LanguageServer/HandlerProvider.cs

﻿using System;
using System.Reflection;
using System.Threading;

namespace LanguageServer {
	internal abstract class HandlerProvider {
		internal void AddHandlers(RequestHandlerCollection requestHandlers, NotificationHandlerCollection notificationHandlers, Type type) {
			foreach(var method in type.GetRuntimeMethods()) {
				var rpcMethod = method.GetCustomAttribute<JsonRpcMethodAttribute>()?.Method;
				if(rpcMethod != null) {
					if(Reflector.IsRequestHandler(method)) {
						var requestHandlerDelegate = Reflector.CreateRequestHandlerDelegate(type, method, this);
						var requestHandler = new RequestHandler(rpcMethod, Reflector.GetRequestType(method),
							Reflector.GetResponseType(method), requestHandlerDelegate);
						requestHandlers.AddRequestHandler(requestHandler);
					}
					else if(Reflector.IsNotificationHandler(method)) {
						var notificationHandlerDelegate =
							Reflector.CreateNotificationHandlerDelegate(type, method, this);
						var notificationHandler = new NotificationHandler(rpcMethod,
							Reflector.GetNotificationType(method), notificationHandlerDelegate);
						notificationHandlers.AddNotificationHandler(notificationHandler);
					}
				}
			}
		}

		internal abstract object CreateTargetObject(Type targetType, Connection connection, CancellationToken token);

		internal abstract object CreateTargetObject(Type targetType, Connection connection);
	}

	internal class ServiceHandlerProvider : HandlerProvider {
		internal override object CreateTargetObject(Type targetType, Connection connection, CancellationToken token) {
			var svc = (Service)Activator.CreateInstance(targetType);
			svc.Connection = connection;
			svc.CancellationToken = token;
			return svc;
		}

		internal override object CreateTargetObject(Type targetType, Connection connection) {
			var svc = (Service)Activator.CreateInstance(targetType);
			svc.Connection = connection;
			return svc;
		}
	}

	internal class ConnectionHandlerProvider : HandlerProvider {
		internal override object CreateTargetObject(Type targetType, Connection connection, CancellationToken token) {
			var sc = (ServiceConnection)connection;
			sc.CancellationToken = token;
			return sc;
		}

		internal override object CreateTargetObject(Type targetType, Connection connection) {
			return connection;
		}
	}
}