wip: Add support for removing an item from inventory

autoloads/inventory_manager.gd

@@ -30,19 +30,26 @@ func _ready() -> void:
 	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"):
+	if event.is_action_pressed("ui_up"):
 		add_to_inventory.emit("003", 1)
+	elif event.is_action_pressed("ui_down"):
+		remove_from_inventory.emit("003", 1)
 
 
-func _find_first_available_stack(item_resource: DBItemResource, item_id: String) -> bool:
+## Find the stack where at least one item can be added
+func _find_available_stack(item_resource: DBItemResource, item_id: String) -> bool:
 	return (
 		item_resource.id == item_id and
 		item_resource.amount < item_resource.max_stack_size
 	)
 
+## Find the stack in which we can remove a specific item
+##   The inventory has a stack, then it should have at least 1 item. Empty stacks are not kept in the inventory.
+func _find_removable_stack(item_resource: DBItemResource, item_id: String) -> bool:
+	return item_resource.id == item_id
+
 
 func _on_add_to_inventory(item_id: String, amount: int = 1) -> void:
 	if not DBItems.data.get(item_id):
@@ -58,7 +65,7 @@ func _on_add_to_inventory(item_id: String, amount: int = 1) -> void:
 	#   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))
+		var first_stack_index: int = inventory.find_custom(_find_available_stack.bind(item_id))
 
 		if first_stack_index == -1 and inventory.size() < max_inventory_items:
 			var stack_resource: DBItemResource = item_resource.duplicate()
@@ -71,7 +78,6 @@ func _on_add_to_inventory(item_id: String, amount: int = 1) -> void:
 				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
@@ -83,14 +89,29 @@ func _on_add_to_inventory(item_id: String, amount: int = 1) -> void:
 				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)
+	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
+	var amount_remaining: int = amount
+	while amount_remaining > 0:
+		var last_stack_index: int = inventory.rfind_custom(_find_removable_stack.bind(item_id))
+
+		if last_stack_index > -1:
+			var stack_resource: DBItemResource = inventory[last_stack_index]
+			var current_stack_amount: int = stack_resource.amount
+			var total_amount: int = current_stack_amount - amount_remaining
+
+			if total_amount > 0: # Stack will not be empty after removing
+				inventory[last_stack_index].amount -= amount_remaining
+				amount_remaining = 0
+			else:
+				var remaining: int = stack_resource.max_stack_size - current_stack_amount
+				inventory.remove_at(last_stack_index)
+				amount_remaining -= remaining
+		else: # Received more to remove than we had stacks of
+			amount_remaining = 0
 
-	#if inventory[item_id].amount > 0:
-		#inventory[item_id].amount -= amount
-		#item_removed.emit(item_id, max(0, amount))
+	item_removed.emit(item_id, amount - amount_remaining)
 
 func _on_item_dropped(item_id: String) -> void:
 	_on_remove_from_inventory(item_id, 1)