class_name Inventory

var _content:Array[ItemStack] = []
const INVENTORY_SIZE:int = 36
const INVENTORY_TOOL_START:int = 36 - 9

func _init() -> void:
	clear()

func get_free_tool_stack_index() -> int:
	for i:int in range(INVENTORY_TOOL_START, _content.size()):
		if _content[i].count == 0:
			return i

	return -1

func get_free_item_stack_index() -> int:
	for i:int in range(_content.size()):
		if _content[i].count == 0:
			return i
	
	return -1

func add_item(item:ItemResource) -> bool:
	for item_stack:ItemStack in _content:
		if item_stack.count == 0:
			continue
		
		if item_stack.item.resource_path != item.resource_path:
			continue
			
		if item_stack.count < item_stack.item.max_stack_size:
			item_stack.count = item_stack.count + 1
			return true

	# First try to put it into the tool stacks...
	var item_stack_index:int = get_free_tool_stack_index()
	
	# ... and if that failed try use the regular inventory.
	if item_stack_index < 0:
		item_stack_index = get_free_item_stack_index()
	
	if item_stack_index >= 0:
		_content[item_stack_index].item = item
		_content[item_stack_index].count = 1
		return true

	return false

func remove_item(item:ItemResource):
	for i in range(_content.size() - 1, -1, -1):
		var item_stack:ItemStack = _content[i]
		if item_stack.count == 0:
			continue
	
		if item_stack.item.resource_path == item.resource_path:
			if item_stack.count > 1:
				item_stack.count = item_stack.count - 1
			
			return


func get_item_stacks() -> Array[ItemStack]:
	return _content


func get_tool_item_stacks() -> Array[ItemStack]:
	return _content.slice(_content.size() - 9)


func clear() -> void:
	_content.clear()
	_content.resize(INVENTORY_SIZE)
	for i:int in range(_content.size()):
		if _content[i] == null:
			_content[i] = ItemStack.new()


func has_all(items:Array[ItemResource]) -> bool:
	var needed:Array[ItemResource] = items.duplicate()
	
	for item_stack:ItemStack in _content:
		if item_stack.count == 0:
			continue
		
		for i in range (item_stack.count):
			needed.erase(item_stack.item)
	
	return needed.is_empty()