local st = require "util.stanza";
local uuid = require "util.uuid";
local mt = require "util.multitable";
local cache = require "util.cache";
local xmlns_pubsub = "http://jabber.org/protocol/pubsub";
local xmlns_pubsub_event = "http://jabber.org/protocol/pubsub#event";
-- TODO persist
-- TODO query known pubsub nodes to sync current subscriptions
-- TODO subscription ids per 'item' would be handy
local pending_subscription = cache.new(256); -- uuid → node
local pending_unsubscription = cache.new(256); -- uuid → node
local active_subscriptions = mt.new() -- service | node | uuid | { item }
function module.save()
return { active_subscriptions = active_subscriptions.data }
end
function module.restore(data)
if data and data.active_subscriptions then
active_subscriptions.data = data.active_subscriptions
end
end
local valid_events = {"subscribed"; "unsubscribed"; "error"; "item"; "retract"; "purge"; "delete"}
local function subscription_added(item_event)
local item = item_event.item;
assert(item.service, "pubsub subscription item MUST have a 'service' field.");
assert(item.node, "pubsub subscription item MUST have a 'node' field.");
local already_subscibed = false;
for _ in active_subscriptions:iter(item.service, item.node, nil) do -- luacheck: ignore 512
already_subscibed = true;
break
end
item._id = uuid.generate();
local iq_id = uuid.generate();
pending_subscription:set(iq_id, item._id);
active_subscriptions:set(item.service, item.node, item._id, item);
if not already_subscibed then
module:send(st.iq({ type = "set", id = iq_id, from = module.host, to = item.service })
:tag("pubsub", { xmlns = xmlns_pubsub })
:tag("subscribe", { jid = module.host, node = item.node }));
end
end
for _, event_name in ipairs(valid_events) do
module:hook("pubsub-event/host/"..event_name, function (event)
for _, _, _, _, cb in active_subscriptions:iter(event.service, event.node, nil, "on_"..event_name) do
pcall(cb, event);
end
end);
end
module:hook("iq/host", function (event)
local stanza = event.stanza;
local service = stanza.attr.from;
if not stanza.attr.id then return end -- shouldn't be possible
local subscribed_node = pending_subscription:get(stanza.attr.id);
pending_subscription:set(stanza.attr.id, nil);
local unsubscribed_node = pending_unsubscription:get(stanza.attr.id);
pending_unsubscription:set(stanza.attr.id, nil);
if stanza.attr.type == "result" then
local pubsub_wrapper = stanza:get_child("pubsub", xmlns_pubsub);
local subscription = pubsub_wrapper and pubsub_wrapper:get_child("subscription");
if not subscription then return end
local node = subscription.attr.node;
local what;
if subscription.attr.subscription == "subscribed" then
what = "on_subscribed";
elseif subscription.attr.subscription == "none" then
what = "on_unsubscribed";
end
if not what then return end -- there are other states but we don't handle them
for _, _, _, _, cb in active_subscriptions:iter(service, node, nil, what) do
cb(event);
end
return true;
elseif stanza.attr.type == "error" then
local node = subscribed_node or unsubscribed_node;
local error_type, error_condition, reason, pubsub_error = stanza:get_error();
local err = { type = error_type, condition = error_condition, text = reason, extra = pubsub_error };
if active_subscriptions:get(service) then
for _, _, _, _, cb in active_subscriptions:iter(service, node, nil, "on_error") do
cb(err);
end
return true;
end
end
end, 1);
local function subscription_removed(item_event)
local item = item_event.item;
active_subscriptions:set(item.service, item.node, item._id, nil);
local node_subs = active_subscriptions:get(item.service, item.node);
if node_subs and next(node_subs) then return end
local iq_id = uuid.generate();
pending_unsubscription:set(iq_id, item._id);
module:send(st.iq({ type = "set", id = iq_id, from = module.host, to = item.service })
:tag("pubsub", { xmlns = xmlns_pubsub })
:tag("unsubscribe", { jid = module.host, node = item.node }))
end
module:handle_items("pubsub-subscription", subscription_added, subscription_removed, true);
module:hook("message/host", function(event)
local origin, stanza = event.origin, event.stanza;
local ret = nil;
local service = stanza.attr.from;
module:log("debug", "Got message/host: %s", stanza:top_tag());
for event_container in stanza:childtags("event", xmlns_pubsub_event) do
for pubsub_event in event_container:childtags() do
module:log("debug", "Got pubsub event %s", pubsub_event:top_tag());
local node = pubsub_event.attr.node;
module:fire_event("pubsub-event/host/"..pubsub_event.name, {
stanza = stanza;
origin = origin;
event = pubsub_event;
service = service;
node = node;
});
ret = true;
end
end
return ret;
end);
module:hook("pubsub-event/host/items", function (event)
for item in event.event:childtags() do
module:log("debug", "Got pubsub item event %s", item:top_tag());
event.item = item;
event.payload = item.tags[1];
module:fire_event("pubsub-event/host/"..item.name, event);
end
end);