[MIRROR] bug fixes and code refactor for AI, malf or otherwise (#27499)

* bug fixes and code refactor for AI, malf or otherwise (#82590)

## About The Pull Request

I was trying to fix a bug with ejecting from mechs as malf AI and the
more I looked the worse it seemed to get? So I'm putting in this PR with
the intent to refactor AI code to not be a Byzantine nightmare of new
objects referencing each other incompletely or with buggy behavior.
Finished PR for #82579 because I didn't want to clutter the comments
with commits of me trying to fix shit with git restore and revert
## Why It's Good For The Game

Fixes #81877
Fixes #82524
Mech dominating now just works off (and integrates with) similar code
for APC shunting
The cores left behind by AIs shunting or controlling mechs now properly
reference the AI instead of only the other way around
Some of these refactors slightly change how malf works; I think most of
it was unintended behavior in the first place, let me know in review if
not
## Changelog

The code for AIs remoting out of their shell has been refactored.
🆑
fix: Mech domination now properly integrates with shunting.
fix: Combat upgraded AIs no longer get two buggy malf ability pickers if
they also become malfunctioning
refactor: Refactored most of the functionality around malf AI shunting,
mech control
/🆑

---------

Co-authored-by: MrMelbert <51863163+MrMelbert@ users.noreply.github.com>

* bug fixes and code refactor for AI, malf or otherwise

---------

Co-authored-by: Joshua Kidder <49173900+Metekillot@users.noreply.github.com>
Co-authored-by: MrMelbert <51863163+MrMelbert@ users.noreply.github.com>

code/game/objects/structures/ai_core.dm

@@ -12,6 +12,8 @@
 	var/datum/ai_laws/laws
 	var/obj/item/circuitboard/aicore/circuit
 	var/obj/item/mmi/core_mmi
+	/// only used in cases of AIs piloting mechs or shunted malf AIs, possible later use cases
+	var/mob/living/silicon/ai/remote_ai = null
 
 /obj/structure/ai_core/Initialize(mapload)
 	. = ..()
@@ -58,11 +60,20 @@
 		update_appearance()
 
 /obj/structure/ai_core/Destroy()
+	if(istype(remote_ai))
+		remote_ai.break_core_link()
+		remote_ai = null
 	QDEL_NULL(circuit)
 	QDEL_NULL(core_mmi)
 	QDEL_NULL(laws)
 	return ..()
 
+/obj/structure/ai_core/take_damage(damage_amount, damage_type, damage_flag, sound_effect, attack_dir, armour_penetration)
+	. = ..()
+	if(. > 0 && istype(remote_ai))
+		to_chat(remote_ai, span_danger("Your core is under attack!"))
+	
+
 /obj/structure/ai_core/deactivated
 	icon_state = "ai-empty"
 	anchored = TRUE
@@ -157,6 +168,8 @@
 			return ITEM_INTERACT_SUCCESS
 
 /obj/structure/ai_core/attackby(obj/item/tool, mob/living/user, params)
+	if(remote_ai)
+		to_chat(remote_ai, span_danger("CORE TAMPERING DETECTED!"))
 	if(!anchored)
 		if(tool.tool_behaviour == TOOL_WELDER)
 			if(state != EMPTY_CORE)
@@ -295,8 +308,17 @@
 				if(tool.tool_behaviour == TOOL_CROWBAR && core_mmi)
 					tool.play_tool_sound(src)
 					balloon_alert(user, "removed [AI_CORE_BRAIN(core_mmi)]")
-					core_mmi.forceMove(loc)
-					return
+					if(remote_ai)
+						var/mob/living/silicon/ai/remoted_ai = remote_ai
+						remoted_ai.break_core_link()
+						if(!IS_MALF_AI(remoted_ai))
+							//don't pull back shunted malf AIs
+							remoted_ai.death(gibbed = TRUE, drop_mmi = FALSE)
+							///the drop_mmi param determines whether the MMI is dropped at their current location
+							///which in this case would be somewhere else, so we drop their MMI at the core instead
+							remoted_ai.make_mmi_drop_and_transfer(core_mmi, src)
+					core_mmi.forceMove(loc) //if they're malf, just drops a blank MMI, or if it's an incomplete shell
+					return					//it drops the mmi that was put in before it was finished
 
 			if(GLASS_CORE)
 				if(tool.tool_behaviour == TOOL_CROWBAR)

code/modules/antagonists/malf_ai/malf_ai.dm

@@ -173,6 +173,8 @@
 
 	to_chat(malf_ai, "Your radio has been upgraded! Use :t to speak on an encrypted channel with Syndicate Agents!")
 
