using System;
using System.Threading;
using Fluctio.FluctioSim.EditorUtils.EditorGeneral;
using Fluctio.FluctioSim.EditorUtils.Gui;
using Fluctio.FluctioSim.Utils.General;
using Fluctio.FluctioSim.Utils.SerializableClasses;
using JetBrains.Annotations;
using UnityEditor;
using UnityEditor.SettingsManagement;
using static Fluctio.FluctioSim.EditorUtils.SettingsManagement.SettingsManager;

namespace Fluctio.FluctioSim.EditorCore.AccountManagement
{
	internal static class License
	{
		public static readonly TimeSpan TrialDuration = TimeSpan.FromDays(14);
		
		[InitializeOnLoadMethod] private static void InitSettings() => AddExecutingAssembly();
		private static readonly UserSetting<SerializableDateTime> FirstInstallDateSetting = Preference("License.FirstInstallDate", DateTime.UtcNow.MakeSerializable());

		private static CancellationTokenSource _scheduledUpdateCancellation;
		
		internal static LicenseType Type { get; private set; } //TODO: add 'update' event
		internal static DateTime ValidTill { get; private set; }
		[CanBeNull] internal static string GiftedBy { get; private set; }

		[InitializeOnLoadMethod]
		private static void Init()
		{
			Account.InfoChanged += UpdateLicenseInfo;
			UpdateLicenseInfo();
		}
		
		private static void UpdateLicenseInfo()
		{
			SetNewLicenseInfo();
			ScheduleNextUpdate();
			ShowNoLicenseBanner();
		}

		private static void SetNewLicenseInfo()
		{
			var useAccountLicense =
				Account.IsLoggedIn &&
				Account.Info.LicenseType > LicenseType.None &&
				Account.Info.LicenseValidTill > DateTime.UtcNow;

			var trialValidTill = FirstInstallDateSetting.value.DateTime + TrialDuration;
			var useMachineTrialLicense = trialValidTill > DateTime.UtcNow;
			
			if (useAccountLicense)
			{
				Type = Account.Info.LicenseType;
				ValidTill = Account.Info.LicenseValidTill;
				GiftedBy = Account.Info.LicenseGiftedBy.NullIfWhiteSpace();
			}
			else if (useMachineTrialLicense)
			{
				Type = LicenseType.Trial;
				ValidTill = trialValidTill;
			}
			else
			{
				Type = LicenseType.None;
				ValidTill = DateTime.MaxValue;
			}
		}

		private static void ScheduleNextUpdate()
		{
			_scheduledUpdateCancellation?.Cancel();
			_scheduledUpdateCancellation = new CancellationTokenSource();
			Util.ExecuteAfter(UpdateLicenseInfo, ValidTill, cancellationToken: _scheduledUpdateCancellation.Token);
		}

		private static void ShowNoLicenseBanner()
		{
			var didEditorJustOpen = EditorUtil.DidEditorJustOpen;
			EditorApplication.delayCall += () =>
			{
				// if trial, open once
				if (Type == LicenseType.Trial && didEditorJustOpen)
				{
					EditorWindow.GetWindow<AccountWindow>();
				}
				
				// if no license, show banner
				ConfigurableEditorWindow.ToggleBanner<AccountWindow>(Type == LicenseType.None);
			};
		}
	}
}