using System;
using System.Collections.Generic;
using System.Threading;

namespace MetaCity.Core.Common
{
    public static class ThreadingUtils
    {
        private static bool _initialised;
        private static Thread _mainThread;
        private static readonly List<Action> ActionsToRunOnMainThread = new();

        public static void Initialise()
        {
            if (_initialised) return;

            _initialised = true;
            _mainThread = Thread.CurrentThread;
            lock (ActionsToRunOnMainThread)
            {
                ActionsToRunOnMainThread.Clear();
            }
        }

        public static void Destroy()
        {
            _initialised = false;
        }

        public static bool IsOnMainThread()
        {
            return _mainThread != null && _mainThread.Equals(Thread.CurrentThread);
        }

        public static void EnqueueActionForMainThread(Action action)
        {
            if (!_initialised) return;

            lock (ActionsToRunOnMainThread)
            {
                ActionsToRunOnMainThread.Add(action);
            }
        }

        public static void EnqueueActionForMainThreadOrRunRightNow(Action action)
        {
            if (!_initialised) return;

            if (IsOnMainThread())
                action();
            else
                EnqueueActionForMainThread(action);
        }

        public static void Update()
        {
            lock (ActionsToRunOnMainThread)
            {
                foreach (var action in ActionsToRunOnMainThread) action();

                ActionsToRunOnMainThread.Clear();
            }
        }
    }
}