+	if(malf_ai.malf_picker)
+		return
 	malf_ai.add_malf_picker()
 
 

code/modules/mob/living/silicon/ai/ai.dm

@@ -41,12 +41,13 @@
 	var/shunted = FALSE //1 if the AI is currently shunted. Used to differentiate between shunted and ghosted/braindead
 	var/obj/machinery/ai_voicechanger/ai_voicechanger = null // reference to machine that holds the voicechanger
 	var/malfhacking = FALSE // More or less a copy of the above var, so that malf AIs can hack and still get new cyborgs -- NeoFite
+	/// List of hacked APCs
+	var/list/hacked_apcs = list() 
 	var/malf_cooldown = 0 //Cooldown var for malf modules, stores a worldtime + cooldown
 
 	var/obj/machinery/power/apc/malfhack
 	var/explosive = FALSE //does the AI explode when it dies?
 
-	var/mob/living/silicon/ai/parent
 	var/camera_light_on = FALSE
 	var/list/obj/machinery/camera/lit_cameras = list()
 
@@ -439,6 +440,10 @@
 		qdel(src)
 	return ai_core
 
+/mob/living/silicon/ai/proc/break_core_link()
+	to_chat(src, span_danger("Your core has been destroyed!"))
+	linked_core = null
+
 /mob/living/silicon/ai/proc/make_mmi_drop_and_transfer(obj/item/mmi/the_mmi, the_core)
 	var/mmi_type
 	if(posibrain_inside)
@@ -947,6 +952,9 @@
 	module_picker.ui_interact(owner)
 
 /mob/living/silicon/ai/proc/add_malf_picker()
+	if (malf_picker)
+		stack_trace("Attempted to give malf AI malf picker to \[[src]\], who already has a malf picker.")
+		return
 	to_chat(src, "In the top left corner of the screen you will find the Malfunction Modules button, where you can purchase various abilities, from upgraded surveillance to station ending doomsday devices.")
 	to_chat(src, "You are also capable of hacking APCs, which grants you more points to spend on your Malfunction powers. The drawback is that a hacked APC will give you away if spotted by the crew. Hacking an APC takes 60 seconds.")
 	view_core() //A BYOND bug requires you to be viewing your core before your verbs update
@@ -1024,13 +1032,16 @@
 			malf_ai_datum.update_static_data_for_all_viewers()
 		else //combat software AIs use a different UI
 			malf_picker.update_static_data_for_all_viewers()
-
-	apc.malfai = parent || src
+	if(apc.malfai) // another malf hacked this one; counter-hack!
+		to_chat(apc.malfai, span_warning("An adversarial subroutine has counter-hacked [apc]!"))
+		apc.malfai.hacked_apcs -= apc
+	apc.malfai = src
 	apc.malfhack = TRUE
 	apc.locked = TRUE
 	apc.coverlocked = TRUE
 	apc.flicker_hacked_icon()
 	apc.set_hacked_hud()
+	hacked_apcs += apc
 	playsound(get_turf(src), 'sound/machines/ding.ogg', 50, TRUE, ignore_walls = FALSE)
 	to_chat(src, "Hack complete. [apc] is now under your exclusive control.")
 

code/modules/mob/living/silicon/ai/ai_defense.dm

@@ -2,6 +2,7 @@
 /mob/living/silicon/ai/attackby(obj/item/W, mob/user, params)
 	if(istype(W, /obj/item/ai_module))
 		var/obj/item/ai_module/MOD = W
+		disconnect_shell()
 		if(!mind) //A player mind is required for law procs to run antag checks.
 			to_chat(user, span_warning("[src] is entirely unresponsive!"))
 			return
@@ -137,7 +138,7 @@
 		return ITEM_INTERACT_SUCCESS
 	balloon_alert(src, "neural network being disconnected...")
 	balloon_alert(user, "disconnecting neural network...")
-	if(!tool.use_tool(src, user, (stat == DEAD ? 40 SECONDS : 5 SECONDS)))
+	if(!tool.use_tool(src, user, (stat == DEAD ? 5 SECONDS : 40 SECONDS)))
 		return ITEM_INTERACT_SUCCESS
 	if(IS_MALF_AI(src))
 		to_chat(user, span_userdanger("The voltage inside the wires rises dramatically!"))

