Post-merge code cleanup for botanic trays (#96352)

## About The Pull Request
Melbert has tasked me to handle fixing and cleaning up a few things from
#96236 after I merged it before they could review it a second time, plus
a few things I've noticed on my own (changing the name and desc is best
handled by the update_name and update_desc proc respectively, and soil
shouldn't process while inside trays).

code/game/objects/items/circuitboards/machines/machine_circuitboards.dm

@@ -1318,24 +1318,23 @@
 
 /obj/item/circuitboard/machine/hydroponics/proc/changeindicators(mob/living/user, obj/item/I)
 	if(build_path == /obj/machinery/hydroponics/constructable/oldstyle)
-		name = "Hydroponics Tray"
+		name = "Hydroponics Tray [name_extension]"
 		build_path = /obj/machinery/hydroponics/constructable
-		balloon_alert(user, "defaulting indicator location.")
+		balloon_alert(user, "defaulting indicator location")
 	else
-		name = "Old-Designed Hydropoincs Tray"
+		name = "Hydroponics Tray (Alt) [name_extension]"
 		build_path = /obj/machinery/hydroponics/constructable/oldstyle
-		balloon_alert(user, "moving the indicators...")
-	return TRUE
+		balloon_alert(user, "moved indicators location")
 
 /obj/item/circuitboard/machine/hydroponics/item_interaction(mob/living/user, obj/item/I, list/modifiers)
 	if(istype(I, /obj/item/plant_analyzer))
 		changeindicators(user)
-	else
-		return ..()
+		return ITEM_INTERACT_SUCCESS
+	return ..()
 
 /obj/item/circuitboard/machine/hydroponics/screwdriver_act(mob/living/user, obj/item/tool)
-	src.changeindicators(user)
-	return
+	changeindicators(user)
+	return ITEM_INTERACT_SUCCESS
 
 /obj/item/circuitboard/machine/hydroponics/fullupgrade
 	build_path = /obj/machinery/hydroponics/constructable/fullupgrade

code/modules/hydroponics/hydroponics.dm

@@ -52,8 +52,6 @@
 	var/datum/weakref/lastuser
 	///If the tray generates nutrients and water on its own
 	var/self_sustaining = FALSE
-	///If the tray is currently able to self-sustain
-	var/can_self_sustain = TRUE
 	///The icon state for the overlay used to represent that this tray is self-sustaining.
 	var/self_sustaining_overlay_icon_state = "gaia_blessing"
 	///Whether the plant is currently being pollinated or polinating the nearby plants
@@ -68,10 +66,8 @@
 	var/plant_offset_y = 0
 	///Suffix things
 	var/alt_tray = FALSE
-	var/indicatorsuffix = ""
 	///Soil things
-	var/obj/machinery/hydroponics/soil/current_soil = null
-	var/current_soil_overlay = null
+	var/obj/machinery/hydroponics/soil/current_soil
 
 /obj/machinery/hydroponics/Initialize(mapload)
 	//ALRIGHT YOU DEGENERATES. YOU HAD REAGENT HOLDERS FOR AT LEAST 4 YEARS AND NONE OF YOU MADE HYDROPONICS TRAYS HOLD NUTRIENT CHEMS INSTEAD OF USING "Points".
@@ -169,12 +165,10 @@
 	return NONE
 
 /obj/machinery/hydroponics/constructable
-	name = "hydroponics tray"
 	icon = 'icons/obj/service/hydroponics/equipment.dmi'
 	icon_state = "hydrotray3"
 
 /obj/machinery/hydroponics/constructable/oldstyle
-	name = "hydroponics tray"
 	icon = 'icons/obj/service/hydroponics/equipment.dmi'
 	icon_state = "hydrotray3-alt"
 	alt_tray = TRUE
@@ -191,9 +185,6 @@
 	AddComponent(/datum/component/usb_port, typecacheof(list(/obj/item/circuit_component/hydroponics), only_root_path = TRUE))
 	AddComponent(/datum/component/fishing_spot, /datum/fish_source/hydro_tray)
 
