using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using MonkeyCache.FileStore;
using Plugin.Connectivity;
using Plugin.Permissions;
using Serilog;
using Serilog.Core;
using Serilog.Events;
using TINK.Model;
using TINK.Model.Connector;
using TINK.Model.Device;
using TINK.Model.Logging;
using TINK.Model.Settings;
using TINK.Model.User.Account;
using TINK.Services;
using TINK.Services.BluetoothLock.Crypto;
using TINK.Services.Geolocation;
using TINK.Services.Permissions;
using TINK.View;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
#if ARENDI
using Arendi.BleLibrary.Local;
#endif

// Required for support of binding package, see  https://github.com/nuitsjp/Xamarin.Forms.GoogleMaps.Bindings.
[assembly: XamlCompilation(XamlCompilationOptions.Compile)]
namespace TINK
{
	public partial class App : Application
	{
		/// <summary>Title of the attachment file.</summary>
		private const string ATTACHMENTTITLE = "Diagnostics.txt";

		/// <summary> Model root. </summary>
		private static TinkApp m_oModelRoot;

		/// <summary>
		/// Gets the model root.
		/// </summary>
		public static TinkApp ModelRoot
		{
			get
			{
				if (m_oModelRoot != null)
				{
					// Root model already exists, nothing to do.
					return m_oModelRoot;
				}

				// Get folder where to read settings from
				var specialFolders = DependencyService.Get<ISpecialFolder>();
				var internalPersonalDir = specialFolders.GetInternalPersonalDir();

				// Delete attachtment from previous session.
				DeleteAttachment(internalPersonalDir);

				// Setup logger using default settings.
				TinkApp.SetupLogging(
					new LoggingLevelSwitch(Model.Settings.Settings.DEFAULTLOGGINLEVEL),
					internalPersonalDir);

				// Subscribe to any unhandled/ unobserved exceptions.
				AppDomain.CurrentDomain.UnhandledException += (sender, unobservedTaskExceptionEventArgs) => { Log.Fatal("Unobserved task exception: {Exception}", unobservedTaskExceptionEventArgs.ExceptionObject); };
				TaskScheduler.UnobservedTaskException += (sender, unhandledExceptionEventArgs) => { Log.Fatal("Unhandled exception: {Exception}", unhandledExceptionEventArgs.Exception); };

				// Restore last model state from json- file.
				Dictionary<string, string> settingsJSON = new Dictionary<string, string>();
				try
				{
					settingsJSON = JsonSettingsDictionary.Deserialize(internalPersonalDir);
				}
				catch (Exception exception)
				{
					Log.Error("Reading application settings from file failed.", exception);
				}

				Model.Settings.Settings settings;
				try
				{
					settings = new Model.Settings.Settings(
						null,  // Turn off filtering for LastenradBayern- context
						null,  // Turn off filtering for LastenradBayern- context
						JsonSettingsDictionary.GetStartupSettings(settingsJSON) ?? new StartupSettings(),
						JsonSettingsDictionary.GetCopriHostUri(settingsJSON),
						JsonSettingsDictionary.GetPollingParameters(settingsJSON),
						JsonSettingsDictionary.GetMinimumLoggingLevel(settingsJSON),
						JsonSettingsDictionary.GetIsReportLevelVerbose(settingsJSON),
						JsonSettingsDictionary.GetExpiresAfter(settingsJSON),
						JsonSettingsDictionary.GetActiveLockService(settingsJSON),
						JsonSettingsDictionary.GetConnectTimeout(settingsJSON),
						JsonSettingsDictionary.GetActiveGeolocationService(settingsJSON),
						JsonSettingsDictionary.GetCenterMapToCurrentLocation(settingsJSON),
						Xamarin.Forms.GoogleMaps.MapSpan.FromCenterAndRadius(new Xamarin.Forms.GoogleMaps.Position(48.945396, 11.395330), Xamarin.Forms.GoogleMaps.Distance.FromKilometers(250)),
						JsonSettingsDictionary.GetLogToExternalFolder(settingsJSON),
						JsonSettingsDictionary.GetIsSiteCachingOn(settingsJSON),
						JsonSettingsDictionary.GetActiveTheme(settingsJSON) ?? typeof(Themes.LastenradBayern).Name);
				}
				catch (Exception exception)
				{
					Log.Error("Deserializing application settings from dictionary failed.", exception);
					settings = new Model.Settings.Settings();
				}

				if (settings.MinimumLogEventLevel != Model.Settings.Settings.DEFAULTLOGGINLEVEL
					|| settings.LogToExternalFolder)
				{
					// Eigher
					// - logging is not set to default value or
					// - logging is performed to external folder.
					// Need to reconfigure.
					Log.CloseAndFlush(); // Close before modifying logger configuration. Otherwise a sharing vialation occurs.

