using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.Threading;
using Plugin.BLE.Abstractions.Contracts;
using Plugin.Connectivity;
using Serilog;
using Serilog.Core;
using Serilog.Events;
using Serilog.Filters;
using ShareeBike.Model.Connector;
using ShareeBike.Model.Device;
using ShareeBike.Model.Logging;
using ShareeBike.Model.Services.CopriApi.ServerUris;
using ShareeBike.Model.Settings;
using ShareeBike.Model.Stations.StationNS;
using ShareeBike.Model.User.Account;
using ShareeBike.Services;
using ShareeBike.Services.BluetoothLock;
using ShareeBike.Services.BluetoothLock.BLE;
using ShareeBike.Services.BluetoothLock.Crypto;
using ShareeBike.Services.Geolocation;
using ShareeBike.Services.Logging;
using ShareeBike.Services.Permissions;
using ShareeBike.Services.ThemeNS;
using ShareeBike.Settings;
using ShareeBike.ViewModel.Map;
using ShareeBike.ViewModel.Settings;

namespace ShareeBike.Model
{
	[DataContract]
	public class ShareeBikeApp : IShareeBikeApp
	{
		/// <summary> Delegate used by login view to commit user name and password. </summary>
		/// <param name="p_strMailAddress">Mail address used as id login.</param>
		/// <param name="p_strPassword">Password for login.</param>
		/// <returns>True if setting credentials succeeded.</returns>
		public delegate bool SetCredentialsDelegate(string p_strMailAddress, string p_strPassword);

		/// <summary>Returns the id of the app (sharee.bike) to be identified by copri.</summary>
		public static string MerchantId { get; private set; }

		/// <summary>
		/// Holds status about whats new page.
		/// </summary>
		public WhatsNew WhatsNew { get; private set; }

		/// <summary>Holds uris of copri servers. </summary>
		public CopriServerUriList Uris { get; private set; }

		/// <summary> Holds the filters loaded from settings. </summary>
		public IGroupFilterSettings FilterGroupSetting { get; set; }

		/// <summary> Settings determining the startup behavior of the app.</summary>
		public IStartupSettings StartupSettings { get; private set; }

		/// <summary> Holds the filter which is applied on the map view. Either Cargo or Citybike stations are displayed. </summary>
		private IGroupFilterMapPage m_oFilterDictionaryMapPage;

		/// <summary> Holds the filter which is applied on the map view. Either Cargo or Citybike stations are displayed. </summary>
		public IGroupFilterMapPage GroupFilterMapPage
		{
			get => m_oFilterDictionaryMapPage;
			set => m_oFilterDictionaryMapPage = value ?? new GroupFilterMapPage();
		}

		/// <summary> Value indicating whether map is centered to current position or not. </summary>
		public bool CenterMapToCurrentLocation { get; set; }

		/// <summary> Holds the map area to display when starting app for first time/ when center map to is off. </summary>
		private Xamarin.Forms.GoogleMaps.MapSpan HomeMapSpan { get; }

		/// <summary> Holds the map area where user is or was located or null if this position is unknown. </summary>
		public Xamarin.Forms.GoogleMaps.MapSpan UserMapSpan { get; set; } = null;

		/// <summary> Holds the map span to display either default span or span centered to current position depending on option <see cref="CenterMapToCurrentLocation"/>.</summary>
		public Xamarin.Forms.GoogleMaps.MapSpan ActiveMapSpan
		{
			get
			{
				if (CenterMapToCurrentLocation == false)
				{
					return HomeMapSpan;
				}

				return UserMapSpan ?? HomeMapSpan;
			}
		}

		/// <summary> Gets the minimum logging level. </summary>
		public LogEventLevel MinimumLogEventLevel { get; set; }

		/// <summary> Gets a value indicating whether reporting level is verbose or not.</summary>
		public bool IsReportLevelVerbose { get; set; }

		/// <summary> Holds the uri which is applied after restart. </summary>
		public Uri NextActiveUri { get; set; }

