using System;

namespace FileInterface.Scheduler
{
    public sealed class CustomFunctionCallResult
    {
        public bool Success { get; set; }
        public string Message { get; set; }

        public static CustomFunctionCallResult Ok(string message)
        {
            return new CustomFunctionCallResult { Success = true, Message = message ?? "OK" };
        }

        public static CustomFunctionCallResult Fail(string message)
        {
            return new CustomFunctionCallResult { Success = false, Message = message ?? "CustomFunction failed" };
        }
    }

    public interface ICustomFunctionInvoker
    {
        CustomFunctionCallResult Invoke(string customFunctionName, string[] inArgs);
    }

    /// <summary>
    /// Lets the existing FileInterface IMS code remain untouched. Wire the current
    /// IMS CustomFunction call into this delegate in Program.cs / service startup.
    /// </summary>
    public sealed class DelegateCustomFunctionInvoker : ICustomFunctionInvoker
    {
        private readonly Func<string, string[], CustomFunctionCallResult> _handler;

        public DelegateCustomFunctionInvoker(Func<string, string[], CustomFunctionCallResult> handler)
        {
            if (handler == null) throw new ArgumentNullException("handler");
            _handler = handler;
        }

        public CustomFunctionCallResult Invoke(string customFunctionName, string[] inArgs)
        {
            return _handler(customFunctionName, inArgs);
        }
    }
}