-/obj/machinery/hydroponics/constructable/on_deconstruction(disassembled)
-	current_soil?.forceMove(drop_location())
-
 /obj/machinery/hydroponics/constructable/RefreshParts()
 	. = ..()
 	var/tmp_capacity = 0
@@ -247,21 +238,27 @@
 	if(myseed)
 		QDEL_NULL(myseed)
 	remove_shared_particles(/particles/pollen)
+	QDEL_NULL(current_soil)
 	return ..()
 
 /obj/machinery/hydroponics/Exited(atom/movable/gone)
 	. = ..()
 	if(!QDELETED(src) && gone == myseed)
 		set_seed(null, FALSE)
-	if(!istype(gone, /obj/item/mob_holder/snail))
 		return
-	var/obj/item/mob_holder/snail_object = gone
-	if(snail_object.held_mob)
-		UnregisterSignal(snail_object.held_mob, list(
-			COMSIG_LIVING_DEATH,
-			COMSIG_MOVABLE_ATTEMPTED_MOVE,
-		))
-	QDEL_NULL(our_snail)
+	if(gone == current_soil)
+		current_soil = null
+		if(!QDELETED(src))
+			update_appearance()
+		return
+	if(istype(gone, /obj/item/mob_holder/snail))
+		var/obj/item/mob_holder/snail_object = gone
+		if(snail_object.held_mob)
+			UnregisterSignal(snail_object.held_mob, list(
+				COMSIG_LIVING_DEATH,
+				COMSIG_MOVABLE_ATTEMPTED_MOVE,
+			))
+		QDEL_NULL(our_snail)
 
 /obj/machinery/hydroponics/constructable/screwdriver_act(mob/living/user, obj/item/tool)
 	return default_deconstruction_screwdriver(user, tool)
@@ -474,8 +471,19 @@
 
 /obj/machinery/hydroponics/update_name(updates)
 	. = ..()
-	if(!GetComponent(/datum/component/rename) && myseed)
-		name = "[initial(name)] ([myseed.plantname])"
+	if(GetComponent(/datum/component/rename))
+		return
+	name = current_soil ? "botanic tray" : initial(name)
+	if(myseed)
+		name += " ([myseed.plantname])"
+
+/obj/machinery/hydroponics/update_desc(updates)
+	. = ..()
+	if(GetComponent(/datum/component/rename))
+		return
+	desc = initial(desc)
+	if(current_soil)
+		desc += " Filled with [current_soil.name]."
 
 /obj/machinery/hydroponics/update_overlays()
 	. = ..()
@@ -483,8 +491,9 @@
 		. += myseed.get_tray_overlay(age, plant_status, plant_offset_y)
 		. += update_status_light_overlays()
 
-	if(current_soil && current_soil_overlay)
-		. += mutable_appearance(icon, current_soil_overlay, OBJ_LAYER + 0.001)
+	if(current_soil)
+		var/soil_overlay = "[current_soil.icon_state]_tray"
+		. += mutable_appearance(icon, soil_overlay, OBJ_LAYER + 0.001)
 
 	if(self_sustaining && self_sustaining_overlay_icon_state)
 		. += mutable_appearance(icon, self_sustaining_overlay_icon_state, OBJ_LAYER + 0.002)
@@ -492,8 +501,7 @@
 
 /obj/machinery/hydroponics/proc/update_status_light_overlays()
 	. = list()
-	if(alt_tray)
-		indicatorsuffix = "-alt"
+	var/indicatorsuffix = alt_tray ? "-alt" : ""
 	if(waterlevel <= 10)
 		. += mutable_appearance('icons/obj/service/hydroponics/equipment.dmi', "over_lowwater3[indicatorsuffix]")
 		. += emissive_appearance(icon, "over_lowwater3[indicatorsuffix]", src, alpha = src.alpha)
@@ -1101,28 +1109,21 @@
 			return
 
 		if(!isnull(current_soil))
-			balloon_alert(user, "tray is full")
+			balloon_alert(user, "tray is full!")
 			return
 
 		balloon_alert(user, "filling the tray...")
 		if(!do_after(user, 2 SECONDS, src))
 			return
 
