TigernetHostBuilder.DI.cs

namespace Tigernet.Hosting
{
    public partial class TigernetHostBuilder
    {
        /// <summary>
        /// DI Container 
        /// </summary>
        private readonly Dictionary<Type, Type> _services;

        /// <summary>
        /// Adds interface and implementation of it to DI
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <typeparam name="TImpl"></typeparam>
        public void AddService<T, TImpl>() where TImpl : T
        {
            _services[typeof(T)] = typeof(TImpl);
        }

        /// <summary>
        /// Get added service
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public T Get<T>()
        {
            return (T)GetService(typeof(T));
        }

        /// <summary>
        /// Gets added service and constructs it returning as object
        /// </summary>
        /// <param name="type"></param>
        /// <returns></returns>
        /// <exception cref="InvalidOperationException"></exception>
        private object GetService(Type type)
        {
            if (_services.TryGetValue(type, out var implementationType))
            {
                var constructor = implementationType.GetConstructors()[0];
                var parameters = constructor.GetParameters();

                if (parameters.Length == 0)
                {
                    return Activator.CreateInstance(implementationType);
                }

                var parameterInstances = new object[parameters.Length];

                for (var i = 0; i < parameters.Length; i++)
                {
                    parameterInstances[i] = GetService(parameters[i].ParameterType);
                }

                return constructor.Invoke(parameterInstances);
            }

            throw new InvalidOperationException($"Type {type} not registered");
        }
    }
}