code/modules/mob/living/silicon/ai/ai_say.dm

@@ -1,20 +1,3 @@
-/mob/living/silicon/ai/say(
-	message,
-	bubble_type,
-	list/spans = list(),
-	sanitize = TRUE,
-	datum/language/language,
-	ignore_spam = FALSE,
-	forced,
-	filterproof = FALSE,
-	message_range = 7,
-	datum/saymode/saymode,
-	list/message_mods = list(),
-)
-	if(istype(parent) && parent.stat != DEAD) //If there is a defined "parent" AI, it is actually an AI, and it is alive, anything the AI tries to say is said by the parent instead.
-		return parent.say(arglist(args))
-	return ..()
-
 /mob/living/silicon/ai/compose_track_href(atom/movable/speaker, namepart)
 	var/mob/M = speaker.GetSource()
 	if(M)

code/modules/mob/living/silicon/ai/death.dm

@@ -1,4 +1,4 @@
-/mob/living/silicon/ai/death(gibbed)
+/mob/living/silicon/ai/death(gibbed, drop_mmi = TRUE)
 	if(stat == DEAD)
 		return
 
@@ -33,7 +33,7 @@
 
 	ShutOffDoomsdayDevice()
 
-	if(gibbed)
+	if(gibbed && drop_mmi)
 		make_mmi_drop_and_transfer()
 
 	if(explosive)

code/modules/power/apc/apc_attack.dm

@@ -110,13 +110,17 @@
 		return TRUE
 	if(!HAS_SILICON_ACCESS(user))
 		return TRUE
+	. = TRUE
 	var/mob/living/silicon/ai/AI = user
 	var/mob/living/silicon/robot/robot = user
-	if(aidisabled || malfhack && istype(malfai) && ((istype(AI) && (malfai != AI && malfai != AI.parent)) || (istype(robot) && (robot in malfai.connected_robots))))
-		if(!loud)
-			balloon_alert(user, "it's disabled!")
-		return FALSE
-	return TRUE
+	if(istype(AI) || istype(robot))
+		if(aidisabled)
+			. = FALSE
+		else if(istype(malfai) && (malfai != AI || !(robot in malfai.connected_robots)))
+			. = FALSE 
+	if (!. && !loud)
+		balloon_alert(user, "it's disabled!")
+	return .
 
 /obj/machinery/power/apc/proc/set_broken()
 	if(machine_stat & BROKEN)

code/modules/power/apc/apc_main.dm

@@ -228,8 +228,11 @@
 	find_and_hang_on_wall()
 
 /obj/machinery/power/apc/Destroy()
-	if(malfai && operating)
-		malfai.malf_picker.processing_time = clamp(malfai.malf_picker.processing_time - 10, 0, 1000)
+	if(malfai)
+		if(operating)
+			malfai.malf_picker.processing_time = clamp(malfai.malf_picker.processing_time - 10, 0, 1000)
+		malfai.hacked_apcs -= src
+		malfai = null
 	disconnect_from_area()
 	QDEL_NULL(alarm_manager)
 	if(occupier)

