using System;
using System.Threading;
using System.Threading.Tasks;
using Unity.Cn.Multiverse;
using UnityEngine;
using UnityEngine.TextCore.Text;

namespace Unity.MegaCity.Gameplay
{
    public class MultiverseSDKWrapper
    {
        private static MultiverseSDKWrapper _instance;
        private MultiverseSdk m_Multiverse = null;
        private CancellationTokenSource cancellationTokenSource = null;

        // Private constructor prevents instantiation from other classes.
        private MultiverseSDKWrapper() { }

        public static MultiverseSDKWrapper Instance
        {
            get
            {
                if (_instance == null)
                {
                    _instance = new MultiverseSDKWrapper();
                }
                return _instance;
            }
        }

        public async void StartMultiverse()
        {
            // init multiverse
            m_Multiverse = await MultiverseSdk.CreateInstance();
            if (m_Multiverse == null)
            {
                Debug.LogError($"MultiverseSdk.CreateInstance() failed");
                Application.Quit();
                return;
            }
            Debug.Log("Multiverse is created");
        }

        public async void ReadyMultiverse()
        {
            // wait until multiverse created
            while(m_Multiverse == null)
            {
                Debug.Log("m_Multiverse is null");
                await Task.Delay(100);
            }

            bool ok = await m_Multiverse.Ready();
            if (!ok)
            {
                Debug.LogError("m_Multiverse.Ready() failed");
                Application.Quit();
                return;
            }

            var gs = await m_Multiverse.GameServer();
            var gsAddress = gs.Status.Address;
            var gsPort = gs.Status.Ports[0].Port;
            Debug.Log($"Multiverse is Ready, IP:{gsAddress}, Port:{gsPort}");
        }

        // Auto shutdown the multiverse in TTL seconds if there is no player connected.
        public async void ShutdownMultiverseInTTL(int ttlInSeconds)
        {
            cancellationTokenSource = new CancellationTokenSource();

            try
            {
                // Wait for the specified delay.
                await Task.Delay(TimeSpan.FromSeconds(ttlInSeconds), cancellationTokenSource.Token);

                // Then shutdown the multiverse.
                if (m_Multiverse != null)
                {
                    bool ok = await m_Multiverse.Shutdown();
                    if (ok) m_Multiverse = null;
                }
            }
            catch (TaskCanceledException)
            {
                Debug.Log("Auto Shutdown task was cancelled.");
            }
        }

        public void CancelShutdown()
        {
            cancellationTokenSource?.Cancel();
            cancellationTokenSource = null;
        }
    }

}