		/// <summary> Saves object to file. </summary>
		public void Save()
		{
			try
			{
				JsonSettingsDictionary.Serialize(
							SettingsFileFolder,
							new Dictionary<string, string>()
								.SetGroupFilterMapPage(GroupFilterMapPage)
								.SetCopriHostUri(NextActiveUri.AbsoluteUri)
								.SetPollingParameters(Polling)
								.SetGroupFilterSettings(FilterGroupSetting)
								.SetStartupSettings(StartupSettings)
								.SetAppVersion(AppVersion)
								.SetMinimumLoggingLevel(MinimumLogEventLevel)
								.SetIsReportLevelVerbose(IsReportLevelVerbose)
								.SetExpiresAfter(ExpiresAfter)
								.SetWhatsNew(AppVersion)
								.SetActiveLockService(LocksServices.Active.GetType().FullName)
								.SetActiveGeolocationService(GeolocationServices.Active.GetType().FullName)
								.SetCenterMapToCurrentLocation(CenterMapToCurrentLocation)
								.SetLogToExternalFolder(LogToExternalFolder)
								.SetConnectTimeout(LocksServices.Active.TimeOut.MultiConnect)
								.SetIsSiteCachingOn(IsSiteCachingOn)
								.SetActiveTheme(Themes.Active));
			}
			catch (Exception exception)
			{
				Log.ForContext<ShareeBikeApp>().Error("Serializing settings failed. {@Exception}", exception);
				throw;
			}

		}
		/// <summary> 
		/// Update connector from filters when
		/// - login state changes
		/// - view is toggled (Cargo to Citybike and vice versa)
		/// </summary>
		public void UpdateConnector()
		{
			// Create filtered connector.
			m_oConnector = FilteredConnectorFactory.Create(
				FilterGroupSetting.DoFilter(ActiveUser.DoFilter(GroupFilterMapPage.DoFilter())),
				m_oConnector.Connector);
		}

		/// <summary>Polling period.</summary>
		public PollingParameters Polling { get; set; }

		public TimeSpan ExpiresAfter { get; set; }

		/// <summary> Holds the version of the app.</summary>
		public Version AppVersion { get; }

		/// <summary>
		/// Holds the default polling value.
		/// </summary>
#if USCSHARP9
        public TimeSpan DefaultPolling => new (0, 0, 10);
#else
		public TimeSpan DefaultPolling => new TimeSpan(0, 0, 10);
#endif

		/// <summary> Constructs ShareeBikeApp object. </summary>
		/// <param name="settings"></param>
		/// <param name="accountStore"></param>
		/// <param name="passwordValidator"></param>
		/// <param name="p_oConnectorFactory"></param>
		/// <param name="geolocationService">Null in productive context. Service to query geolocation for testing purposes. Parameter can be made optional.</param>
		/// <param name="locksService">Null in productive context. Service to control locks/ get locks information for testing proposes. Parameter can be made optional.</param>
		/// <param name="device">Object allowing platform specific operations.</param>
		/// <param name="specialFolder"></param>
		/// <param name="p_oDateTimeProvider"></param>
		/// <param name="isConnectedFunc">True if connector has access to copri server, false if cached values are used.</param>
		/// <param name="currentVersion">Version of the app. If null version is set to a fixed dummy value (3.0.122) for testing purposes.</param>
		/// <param name="lastVersion">Version of app which was used before this session, null if app is installed for the first time.</param>
		/// <param name="whatsNewShownInVersion"> Holds 
		/// - the version when whats new info was shown last or 
		/// - version of application used last if whats new functionality was not implemented in this version or
		/// - null if app is installed for the first time.
		/// /// </param>
		public ShareeBikeApp(
			Settings.Settings settings,
			IStore accountStore,
			Func<bool> isConnectedFunc,
			Func<bool, Uri, string /* session cookie*/, string /* mail address*/, TimeSpan, IConnector> connectorFactory,
			string merchantId,
			IBluetoothLE bluetoothService,
			ILocationPermission locationPermissionsService,
			IServicesContainer<IGeolocationService> locationServicesContainer,
			ILocksService locksService,
			ISmartDevice device,
			ISpecialFolder specialFolder,
			ICipher cipher,
			ITheme theme,
			Action<SendOrPostCallback, object> postAction = null,
			Version currentVersion = null,
			Version lastVersion = null,
			Version whatsNewShownInVersion = null,
			AppFlavor flavor = AppFlavor.ShareeBike)
		{
			PostAction = postAction
				?? ((d, obj) => d(obj));

			ConnectorFactory = connectorFactory
				?? throw new ArgumentException($"Can not instantiate {nameof(ShareeBikeApp)}- object. No connector factory object available.");