code/modules/power/apc/apc_malf.dm

@@ -1,7 +1,7 @@
 /obj/machinery/power/apc/proc/get_malf_status(mob/living/silicon/ai/malf)
 	if(!istype(malf) || !malf.malf_picker)
 		return APC_AI_NO_MALF
-	if(malfai != (malf.parent || malf))
+	if(malfai != malf)
 		return APC_AI_NO_HACK
 	if(occupier == malf)
 		return APC_AI_HACK_SHUNT_HERE
@@ -12,7 +12,7 @@
 /obj/machinery/power/apc/proc/malfhack(mob/living/silicon/ai/malf)
 	if(!istype(malf))
 		return
-	if(get_malf_status(malf) != 1)
+	if(get_malf_status(malf) != APC_AI_HACK_NO_SHUNT || get_malf_status(malf) != APC_AI_NO_HACK)
 		return
 	if(malf.malfhacking)
 		to_chat(malf, span_warning("You are already hacking an APC!"))
@@ -37,18 +37,16 @@
 	if(!is_station_level(z))
 		return
 	malf.ShutOffDoomsdayDevice()
-	occupier = new /mob/living/silicon/ai(src, malf.laws.copy_lawset(), malf) //DEAR GOD WHY? //IKR????
-	occupier.adjustOxyLoss(malf.getOxyLoss())
+	occupier = malf
+	if (isturf(malf.loc)) // create a deactivated AI core if the AI isn't coming from an emergency mech shunt
+		malf.linked_core = new /obj/structure/ai_core/deactivated
+		malf.linked_core.remote_ai = malf // note that we do not set the deactivated core's core_mmi.brainmob
+	malf.forceMove(src) // move INTO the APC, not to its tile
 	if(!findtext(occupier.name, "APC Copy"))
 		occupier.name = "[malf.name] APC Copy"
-	if(malf.parent)
-		occupier.parent = malf.parent
-	else
-		occupier.parent = malf
 	malf.shunted = TRUE
 	occupier.eyeobj.name = "[occupier.name] (AI Eye)"
-	if(malf.parent)
-		qdel(malf)
+	occupier.eyeobj.forceMove(src.loc)
 	for(var/obj/item/pinpointer/nuke/disk_pinpointers in GLOB.pinpointer_list)
 		disk_pinpointers.switch_mode_to(TRACK_MALF_AI) //Pinpointer will track the shunted AI
 	var/datum/action/innate/core_return/return_action = new
@@ -58,12 +56,11 @@
 /obj/machinery/power/apc/proc/malfvacate(forced)
 	if(!occupier)
 		return
-	if(occupier.parent && occupier.parent.stat != DEAD)
-		occupier.mind.transfer_to(occupier.parent)
-		occupier.parent.shunted = FALSE
-		occupier.parent.setOxyLoss(occupier.getOxyLoss())
-		occupier.parent.cancel_camera()
-		qdel(occupier)
+	if(occupier.linked_core)
+		occupier.shunted = FALSE
+		occupier.forceMove(occupier.linked_core.loc)
+		qdel(occupier.linked_core)
+		occupier.cancel_camera()
 		return
 	to_chat(occupier, span_danger("Primary core damaged, unable to return core processes."))
 	if(forced)
@@ -89,7 +86,7 @@
 	if(!occupier.mind || !occupier.client)
 		to_chat(user, span_warning("[occupier] is either inactive or destroyed!"))
 		return FALSE
-	if(!occupier.parent.stat)
+	if(occupier.linked_core) //if they have an active linked_core, they can't be transferred from an APC
 		to_chat(user, span_warning("[occupier] is refusing all attempts at transfer!") )
 		return FALSE
 	if(transfer_in_progress)
@@ -127,7 +124,7 @@
 	to_chat(occupier, span_notice("Transfer complete! You've been stored in [user]'s [card.name]."))
 	occupier.forceMove(card)
 	card.AI = occupier
-	occupier.parent.shunted = FALSE
+	occupier.shunted = FALSE
 	occupier.cancel_camera()
 	occupier = null
 	transfer_in_progress = FALSE

code/modules/vehicles/mecha/_mecha.dm

@@ -274,7 +274,7 @@
 	/// and gets deleted with the mech. However, they do remain in .contents
 	var/list/potential_occupants = contents | occupants
 	for(var/mob/buggy_ejectee in potential_occupants)
-		mob_exit(buggy_ejectee, silent = TRUE)
+		mob_exit(buggy_ejectee, silent = TRUE, forced = TRUE)
 
 	if(LAZYLEN(flat_equipment))
 		for(var/obj/item/mecha_parts/mecha_equipment/equip as anything in flat_equipment)
@@ -328,7 +328,7 @@
 	for(var/mob/living/occupant as anything in occupants)
 		if(isAI(occupant))
 			var/mob/living/silicon/ai/ai = occupant
-			if(!ai.linked_core) // we probably shouldnt gib AIs with a core
+			if(!ai.linked_core && !ai.can_shunt) // we probably shouldnt gib AIs with a core or shunting abilities
 				unlucky_ai = occupant
 				ai.investigate_log("has been gibbed by having their mech destroyed.", INVESTIGATE_DEATHS)
 				ai.gib(DROP_ALL_REMAINS) //No wreck, no AI to recover

code/modules/vehicles/mecha/mecha_ai_interaction.dm

@@ -67,6 +67,7 @@
 
 		if(AI_MECH_HACK) //Called by AIs on the mech
 			AI.linked_core = new /obj/structure/ai_core/deactivated(AI.loc)
+			AI.linked_core.remote_ai = AI
 			if(AI.can_dominate_mechs && LAZYLEN(occupants)) //Oh, I am sorry, were you using that?
 				to_chat(AI, span_warning("Occupants detected! Forced ejection initiated!"))
 				to_chat(occupants, span_danger("You have been forcibly ejected!"))
@@ -101,6 +102,7 @@
 	AI.eyeobj?.RegisterSignal(src, COMSIG_MOVABLE_MOVED, TYPE_PROC_REF(/mob/camera/ai_eye, update_visibility))
 	AI.controlled_equipment = src
 	AI.remote_control = src
+	AI.ShutOffDoomsdayDevice()
 	to_chat(AI, AI.can_dominate_mechs ? span_greenannounce("Takeover of [name] complete! You are now loaded onto the onboard computer. Do not attempt to leave the station sector!") :\
 		span_notice("You have been uploaded to a mech's onboard computer."))
 	to_chat(AI, "<span class='reallybig boldnotice'>Use Middle-Mouse or the action button in your HUD to toggle equipment safety. Clicks with safety enabled will pass AI commands.</span>")

