PageTypeRouteAttributeCacheHelperCacheHelper.cs

public static class PageTypeRouteAttributeCacheHelper
{
    public static readonly Dictionary<string, ControllerActionPair> ClassNameLookup;

    static PageTypeRouteAttributeCacheHelper()
    {
        var controllerTypes = typeof(PageTypeRouteAttributeCacheHelper)
            .Assembly
            .GetTypes()
            .Where(t =>
                t.IsPublic &&
                t != typeof(Controller) &&
                typeof(Controller).IsAssignableFrom(t));

        var dictionary = new Dictionary<string, ControllerActionPair>();

        foreach (var controllerType in controllerTypes)
        {
            var actions = controllerType
                .GetMethods(BindingFlags.Public | BindingFlags.Instance)
                .Where(m => m.IsDefined(typeof(PageTypeRouteAttribute)));

            foreach (var action in actions)
            {
                string[] classNames = action.GetCustomAttribute<PageTypeRouteAttribute>().ClassNames;

                foreach (string className in classNames)
                {
                    if (dictionary.ContainsKey(className))
                    {
                        var pair = dictionary[className];

                        throw new Exception(
                            "Duplicate Annotation: " +
                            $"{pair.ControllerName}Controller.{pair.ActionName} already registered for NodeClassName {className}. " +
                            $"Cannot be registered for {controllerType.Name}.{action.Name}"
                        );
                    }

                    dictionary.Add(className, new ControllerActionPair(controllerType.RemoveControllerSuffix(), action.Name));
                }
            }
        }

        ClassNameLookup = dictionary;
    }
    
    private const int CONTROLLER_SUFFIX_LENGTH = 10;

    public static string RemoveControllerSuffix(this Type controllerType)
    {
        if (!typeof(Controller).IsAssignableFrom(controllerType))
        {
            throw new ArgumentException($"Type [{controllerType.Name}] is not assignable from [{nameof(Controller)}]");
        }

        return controllerType
            .Name
            .Substring(0, controllerType.Name.Length - CONTROLLER_SUFFIX_LENGTH);
    }

    public readonly struct ControllerActionPair
    {
        public string ControllerName { get; }
        public string ActionName { get; }

        public ControllerActionPair(string controllerName, string actionName)
        {
            ControllerName = controllerName;
            ActionName = actionName;
        }
    }
}