//Used to process objects. Fires once every second.

SUBSYSTEM_DEF(processing)
	name = "Processing"
	priority = FIRE_PRIORITY_PROCESS
	flags = SS_BACKGROUND|SS_POST_FIRE_TIMING|SS_NO_INIT
	wait = 1 SECONDS

	var/stat_tag = "P" //Used for logging
	var/list/processing = list()
	var/list/currentrun = list()

/datum/controller/subsystem/processing/stat_entry(msg)
	msg = "[stat_tag]:[length(processing)]"
	return ..()

/datum/controller/subsystem/processing/fire(resumed = 0)
	if (!resumed)
		currentrun = processing.Copy()
	//cache for sanic speed (lists are references anyways)
	var/list/current_run = currentrun

	while(current_run.len)
		var/datum/thing = current_run[current_run.len]
		current_run.len--
		if(QDELETED(thing))
			processing -= thing
		else if(thing.process(wait * 0.1) == PROCESS_KILL)
			// fully stop so that a future START_PROCESSING will work
			STOP_PROCESSING(src, thing)
		if (MC_TICK_CHECK)
			return

/**
  * This proc is called on a datum on every "cycle" if it is being processed by a subsystem. The time between each cycle is determined by the subsystem's "wait" setting.
  * You can start and stop processing a datum using the START_PROCESSING and STOP_PROCESSING defines.
  *
  * Since the wait setting of a subsystem can be changed at any time, it is important that any rate-of-change that you implement in this proc is multiplied by the delta_time that is sent as a parameter,
  * Additionally, any "prob" you use in this proc should instead use the DT_PROB define to make sure that the final probability per second stays the same even if the subsystem's wait is altered.
  * Examples where this must be considered:
  * - Implementing a cooldown timer, use `mytimer -= delta_time`, not `mytimer -= 1`. This way, `mytimer` will always have the unit of seconds
  * - Damaging a mob, do `L.adjustFireLoss(20 * delta_time)`, not `L.adjustFireLoss(20)`. This way, the damage per second stays constant even if the wait of the subsystem is changed
  * - Probability of something happening, do `if(DT_PROB(25, delta_time))`, not `if(prob(25))`. This way, if the subsystem wait is e.g. lowered, there won't be a higher chance of this event happening per second
  *
  * If you override this do not call parent, as it will return PROCESS_KILL. This is done to prevent objects that dont override process() from staying in the processing list
  */
 
/datum/proc/process(delta_time)
	set waitfor = 0
	return PROCESS_KILL