using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace TransportGame.Utils
{
    public class Task
    {
        public bool? Success { get; private set; }

        private Exception thrownException;
        private Action action;
        private Thread thread;

        private Task()
        {
        }

        private static void RunAsync_ActionThread(object info)
        {
            Task taskInfo = (Task)info;

            try
            {
                taskInfo.action();
                taskInfo.Success = true;
            }
            catch (Exception ex)
            {
                taskInfo.thrownException = ex;
                taskInfo.Success = false;
            }
        }

        public static Task RunAsync(Action action)
        {
            // Set up task info object
            Task taskInfo = new Task();
            taskInfo.action = action;
            taskInfo.thread = new Thread(RunAsync_ActionThread);

            // Start thread
            taskInfo.thread.Start(taskInfo);

            // Return task info
            return taskInfo;
        }

        public static IEnumerable Await(Action action)
        {
            return Task.RunAsync(action).Await();
        }

        public IEnumerable Await()
        {
            // Wait for thread to finish
            while (thread.ThreadState == ThreadState.Running)
                yield return null;

            thread.Join();

            // Rethrow exception
            if (Success.HasValue && !Success.Value)
                throw new Exception("Task failed", thrownException);
        }
    }
}