module:set_global();

local s_format = string.format;

local t_insert = table.insert;

local t_concat = table.concat;

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 = stat:match("^([^.]+)%.(.+):(%a+)$");

			elseif host == "*" then

				host = nil;

			end

			if sect:find("^mod_measure_.") then

				sect = sect:sub(13);

			elseif sect:find("^mod_statistics_.") then

				sect = sect:sub(16);

			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));

				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);

local function openmetrics_handler(event)

	local registry = event.metric_registry

	local host, sect, name, typ, key;

	for family_name, metric_family in pairs(registry:get_metric_families()) do

		if not ignore_stats:contains(family_name) then

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

			local host_key

			if metric_family.label_keys[1] == "host" then

				host_key = 1

			end

			if family_name:sub(1, 12) == "prosody_mod_" then

				sect, name = family_name:match("^prosody_mod_([^/]+)/(.+)$")

			else

				sect, name = family_name:match("^([^_]+)_(.+)$")

			end

			name = clean_fieldname(name)

			local metric_type = metric_family.type_

			if metric_type == "gauge" or metric_type == "unknown" then

				typ = "GAUGE"

			else

				typ = "DCOUNTER"

			end

			for labelset, metric in metric_family:iter_metrics() do

				host = host_key and labelset[host_key] or "global"

				local name_parts = {}

				for i, label in ipairs(labelset) do

					if i ~= host_key then

						t_insert(name_parts, label)

					end

				end

				local full_name = t_concat(name_parts, "_")

				local display_name = #name_parts > 0 and full_name or name

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

				local unit

				local factor = 1

				unit = metric_family.unit

				if unit == "seconds" and typ == "DCOUNTER" then

					factor = 100

					unit = "%time"

				elseif typ == "DCOUNTER" then

					unit = unit .. "/s"

				end

				if not meta:get(key, "") then

					meta:set(key, "", "graph_title", s_format(metric_family.description));

					if unit ~= "" then

						meta:set(key, "", "graph_vlabel", unit);

					end

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

				end

				if not meta:get(key, display_name) then

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

					meta:set(key, display_name, "type", typ)

				end

				for suffix, extra_labels, value in metric:iter_samples() do

					if metric_type == "histogram" or metric_type == "summary" then

						if suffix == "_sum" then

							data:set(key, display_name, value * factor)

						end

					elseif suffix == "_total" or suffix == "" then

						data:set(key, display_name, value * factor)

					end

				end

			end

		end

	end

end

module:hook("openmetrics-updated", openmetrics_handler);

module:provides("net", {

	listener = munin_listener;

	default_mode = "*l";

	default_port = 4949;

});