@tool

extends Inventory

## Base class for FIFO inventories.

class_name Queue

## Amount of stacks that can be held in storage
@export var capacity : int:
	set(value):
		if value < 0:
			return
		if value == capacity:
			return
		capacity = value
	get:
		return capacity

## :3
@export_storage var internal_array : Array[InventorySlot] = []


func _init() -> void:
	super()
	internal_array.resize(capacity)
	for i in range(capacity):
		internal_array[i] = InventorySlot.new()

## Finds first entry of item. Returns -1 if no item found
func find(item : Item) -> int:
	for i in range(len(internal_array)):
		if internal_array[i].held_item == item:
			return i
	return -1

## Tries to add an item into inventory. Returns not stored stack of item.
func add(stack: Stack) -> Stack:
	for i in range(len(internal_array)):
		if internal_array[i].held_item == null or internal_array[i].held_item == stack.held_item:
			stack_added.emit(stack,i)
			stack = internal_array[i].merge_stack(stack)
		if stack == null:
			return null
	return stack

func can_add() -> bool:
	for i in range(capacity):
		if internal_array[i].amount == 0:
			return true
	return false

## Tries to take first item. Returns null if no items in inventory
func pop() -> Stack:
	if internal_array[0].held_item == null:
		return null
	var stack_to_return = internal_array[0].extract()
	stack_taken.emit(stack_to_return,0)
	sort()
	return stack_to_return

## Tries to take certain item from inventory. Returns null if no item found
func take(item: Item,amount: int) -> Stack:
	var found = find(item)
	if found == -1:
		return null
	var stack_to_return = internal_array[found].extract_stack(amount)
	stack_taken.emit(stack_to_return,found)
	sort()
	return stack_to_return

func sort() -> void:
	for i in range(len(internal_array)-1):
		if internal_array[i] == null:
			internal_array[i].merge_stack(internal_array[i+1].extract())