private object? ActivateGenericMember()

in rd-net/RdFramework.Reflection/ReflectionRdActivator.cs [353:415]
53 lines of code
18 McCabe index (conditional complexity)

    private object? ActivateGenericMember(string memberName, TypeInfo memberType)
    {
      var implementingType = ReflectionSerializerVerifier.GetImplementingType(memberType);
      var genericDefinition = implementingType.GetGenericTypeDefinition();

      var genericArguments = implementingType.GetTypeInfo().GetGenericArguments();
      var argument = genericArguments[0];
      var serializerPair = GetProperSerializer(argument);
      
      if (genericDefinition == typeof(RdProperty<>) ||
          genericDefinition == typeof(RdSignal<>) ||
          genericDefinition == typeof(RdSet<>))
      {
        var instance = Activator.CreateInstance(implementingType, serializerPair.Reader, serializerPair.Writer);
        if (IsMonomorphic(argument))
          ReflectionUtil.InvokeStaticGeneric(typeof(ReflectionRdActivator), nameof(SetOptimizeNested1), argument, instance);
        return instance;
      }

      if (genericDefinition == typeof(RdList<>))
      {
        var instance = Activator.CreateInstance(implementingType, serializerPair.Reader, serializerPair.Writer, 1L /*nextVersion*/);
        if (IsMonomorphic(argument))
          ReflectionUtil.InvokeStaticGeneric(typeof(ReflectionRdActivator), nameof(SetOptimizeNested1), argument, instance);
        return instance;
      }

      if (genericArguments.Length == 2)
      {
        var argument2 = genericArguments[1];
        var serializerPair2 = GetProperSerializer(argument2);
        var instance = Activator.CreateInstance(implementingType, serializerPair.Reader, serializerPair.Writer, serializerPair2.Reader, serializerPair2.Writer);
        if (IsMonomorphic(argument2))
          ReflectionUtil.InvokeStaticGeneric2(typeof(ReflectionRdActivator), nameof(SetOptimizeNested2), argument, argument2, instance);
        return instance;
      }

      if (genericDefinition == typeof(Nullable<>))
      {
        // already initialized to null
        return null;
      }

      // hack for UProperty & USignal
      if (genericArguments.Length == 1 && typeof(IRdBindable).IsAssignableFrom(implementingType) && implementingType.IsClass)
      {
        foreach (var ctor in implementingType.GetTypeInfo().GetConstructors(BindingFlags.Public | BindingFlags.Instance))
        {
          var parameters = ctor.GetParameters();
          if (parameters.Length == 3 && parameters[0].Name == "id")
          {
            return Activator.CreateInstance(implementingType, memberName, serializerPair.Reader, serializerPair.Writer);
          }
        }
      }

      throw new Assertion.AssertionException($"Unable to activate generic type: {memberType}");

      static bool IsMonomorphic(Type type)
      {
        return type.IsValueType || (!typeof(IRdBindable).IsAssignableFrom(type) && type.IsSealed);
      }
    }