using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Plugin.BLE.Abstractions.Contracts;
using Serilog;
using TINK.Model;
using TINK.Model.Bikes;
using TINK.Model.Bikes.BikeInfoNS.BluetoothLock;
using TINK.Model.Connector;
using TINK.Model.Device;
using TINK.Model.Stations.StationNS;
using TINK.Model.User;
using TINK.MultilingualResources;
using TINK.Services.BluetoothLock;
using TINK.Services.BluetoothLock.Tdo;
using TINK.Services.Geolocation;
using TINK.Services.Permissions;
using TINK.Settings;
using TINK.View;
using TINK.ViewModel.Bikes;
using Xamarin.Essentials;
using Xamarin.Forms;
using Command = Xamarin.Forms.Command;

namespace TINK.ViewModel.MyBikes
{
	public class MyBikesPageViewModel : BikesViewModel, INotifyCollectionChanged, INotifyPropertyChanged
	{
		/// <summary> Holds the stations to get station names form station ids. </summary>
		private IEnumerable<IStation> Stations { get; }

		/// <summary>
		/// True if ListView of Bikes is refreshing after user pulled;
		/// </summary>
		private bool _isRefreshing = false;
		public bool IsRefreshing
		{
			get { return _isRefreshing; }
			set
			{
				_isRefreshing = value;
				OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsRefreshing)));
			}
		}

		/// <summary>
		/// Holds what should be executed on pull to refresh
		/// </summary>
		public Command RefreshCommand { get; }

		/// <summary>
		/// Constructs bike collection view model in case information about occupied bikes is available.
		/// </summary>
		/// <param name="user">Mail address of active user.</param>
		/// <param name="isReportLevelVerbose">True if report level is verbose, false if not.</param>
		/// <param name="permissions">Holds object to query location permissions.</param>
		/// <param name="bluetoothLE">Holds object to query bluetooth state.</param>
		/// <param name="runtimPlatform">Specifies on which platform code is run.</param>
		/// <param name="isConnectedDelegate">Returns if mobile is connected to web or not.</param>
		/// <param name="connectorFactory">Connects system to copri.</param>
		/// <param name="lockService">Service to control lock retrieve info.</param>
		/// <param name="stations">Stations to get station name from station id.</param>
		/// <param name="polling"> Holds whether to poll or not and the period length is polling is on. </param>
		/// <param name="postAction">Executes actions on GUI thread.</param>
		/// <param name="smartDevice">Provides info about the smart device (phone, tablet, ...).</param>
		/// <param name="viewService">Interface to actuate methods on GUI.</param>
		/// <param name="openUrlInBrowser">Delegate to open browser.</param>
		public MyBikesPageViewModel(
			User user,
			ILocationPermission permissions,
			IBluetoothLE bluetoothLE,
			string runtimPlatform,
			Func<bool> isConnectedDelegate,
			Func<bool, IConnector> connectorFactory,
			IGeolocationService geolocation,
			ILocksService lockService,
			IEnumerable<IStation> stations,
			PollingParameters polling,
			Action<SendOrPostCallback, object> postAction,
			ISmartDevice smartDevice,
			IViewService viewService,
			Action<string> openUrlInBrowser) : base(user, new ViewContext(PageContext.MyBikes), permissions, bluetoothLE, runtimPlatform, isConnectedDelegate, connectorFactory, geolocation, lockService, polling, postAction, smartDevice, viewService, openUrlInBrowser, () => new MyBikeInUseStateInfoProvider())
		{
			CollectionChanged += (sender, eventargs) =>
			{
				OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsNoBikesOccupiedVisible)));
				OnPropertyChanged(new PropertyChangedEventArgs(nameof(NoBikesOccupiedText)));
			};

			Stations = stations ?? throw new ArgumentException(nameof(stations));

			RefreshCommand = new Command(async () => {

				IsRefreshing = false;
				await OnAppearingOrRefresh();

			});
		}

		/// <summary> Returns if info about the fact that user did not request or book any bikes is visible or not.<summary>
		/// Gets message that logged in user has not booked any bikes.
		/// </summary>
		public bool IsNoBikesOccupiedVisible
		{
			get
			{
				return Count <= 0 && IsIdle == true;
			}
		}

		/// <summary> Info about the fact that user did not request or book any bikes. </summary>
		public string NoBikesOccupiedText
		{
			get
			{
				return IsNoBikesOccupiedVisible
					? string.Format(AppResources.MarkingMyBikesNoBikesReservedRented, ActiveUser?.Mail)
					: string.Empty;
			}
		}

		/// <summary>
		/// Invoked when page is shown. 
		/// Starts update process.
		/// </summary>
		public async Task OnAppearingOrRefresh()
		{
			IsIdle = false;

			IsConnected = IsConnectedDelegate();

			// Get my bikes from COPRI
			Log.ForContext<MyBikesPageViewModel>().Information("User request to show page MyBikes/ page re-appearing");

			ActionText = AppResources.ActivityTextMyBikesLoadingBikes;

			// Stop polling before getting bikes info.
			await m_oViewUpdateManager.StopUpdatePeridically();

			var bikesOccupied = await ConnectorFactory(IsConnected).Query.GetBikesOccupiedAsync();

