ISettings interface

//ISettings interface
    public interface ISettings
    {
        string FacturFilePath { get; }
        bool IsDebug { get; }
        string DeronDomain { get; }
        string SmtpServer { get; }
        int SmtpPort { get; }
        string DeronEMail { get; }
        string AdminEmail { get; }
    }

    public class ConfigFileSettings : ISettings
    {
        public string FacturFilePath
        {
            get { return ConfigurationManager.AppSettings["FacturFilePath"]; }
        }

        public bool IsDebug
        {
            get { return Convert.ToBoolean(ConfigurationManager.AppSettings["IsDebug"]); }
        }

        public string DeronDomain
        {
            get { return ConfigurationManager.AppSettings["DeronDomain"]; }
        }

        public string SmtpServer
        {
            get { return ConfigurationManager.AppSettings["SmtpServer"]; }
        }

        public int SmtpPort
        {
            get { return Convert.ToInt32(ConfigurationManager.AppSettings["SmtpPort"]); }
        }

        public string DeronEMail
        {
            get { return ConfigurationManager.AppSettings["DeronEMail"]; }
        }

        public string AdminEmail
        {
            get { return ConfigurationManager.AppSettings["AdminEmail"]; }
        }
    }
}

//Koristenje u kontroleru
    public class AccountController : BaseController
    {
        private readonly ISettings _settings;

        public AccountController(ISettings settings)
        {
            _settings = settings;
        }