-		if(!oursoil.stored_soil)
-			balloon_alert(user, "sack is empty!")
-			return
-
-		current_soil = new oursoil.stored_soil(src)
+		oursoil.transfer_soil(src, inside_tray = TRUE)
 
 		RefreshParts()
 		tray_flags = current_soil.tray_flags
-		current_soil_overlay = "[current_soil.icon_state]_tray"
-		name = "botanic tray"
-		desc = "A basin used to grow plants in. Filled with [current_soil.name]."
 
 		qdel(oursoil)
 		update_appearance()
-		return
+		return TRUE
 
 	else
 		return ..()
@@ -1166,10 +1167,6 @@
 		update_use_power(NO_POWER_USE)
 		return CLICK_ACTION_BLOCKING
 
-	if(!can_self_sustain)
-		balloon_alert(user, "no self-sustain mode!")
-		return CLICK_ACTION_BLOCKING
-
 	set_self_sustaining(!self_sustaining)
 	to_chat(user, span_notice("You [self_sustaining ? "activate" : "deactivated"] [src]'s autogrow function[self_sustaining ? ", maintaining the tray's health while using high amounts of power" : ""]."))
 	return CLICK_ACTION_SUCCESS

code/modules/hydroponics/soil.dm

@@ -150,6 +150,12 @@
 		animate(time = 100 MILLISECONDS, pixel_z = 0, easing = QUAD_EASING | EASE_IN)
 		animate(time = 250 MILLISECONDS, pixel_x = rand(-6, 6), pixel_y = rand(-4, 4), flags = ANIMATION_PARALLEL)
 
+/obj/item/soil_sack/Exited(atom/movable/gone)
+	. = ..()
+	if(gone == stored_soil)
+		stored_soil = null
+		qdel(src)
+
 /obj/item/soil_sack/interact_with_atom(atom/interacting_with, mob/living/user, list/modifiers)
 	if(!isopenturf(interacting_with) || isgroundlessturf(interacting_with))
 		return ..()
@@ -161,19 +167,24 @@
 	if(!do_after(user, 1 SECONDS, interacting_with))
 		return ITEM_INTERACT_BLOCKING
 
+	transfer_soil(interacting_with)
+	return ITEM_INTERACT_SUCCESS
+
+//Proc responsible for placing the soil inside track onto the turf or inside a hydroponic tray
+/obj/item/soil_sack/proc/transfer_soil(atom/target, inside_tray = FALSE)
 	if(ispath(stored_soil))
 		stored_soil = new stored_soil(src)
+		if(inside_tray)
+			STOP_PROCESSING(SSmachines, stored_soil)
 		stored_soil.reagents.add_reagent(/datum/reagent/plantnutriment/eznutriment, stored_soil.maxnutri / 2)
 		stored_soil.waterlevel = stored_soil.maxwater
-	else
+	else if(!inside_tray)
 		START_PROCESSING(SSmachines, stored_soil)
 
-
-	stored_soil.forceMove(interacting_with)
-	playsound(stored_soil, placement_sound, 65, vary = TRUE)
-	stored_soil.on_place()
-	qdel(src)
-	return ITEM_INTERACT_SUCCESS
+	playsound(target, placement_sound, 65, vary = TRUE)
+	if(!inside_tray)
+		stored_soil.on_place()
+	stored_soil.forceMove(target) //stored_soil is set to null at this point, and the soil sack is deleted when that happens
 
 /obj/item/soil_sack/hit_reaction(mob/living/carbon/human/owner, atom/movable/hitby, attack_text = "the attack", final_block_chance = 0, damage = 0, attack_type = MELEE_ATTACK, damage_type = BRUTE)
 	if(attack_type == OVERWHELMING_ATTACK)