Fixes thermite (#22777)

* thermite fix

* stuff

* space

code/datums/components/thermite.dm

@@ -1,48 +1,67 @@
+#define IGNITION_TEMP 1922
+
 /datum/component/thermite
 	dupe_mode = COMPONENT_DUPE_UNIQUE_PASSARGS
 	var/amount
 	var/overlay
+	var/melting_point = 50
 
 	var/static/list/blacklist = typecacheof(list(
 		/turf/open/lava,
 		/turf/open/space,
 		/turf/open/water,
-		/turf/open/chasm)
-		)
+		/turf/open/chasm,
+		/turf/open/openspace,
+	))
 
 	var/static/list/immunelist = typecacheof(list(
 		/turf/closed/wall/mineral/diamond,
 		/turf/closed/indestructible,
 		/turf/open/indestructible,
-		/turf/closed/wall/r_wall)
-		)
+		/turf/closed/wall/r_wall,
+	))
 
 	var/static/list/resistlist = typecacheof(
-		/turf/closed/wall/mineral
-		)
+		/turf/closed/wall/mineral,
+	)
 
 /datum/component/thermite/Initialize(_amount)
-	if(!istype(parent, /turf) || blacklist[parent.type])
+	if(!istype(parent, /turf) || is_type_in_typecache(parent, blacklist))
 		return COMPONENT_INCOMPATIBLE
 	if(immunelist[parent.type])
-		_amount*=0 //Yeah the overlay can still go on it and be cleaned but you arent burning down a diamond wall
+		melting_point = INFINITY //Yeah the overlay can still go on it and be cleaned but you arent burning down a diamond wall
 	if(resistlist[parent.type])
-		_amount*=0.25
+		melting_point = 200
 
 	amount = _amount*10
 
 	var/turf/master = parent
 	overlay = mutable_appearance('icons/effects/effects.dmi', "thermite")
 	master.add_overlay(overlay)
 
+/datum/component/thermite/RegisterWithParent()
 	RegisterSignal(parent, COMSIG_COMPONENT_CLEAN_ACT, PROC_REF(clean_react))
+	RegisterSignal(parent, COMSIG_ATOM_UPDATE_OVERLAYS, PROC_REF(on_overlay_update))
+	RegisterSignal(parent, COMSIG_ATOM_TOOL_ACT(TOOL_WELDER), PROC_REF(welder_act))
 	RegisterSignal(parent, COMSIG_ATOM_ATTACKBY, PROC_REF(attackby_react))
 	RegisterSignal(parent, COMSIG_ATOM_FIRE_ACT, PROC_REF(flame_react))
 
+/datum/component/thermite/UnregisterFromParent()
+	UnregisterSignal(parent, list(
+		COMSIG_ATOM_TOOL_ACT(TOOL_WELDER),
+		COMSIG_COMPONENT_CLEAN_ACT,
+		COMSIG_ATOM_UPDATE_OVERLAYS,
+		COMSIG_ATOM_ATTACKBY,
+		COMSIG_ATOM_FIRE_ACT,
+	))
+
+/datum/component/thermite/proc/on_overlay_update(datum/source, list/overlays)
+	overlays += overlay
+
 /datum/component/thermite/Destroy()
 	var/turf/master = parent
-	master.cut_overlay(overlay)
-	return ..()
+	. = ..()
+	master.update_overlays()
 
 /datum/component/thermite/InheritComponent(datum/component/thermite/newC, i_am_original, _amount)
 	if(!i_am_original)
@@ -59,7 +78,7 @@
 
 	playsound(master, 'sound/items/welder.ogg', 100, 1)
 
-	if(amount >= 50)
+	if(amount >= melting_point)
 		var/burning_time = max(100, 100-amount)
 		master = master.Melt()
 		master.burn_tile()
@@ -75,9 +94,21 @@
 	return TRUE
 
 /datum/component/thermite/proc/flame_react(datum/source, exposed_temperature, exposed_volume)
-	if(exposed_temperature > 1922) // This is roughly the real life requirement to ignite thermite
+	if(exposed_temperature > IGNITION_TEMP) // This is roughly the real life requirement to ignite thermite
 		thermite_melt()
 
 /datum/component/thermite/proc/attackby_react(datum/source, obj/item/thing, mob/user, params)
-	if(thing.is_hot())
+	if(thing.is_hot() > IGNITION_TEMP)
 		thermite_melt(user)
+		return COMPONENT_BLOCK_TOOL_ATTACK
+	else if(thing.is_hot())
+		to_chat(user, span_warning("[thing] isn't hot enough!"))
+
+/datum/component/thermite/proc/welder_act(datum/source, mob/user, obj/item/tool, params)
+	if(tool.is_hot() > IGNITION_TEMP)
+		thermite_melt(user)
+		return COMPONENT_BLOCK_TOOL_ATTACK
+	else if(tool.is_hot())
+		to_chat(user, span_warning("[tool] isn't hot enough!"))
+
+#undef IGNITION_TEMP