Door rigging tool (#18899)

Added a door rigging tool, it allows you to mine a door, so that when it
opens, it explodes. Requires the door to be welded shut first.
Added a box and antag uplink item for the above.

---------

Signed-off-by: Fluffy <65877598+FluffyGhoster@users.noreply.github.com>
Co-authored-by: Geeves <ggrobler447@gmail.com>

code/game/objects/items/weapons/landmines.dm

@@ -196,6 +196,69 @@
 	fragem(src,num_fragments,num_fragments,explosion_size,explosion_size+1,fragment_damage,damage_step,TRUE)
 	qdel(src)
 
+/**
+ * # Door Rigging Landmine
+ *
+ * A landmine that will explode when the door it is attached to opens
+ */
+/obj/item/landmine/frag/door_rigging
+	name = "door rigging landmine"
+	fragment_damage = 20
+
+	///The airlock that we are observing for when it opens, to explode
+	var/obj/machinery/door/airlock/door_rigged
+
+//Prevent this mine to be used like a normal one
+/obj/item/landmine/frag/door_rigging/attack_self(mob/user)
+	to_chat(user, SPAN_ALERT("This landmine is not usable in this way, you need to apply it to a door."))
+	return
+
+/obj/item/landmine/frag/door_rigging/resolve_attackby(atom/A, mob/user, click_parameters)
+	. = ..()
+
+	if(istype(A, /obj/machinery/door/airlock))
+
+		door_rigged = A
+		var/turf/turf_under_door = get_turf(door_rigged)
+
+		//Prevent people from exploding themselves by targeting a door that will open once clicked
+		if(!door_rigged.welded || !door_rigged.density || !istype(turf_under_door) || locate(/obj/item/landmine) in turf_under_door)
+			to_chat(user, SPAN_WARNING("The door is not welded, is open, is already rigged or does not have a turf below it."))
+			door_rigged = null //Clean up the var
+			return
+
+		//Take a little to do this
+		if(!do_after(user, 10 SECONDS, door_rigged))
+			door_rigged = null
+			return
+
+		RegisterSignal(door_rigged, COMSIG_QDELETING, PROC_REF(handle_door_qdel))
+
+		deploy(user)
+		src.forceMove(turf_under_door)
+
+		activate(user)
+
+		START_PROCESSING(SSfast_process, src)
+
+/obj/item/landmine/frag/door_rigging/process(seconds_per_tick)
+	if(QDELETED(door_rigged))
+		STOP_PROCESSING(SSfast_process, src)
+		qdel(src)
+
+	if(!door_rigged.density)
+		STOP_PROCESSING(SSfast_process, src)
+		trigger(null)
+
+///Clear the reference and delete the mine if the door gets deleted
+/obj/item/landmine/frag/door_rigging/proc/handle_door_qdel()
+	SIGNAL_HANDLER
+
+	door_rigged = null
+	STOP_PROCESSING(SSfast_process, src)
+	qdel(src)
+
+
 /**
  * # Radiation Landmine
  *

code/game/objects/items/weapons/storage/boxes.dm

@@ -1276,6 +1276,11 @@
 	desc = "A box containing 5 standstill landmines."
 	starts_with = list(/obj/item/landmine/standstill = 5)
 
+/obj/item/storage/box/landmines/door_rigging
+	name = "box of door rigging landmines"
+	desc = "A box containing 5 door rigging landmines."
+	starts_with = list(/obj/item/landmine/frag/door_rigging = 5)
+
 /obj/item/storage/box/landmines/claymore
 	name = "box of claymore landmines"
 	desc = "A box containing 5 claymore landmines, relative detonators, and a spare one to trigger them all."