			MerchantId = merchantId
				?? throw new ArgumentException($"Can not instantiate {nameof(ShareeBikeApp)}- object. No merchant id available.");

			if (settings == null)
				throw new ArgumentException($"Can not instantiate {nameof(ShareeBikeApp)}- object. Settings must not be null.");

			Cipher = cipher ?? new Cipher();

			Flavor = flavor;

			// Log application and environment information.
			new AppAndEnvironmentInfo().LogHeader(device, flavor, currentVersion);
			
			var locksServices = locksService != null
				? new HashSet<ILocksService> { locksService }
				: new HashSet<ILocksService> {
					new LockItByScanServiceEventBased(
						Cipher,
						bluetoothService,
						async () => device.Platform == Xamarin.Essentials.DevicePlatform.Android &&  await locationPermissionsService.CheckStatusAsync() != Status.Granted,
						() => device.Platform == Xamarin.Essentials.DevicePlatform.Android && !locationServicesContainer.Active.IsGeolcationEnabled),
					new LockItByScanServicePolling(
						Cipher,
						bluetoothService,
						async () => device.Platform == Xamarin.Essentials.DevicePlatform.Android &&  await locationPermissionsService.CheckStatusAsync() != Status.Granted,
						() => device.Platform == Xamarin.Essentials.DevicePlatform.Android && !locationServicesContainer.Active.IsGeolcationEnabled),
					new LockItByGuidService(Cipher),
#if BLUETOOTHLE // Requires LockItBluetoothle library.
                    new Bluetoothle.LockItByGuidService(Cipher),
#endif
					new LocksServiceInReach(),
					new LocksServiceOutOfReach(),
				};

			LocksServices = new LocksServicesContainerMutable(
				lastVersion >= new Version(3, 0, 173) ? settings.ActiveLockService : LocksServicesContainerMutable.DefaultLocksservice,
				locksServices);

			LocksServices.SetTimeOut(settings.ConnectTimeout);

			Themes = new ServicesContainerMutable(
				new HashSet<string> {
					ThemeSet.ShareeBike.ToString(),
					ThemeSet.LastenradBayern.ToString()
				},
				Enum.TryParse(settings.ActiveTheme, true, out ThemeSet active) ? active.ToString() : ThemeSet.ShareeBike.ToString());

			GeolocationServices = locationServicesContainer
				?? throw new ArgumentException($"Can not instantiate {nameof(ShareeBikeApp)}- object. No geolocation services container object available.");

			FilterGroupSetting = settings.GroupFilterSettings;
			GroupFilterMapPage = settings.GroupFilterMapPage;

			StartupSettings = settings.StartupSettings;

			CenterMapToCurrentLocation = settings.CenterMapToCurrentLocation;

			HomeMapSpan = settings.MapSpan;

			SmartDevice = device
			   ?? throw new ArgumentException("Can not instantiate ShareeBikeApp- object. No device information provider available.");

			if (specialFolder == null)
			{
				throw new ArgumentException("Can not instantiate ShareeBikeApp- object. No special folder provider available.");
			}

			// Set logging level.
			Level.MinimumLevel = settings.MinimumLogEventLevel;

			LogToExternalFolder = settings.LogToExternalFolder;

			IsSiteCachingOn = settings.IsSiteCachingOn;

			ExternalFolder = specialFolder.GetExternalFilesDir();

			SettingsFileFolder = specialFolder.GetInternalPersonalDir();

			ActiveUser = new User.User(
				accountStore.GetType().Name == "StoreLegacy" ? new Store() : accountStore,
				accountStore.Load().Result,
				device.Identifier);

			this.isConnectedFunc = isConnectedFunc ?? (() => CrossConnectivity.Current.IsConnected);

			ExpiresAfter = settings.ExpiresAfter;

			// Create filtered connector for offline mode.
			m_oConnector = FilteredConnectorFactory.Create(
				FilterGroupSetting.DoFilter(GroupFilterMapPage.DoFilter()),
				ConnectorFactory(GetIsConnected(), settings.ActiveUri, ActiveUser.SessionCookie, ActiveUser.Mail, ExpiresAfter));

			// Get uris from file.
			// Initialize all settings to defaults
			// Process uris.
			Uris = new CopriServerUriList(settings.ActiveUri);

