local json = require "util.json";

local array = require "util.array";

local add_task = require "util.timer".add_task;

local get_stats = require "core.statsmanager".get_stats;

local list_users = require "core.usermanager".users;

local os_time = os.time;

assert(get_stats, "not compatible with trunk based on openmetrics");

module:depends("http");

local expose_users = module:get_option_boolean("nodeinfo2_expose_users", true);

if expose_users then

	module:depends("lastlog");

end

local expose_posts = module:get_option_boolean("nodeinfo2_expose_posts", true);

if expose_posts then

	module:depends("measure_message_e2ee");

end

local main_store = module:open_store();

local lastlog_store = module:open_store("lastlog");

local data;

if expose_posts then

	data = main_store:get("nodeinfo2") or { message_count = 0 };

end

local total_users = 0;

local week_users = 0;

local month_users = 0;

local half_year_users = 0;

local function update_user_list()

	for user in list_users(module.host) do

		total_users = total_users + 1;

		local lastlog = lastlog_store:get(user);

		if lastlog and lastlog.timestamp then

			local delta = os_time() - lastlog.timestamp;

			if delta < 7 * 86400 then

				week_users = week_users + 1;

			end

			if delta < 30 * 86400 then

				month_users = month_users + 1;

			end

			if delta < 6 * 30 * 86400 then

				half_year_users = half_year_users + 1;

			end

		end

	end

	-- Remove the properties if we couldn’t find a single active user.  It most likely means mod_lastlog isn’t in use.

	if half_year_users == 0 and month_users == 0 and week_users == 0 then

		week_users = nil;

		month_users = nil;

		half_year_users = nil;

	end

end

if expose_users then

	add_task(86400, update_user_list);

	update_user_list();

end

module:provides("http", {

	default_path = "/.well-known/x-nodeinfo2";

	route = {

		GET = function (event)

			local usage = {};

			if expose_users then

				usage.users = {

					total = total_users;

					activeWeek = week_users;

					activeMonth = month_users;

					activeHalfyear = half_year_users;

				};

			end

			if expose_posts then

				local stats, changed_only, extras = get_stats();

				for stat, _ in pairs(stats) do

					if stat == "/"..module.host.."/mod_measure_message_e2ee/message:rate" then

						local new_message_count = extras[stat].total;

						if new_message_count ~= data.message_count then

							data = { message_count = new_message_count };

							main_store:set("nodeinfo2", data);

						end

					end

				end

				usage.localPosts = data.message_count;

				-- TODO: also count PubSub replies here.

				usage.localComments = 0;

			end

			event.response.headers.content_type = "application/json";

			return json.encode({

				version = "1.0";

				server = {

					baseUrl = module:http_url("","/");

					name = module.host;

					software = "Prosody";

					version = prosody.version;

				};

				--[[ TODO re-use data from mod_server_contact_info ?

				organization = {

					name = "";

					contact = "";

					account = "";

				};

				--]]

				protocols = array {

					"xmpp",

				};

				services = {

					inbound = array {

						"xmpp";

					};

					outbound = array {

						"xmpp";

					};

				};

				openRegistrations = module:get_option_boolean("allow_registration", false);

				usage = usage;

			});

		end;

	}

});