local S = technic.getter

-- the interval between technic_run calls
local technic_run_interval = 1.0
local set_default_timeout = technic.set_default_timeout

-- iterate over all collected switching stations and execute the technic_run function
local timer = 0
minetest.register_globalstep(function(dtime)
	timer = timer + dtime
	if timer < technic_run_interval or not technic.powerctrl_state then
		return
	end
	timer = 0

	local max_lag = technic.get_max_lag()
	-- slow down technic execution if the lag is higher than usual
	if max_lag > 5.0 then
		technic_run_interval = 5.0
	elseif max_lag > 2.0 then
		technic_run_interval = 4.0
	elseif max_lag > 1.5 then
		technic_run_interval = 3.0
	elseif max_lag > 1.0 then
		technic_run_interval = 1.5
	else
		-- normal run_interval
		technic_run_interval = 1.0
	end
	set_default_timeout(math.ceil(technic_run_interval) + 1)

	local now = minetest.get_us_time()

	for network_id, network in pairs(technic.active_networks) do
		if network.timeout > now and not technic.is_overloaded(network_id) then
			-- station active
			if network.skip > 0 then
				network.skip = network.skip - 1
			else
				local start = minetest.get_us_time()
				technic.network_run(network_id)
				local switch_diff = network.average_lag(minetest.get_us_time() - start)

				-- set lag in microseconds into the "lag" meta field
				network.lag = switch_diff

				-- overload detection
				if switch_diff > 250000 then
					network.skip = 30
				elseif switch_diff > 150000 then
					network.skip = 20
				elseif switch_diff > 75000 then
					network.skip = 10
				elseif switch_diff > 50000 then
					network.skip = 2
				end

				if network.skip > 0 then
					-- calculate efficiency in percent and display it
					local efficiency = math.floor(1/network.skip*100)
					technic.network_infotext(network_id,
						S("Polyfuse triggered, current efficiency: @1%, generated lag: @2 ms",
							efficiency, math.floor(switch_diff/1000)))

					-- remove laggy network from active index
					-- it will be reactivated when a player is near it
					technic.active_networks[network_id] = nil
				end
			end

		else
			-- network timed out
			technic.active_networks[network_id] = nil
		end
	end
end)