Fixes + expands vending machine returned purchases (#64314)

Fixes vending machine returns, also makes it so you can return anything to (nearly) any vending machine. New stuff vends first. Secondhand stuff last.

code/modules/vending/_vending.dm

@@ -36,6 +36,8 @@
 	var/age_restricted = FALSE
 	///Whether the product can be recolored by the GAGS system
 	var/colorable
+	///List of items that have been returned to the vending machine.
+	var/list/returned_products
 
 /**
  * # vending machines
@@ -278,6 +280,14 @@
 		found_anything = FALSE
 		for(var/record in shuffle(product_records))
 			var/datum/data/vending_product/R = record
+
+			//first dump any of the items that have been returned, in case they contain the nuke disk or something
+			for(var/obj/returned_obj_to_dump in R.returned_products)
+				LAZYREMOVE(R.returned_products, returned_obj_to_dump)
+				returned_obj_to_dump.forceMove(get_turf(src))
+				step(returned_obj_to_dump, pick(GLOB.alldirs))
+				R.amount--
+
 			if(R.amount <= 0) //Try to use a record that actually has something to dump.
 				continue
 			var/dump_path = R.product_path
@@ -288,8 +298,8 @@
 			if(found_anything && prob(80))
 				continue
 
-			var/obj/O = new dump_path(loc)
-			step(O, pick(GLOB.alldirs))
+			var/obj/obj_to_dump = new dump_path(loc)
+			step(obj_to_dump, pick(GLOB.alldirs))
 			found_anything = TRUE
 			dump_amount++
 			if (dump_amount >= 16)
@@ -511,9 +521,13 @@ GLOBAL_LIST_EMPTY(vending_products)
 			var/dump_path = R.product_path
 			if(!dump_path)
 				continue
-
+			if(R.amount > LAZYLEN(R.returned_products)) //always give out new stuff that costs before free returned stuff, because of the risk getting gibbed involved
+				new dump_path(get_turf(src))
+			else
+				var/obj/returned_obj_to_dump = LAZYACCESS(R.returned_products, LAZYLEN(R.returned_products)) //first in, last out
+				LAZYREMOVE(R.returned_products, returned_obj_to_dump)
+				returned_obj_to_dump.forceMove(get_turf(src))
 			R.amount--
-			new dump_path(get_turf(src))
 			break
 
 ///Tilts ontop of the atom supplied, if crit is true some extra shit can happen. Returns TRUE if it dealt damage to something.
@@ -646,11 +660,18 @@ GLOBAL_LIST_EMPTY(vending_products)
 	. = TRUE
 	if(!user.transferItemToLoc(I, src))
 		return FALSE
+	to_chat(user, span_notice("You insert [I] into [src]'s input compartment."))
+
+	for(var/datum/data/vending_product/product_datum in product_records + coin_records + hidden_records)
+		if(ispath(I.type, product_datum.product_path))
+			product_datum.amount++
+			LAZYADD(product_datum.returned_products, I)
+			return
+
 	if(vending_machine_input[format_text(I.name)])
 		vending_machine_input[format_text(I.name)]++
 	else
 		vending_machine_input[format_text(I.name)] = 1
-	to_chat(user, span_notice("You insert [I] into [src]'s input compartment."))
 	loaded_items++
 
 /obj/machinery/vending/unbuckle_mob(mob/living/buckled_mob, force = FALSE, can_fall = TRUE)
@@ -926,6 +947,8 @@ GLOBAL_LIST_EMPTY(vending_products)
 			price_to_use = max(round(price_to_use * VENDING_DISCOUNT), 1) //No longer free, but signifigantly cheaper.
 		if(coin_records.Find(R) || hidden_records.Find(R))
 			price_to_use = R.custom_premium_price ? R.custom_premium_price : extra_price
+		if(LAZYLEN(R.returned_products))
+			price_to_use = 0 //returned items are free
 		if(price_to_use && !account.adjust_money(-price_to_use))
 			say("You do not possess the funds to purchase [R.name].")
 			flick(icon_deny,src)
@@ -945,7 +968,13 @@ GLOBAL_LIST_EMPTY(vending_products)
 	if(icon_vend) //Show the vending animation if needed
 		flick(icon_vend,src)
 	playsound(src, 'sound/machines/machine_vend.ogg', 50, TRUE, extrarange = -3)
-	var/obj/item/vended_item = new R.product_path(get_turf(src))
+	var/obj/item/vended_item
+	if(!LAZYLEN(R.returned_products)) //always give out free returned stuff first, e.g. to avoid walling a traitor objective in a bag behind paid items
+		vended_item = new R.product_path(get_turf(src))
+	else
+		vended_item = LAZYACCESS(R.returned_products, LAZYLEN(R.returned_products)) //first in, last out
+		LAZYREMOVE(R.returned_products, vended_item)
+		vended_item.forceMove(get_turf(src))
 	if(greyscale_colors)
 		vended_item.set_greyscale(colors=greyscale_colors)
 	R.amount--
@@ -1013,9 +1042,13 @@ GLOBAL_LIST_EMPTY(vending_products)
 		var/dump_path = R.product_path
 		if(!dump_path)
 			continue
-
+		if(R.amount > LAZYLEN(R.returned_products)) //always throw new stuff that costs before free returned stuff, because of the hacking effort and time between throws involved
+			throw_item = new dump_path(loc)
+		else
+			throw_item = LAZYACCESS(R.returned_products, LAZYLEN(R.returned_products)) //first in, last out
+			throw_item.forceMove(loc)
+			LAZYREMOVE(R.returned_products, throw_item)
 		R.amount--
-		throw_item = new dump_path(loc)
 		break
 	if(!throw_item)
 		return FALSE
@@ -1064,6 +1097,9 @@ GLOBAL_LIST_EMPTY(vending_products)
  * * user - the user doing the loading
  */
 /obj/machinery/vending/proc/canLoadItem(obj/item/I, mob/user)
+	if((I.type in products) || (I.type in premium) || (I.type in contraband))
+		return TRUE
+	to_chat(user, span_warning("[src] does not accept [I]!"))
 	return FALSE
 
 /obj/machinery/vending/hitby(atom/movable/AM, skipcatch, hitpush, blocked, datum/thrownthing/throwingdatum)

code/modules/vending/autodrobe.dm

@@ -165,9 +165,6 @@
 	payment_department = ACCOUNT_SRV
 	light_mask="theater-light-mask"
 
-/obj/machinery/vending/autodrobe/canLoadItem(obj/item/I,mob/user)
-	return (I.type in products)
-
 /obj/machinery/vending/autodrobe/all_access
 	desc = "A vending machine for costumes. This model appears to have no access restrictions."
 	req_access = null

code/modules/vending/clothesmate.dm

@@ -208,9 +208,6 @@
 	light_mask = "wardrobe-light-mask"
 	light_color = LIGHT_COLOR_ELECTRIC_GREEN
 
-/obj/machinery/vending/clothing/canLoadItem(obj/item/I,mob/user)
-	return (I.type in products)
-
 /obj/item/vending_refill/clothing
 	machine_name = "ClothesMate"
 	icon_state = "refill_clothes"

code/modules/vending/wardrobes.dm

@@ -9,9 +9,6 @@
 	panel_type = "panel19"
 	light_mask = "wardrobe-light-mask"
 
-/obj/machinery/vending/wardrobe/canLoadItem(obj/item/I,mob/user)
-	return (I.type in products)
-
 /obj/machinery/vending/wardrobe/sec_wardrobe
 	name = "\improper SecDrobe"
 	desc = "A vending machine for security and security-related clothing!"