Add deathrattle implant for nuclear operatives (#55903)

Deathrattle implant, comes in box of 8, implant yourself and others, and
you'll get a little notification when they die.

Intended for nuke ops, price around the same as the codebook, since it's
a utility communication item, that actually "plans to fail", so it can't
be too expensive, because it doesn't help them win, just lets them know
how much they are losing by.

code/game/objects/items/implants/implant.dm

@@ -83,6 +83,7 @@
 	if(user)
 		log_combat(user, target, "implanted", "\a [name]")
 
+	SEND_SIGNAL(src, COMSIG_IMPLANT_IMPLANTED, target, user, silent, force)
 	return TRUE
 
 /obj/item/implant/proc/removed(mob/living/source, silent = FALSE, special = 0)
@@ -96,7 +97,8 @@
 		var/mob/living/carbon/human/H = source
 		H.sec_hud_set_implants()
 
-	return 1
+	SEND_SIGNAL(src, COMSIG_IMPLANT_REMOVED, source, silent, special)
+	return TRUE
 
 /obj/item/implant/Destroy()
 	if(imp_in)

code/game/objects/items/implants/implant_deathrattle.dm

@@ -0,0 +1,77 @@
+/datum/deathrattle_group
+	var/name
+	var/list/implants = list()
+
+/datum/deathrattle_group/New(name)
+	if(name)
+		src.name = name
+	else
+		// Give the group a unique name for debugging, and possible future
+		// use for making custom linked groups.
+		src.name = "[rand(100,999)] [pick(GLOB.phonetic_alphabet)]"
+
+/*
+ * Proc called by new implant being added to the group. Listens for the
+ * implant being implanted, removed and destroyed.
+ *
+ * If implant is already implanted in a person, then trigger the implantation
+ * code.
+ */
+/datum/deathrattle_group/proc/register(obj/item/implant/deathrattle/implant)
+	if(implant in implants)
+		return
+	RegisterSignal(implant, COMSIG_IMPLANT_IMPLANTED, .proc/on_implant_implantation)
+	RegisterSignal(implant, COMSIG_IMPLANT_REMOVED, .proc/on_implant_removal)
+	RegisterSignal(implant, COMSIG_PARENT_QDELETING, .proc/on_implant_destruction)
+
+	implants += implant
+
+	if(implant.imp_in)
+		on_implant_implantation(implant.imp_in)
+
+/datum/deathrattle_group/proc/on_implant_implantation(obj/item/implant/implant, mob/living/target, mob/user, silent = FALSE, force = FALSE)
+	SIGNAL_HANDLER
+
+	RegisterSignal(target, COMSIG_MOB_STATCHANGE, .proc/on_user_statchange)
+
+/datum/deathrattle_group/proc/on_implant_removal(obj/item/implant/implant, mob/living/source, silent = FALSE, special = 0)
+	SIGNAL_HANDLER
+
+	UnregisterSignal(source, COMSIG_MOB_STATCHANGE)
+
+/datum/deathrattle_group/proc/on_implant_destruction(obj/item/implant/implant)
+	implants -= implant
+
+/datum/deathrattle_group/proc/on_user_statchange(mob/living/owner, new_stat)
+	SIGNAL_HANDLER
+
+	if(new_stat != DEAD)
+		return
+
+	var/name = owner.mind ? owner.mind.name : owner.real_name
+	var/area = get_area_name(get_turf(owner))
+
+	for(var/_implant in implants)
+		var/obj/item/implant/deathrattle/implant = _implant
+
+		// Skip the unfortunate soul, and any unimplanted implants
+		if(implant.imp_in == owner || !implant.imp_in)
+			continue
+
+		// Deliberately the same message framing as nanite message + ghost deathrattle
+		to_chat(implant.imp_in, "<i>You hear a strange, robotic voice in your head...</i> \"<span class='robot'><b>[name]</b> has died at <b>[area]</b>.</span>\"")
+
+/obj/item/implant/deathrattle
+	name = "deathrattle implant"
+	desc = "Hope no one else dies, prepare for when they do."
+
+	activated = FALSE
+
+/obj/item/implant/deathrattle/can_be_implanted_in(mob/living/target)
+	// Can be implanted in anything that's a mob. Syndicate cyborgs, talking fish, humans...
+	return TRUE
+
+/obj/item/implantcase/deathrattle
+	name = "implant case - 'Deathrattle'"
+	desc = "A glass case containing a deathrattle implant."
+	imp_type = /obj/item/implant/deathrattle

code/game/objects/items/storage/uplink_kits.dm

@@ -565,3 +565,21 @@
 /obj/item/storage/box/syndie_kit/signaler/PopulateContents()
 	for(var/i in 1 to 6)
 		new /obj/item/assembly/signaler(src)
+
+/obj/item/storage/box/syndie_kit/imp_deathrattle
+	name = "deathrattle implant box"
+	desc = "Contains eight linked deathrattle implants."
+
+/obj/item/storage/box/syndie_kit/imp_deathrattle/PopulateContents()
+	new /obj/item/implanter(src)
+
+	var/datum/deathrattle_group/group = new
+
+	var/implants = list()
+	for(var/j in 1 to 8)
+		var/obj/item/implantcase/deathrattle/case = new (src)
+		implants += case.imp
+
+	for(var/i in implants)
+		group.register(i)
+	desc += " The implants are registered to the \"[group.name]\" group."