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.Services.CopriApi;
using TINK.Model.Station;
using TINK.Model.User;
using TINK.MultilingualResources;
using TINK.Repository.Exception;
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.Forms;

namespace TINK.ViewModel.FindBike
{
	public class FindBikePageViewModel : BikesViewModel, INotifyCollectionChanged, INotifyPropertyChanged
	{
		private string bikeIdUserInput = string.Empty;

		/// <summary> Text entered by user to specify a bike.</summary>
		public string BikeIdUserInput
		{
			get => bikeIdUserInput;
			set
			{
				if (value == bikeIdUserInput)
				{
					return;
				}

				bikeIdUserInput = value;
				base.OnPropertyChanged(new PropertyChangedEventArgs(nameof(BikeIdUserInput)));
				base.OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsSelectBikeEnabled)));
			}
		}

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

				Log.ForContext<FindBikePageViewModel>().Debug($"Switch value of {nameof(IsIdle)} to {value}.");
				base.IsIdle = value;
				OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsSelectBikeEnabled))); // Enable select bike button.
			}
		}

		/// <summary> Holds all bikes available.</summary>
		public BikeCollection Bikes { get; set; }

		/// <summary> Do not allow to select bike if id is not set.</summary>
		public bool IsSelectBikeEnabled => IsIdle && BikeIdUserInput != null && BikeIdUserInput.Length > 0;

		/// <summary> Hide id input fields as soon as bike is found.</summary>
		public bool IsSelectBikeVisible => BikeCollection != null && BikeCollection.Count == 0;

		/// <summary> Holds the stations to get station names form station ids. </summary>
		private IEnumerable<IStation> Stations { get; }

		/// <summary>
		/// Constructs bike collection view model in case information about occupied bikes is available.
		/// </summary>
		/// <param name="p_oUser">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 permisions.</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 periode leght 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 methodes on GUI.</param>
		/// <param name="openUrlInBrowser">Delegate to open browser.</param>
		public FindBikePageViewModel(
			User p_oUser,
			ILocationPermission permissions,
			IBluetoothLE bluetoothLE,
			string runtimPlatform,
			Func<bool> isConnectedDelegate,
			Func<bool, IConnector> connectorFactory,
			IGeolocation geolocation,
			ILocksService lockService,
			IEnumerable<IStation> stations,
			PollingParameters polling,
			Action<SendOrPostCallback, object> postAction,
			ISmartDevice smartDevice,
			IViewService viewService,
			Action<string> openUrlInBrowser) : base(p_oUser, permissions, bluetoothLE, runtimPlatform, isConnectedDelegate, connectorFactory, geolocation, lockService, polling, postAction, smartDevice, viewService, openUrlInBrowser, () => new MyBikeInUseStateInfoProvider())
		{
			CollectionChanged += (sender, eventargs) =>
			{
				OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsSelectBikeVisible)));
			};

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

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

			Log.ForContext<FindBikePageViewModel>().Information("User request to show page FindBike- page re-appearing");

			if (string.IsNullOrEmpty(BikeIdUserInput) /* Find bike page flyout was taped */
				&& BikeCollection.Count > 0 /* Bike was successfully selected */)
			{
				// Find bike page flyout was taped and page was already opened before and bike has been selected.
				// Clear bike collection to allow user to enter bike id and search for bike.
				BikeCollection.Clear();
			}

			if (BikeCollection.Count > 0)
			{
				// Page is appearing not because page flyout was taped.
				// Bike has already been selected.
				// Restart update.
				await StartUpdateTask(() => UpdateTask());

				ActionText = "";
				IsIdle = true;
				return;
			}

			ActionText = "";
			IsIdle = true;
		}

		/// <summary> Command object to bind select bike button to view model. </summary>
		public System.Windows.Input.ICommand OnSelectBikeRequest => new Xamarin.Forms.Command(async () => await SelectBike(), () => IsSelectBikeEnabled);

		/// <summary> Select a bike by ID</summary>
		public async Task SelectBike()
		{
			// Get List of bike to be able to connect to.
			ActionText = AppResources.ActivityTextFindBikeLoadingBikes;
			IsIdle = false;

