module:set_global();

local s_format = string.format;

local array = require"util.array";

local it = require"util.iterators";

local mt = require"util.multitable";

local meta = mt.new(); meta.data = module:shared"meta";

local data = mt.new(); data.data = module:shared"data";

local munin_listener = {};

local munin_commands = {};

local node_name = module:get_option_string("munin_node_name", "localhost");

local ignore_stats = module:get_option_set("munin_ignored_stats", { });

local function clean_fieldname(name)

	return (name:gsub("[^A-Za-z0-9_]", "_"):gsub("^[^A-Za-z_]", "_%1"));

end

function munin_listener.onconnect(conn)

	-- require"core.statsmanager".collect();

	conn:write("# munin node at "..node_name.."\n");

end

function munin_listener.onincoming(conn, line)

	line = line and line:match("^[^\r\n]+");

	if type(line) ~= "string" then return end

	-- module:log("debug", "incoming: %q", line);

	local command = line:match"^%w+";

	command = munin_commands[command];

	if not command then

		conn:write("# Unknown command.\n");

		return;

	end

	local ok, err = pcall(command, conn, line);

	if not ok then

		module:log("error", "Error running %q: %s", line, err);

		conn:close();

	end

end

function munin_listener.ondisconnect() end

function munin_commands.cap(conn)

	conn:write("cap\n");

end

function munin_commands.list(conn)

	conn:write(array(it.keys(data.data)):concat(" ") .. "\n");

end

function munin_commands.config(conn, line)

	-- TODO what exactly?

	local stat = line:match("%s(%S+)");

	if not stat then conn:write("# Unknown service\n.\n"); return end

	for _, _, k, value in meta:iter(stat, "", nil) do

		conn:write(s_format("%s %s\n", k, value));

	end

	for _, name, k, value in meta:iter(stat, nil, nil) do

		if name ~= "" and not ignore_stats:contains(name) then

			conn:write(s_format("%s.%s %s\n", name, k, value));

		end

	end

	conn:write(".\n");

end

function munin_commands.fetch(conn, line)

	local stat = line:match("%s(%S+)");

	if not stat then conn:write("# Unknown service\n.\n"); return end

	for _, name, value in data:iter(stat, nil) do

		if not ignore_stats:contains(name) then

			conn:write(s_format("%s.value %.12f\n", name, value));

		end

	end

	conn:write(".\n");

end

function munin_commands.quit(conn)

	conn:close();

end

module:hook("stats-updated", function (event)

	local all_stats, this = event.stats_extra;

	local host, sect, name, typ, key;

	for stat, value in pairs(event.changed_stats) do

		if not ignore_stats:contains(stat) then

			this = all_stats[stat];

			-- module:log("debug", "changed_stats[%q] = %s", stat, tostring(value));

			host, sect, name, typ = stat:match("^/([^/]+)/([^/]+)/(.+):(%a+)$");

			if host == nil then

				sect, name, typ, host = stat:match("^([^.]+)%.([^:]+):(%a+)$");

			elseif host == "*" then

				host = nil;

			end

			key = clean_fieldname(s_format("%s_%s_%s", host or "global", sect, typ));

			if not meta:get(key) then

				if host then

					meta:set(key, "", "graph_title", s_format("%s %s on %s", sect, typ, host));

				else

					meta:set(key, "", "graph_title", s_format("Global %s %s", sect, typ, host));

				end

				meta:set(key, "", "graph_vlabel", this and this.units or typ);

				meta:set(key, "", "graph_category", sect);

				meta:set(key, name, "label", name);

			elseif not meta:get(key, name, "label") then

				meta:set(key, name, "label", name);

			end

			data:set(key, name, value);

		end

	end

end);

module:provides("net", {

	listener = munin_listener;

	default_mode = "*l";

	default_port = 4949;

});