code/modules/vehicles/mecha/mecha_mob_interaction.dm

@@ -119,19 +119,29 @@
 		//stop listening to this signal, as the static update is now handled by the eyeobj's setLoc
 		AI.eyeobj?.UnregisterSignal(src, COMSIG_MOVABLE_MOVED)
 		AI.eyeobj?.forceMove(newloc) //kick the eye out as well
-		if(forced)//This should only happen if there are multiple AIs in a round, and at least one is Malf.
+		if(forced)
+			AI.controlled_equipment = null
+			AI.remote_control = null
 			if(!AI.linked_core) //if the victim AI has no core
-				AI.investigate_log("has been gibbed by being forced out of their mech by another AI.", INVESTIGATE_DEATHS)
-				AI.gib(DROP_ALL_REMAINS)  //If one Malf decides to steal a mech from another AI (even other Malfs!), they are destroyed, as they have nowhere to go when replaced.
-			AI = null
-			mecha_flags &= ~SILICON_PILOT
-			return
+				if (!AI.can_shunt || !length(AI.hacked_apcs))
+					AI.investigate_log("has been gibbed by being forced out of their mech.", INVESTIGATE_DEATHS)
+					/// If an AI with no core (and no shunting abilities) gets forced out of their mech
+					/// (in a way that isn't handled by the normal handling of their mech being destroyed)
+					/// we gib 'em here, too.
+					AI.gib(DROP_ALL_REMAINS)
+					AI = null
+					mecha_flags &= ~SILICON_PILOT
+					return
+				else
+					var/obj/machinery/power/apc/emergency_shunt_apc = pick(AI.hacked_apcs)
+					emergency_shunt_apc.malfoccupy(AI) //get shunted into a random APC (you don't get to choose which)
+					AI = null
+					mecha_flags &= ~SILICON_PILOT
+					return
+			newloc = get_turf(AI.linked_core)
+			qdel(AI.linked_core)
+			AI.forceMove(newloc)
 		else
-			if(!AI.linked_core)
-				if(!silent)
-					to_chat(AI, span_userdanger("Inactive core destroyed. Unable to return."))
-				AI.linked_core = null
-				return
 			if(!silent)
 				to_chat(AI, span_notice("Returning to core..."))
 			AI.controlled_equipment = null
@@ -139,6 +149,7 @@
 			mob_container = AI
 			newloc = get_turf(AI.linked_core)
 			qdel(AI.linked_core)
+			AI.forceMove(newloc)
 	else if(isliving(M))
 		mob_container = M
 	else
@@ -186,9 +197,20 @@
 /obj/vehicle/sealed/mecha/container_resist_act(mob/living/user)
 	if(isAI(user))
 		var/mob/living/silicon/ai/AI = user
-		if(!AI.can_shunt)
-			to_chat(AI, span_notice("You can't leave a mech after dominating it!."))
-			return FALSE
+		if(!AI.linked_core)
+			to_chat(AI, span_userdanger("Inactive core destroyed. Unable to return."))
+			if(!AI.can_shunt || !AI.hacked_apcs.len)
+				to_chat(AI, span_warning("[AI.can_shunt ? "No hacked APCs available." : "No shunting capabilities."]"))
+				return
+			var/confirm = tgui_alert(AI, "Shunt to a random APC? You won't have anywhere else to go!", "Confirm Emergency Shunt", list("Yes", "No"))
+			if(confirm == "Yes")
+				/// Mechs with open cockpits can have the pilot shot by projectiles, or EMPs may destroy the AI inside
+				/// Alternatively, destroying the mech will shunt the AI if they can shunt, or a deadeye wizard can hit
+				/// them with a teleportation bolt
+				if (AI.stat == DEAD || AI.loc != src)
+					return
+				mob_exit(AI, forced = TRUE)
+			return
 	to_chat(user, span_notice("You begin the ejection procedure. Equipment is disabled during this process. Hold still to finish ejecting."))
 	is_currently_ejecting = TRUE
 	if(do_after(user, has_gravity() ? exit_delay : 0 , target = src))