					TinkApp.SetupLogging(
						new LoggingLevelSwitch(settings.MinimumLogEventLevel),
						!settings.LogToExternalFolder
							? internalPersonalDir
							: specialFolders.GetExternalFilesDir());
				}

				// Get auth cookie
				Log.Debug("Get auth cookie.");
				IStore store = null;

				var lastVersion = JsonSettingsDictionary.GetAppVersion(settingsJSON);
				if (new Version(3, 0, 290) <= lastVersion)
				{
					// App versions newer than 3.0.173 stored geolocation service in configuration.
					// Version 3.0.290: Geolocation service "GeolocationService" is no more supported.
					// For this reasons a swich of geolocation service is forced when loading configurations from ealier versions.
					LocationServicesContainer.SetActive(settings.ActiveGeolocationService);
				}

				store = new Store();

				Barrel.ApplicationId = System.Reflection.Assembly.GetExecutingAssembly().GetName().Name;

				var context = SynchronizationContext.Current;

				var appInfoService = DependencyService.Get<IAppInfo>();

				const string MERCHANTID = "0000000000";

				// Create new app instnace.
				Log.Debug("Constructing main model...");
				m_oModelRoot = new TinkApp(
					settings,
					store, // Manages user account
					isConnectedFunc: () => CrossConnectivity.Current.IsConnected,
					connectorFactory: (isConnected, activeUri, sessionCookie, mail, expiresAfter) => ConnectorFactory.Create(
						isConnected,
						activeUri,
						new Repository.AppContextInfo(MERCHANTID, AppFlavor.LastenradBayern.GetDisplayName().Replace(" ", ""), appInfoService.Version),
						CultureInfo.CurrentUICulture.TwoLetterISOLanguageName,
						sessionCookie,
						mail,
						expiresAfter),
					merchantId: MERCHANTID,
					bluetoothService: BluetoothService, /* locksService */
					locationPermissionsService: PermissionsService,
					locationServicesContainer: LocationServicesContainer,
					locksService: null,
					device: DependencyService.Get<ISmartDevice>(),
					specialFolder: specialFolders,
					cipher: new Cipher(),
					new TINK.Services.ThemeNS.Theme(Application.Current.Resources.MergedDictionaries),
					arendiCentral:
#if ARENDI
                    DependencyService.Get<ICentral>(),
#else

					null,
#endif
					postAction: (d, obj) => context.Post(d, obj),
					currentVersion: appInfoService.Version,
					lastVersion: lastVersion,
					whatsNewShownInVersion: JsonSettingsDictionary.GetWhatsNew(settingsJSON) ?? settingsJSON.GetAppVersion(),
					flavor: AppFlavor.LastenradBayern);

				Log.Debug("Main model successfully constructed.");
				return m_oModelRoot;
			}
		}

		/// <summary>
		/// Entry point of application.
		/// </summary>
		public App()
		{
			InitializeComponent();

#if USEFLYOUT
            // Use flyout page.
            MainPage = ModelRoot.WhatsNew.IsShowRequired
                ? new View.WhatsNew.WhatsNewPage(() => MainPage = new View.Root.RootPage()) // Show whats new info.
                : (Page)new View.Root.RootPage(); // Just start sharee- app            
#else
			// Check which page to show first.
			var mainPage = new View.RootShell.AppShell();

			MainPage = ModelRoot.WhatsNew.IsShowRequired
			? new View.WhatsNew.WhatsNewPage(() => MainPage = mainPage) // Show whats new info.
				: (Page)mainPage; // Just start sharee- app
#endif
		}

		/// <summary> Concatenates all log files to a single one. </summary>
		/// <returns>Full file name of attachment.</returns>
		public static string CreateAttachment()
		{
			var sessionLogFiles = Log.Logger.GetLogFiles().ToArray();

			if (sessionLogFiles.Length < 1)
			{
				// Either
				// - there is no logging file 
				// - an error occurred getting list of log files.
				return string.Empty;
			}

			var fullLogFileName = System.IO.Path.Combine(ModelRoot.LogFileParentFolder, ATTACHMENTTITLE);

