Init

Prefab.Base/PrefabEnum.cs

@@ -0,0 +1,57 @@
+namespace Prefab.Base;
+
+/// <summary>
+/// Base type for rich enumerations that behave like enums but support additional metadata and behavior.
+/// </summary>
+/// <typeparam name="TEnum">Concrete enumeration type deriving from <see cref="PrefabEnum{TEnum}"/>.</typeparam>
+public abstract class PrefabEnum<TEnum> where TEnum : PrefabEnum<TEnum>
+{
+    private static readonly List<TEnum> Instances = [];
+
+    /// <summary>
+    /// Gets the canonical name of the enumeration value.
+    /// </summary>
+    public string Name { get; }
+
+    /// <summary>
+    /// Gets the integral value associated with the enumeration value.
+    /// </summary>
+    public int Value { get; }
+
+    /// <summary>
+    /// Initializes a new enumeration value and registers it in the global instance list.
+    /// </summary>
+    /// <param name="name">Logical name exposed to consumers.</param>
+    /// <param name="value">Numeric identifier for persistence.</param>
+    protected PrefabEnum(string name, int value)
+    {
+        Name = name;
+        Value = value;
+        Instances.Add(this as TEnum ?? throw new InvalidOperationException("PrefabEnum must be instantiated with a derived type."));
+    }
+
+    /// <summary>
+    /// Gets all declared enumeration values for <typeparamref name="TEnum"/>.
+    /// </summary>
+    public static IReadOnlyList<TEnum> List => Instances;
+
+    /// <summary>
+    /// Resolves an enumeration value by its logical name.
+    /// </summary>
+    /// <param name="name">The name to match.</param>
+    /// <returns>The matching enumeration.</returns>
+    /// <exception cref="ArgumentException">Thrown when no enumeration value matches the supplied name.</exception>
+    public static TEnum FromName(string name) =>
+        Instances.FirstOrDefault(x => x.Name.Equals(name, StringComparison.OrdinalIgnoreCase))
+        ?? throw new ArgumentException($"Invalid name: {name}", nameof(name));
+
+    /// <summary>
+    /// Resolves an enumeration value by its integral value.
+    /// </summary>
+    /// <param name="value">The integer value to match.</param>
+    /// <returns>The matching enumeration.</returns>
+    /// <exception cref="ArgumentException">Thrown when no enumeration value matches the supplied value.</exception>
+    public static TEnum FromValue(int value) =>
+        Instances.FirstOrDefault(x => x.Value == value)
+        ?? throw new ArgumentException($"Invalid value: {value}", nameof(value));
+}