local it = require "util.iterators";
local new_id = require "util.id".medium;
local max_user_devices = module:get_option_number("max_user_devices", 5);
local device_store = module:open_store("devices");
local device_map_store = module:open_store("devices", "map");
--- Helper functions
local function _compare_device_timestamps(a, b)
return (a.last_activity_at or 0) < (b.last_activity_at or 0);
end
local function sorted_devices(devices)
return it.sorted_pairs(devices, _compare_device_timestamps);
end
local function new_device(username, alt_ids)
local current_time = os.time();
local device = {
id = "dv-"..new_id();
created_at = current_time;
last_activity = "created";
last_activity_at = current_time;
alt_ids = alt_ids or {};
};
local devices = device_store:get(username);
if not devices then
devices = {};
end
devices[device.id] = device;
local devices_ordered = {};
for id in sorted_devices(devices) do
table.insert(devices_ordered, id);
end
if #devices_ordered > max_user_devices then
-- Iterate through oldest devices that are above limit, backwards
for i = #devices_ordered, max_user_devices+1, -1 do
local id = table.remove(devices_ordered, i);
devices[id] = nil;
module:log("debug", "Removing old device for %s: %s", username, id);
end
end
device_store:set(username, devices);
return device;
end
local function get_device_with_alt_id(username, alt_id_type, alt_id)
local devices = device_store:get(username);
if not devices then
return nil;
end
for _, device in pairs(devices) do
if device.alt_ids[alt_id_type] == alt_id then
return device;
end
end
end
local function set_device_alt_id(username, device_id, alt_id_type, alt_id)
local devices = device_store:get(username);
if not devices or not devices[device_id] then
return nil, "no such device";
end
devices[device_id].alt_ids[alt_id_type] = alt_id;
end
local function record_device_state(username, device_id, activity, time)
local device = device_map_store:get(username, device_id);
device.last_activity = activity;
device.last_activity_at = time or os.time();
device_map_store:set(username, device_id, device);
end
local function find_device(username, info)
for _, alt_id_type in ipairs({ "resumption_token", "resource" }) do
local alt_id = info[alt_id_type];
if alt_id then
local device = get_device_with_alt_id(username, alt_id_type, alt_id);
if device then
return device, alt_id_type;
end
end
end
end
--- Information gathering
module:hook("pre-resource-bind", function (event)
event.session.device_requested_resource = event.resource;
end, 1000);
local function store_resumption_token(session, stanza)
session.device_requested_resume = stanza.attr.previd;
end
module:hook_stanza("urn:xmpp:sm:2", "resume", store_resumption_token, 5);
module:hook_stanza("urn:xmpp:sm:3", "resume", store_resumption_token, 5);
--- Identify device after resource bind
module:hook("resource-bind", function (event)
local info = {
resource = event.session.device_requested_resource;
resumption_token = event.session.device_requested_resume;
};
local device, source = find_device(event.session.username, info);
if device then
event.session.log("debug", "Associated with device %s (from %s)", device.id, source);
event.session.device_id = device.id;
else
device = new_device(event.session.username, info);
event.session.log("debug", "Creating new device %s for session", device.id);
event.session.device_id = device.id;
end
record_device_state(event.session.username, device.id, "login");
end, 1000);
module:hook("resource-unbind", function (event)
if event.session.device_id then
record_device_state(event.session.username, event.session.device_id, "logout");
end
end);