			// Stop logging to avoid file access exception.
			Log.CloseAndFlush();

			System.IO.File.WriteAllLines(
				fullLogFileName,
				sessionLogFiles.SelectMany(name =>
					 (new List<string> { $"{{\"SessionFileName\":\"{name}\"}}" })
						.Concat(System.IO.File.ReadLines(name).ToArray())));

			// Resume logging
			TinkApp.SetupLogging(
				ModelRoot.Level,
				ModelRoot.LogFileParentFolder);

			return fullLogFileName;
		}

		/// <summary>Deletes an attachment if there is one.</summary>
		/// <param name="folder">Folder to delete, is null folder is queried from model.</param>
		private static void DeleteAttachment(string folder = null)
		{
			var attachment = System.IO.Path.Combine(folder ?? ModelRoot.LogFileParentFolder, ATTACHMENTTITLE);
			if (!System.IO.File.Exists(attachment))
			{
				// No attachment found.
				return;
			}

			System.IO.File.Delete(attachment);
		}

		protected override void OnSleep()
		{
			// Handle when your app sleeps
			Log.CloseAndFlush();
		}

		protected override void OnResume()
		{
			DeleteAttachment();

			TinkApp.SetupLogging(
				ModelRoot.Level,
				ModelRoot.LogFileParentFolder);
		}

		/// <param name="uri">The URI for the request.</param>
		/// <summary>Overriden to respond when the user initiates an app link request.</summary>
		protected override void OnAppLinkRequestReceived(Uri uri)
		{
			base.OnAppLinkRequestReceived(uri);
			if (uri.Host.ToLower() == "sharee.bike")
			{
				// Input e.g. sharee.bike/sharee?lat=49.921&long=32.51
				Array segments = Array.ConvertAll(uri.Segments, segment => segment.Replace("/", "")).Skip(1).ToArray();
				if (uri.Query.Length > 0)
				{
					Dictionary<string, string> queryDict = uri.Query
						.Substring(1)
						.Split("&")
						.Select(query => query.Split('='))
						.ToDictionary(query => query.FirstOrDefault(), query => query.Skip(1).FirstOrDefault());
				}
				// segments == ["sharee"]
				// queryDict == [{["lat", "49.921"]}], {["long", "32.51"]}]
				// => Navigate and pass params depending on linkinput
				// If no custom navigation is configured, the app just opens as if the user opened it
			}
		}

		/// <summary> Gets the current logging level.</summary>
		/// <returns></returns>
		private static LogEventLevel GetCurrentLogEventLevel()
		{
			foreach (LogEventLevel level in Enum.GetValues(typeof(LogEventLevel)))
			{
				if (Log.IsEnabled(level))
					return level;
			}

			return LogEventLevel.Error;
		}

		/// <summary>
		/// Holds the permission service instance.
		/// </summary>
		private static ILocationPermission _PermissionsService = null;

		/// <summary>
		/// Service to manage permissions (location) of the app.
		/// </summary>
		public static ILocationPermission PermissionsService
		{
			get
			{
				if (_PermissionsService != null)
					return _PermissionsService;

				_PermissionsService = new TINK.Services.Permissions.Essentials.LocationPermissions();
				return _PermissionsService;
			}
		}

		/// <summary> Service to manage bluetooth stack.</summary>
		public static Plugin.BLE.Abstractions.Contracts.IBluetoothLE BluetoothService => Plugin.BLE.CrossBluetoothLE.Current;

		/// <summary>
		/// Service container to manage geolocation services.
		/// </summary>
		public static IServicesContainer<IGeolocation> LocationServicesContainer { get; }
			= new ServicesContainerMutableT<IGeolocation>(
					new HashSet<IGeolocation> {
						new LastKnownGeolocationService(DependencyService.Get<IGeolodationDependent>()),
						new SimulatedGeolocationService(DependencyService.Get<IGeolodationDependent>()),
						new GeolocationAccuracyMediumService(DependencyService.Get<IGeolodationDependent>()),
						new GeolocationAccuracyHighService(DependencyService.Get<IGeolodationDependent>()),
						new GeolocationAccuracyBestService(DependencyService.Get<IGeolodationDependent>())},
					Model.Settings.Settings.DefaultLocationService.FullName);
	}
}