Clean up firedoors and add proper emag behavior (#28087)

* That was a lot of running around

* This ordering is better

* Update areas.dm

* Update firedoor.dm

code/game/area/areas.dm

@@ -301,10 +301,17 @@
 			continue
 
 		// At this point, the area is safe and the door is technically functional.
+		// Firedoors do not close automatically by default, and setting it to false when the alarm is off prevents unnecessary timers from being created. Emagged doors are permanently disabled from automatically closing, or being operated by alarms altogether apart from the lights.
+		if(!D.emagged)
+			if(opening)
+				D.autoclose = FALSE
+			else
+				D.autoclose = TRUE
 
 		INVOKE_ASYNC(D, (opening ? TYPE_PROC_REF(/obj/machinery/door/firedoor, deactivate_alarm) : TYPE_PROC_REF(/obj/machinery/door/firedoor, activate_alarm)))
-		if(D.welded)
+		if(D.welded || D.emagged)
 			continue // Alarm is toggled, but door stuck
+
 		if(D.operating)
 			if((D.operating == DOOR_OPENING && opening) || (D.operating == DOOR_CLOSING && !opening))
 				continue

code/game/machinery/doors/firedoor.dm

@@ -122,7 +122,7 @@
 		user.visible_message(
 			"<span class='notice'>[user] opens [src].</span>",
 			"<span class='notice'>You open [src].</span>")
-		open(auto_close = FALSE)
+		open()
 
 /obj/machinery/door/firedoor/item_interaction(mob/living/user, obj/item/used, list/modifiers)
 	add_fingerprint(user)
@@ -187,6 +187,12 @@
 	welded = !welded
 	update_icon(UPDATE_OVERLAYS)
 
+/obj/machinery/door/firedoor/emag_act(mob/user)
+	if(!density)
+		return
+	autoclose = FALSE
+	return ..()
+
 /obj/machinery/door/firedoor/try_to_crowbar(obj/item/I, mob/user)
 	if(welded || operating)
 		return
@@ -245,15 +251,13 @@
 	adjust_light()
 	update_icon()
 
-/obj/machinery/door/firedoor/open(auto_close = TRUE)
+/obj/machinery/door/firedoor/open()
 	if(welded)
 		return
 	. = ..()
-	latetoggle(auto_close)
+	latetoggle()
 	if(active_alarm)
 		layer = closingLayer // Active firedoors take precedence and remain visible over closed airlocks.
-	if(auto_close)
-		autoclose = TRUE
 
 /obj/machinery/door/firedoor/close()
 	. = ..()
@@ -263,20 +267,20 @@
 	if(active_alarm)
 		. = ..()
 
-/obj/machinery/door/firedoor/proc/latetoggle(auto_close = TRUE)
+/obj/machinery/door/firedoor/proc/latetoggle()
 	if(operating || !hasPower() || !nextstate)
 		return
 	if(nextstate == FD_OPEN)
-		INVOKE_ASYNC(src, PROC_REF(open), auto_close)
+		INVOKE_ASYNC(src, PROC_REF(open))
 	if(nextstate == FD_CLOSED)
 		INVOKE_ASYNC(src, PROC_REF(close))
 	nextstate = null
 
-/obj/machinery/door/firedoor/proc/forcetoggle(magic = FALSE, auto_close = TRUE)
+/obj/machinery/door/firedoor/proc/forcetoggle(magic = FALSE)
 	if(!magic && (operating || !hasPower()))
 		return
 	if(density)
-		open(auto_close)
+		open()
 	else
 		close()