			Result<BikeCollection> bikes = null;
			try
			{
				bikes = await ConnectorFactory(IsConnected).Query.GetBikesAsync();
			}
			catch (Exception exception)
			{
				if (exception is WebConnectFailureException)
				{
					// Copri server is not reachable.
					Log.ForContext<FindBikePageViewModel>().Information("Getting bikes failed failed (Copri server not reachable).");

					await ViewService.DisplayAdvancedAlert(
						AppResources.ErrorReturnBikeNoWebTitle,
						string.Format("{0}\r\n{1}", AppResources.ErrorReturnBikeNoWebMessage, WebConnectFailureException.GetHintToPossibleExceptionsReasons),
						exception.Message,
						AppResources.MessageAnswerOk);
				}
				else
				{
					Log.ForContext<FindBikePageViewModel>().Error("Getting bikes failed. {Exception}", exception);

					await ViewService.DisplayAlert(
						AppResources.MessageTitleHint,
						exception.Message,
						AppResources.MessageAnswerOk);
				}

				ActionText = "";
				IsIdle = true;
				return;
			}
			finally
			{
				Exception = bikes?.Exception ?? null; // Update communication error from query for bikes occupied.
				Bikes = bikes.Response;
			}

			try
			{
				var selectedBike = Bikes.FirstOrDefault(x => x.Id.Equals(BikeIdUserInput.Trim(), StringComparison.OrdinalIgnoreCase));

				if (selectedBike == null)
				{
					await ViewService.DisplayAlert(
						AppResources.MessageTitleHint,
						string.Format(AppResources.MessageErrorSelectBikeNoBikeFound, BikeIdUserInput),
						AppResources.MessageAnswerOk);

					ActionText = "";
					IsIdle = true;
					return;
				}

				var bikeCollection = new BikeCollection(new Dictionary<string, Model.Bikes.BikeInfoNS.BC.BikeInfo> { { selectedBike.Id, selectedBike } });

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

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

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

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

									await StartUpdateTask(() => UpdateTask());

									ActionText = "";
									IsIdle = true;
									return;
								}

								// Open permissions dialog.
								PermissionsService.OpenAppSettings();
							}
						}
						else
						{
								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(bikeCollection, Stations);

									await StartUpdateTask(() => UpdateTask());

									ActionText = "";
									IsIdle = true;
									return;
								}

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

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

						BikeCollection.Update(bikeCollection, Stations);

						await StartUpdateTask(() => UpdateTask());

						ActionText = "";
						IsIdle = true;
						return;
					}

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

						BikeCollection.Update(bikeCollection, Stations);

						await StartUpdateTask(() => UpdateTask());

						ActionText = "";
						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<FindBikePageViewModel>().Error("Getting bluetooth state failed. {Exception}", exception);
					locksInfoTdo = new List<LockInfoTdo>();
				}

				var locksInfo = lockIdList.UpdateById(locksInfoTdo);

				BikeCollection.Update(bikeCollection.UpdateLockInfo(locksInfo), Stations);

				await StartUpdateTask(() => UpdateTask());

				ActionText = "";
				IsIdle = true;
			}
			catch (Exception exception)
			{
				await ViewService.DisplayAlert(
					AppResources.MessageErrorSelectBikeTitle,
					exception.Message,
					AppResources.MessageAnswerOk);

				Log.ForContext<FindBikePageViewModel>().Error("Running command to select bike failed. {Exception}", exception);

				ActionText = "";
				IsIdle = true;
				return;
			}
		}

		/// <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.GetBikesAsync().Result;

			var bikes = result.Response;

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

			var selectedBike = bikes.FirstOrDefault(x => x.Id.Equals(BikeIdUserInput.Trim(), StringComparison.OrdinalIgnoreCase));

			bikes = selectedBike != null
				? new BikeCollection(new Dictionary<string, Model.Bikes.BikeInfoNS.BC.BikeInfo> { { selectedBike.Id, selectedBike } })
				: new BikeCollection();

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