Hazardous Area Component | Free Golem Soft-Restriction (#65720)

Co-authored-by: Mothblocks <35135081+Mothblocks@users.noreply.github.com>

code/datums/components/hazard_area.dm

@@ -0,0 +1,130 @@
+/**
+ * This is a relatively simple component that attempts to deter the parent of the component away
+ * from a specific area or areas. By default it simply applies a penalty where all movement is
+ * four times slower than usual and any action that would affect your 'next move' has a penalty
+ * multiplier of 4 attached.
+ */
+/datum/component/hazard_area
+	/// The blacklist of areas that the parent will be penalized for entering
+	var/list/area_blacklist
+	/// The whitelist of areas that the parent is allowed to be in. If set this overrides the blacklist
+	var/list/area_whitelist
+	/// A variable storing the typepath of the last checked area to prevent any further logic running if it has not changed
+	VAR_PRIVATE/last_parent_area
+
+/datum/component/hazard_area/Initialize(area_blacklist, area_whitelist)
+	. = ..()
+	if(!ismob(parent))
+		return COMPONENT_INCOMPATIBLE
+	if(!islist(area_blacklist) && !islist(area_whitelist))
+		stack_trace("[type] - neither area_blacklist nor area_whitelist were provided.")
+		return COMPONENT_INCOMPATIBLE
+	src.area_blacklist = area_blacklist
+	src.area_whitelist = area_whitelist
+
+/datum/component/hazard_area/RegisterWithParent()
+	var/mob/parent_mob = parent
+	parent_mob.become_area_sensitive(type)
+	RegisterSignal(parent_mob, COMSIG_ENTER_AREA, .proc/handle_parent_area_change)
+	RegisterSignal(parent_mob, COMSIG_LADDER_TRAVEL, .proc/reject_ladder_movement)
+	RegisterSignal(parent_mob, COMSIG_VEHICLE_RIDDEN, .proc/reject_vehicle)
+
+/datum/component/hazard_area/UnregisterFromParent()
+	var/mob/parent_mob = parent
+	UnregisterSignal(parent_mob, list(COMSIG_ENTER_AREA, COMSIG_LADDER_TRAVEL, COMSIG_VEHICLE_RIDDEN))
+	parent_mob.lose_area_sensitivity(type)
+
+/**
+ * This signal handler checks the area the target ladder is in and if hazardous prevents them from using it
+ */
+/datum/component/hazard_area/proc/reject_ladder_movement(mob/source, obj/entrance_ladder, exit_ladder, going_up)
+	SIGNAL_HANDLER
+
+	if(check_area_hazardous(get_area(exit_ladder)))
+		entrance_ladder.balloon_alert(parent, "the path is too dangerous for you!")
+		return LADDER_TRAVEL_BLOCK
+
+/**
+ * A simple signal handler that informs the parent they cannot ride a vehicle and ejects them
+ */
+/datum/component/hazard_area/proc/reject_vehicle(mob/source, obj/vehicle/vehicle)
+	SIGNAL_HANDLER
+
+	if(!check_area_hazardous(last_parent_area))
+		return
+
+	vehicle.balloon_alert(parent, "you slip and fall off!")
+	var/mob/living/parent_living = parent
+	parent_living.Stun(0.5 SECONDS)
+	return EJECT_FROM_VEHICLE
+
+/**
+ * Checks if the area being checked is considered hazardous
+ * The whitelist is checked first if it exists, otherwise it checks if it is in the blacklist
+ *
+ * * checking - This should be the typepath of the area being checked, but there is a conversion handler if you pass in a reference instead
+ */
+/datum/component/hazard_area/proc/check_area_hazardous(area/checking)
+	if(!ispath(checking))
+		checking = checking.type
+	if(area_whitelist)
+		return !(checking in area_whitelist)
+	return checking in area_blacklist
+
+/**
+ * This proc handles the status effect applied to the parent, most noteably applying or removing it as required
+ */
+/datum/component/hazard_area/proc/update_parent_status_effect()
+	if(QDELETED(parent))
+		return
+
+	var/mob/living/parent_living = parent
+	var/datum/status_effect/hazard_area/effect = parent_living.has_status_effect(/datum/status_effect/hazard_area)
+	var/should_have_status_effect = check_area_hazardous(last_parent_area)
+
+	if(should_have_status_effect && !effect) // Should have the status - and doesnt
+		parent_living.apply_status_effect(/datum/status_effect/hazard_area)
+		if(parent_living.buckled)
+			parent_living.buckled.balloon_alert(parent, "you fall off!")
+			parent_living.buckled.unbuckle_mob(parent_living, force=TRUE)
+		return
+
+	if(!should_have_status_effect && effect) // Shouldn't have the status - and does
+		parent_living.remove_status_effect(/datum/status_effect/hazard_area)
+
+/**
+ * This signal should be called whenever our parent moves.
+ */
+/datum/component/hazard_area/proc/handle_parent_area_change(mob/source, area/new_area)
+	SIGNAL_HANDLER
+
+	if(new_area.type == last_parent_area)
+		return
+	last_parent_area = new_area.type
+
+	INVOKE_ASYNC(src, .proc/update_parent_status_effect)
+
+/// The dedicated status effect for the hazard_area component - use with caution and know what it does!
+/datum/status_effect/hazard_area
+	id = "hazard_area"
+	examine_text = "SUBJECTPRONOUN appears to be largely immobilized through unknown means."
+	status_type = STATUS_EFFECT_UNIQUE
+	alert_type = /atom/movable/screen/alert/status_effect/hazard_area
+
+/datum/status_effect/hazard_area/nextmove_modifier()
+	return 4
+
+/datum/status_effect/hazard_area/on_apply()
+	. = ..()
+	owner.add_movespeed_modifier(/datum/movespeed_modifier/status_effect/hazard_area, update=TRUE)
+	owner.add_actionspeed_modifier(/datum/actionspeed_modifier/status_effect/hazard_area, update=TRUE)
+
+/datum/status_effect/hazard_area/on_remove()
+	. = ..()
+	owner.remove_movespeed_modifier(/datum/movespeed_modifier/status_effect/hazard_area, update=TRUE)
+	owner.remove_actionspeed_modifier(/datum/actionspeed_modifier/status_effect/hazard_area, update=TRUE)
+
+/atom/movable/screen/alert/status_effect/hazard_area
+	name = "Hazardous Area"
+	desc = "The area you are currently within is incredibly hazardous to you. Check your surroudings and vacate as soon as possible."
+	icon_state = "hazard_area"