			NextActiveUri = Uris.ActiveUri;

			if (settings.PollingParameters == null)
				throw new ArgumentException($"Can not instantiate {nameof(ShareeBikeApp)}- object. Polling parameters must never be null.");

			Polling = (lastVersion  != null && lastVersion < new Version(3, 0, 358))
				? PollingParameters.Default // Default polling period was 10s up to 3.0.357. Is 60s for later versions.
				: settings.PollingParameters;

			AppVersion = currentVersion ?? new Version(3, 0, 122);

			var loggingLevel = settings.MinimumLogEventLevel;
			if (new Version(3, 0, 376) <= (lastVersion ?? new Version(1, 0))
				&& loggingLevel == LogEventLevel.Error)
			{
				// Up to version 3.0.376 default logging level was Error.
				// Switch to level Information for older versions if level error is detected.
				loggingLevel = Settings.Settings.DEFAULTLOGGINLEVEL;
			}

			MinimumLogEventLevel = loggingLevel;

			if (loggingLevel != settings.MinimumLogEventLevel)
			{
				// Logging level was overridden due to update.
				// Activate modified level.
				UpdateLoggingLevel(loggingLevel);

				// Save modified logging level to file.
				Save();
			}

			IsReportLevelVerbose = settings.IsReportLevelVerbose;

			WhatsNew = new WhatsNew(AppVersion, lastVersion, whatsNewShownInVersion, Flavor, SmartDevice.Platform);

			if (Themes.Active.GetType().FullName == typeof(Themes.ShareeBike).FullName)
			{
				// Nothing to do.
				// Theme to activate is default theme.
				return;
			}

			// Set active app theme from settings.
			// Value might differ from default scheme value defined in ResourceDictionary.MergedDictionaries (App.xaml)
			if (theme == null)
			{
				Log.ForContext<ShareeBikeApp>().Error("No merged dictionary available.");
				return;
			}

			theme.SetActiveTheme(Themes.Active);
		}

		/// <summary> Holds the user of the app. </summary>
		[DataMember]
		public User.User ActiveUser { get; }

		/// <summary> Reference of object which provides device information. </summary>
		public ISmartDevice SmartDevice { get; }

		/// <summary> Holds delegate to determine whether device is connected or not.</summary>
		private readonly Func<bool> isConnectedFunc;

		/// <summary> Gets whether device is connected to Internet or not. </summary>
		public bool GetIsConnected() => isConnectedFunc();

		/// <summary> Holds the folder where settings files are stored. </summary>
		public string SettingsFileFolder { get; }

		/// <summary> Holds folder parent of the folder where log files are stored. </summary>
		public string LogFileParentFolder => LogToExternalFolder && !string.IsNullOrEmpty(ExternalFolder) ? ExternalFolder : SettingsFileFolder;

		/// <summary> Holds a value indicating whether to log to external or internal folder. </summary>
		public bool LogToExternalFolder { get; set; }

		/// <summary> Holds a value indicating whether Site caching is on or off. </summary>
		public bool IsSiteCachingOn { get; set; }

		/// <summary> External folder. </summary>
		public string ExternalFolder { get; }

		public ICipher Cipher { get; }

		/// <summary> Name of the station which is selected. </summary>
		public IStation SelectedStation { get; set; } = new NullStation();

		/// <summary> Holds the stations centered. </summary>
		public IEnumerable<IStation> Stations { get; set; } = new List<Station>();

		public IResourceUrls ResourceUrls { get; set; } = new ResourceUrls();

		/// <summary> Action to post to GUI thread.</summary>
		public Action<SendOrPostCallback, object> PostAction { get; }

		/// <summary> Function which creates a connector depending on connected status.</summary>
		private Func<bool, Uri, string /*userAgent*/, string /*sessionCookie*/, TimeSpan, IConnector> ConnectorFactory { get; }

		/// <summary> Holds the object which provides offline data.</summary>
		private IFilteredConnector m_oConnector;

		/// <summary> Holds the system to copri.</summary>
		public IFilteredConnector GetConnector(bool isConnected)
		{
			if (m_oConnector.IsConnected == isConnected
				&& m_oConnector.Command.SessionCookie == ActiveUser.SessionCookie)
			{
				// Neither connection nor logged in stated changed.
				return m_oConnector;
			}

