namespace AsyncTests.Infrastructure.Commands
{
    #region using

    using System;
    using System.Threading.Tasks;

    using log4net;

    #endregion

    /// <summary>
    /// Async command execution.
    /// </summary>
    public static class AsyncCommandExecutor<T>
    {
// NOTE: don't care about sharing this between instances.
// ReSharper disable StaticFieldInGenericType
        private static readonly ILog Log = LogManager.GetLogger(typeof(AsyncCommandExecutor<>));
// ReSharper restore StaticFieldInGenericType

        /// <summary>
        /// Executes the supplied command asynchronously.
        /// </summary>
        /// <param name="command">The command to execute.</param>
        public static async Task<T> Execute(IAsyncCommand<T> command, Action success = null, Action error = null)
        {

            var task = Task.Factory.StartNew(
                () =>
                    {
                        return command.Execute();
                    });
            task.ContinueWith(
                t =>
                Log.Error(string.Format("'{0}' failed, something terrible happened.", command.GetType()), t.Exception),
                TaskContinuationOptions.OnlyOnFaulted);

            T result = await task;

            if (success != null && command.Successful)
            {
                success();
            }
            if (error != null && !command.Successful)
            {
                error();
            }

            return result;
        }
    }
}