extends Node

signal next_quick_slot
signal previous_quick_slot
signal select_quick_slot(slot_index: int)
signal quick_slot_item_changed(item_id: String)
signal item_picked_up(item: DBItemResource)
signal item_dropped(item: DBItemResource)
signal inventory_opened
signal inventory_closed

signal add_to_inventory(item_id: String, amount: int)
signal remove_from_inventory(item_id: String, amount: int)
signal item_added(item_id: String, amount: int)
signal item_removed(item_id: String, amount: int)

var quick_slot_item_id: String = "001"

var max_inventory_items: int = 40 # 4 rows of 10

var inventory: Array[DBItemResource] = []


func _ready() -> void:
	self.quick_slot_item_changed.connect(_on_quick_slot_item_changed)
	self.item_picked_up.connect(_on_item_picked_up)
	self.item_dropped.connect(_on_item_dropped)

	self.add_to_inventory.connect(_on_add_to_inventory)
	self.remove_from_inventory.connect(_on_remove_from_inventory)



# TODO: REMOVE ME
func _unhandled_input(event: InputEvent) -> void:
	if event.is_action_pressed("ui_cancel"):
		add_to_inventory.emit("003", 1)


func _find_first_available_stack(item_resource: DBItemResource, item_id: String) -> bool:
	return (
		item_resource.id == item_id and
		item_resource.amount < item_resource.max_stack_size
	)


func _on_add_to_inventory(item_id: String, amount: int = 1) -> void:
	if not DBItems.data.get(item_id):
		printerr("Cannot add item, ", item_id, ", to inventory. Could not find item within DBItems.data.")
		return
	if amount < 1:
		printerr("Cannot add item, ", item_id, ", to inventory. Amount to add cannot be less then 1.")
		return

	var item_resource: DBItemResource = DBItems.data[item_id]

	# This logic seems overly complicated and is a mess.
	#   Should look into fixing/simplifying this in the future
	var amount_remaining: int = amount
	while amount_remaining > 0:
		var first_stack_index: int = inventory.find_custom(_find_first_available_stack.bind(item_id))

		if first_stack_index == -1 and inventory.size() < max_inventory_items:
			var stack_resource: DBItemResource = item_resource.duplicate()
			inventory.append(stack_resource)

			if amount_remaining <= stack_resource.max_stack_size:
				inventory[-1].amount += amount_remaining
				amount_remaining = 0
			else:
				inventory[-1].amount = stack_resource.max_stack_size
				amount_remaining -= stack_resource.max_stack_size

			item_added.emit(item_id, amount - amount_remaining)
		elif first_stack_index > -1:
			var stack_resource: DBItemResource = inventory[first_stack_index]
			var current_amount: int = stack_resource.amount
			var total_amount: int = current_amount + amount_remaining
			if total_amount < stack_resource.max_stack_size: # Stack not full and can hold
				inventory[first_stack_index].amount = total_amount
				amount_remaining = 0
			else:
				inventory[first_stack_index].amount = stack_resource.max_stack_size
				amount_remaining -= stack_resource.max_stack_size

			item_added.emit(item_id, amount - amount_remaining)

func _on_remove_from_inventory(item_id: String, amount: int = 1) -> void:
	if not inventory.has(item_id): return

	#if inventory[item_id].amount > 0:
		#inventory[item_id].amount -= amount
		#item_removed.emit(item_id, max(0, amount))

func _on_item_dropped(item_id: String) -> void:
	_on_remove_from_inventory(item_id, 1)

func _on_item_picked_up(item_id: String) -> void:
	_on_add_to_inventory(item_id, 1)

func _on_quick_slot_item_changed(item_id: String) -> void:
	quick_slot_item_id = item_id