--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_service_directories/mod_service_directories.lua	Sun Jan 15 02:56:51 2012 +0500
@@ -0,0 +1,179 @@
+-- Prosody IM
+-- Copyright (C) 2011 Waqas Hussain
+-- 
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+-- An implementation of [XEP-0309: Service Directories]
+
+-- Imports and defines
+
+local st = require "util.stanza";
+local jid_split = require "util.jid".split;
+local adhoc_new = module:require "adhoc".new;
+local to_ascii = require "util.encodings".idna.to_ascii;
+local nameprep = require "util.encodings".stringprep.nameprep;
+local core_post_stanza = core_post_stanza;
+local pairs, ipairs = pairs, ipairs;
+local module = module;
+local hosts = hosts;
+
+local subscription_from = {};
+local subscription_to = {};
+local contact_features = {};
+local contact_vcards = {};
+
+-- Advertise in disco
+
+module:add_identity("server", "directory", "Prosody");
+module:add_feature("urn:xmpp:server-presence");
+
+-- Handle subscriptions
+
+module:hook("presence/host", function(event) -- inbound presence to the host
+	local origin, stanza = event.origin, event.stanza;
+
+	local node, host, resource = jid_split(stanza.attr.from);
+	if stanza.attr.from ~= host then return; end -- not from a host
+
+	local t = stanza.attr.type;
+	if t == "probe" then
+		core_post_stanza(hosts[module.host], st.presence({ from = module.host, to = host, id = stanza.attr.id }));
+	elseif t == "subscribe" then
+		subscription_from[host] = true;
+		core_post_stanza(hosts[module.host], st.presence({ from = module.host, to = host, id = stanza.attr.id, type = "subscribed" }));
+		core_post_stanza(hosts[module.host], st.presence({ from = module.host, to = host, id = stanza.attr.id }));
+		add_contact(host);
+	elseif t == "subscribed" then
+		subscription_to[host] = true;
+		query_host(host);
+	elseif t == "unsubscribe" then
+		subscription_from[host] = nil;
+		core_post_stanza(hosts[module.host], st.presence({ from = module.host, to = host, id = stanza.attr.id, type = "unsubscribed" }));
+		remove_contact(host);
+	elseif t == "unsubscribed" then
+		subscription_to[host] = nil;
+		remove_contact(host);
+	end
+	return true;
+end, 10); -- priority over mod_presence
+
+function remove_contact(host, id)
+	contact_features[host] = nil;
+	contact_vcards[host] = nil;
+	if subscription_to[host] then
+		subscription_to[host] = nil;
+		core_post_stanza(hosts[module.host], st.presence({ from = module.host, to = host, id = id, type = "unsubscribe" }));
+	end
+	if subscription_from[host] then
+		subscription_from[host] = nil;
+		core_post_stanza(hosts[module.host], st.presence({ from = module.host, to = host, id = id, type = "unsubscribed" }));
+	end
+end
+function add_contact(host, id)
+	if not subscription_to[host] then
+		core_post_stanza(hosts[module.host], st.presence({ from = module.host, to = host, id = id, type = "subscribe" }));
+	end
+end
+
+-- Admin ad-hoc command to subscribe
+
+local function add_contact_handler(self, data, state)
+	local layout = {
+		title = "Adding a Server Buddy";
+		instructions = "Fill out this form to add a \"server buddy\".";
+
+		{ name = "FORM_TYPE", type = "hidden", value = "http://jabber.org/protocol/admin" };
+		{ name = "peerjid", type = "jid-single", required = true, label = "The server to add" };
+	};
+
+	if not state then
+		return { status = "executing", form = layout }, "executing";
+	elseif data.action == "canceled" then
+		return { status = "canceled" };
+	else
+		local fields = layout:data(data);
+		local peerjid = nameprep(fields.peerjid);
+		if not peerjid or peerjid == "" or #peerjid > 1023 or not to_ascii(peerjid) then
+			return { status = "completed", error = { message = "Invalid JID" } };
+		end
+		add_contact(peerjid);
+		return { status = "completed" };
+	end
+end
+
+local add_contact_command = adhoc_new("Adding a Server Buddy", "http://jabber.org/protocol/admin#server-buddy", add_contact_handler, "admin");
+module:add_item("adhoc", add_contact_command);
+
+-- Disco query remote host
+function query_host(host)
+	local stanza = st.iq({ from = module.host, to = host, type = "get", id = "mod_service_directories:disco" })
+		:query("http://jabber.org/protocol/disco#info");
+	core_post_stanza(hosts[module.host], stanza);
+end
+
+-- Handle disco query result
+module:hook("iq-result/bare/mod_service_directories:disco", function(event)
+	local origin, stanza = event.origin, event.stanza;
+
+	if not subscription_to[stanza.attr.from] then return; end -- not from a contact
+	local host = stanza.attr.from;
+
+	local query = stanza:get_child("query", "http://jabber.org/protocol/disco#info")
+	if not query then return; end
+
+	-- extract disco features
+	local features = {};
+	for _,tag in ipairs(query.tags) do
+		if tag.name == "feature" and tag.attr.var then
+			features[tag.attr.var] = true;
+		end
+	end
+	contact_features[host] = features;
+
+	if features["urn:ietf:params:xml:ns:vcard-4.0"] then
+		local stanza = st.iq({ from = module.host, to = host, type = "get", id = "mod_service_directories:vcard" })
+			:tag("vcard", { xmlns = "urn:ietf:params:xml:ns:vcard-4.0" });
+		core_post_stanza(hosts[module.host], stanza);
+	end
+	return true;
+end);
+
+-- Handle vcard result
+module:hook("iq-result/bare/mod_service_directories:vcard", function(event)
+	local origin, stanza = event.origin, event.stanza;
+
+	if not subscription_to[stanza.attr.from] then return; end -- not from a contact
+	local host = stanza.attr.from;
+
+	local vcard = stanza:get_child("vcard", "urn:ietf:params:xml:ns:vcard-4.0");
+	if not vcard then return; end
+
+	contact_vcards[host] = st.clone(vcard);
+	return true;
+end);
+
+-- PubSub
+
+-- TODO the following should be replaced by mod_pubsub
+
+module:hook("iq-get/host/http://jabber.org/protocol/pubsub:pubsub", function(event)
+	local origin, stanza = event.origin, event.stanza;
+	local payload = stanza.tags[1];
+
+	local items = payload:get_child("items", "http://jabber.org/protocol/pubsub");
+	if items and items.attr.node == "urn:xmpp:contacts" then
+		local reply = st.reply(stanza)
+			:tag("pubsub", { xmlns = "http://jabber.org/protocol/pubsub" })
+				:tag("items", { node = "urn:xmpp:contacts" });
+		for host, vcard in pairs(contact_vcards) do
+			reply:tag("item", { id = host })
+				:add_child(vcard)
+			:up();
+		end
+		origin.send(reply);
+		return true;
+	end
+end);
+