			// Connected state changed. New connection object has to be created.
			m_oConnector = FilteredConnectorFactory.Create(
				FilterGroupSetting.DoFilter(ActiveUser.DoFilter(GroupFilterMapPage.DoFilter())),
				ConnectorFactory(
					isConnected,
					Uris.ActiveUri,
					ActiveUser.SessionCookie,
					ActiveUser.Mail,
					ExpiresAfter));

			return m_oConnector;
		}

		/// <summary> Manages the different types of LocksService objects.</summary>
		public LocksServicesContainerMutable LocksServices { get; set; }

		/// <summary> Holds available app themes.</summary>
		public IServicesContainer<IGeolocationService> GeolocationServices { get; }

		/// <summary> Holds the flavor of the app, i.e. specifies if app is sharee.bike or LastenRad Bayern.</summary>
		public AppFlavor Flavor { get; private set; }

		/// <summary> Manages the different types of LocksService objects.</summary>
		public ServicesContainerMutable Themes { get; private set; }

		/// <summary> Object to switch logging level. </summary>
		private LoggingLevelSwitch m_oLoggingLevelSwitch;

		/// <summary>
		/// Object to allow switching logging level
		/// </summary>
		public LoggingLevelSwitch Level
		{
			get
			{
				if (m_oLoggingLevelSwitch == null)
				{
					m_oLoggingLevelSwitch = new LoggingLevelSwitch
					{

						// Set warning level to error.
						MinimumLevel = Settings.Settings.DEFAULTLOGGINLEVEL
					};
				}

				return m_oLoggingLevelSwitch;
			}
		}

		/// <summary> Updates logging level. </summary>
		/// <param name="minimumLevel">New level to set.</param>
		public void UpdateLoggingLevel(LogEventLevel minimumLevel)
		{
			if (Level.MinimumLevel == minimumLevel)
			{
				// Nothing to do.
				return;
			}

			Log.CloseAndFlush(); // Close before modifying logger configuration. Otherwise a sharing violation occurs.

			Level.MinimumLevel = minimumLevel;

			SetupLogging(Level, LogFileParentFolder);
		}

		/// <summary>
		/// Sets up logging.
		/// </summary>
		/// <param name="levelSwitch">Logging level to use.</param>
		/// <param name="logFilePath">Path to logging file.</param>
		public static void SetupLogging(
			LoggingLevelSwitch levelSwitch,
			string logFilePath)
		{
			bool LogToFileFilter(LogEvent e)
			{
				if (e.Level >= levelSwitch.MinimumLevel)
				{
					// If level is above global logging level do log.
					return true;
				}

				if (!e.Properties.ContainsKey(Constants.SourceContextPropertyName))
				{
					// Do not log if source context is not available.
					return false;
				}
				var sourceContex = e.Properties[Constants.SourceContextPropertyName].ToString();

				if ((e.Level == LogEventLevel.Information) &&
					(sourceContex.Contains(typeof(AppAndEnvironmentInfo).Namespace) /* Log App and environment info. */
					|| sourceContex.Contains(typeof(ViewModel.Bikes.Bike.BluetoothLock.RequestHandler.Base).Namespace /* Log info-level messages to provide context for bluetooth log. */ )))
				{
					return true;
				}

				if (e.Level >= LogEventLevel.Debug
					&& sourceContex.Contains(typeof(LockItBase).Namespace /*Scanning, connect and management functionality */))
				{
					return true;
				}

				return false;
			}

			Log.Logger = new LoggerConfiguration()
				.MinimumLevel.Verbose()
				.WriteTo.Logger(consoleLoggerConfig => consoleLoggerConfig
					.MinimumLevel.Information()
					.WriteTo.Debug()
				)
				.WriteTo.Logger(fileLoggerConfig => fileLoggerConfig
					.Filter.ByIncludingOnly(e => LogToFileFilter(e))
					.WriteTo.File(logFilePath, Logging.RollingInterval.Session)
				)
				.WriteTo.Logger(copriLoggerConfig => copriLoggerConfig
					.MinimumLevel.Debug()
					.Filter.ByIncludingOnly(Matching.FromSource(typeof(LockItBase/*Scanning, connect and management functionality */).Namespace))
					.WriteTo.MemoryQueueSink()
				)
				.CreateLogger();
		}
	}
}