			Exception = bikesOccupied.Exception; // Update communication error from query for bikes occupied.

			var lockIdList = bikesOccupied.Response
				.GetLockIt()
				.Cast<BikeInfo>()
				.Select(x => x.LockInfo)
				.ToList();

			if (LockService is ILocksServiceFake serviceFake)
			{
				serviceFake.UpdateSimulation(bikesOccupied.Response);
			}

			// Check bluetooth and location permission and states
			ActionText = AppResources.ActivityTextCheckBluetoothState;

			if (bikesOccupied.Response.FirstOrDefault(x => x is BikeInfo btBike) != null
				&& RuntimePlatform == Device.Android)
			{
				// Check location permission
				var status = await PermissionsService.CheckStatusAsync();
				if (status != Status.Granted)
				{
					var permissionResult = await PermissionsService.RequestAsync();

					if (permissionResult != Status.Granted)
					{
						var dialogResult = await ViewService.DisplayAlert(
							AppResources.MessageTitleHint,
							AppResources.MessageBikesManagementLocationPermissionOpenDialog,
							AppResources.MessageAnswerYes,
							AppResources.MessageAnswerNo);

						if (!dialogResult)
						{
							// User decided not to give access to locations permissions.
							BikeCollection.Update(bikesOccupied.Response, Stations);

							await OnAppearing(() => UpdateTask());

							ActionText = string.Empty;
							IsIdle = true;
							return;
						}

						// Open permissions dialog.
						PermissionsService.OpenAppSettings();
					}
				}

				// Location state
				if (GeolocationService.IsGeolcationEnabled == false)
				{
					await ViewService.DisplayAlert(
						AppResources.MessageTitleHint,
						AppResources.MessageBikesManagementLocationActivation,
						AppResources.MessageAnswerOk);

					BikeCollection.Update(bikesOccupied.Response, Stations);

					await OnAppearing(() => UpdateTask());

					ActionText = string.Empty;
					IsIdle = true;
					return;
				}

				// Bluetooth state
				if (await BluetoothService.GetBluetoothState() != BluetoothState.On)
				{
					await ViewService.DisplayAlert(
						AppResources.MessageTitleHint,
						AppResources.MessageBikesManagementBluetoothActivation,
						AppResources.MessageAnswerOk);

					BikeCollection.Update(bikesOccupied.Response, Stations);

					await OnAppearing(() => UpdateTask());

					ActionText = string.Empty;
					IsIdle = true;
					return;
				}
			}

			// Connect to bluetooth devices.
			ActionText = AppResources.ActivityTextSearchBikes;
			IEnumerable<LockInfoTdo> locksInfoTdo;
			try
			{
				locksInfoTdo = await LockService.GetLocksStateAsync(
					lockIdList.Select(x => x.ToLockInfoTdo()).ToList(),
					LockService.TimeOut.MultiConnect);
			}
			catch (Exception exception)
			{
				Log.ForContext<MyBikesPageViewModel>().Error("Getting bluetooth state failed. {Exception}", exception);
				locksInfoTdo = new List<LockInfoTdo>();
			}

			var locksInfo = lockIdList.UpdateById(locksInfoTdo);

			BikeCollection.Update(bikesOccupied.Response.UpdateLockInfo(locksInfo), Stations);

			await OnAppearing(() => UpdateTask());

			ActionText = string.Empty;
			IsIdle = true;
		}

		/// <summary>
		/// True if any action can be performed (request and cancel request)
		/// </summary>
		public override bool IsIdle
		{
			get => base.IsIdle;
			set
			{
				if (value == base.IsIdle)
					return;

				Log.ForContext<BikesViewModel>().Debug($"Switch value of {nameof(IsIdle)} to {value}.");
				base.IsIdle = value;
				base.OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsNoBikesOccupiedVisible)));
				base.OnPropertyChanged(new PropertyChangedEventArgs(nameof(NoBikesOccupiedText)));
				base.OnPropertyChanged(new PropertyChangedEventArgs(nameof(FlyoutBehavior))); // Hide flyout menu if app is busy. Prevents especially navigation on returning bike.
			}
		}

		/// <summary>
		/// Determines if flyout menu is available or not. 
		/// </summary>
		public FlyoutBehavior FlyoutBehavior => base.IsIdle ? FlyoutBehavior.Flyout : FlyoutBehavior.Disabled;


		/// <summary> Create task which updates my bike view model.</summary>
		private void UpdateTask()
		{
			// Start task which periodically updates pins.
			PostAction(
				unused =>
				{
					ActionText = AppResources.ActivityTextUpdating;
					IsConnected = IsConnectedDelegate();
				},
				null);

			var result = ConnectorFactory(IsConnected).Query.GetBikesOccupiedAsync().Result;

			var bikes = result.Response;

			var exception = result.Exception;
			if (exception != null)
			{
				Log.ForContext<MyBikesPageViewModel>().Error("Getting bikes occupied in polling context failed with exception {Exception}.", exception);
			}

			PostAction(
				unused =>
				{
					BikeCollection.Update(bikes, Stations); // Updating collection leads to update of GUI.
					Exception = result.Exception;
					ActionText = string.Empty;
				},
				null);
		}
	}
}