Begin work on outlining dynamic side

PkmnLib.Dynamic/ScriptHandling/Registry/ScriptRegistry.cs

@@ -0,0 +1,56 @@
+using System.Linq.Expressions;
+using System.Reflection;
+using PkmnLib.Dynamic.Libraries;
+
+namespace PkmnLib.Dynamic.ScriptHandling;
+
+public class ScriptRegistry
+{
+    private Dictionary<(ScriptCategory category, string name), Func<Script>> _scriptTypes = new();
+    private IBattleStatCalculator? _battleStatCalculator;
+    private IDamageCalculator? _damageCalculator;
+    private IMiscLibrary? _miscLibrary;
+
+    public void RegisterAssemblyScripts(Assembly assembly)
+    {
+        var baseType = typeof(Script);
+        foreach (var type in assembly.GetTypes().Where(t => baseType.IsAssignableFrom(t)))
+        {
+            var attribute = type.GetCustomAttribute<ScriptAttribute>();
+            if (attribute == null)
+                continue;
+
+            RegisterScriptType(attribute.Category, attribute.Name, type);
+        }
+    }
+
+    public void RegisterScriptType(ScriptCategory category, string name, Type type)
+    {
+        if (name == null)
+            throw new ArgumentNullException(nameof(name));
+        if (type == null)
+            throw new ArgumentNullException(nameof(type));
+
+        var constructor = type.GetConstructor(Type.EmptyTypes);
+        if (constructor == null)
+            throw new ArgumentException("The type must have a parameterless constructor.");
+
+        // We create a lambda that creates a new instance of the script type.
+        // This is more performant than using Activator.CreateInstance.
+        _scriptTypes[(category, name)] = Expression.Lambda<Func<Script>>(Expression.New(constructor)).Compile();
+    }
+
+    public void RegisterBattleStatCalculator<T>(T battleStatCalculator)
+        where T : IBattleStatCalculator => _battleStatCalculator = battleStatCalculator;
+
+    public void RegisterDamageCalculator<T>(T damageCalculator)
+        where T : IDamageCalculator => _damageCalculator = damageCalculator;
+
+    public void RegisterMiscLibrary<T>(T miscLibrary) where T : IMiscLibrary
+        => _miscLibrary = miscLibrary;
+
+    internal Dictionary<(ScriptCategory category, string name), Func<Script>> ScriptTypes => _scriptTypes;
+    internal IBattleStatCalculator? BattleStatCalculator => _battleStatCalculator;
+    internal IDamageCalculator? DamageCalculator => _damageCalculator;
+    internal IMiscLibrary? MiscLibrary => _miscLibrary;
+}