--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/muc/occupant.lib.lua	Thu Mar 27 19:16:13 2014 -0400
@@ -0,0 +1,85 @@
+local next = next;
+local pairs = pairs;
+local setmetatable = setmetatable;
+local st = require "util.stanza";
+
+local get_filtered_presence do
+	local presence_filters = {
+		["http://jabber.org/protocol/muc"] = true;
+		["http://jabber.org/protocol/muc#user"] = true;
+	}
+	local function presence_filter(tag)
+		if presence_filters[tag.attr.xmlns] then
+			return nil;
+		end
+		return tag;
+	end
+	function get_filtered_presence(stanza)
+		return st.clone(stanza):maptags(presence_filter);
+	end
+end
+
+local occupant_mt = {};
+occupant_mt.__index = occupant_mt;
+
+local function new_occupant(bare_real_jid, nick)
+	return setmetatable({
+		bare_jid = bare_real_jid;
+		nick = nick; -- in-room jid
+		sessions = {}; -- hash from real_jid to presence stanzas. stanzas should not be modified
+		role = nil;
+		jid = nil; -- Primary session
+	}, occupant_mt);
+end
+
+-- Deep copy an occupant
+local function copy_occupant(occupant)
+	local sessions = {};
+	for full_jid, presence_stanza in pairs(occupant.sessions) do
+		if presence_stanza.attr.type ~= "unavailable" then
+			sessions[full_jid] = presence_stanza;
+		end
+	end
+	return setmetatable({
+		bare_jid = occupant.bare_jid;
+		nick = occupant.nick;
+		sessions = sessions;
+		role = occupant.role;
+		jid = occupant.jid;
+	}, occupant_mt);
+end
+
+function occupant_mt:set_session(real_jid, presence_stanza, replace_primary)
+	local pr = get_filtered_presence(presence_stanza);
+	pr.attr.from = self.nick;
+	pr.attr.to = real_jid;
+
+	self.sessions[real_jid] = pr;
+	if replace_primary or self.jid == nil then
+		self.jid = real_jid;
+	end
+end
+
+function occupant_mt:remove_session(real_jid)
+	-- Delete original session
+	local presence_stanza = self.sessions[real_jid];
+	self.sessions[real_jid] = nil;
+	if self.jid == real_jid then
+		-- find another session to be the primary (might be nil)
+		self.jid = next(self.sessions);
+	end
+end
+
+function occupant_mt:each_session()
+	return pairs(self.sessions)
+end
+
+function occupant_mt:get_presence(real_jid)
+	return self.sessions[real_jid or self.jid]
+end
+
+return {
+	new = new_occupant;
+	copy = copy_occupant;
+	mt = occupant_mt;
+}