	if not stanza:get_child("private", xmlns_carbons)
+			and not stanza:get_child("forwarded", xmlns_forward) then
+		user_sessions = user_sessions and user_sessions.sessions;
+		for resource, session in pairs(user_sessions) do
+			local full_jid = bare_jid .. "/" .. resource;
+			if not no_carbon_to[resource] and session.want_carbons then
+				local msg = st.clone(stanza);
+				msg.attr.xmlns = msg.attr.xmlns or "jabber:client";
+				local fwd = st.message{
+							from = bare_jid,
+							to = full_jid,
+							type = orig_type,
+						}
+					:tag("forwarded", { xmlns = xmlns_forward })
+						:tag("received", { xmlns = xmlns_carbons }):up()
+							:add_child(msg);
+				core_route_stanza(origin, fwd);
+			end
+		end
+	end
+end
+
+-- Stanzas sent by local clients
+module:hook("pre-message/bare", c2s_message_handler, 1);
+module:hook("pre-message/full", c2s_message_handler, 1);
+-- Stanszas to local clients
+module:hook("message/bare", s2c_message_handler, 1); -- this will suck
+module:hook("message/full", s2c_message_handler, 1);
+
+module:add_feature(xmlns_carbons);