feat: add location-based food storage loop

simulation/state/StorageStateRecord.gd

@@ -0,0 +1,73 @@
+class_name StorageStateRecord
+extends RefCounted
+
+const SCHEMA_VERSION := 1
+
+var data: Dictionary
+
+func _init(record_data: Dictionary = {}) -> void:
+	data = record_data.duplicate(true)
+
+static func create(
+	storage_id: StringName,
+	initial_amounts: Dictionary,
+	capacity: float = 100.0
+) -> StorageStateRecord:
+	return StorageStateRecord.new({
+		"schema_version": SCHEMA_VERSION,
+		"storage_id": String(storage_id),
+		"amounts": initial_amounts.duplicate(true),
+		"capacity": capacity
+	})
+
+static func from_dictionary(record_data: Dictionary) -> StorageStateRecord:
+	if int(record_data.get("schema_version", -1)) != SCHEMA_VERSION:
+		return null
+	if not record_data.has_all(["storage_id", "amounts", "capacity"]):
+		return null
+	if String(record_data["storage_id"]).is_empty():
+		return null
+	if not record_data["amounts"] is Dictionary:
+		return null
+	var normalized := record_data.duplicate(true)
+	normalized["schema_version"] = SCHEMA_VERSION
+	normalized["capacity"] = float(record_data["capacity"])
+	var normalized_amounts := {}
+	for item_id in record_data["amounts"]:
+		normalized_amounts[String(item_id)] = float(
+			record_data["amounts"][item_id]
+		)
+	normalized["amounts"] = normalized_amounts
+	return StorageStateRecord.new(normalized)
+
+func get_storage_id() -> StringName:
+	return StringName(data["storage_id"])
+
+func get_amount(item_id: StringName) -> float:
+	return float(data["amounts"].get(String(item_id), 0.0))
+
+func get_total_amount() -> float:
+	var total := 0.0
+	for amount in data["amounts"].values():
+		total += float(amount)
+	return total
+
+func deposit(item_id: StringName, requested_amount: float) -> float:
+	var accepted := minf(
+		maxf(requested_amount, 0.0),
+		maxf(float(data["capacity"]) - get_total_amount(), 0.0)
+	)
+	if accepted <= 0.0:
+		return 0.0
+	data["amounts"][String(item_id)] = get_amount(item_id) + accepted
+	return accepted
+
+func withdraw(item_id: StringName, requested_amount: float) -> float:
+	var removed := minf(maxf(requested_amount, 0.0), get_amount(item_id))
+	if removed <= 0.0:
+		return 0.0
+	data["amounts"][String(item_id)] = get_amount(item_id) - removed
+	return removed
+
+func to_dictionary() -> Dictionary:
+	return data.duplicate(true)