wip: Add _inventory_cache and available_space()

autoloads/inventory_manager.gd

@@ -19,7 +19,7 @@ var quick_slot_item_id: String = "001"
 var max_inventory_items: int = 40 # 4 rows of 10
 
 var inventory: Array[DBItemResource] = []
-
+var _inventory_cache: Dictionary[String, Dictionary] = {} ## Used for caching certain information
 
 func _ready() -> void:
 	self.quick_slot_item_changed.connect(_on_quick_slot_item_changed)
@@ -38,17 +38,36 @@ func _unhandled_input(event: InputEvent) -> void:
 		remove_from_inventory.emit("003", 1)
 
 
+func available_space(item_id: String) -> int:
+	var full_stacks: int = floor(_inventory_cache[item_id].total / DBItems.data[item_id].max_stack_size)
+	var space_in_stacks: int = (
+		DBItems.data[item_id].max_stack_size - abs(
+			_inventory_cache[item_id].total - (DBItems.data[item_id].max_stack_size * full_stacks)
+		)
+	)
+
+	# This is a bit of a hack because I'm a math/logic noob
+	if space_in_stacks == DBItems.data[item_id].max_stack_size:
+		space_in_stacks = 0
+
+	var open_stack_amount: int = (max_inventory_items - inventory.size()) * DBItems.data[item_id].max_stack_size
+	return open_stack_amount + space_in_stacks
+
+
+func _find_stacks_by_id(item_resource: DBItemResource, item_id: String) -> bool:
+	return item_resource.id == item_id
+
 ## Find the stack where at least one item can be added
-func _find_available_stack(item_resource: DBItemResource, item_id: String) -> bool:
+func _find_stacks_with_space(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 _update_cache_total(item_id: String, amount: int) -> void:
+	if not _inventory_cache.get(item_id):
+		_inventory_cache[item_id] = {"total": 0}
+	_inventory_cache[item_id].total += amount
 
 
 func _on_add_to_inventory(item_id: String, amount: int = 1) -> void:
@@ -65,27 +84,30 @@ 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_available_stack.bind(item_id))
+		var first_stack_index: int = inventory.find_custom(_find_stacks_with_space.bind(item_id))
 
-		if first_stack_index == -1 and inventory.size() < max_inventory_items:
+		if first_stack_index == -1 and inventory.size() < max_inventory_items: # No existing stack and empty slots available
 			var stack_resource: DBItemResource = item_resource.duplicate()
 			inventory.append(stack_resource)
 
 			if amount_remaining <= stack_resource.max_stack_size:
+				_update_cache_total(item_id, amount_remaining)
 				inventory[-1].amount += amount_remaining
 				amount_remaining = 0
 			else:
+				_update_cache_total(item_id, stack_resource.max_stack_size)
 				inventory[-1].amount = stack_resource.max_stack_size
 				amount_remaining -= stack_resource.max_stack_size
-
 		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
+			if total_amount < stack_resource.max_stack_size: # Stack not full and has space
+				_update_cache_total(item_id, amount_remaining)
 				inventory[first_stack_index].amount = total_amount
 				amount_remaining = 0
 			else:
+				_update_cache_total(item_id, stack_resource.max_stack_size - current_amount)
 				inventory[first_stack_index].amount = stack_resource.max_stack_size
 				amount_remaining -= stack_resource.max_stack_size
 
@@ -94,7 +116,7 @@ func _on_add_to_inventory(item_id: String, amount: int = 1) -> void:
 func _on_remove_from_inventory(item_id: String, amount: int = 1) -> void:
 	var amount_remaining: int = amount
 	while amount_remaining > 0:
-		var last_stack_index: int = inventory.rfind_custom(_find_removable_stack.bind(item_id))
+		var last_stack_index: int = inventory.rfind_custom(_find_stacks_by_id.bind(item_id))
 
 		if last_stack_index > -1:
 			var stack_resource: DBItemResource = inventory[last_stack_index]
@@ -102,12 +124,14 @@ func _on_remove_from_inventory(item_id: String, amount: int = 1) -> void:
 			var total_amount: int = current_stack_amount - amount_remaining
 
 			if total_amount > 0: # Stack will not be empty after removing
+				_update_cache_total(item_id, -amount_remaining)
 				inventory[last_stack_index].amount -= amount_remaining
 				amount_remaining = 0
 			else:
-				var remaining: int = stack_resource.max_stack_size - current_stack_amount
+				var to_remove: int = stack_resource.max_stack_size - current_stack_amount
+				_update_cache_total(item_id, -amount_remaining)
 				inventory.remove_at(last_stack_index)
-				amount_remaining -= remaining
+				amount_remaining -= to_remove
 		else: # Received more to remove than we had stacks of
 			amount_remaining = 0