1 files changed, 81 insertions, 1 deletions
diff --git a/extension/src/openvic2/Types.hpp b/extension/src/openvic2/Types.hpp
index b20db10..98e92ce 100644
--- a/extension/src/openvic2/Types.hpp
+++ b/extension/src/openvic2/Types.hpp
@@ -10,11 +10,91 @@ namespace OpenVic2 {
 	// This mirrors godot::Error, where `OK = 0` and `FAILED = 1`.
 	static constexpr return_t SUCCESS = false, FAILURE = true;
 
+	/*
+	 * Base class for objects with a non-empty string identifier,
+	 * uniquely named instances of which can be entered into an
+	 * IdentifierRegistry instance.
+	 */
 	class HasIdentifier {
-		std::string identifier;
+		const std::string identifier;
 	protected:
 		HasIdentifier(std::string const& new_identifier);
 	public:
+		HasIdentifier(HasIdentifier const&) = delete;
+		HasIdentifier(HasIdentifier&&) = default;
+		HasIdentifier& operator=(HasIdentifier const&) = delete;
+		HasIdentifier& operator=(HasIdentifier&&) = delete;
+
 		std::string const& get_identifier() const;
 	};
+
+	/*
+	 * Template for a list of objects with unique string identifiers that can
+	 * be locked to prevent any further additions. The template argument T is
+	 * the type of object that the registry will store, and the second part ensures
+	 * that HasIdentifier is a base class of T.
+	 */
+	template<class T, typename std::enable_if<std::is_base_of<HasIdentifier, T>::value>::type* = nullptr>
+	class IdentifierRegistry {
+		const std::string name;
+		std::vector<T> items;
+		bool locked = false;
+	public:
+		IdentifierRegistry(std::string const& new_name) : name(new_name) {}
+		return_t add_item(T&& item) {
+			if (locked) {
+				Logger::error("Cannot add item to the ", name, " registry - locked!");
+				return FAILURE;
+			}
+			T const* old_item = get_item_by_identifier(item.get_identifier());
+			if (old_item != nullptr) {
+				Logger::error("Cannot add item to the ", name, " registry - an item with the identifier \"", item.get_identifier(), "\" already exists!");
+				return FAILURE;
+			}
+			items.push_back(std::move(item));
+			return SUCCESS;
+		}
+		void lock(bool log = true) {
+			if (locked) {
+				Logger::error("Failed to lock ", name, " registry - already locked!");
+			} else {
+				locked = true;
+				if (log) Logger::info("Locked ", name, " registry after registering ", get_item_count(), " items");
+			}
+		}
+		bool is_locked() const {
+			return locked;
+		}
+		void reset() {
+			items.clear();
+			locked = false;
+		}
+		size_t get_item_count() const {
+			return items.size();
+		}
+		T* get_item_by_identifier(std::string const& identifier) {
+			if (!identifier.empty())
+				for (T& item : items)
+					if (item.get_identifier() == identifier) return &item;
+			return nullptr;
+		}
+		T const* get_item_by_identifier(std::string const& identifier) const {
+			if (!identifier.empty())
+				for (T const& item : items)
+					if (item.get_identifier() == identifier) return &item;
+			return nullptr;
+		}
+		T* get_item_by_index(size_t index) {
+			return index < items.size() ? &items[index] : nullptr;
+		}
+		T const* get_item_by_index(size_t index) const {
+			return index < items.size() ? &items[index] : nullptr;
+		}
+		std::vector<T>& get_items() {
+			return items;
+		}
+		std::vector<T> const& get_items() const {
+			return items;
+		}
+	};
 }