local st = require "prosody.util.stanza";
local xmlns_csi = "urn:xmpp:csi:0";
local csi_feature = st.stanza("csi", { xmlns = xmlns_csi });

local change = module:metric("counter", "changes", "events", "CSI state changes", {"csi_state"});
local count = module:metric("gauge", "state", "sessions", "", { "csi_state" });

module:hook("stream-features", function (event)
	if event.origin.username then
		event.features:add_child(csi_feature);
	end
end);

function refire_event(name)
	return function (event)
		if event.origin.username then
			event.origin.state = event.stanza.name;
			change:with_labels(event.stanza.name):add(1);
			module:fire_event(name, event);
			return true;
		end
	end;
end

module:hook("stanza/"..xmlns_csi..":active", refire_event("csi-client-active"));
module:hook("stanza/"..xmlns_csi..":inactive", refire_event("csi-client-inactive"));

module:hook_global("stats-update", function()
	local sessions = prosody.hosts[module.host].sessions;
	if not sessions then return end
	local active, inactive, flushing = 0, 0, 0;
	for _, user_session in pairs(sessions) do
		for _, session in pairs(user_session.sessions) do
			if session.state == "inactive" then
				inactive = inactive + 1;
			elseif session.state == "active" then
				active = active + 1;
			elseif session.state == "flushing" then
				flushing = flushing + 1;
			end
		end
	end
	count:with_labels("active"):set(active);
	count:with_labels("inactive"):set(inactive);
	count:with_labels("flushing"):set(flushing);
end);