using Google.Apis.Auth.OAuth2;
using Google.Apis.Oauth2.v2;
using System;
using System.Threading.Tasks;
using Windows.Security.Authentication.Web;
using YouTube.Authorization;
using Windows.Security.Credentials;
using FoxTube.Models;
using YouTube;
using System.Threading;
using Google.Apis.YouTube.v3;
using Google.Apis.YouTube.v3.Data;
using Windows.UI.Xaml.Controls;
using FoxTube.Utils;
using YoutubeExplode;
using System.Linq;
using Newtonsoft.Json;
using Windows.Storage;
using Google.Apis.Oauth2.v2.Data;

namespace FoxTube
{
	public static class UserManagement
	{
		public const int MaxUsersCount = 2;

		#region Private members
		private static readonly ApplicationDataContainer storage = ApplicationData.Current.LocalSettings;

		private static readonly ExtendedYouTubeService _defaultService = new ExtendedYouTubeService(new Google.Apis.Services.BaseClientService.Initializer
		{
			ApplicationName = "FoxTube",
			ApiKey = "AIzaSyBgHrCnrlzlVmk0cJKL8RqP9Y8x6XSuk_0",
			//ApiKey = "AIzaSyD7tpbuvmYDv9h4udo9L_g3r0sLPFAnN00"
		});
		private static readonly YoutubeClient _defaultYteClient = new YoutubeClient();

		private static string[] Scopes { get; } = new string[]
		{
			Oauth2Service.Scope.UserinfoProfile,
			Oauth2Service.Scope.UserinfoEmail,
			YouTubeService.Scope.YoutubeForceSsl
		};

		private static ClientSecrets[] ClientSecrets { get; } = new ClientSecrets[MaxUsersCount]
		{
			new ClientSecrets
			{
				ClientId = "349735264870-2ekqlm0a4mkg3mmrfcv90s3qp3o15dq0.apps.googleusercontent.com",
				ClientSecret = "BkVZOAaCU2Zclf0Zlicg6y2_"
			},
			new ClientSecrets		// DISABLED
			{
				ClientId = "1096685398208-u95rcpkqb4e1ijfmb8jdq3jsg37l8igv.apps.googleusercontent.com",
				ClientSecret = "IU5bbdjwvmx8ttJoXQ7e6JWd"
			}
		};
		#endregion

		public static Userinfoplus[] Users { get; private set; } = new Userinfoplus[MaxUsersCount];
		public static User CurrentUser { get; set; }
		public static bool Authorized => CurrentUser != null;
		public static ExtendedYouTubeService Service => CurrentUser?.Service ?? _defaultService;
		public static YoutubeClient YoutubeClient => CurrentUser?.Client ?? _defaultYteClient;

		public static event EventHandler<bool> UserStateUpdated;
		public static event EventHandler<Subscription> SubscriptionsChanged;

		public static async Task<bool> AddUser()
		{
			int queueIndex = Users.ToList().FindIndex(i => i == null);

			if (queueIndex < 0)
				throw new StackOverflowException("The maximum accounts limit is reached");

			ClientSecrets secrets = ClientSecrets[queueIndex];

			Uri requestString = AuthorizationHelpers.FormQueryString(secrets, Scopes);

			WebAuthenticationResult result = await WebAuthenticationBroker.AuthenticateAsync(WebAuthenticationOptions.UseTitle, requestString, AuthorizationHelpers.Endpoint);
			switch (result.ResponseStatus)
			{
				case WebAuthenticationStatus.Success:
					string successCode = AuthorizationHelpers.ParseSuccessCode(result.ResponseData);

					YouTube.Authorization.UserCredential credential = await AuthorizationHelpers.ExchangeToken(secrets, successCode);

					await LoadUser(credential, queueIndex);
					return true;
				case WebAuthenticationStatus.UserCancel:
					break;
				case WebAuthenticationStatus.ErrorHttp:
					await new ContentDialog
					{
						Title = "Something went wrong...",
						Content = "It may be a bug or temporary server issues. Please, try again later"
					}.ShowAsync();

					Metrics.SendReport(new Exception("Authorization failed (HTTP Error)"), null,
						("Response status", result.ResponseStatus.ToString()),
						("Response data", result.ResponseData),
						("Error details", result.ResponseErrorDetail.ToString()));
					break;
			}
			 
			return false;
		}

		public static async Task Initialize()
		{
			Users = JsonConvert.DeserializeObject<Userinfoplus[]>(storage.Values["UserManagement.Users"] as string);
			int? lastUserIndex = storage.Values["UserManagement.LastUser"] as int?;

			if (lastUserIndex.HasValue && Users[lastUserIndex.Value] != null ||
				(lastUserIndex = Users.ToList().FindIndex(i => i != null)) > -1)
				await SwitchUser(lastUserIndex.Value);
		}

		public static async Task<bool> Logout()
		{
			if (CurrentUser?.UserInfo?.Id == null)
				return false;

			try
			{
				string userId = CurrentUser.UserInfo.Id;

				PasswordVault passwordVault = new PasswordVault();
				PasswordCredential credential = passwordVault.Retrieve("foxtube", userId);
				passwordVault.Remove(credential);

				await CurrentUser.Credential.RevokeTokenAsync(CancellationToken.None);

				storage.Values.Remove($"Subscriptions.{CurrentUser.UserInfo.Id}");
				CurrentUser = null;
				Users[Users.ToList().FindIndex(i => i.Id == userId)] = null;

				storage.Values["UserManagement.Users"] = JsonConvert.SerializeObject(Users);
				storage.Values["UserManagement.LastUser"] = null;

				if (Users.Any(i => i != null))
					await SwitchUser(Users.ToList().FindIndex(i => i != null));
				else
					UserStateUpdated?.Invoke(Users, false);

				return true;
			}
			catch (Exception e)
			{
				Metrics.SendReport(new Exception("Failed to logout", e));

				await new ContentDialog
				{
					Title = "Something went wrong...",
					Content = "It may be a bug or temporary server issues. Please, try again later"
				}.ShowAsync();

				return false;
			}
		}

		public static async Task SwitchUser(int userIndex)
		{
			Userinfoplus userInfo = Users[userIndex];

			PasswordVault valut = new PasswordVault();
			PasswordCredential vaultCredential = valut.Retrieve("foxtube", userInfo.Id);
			if (vaultCredential == null)
				throw new NullReferenceException("No user found to switch on");

			vaultCredential.RetrievePassword();
			string token = vaultCredential.Password;
			YouTube.Authorization.UserCredential credential = await AuthorizationHelpers.RestoreUser(ClientSecrets[userIndex], token);

			await LoadUser(credential, userIndex);
		}

		private static async Task LoadUser(YouTube.Authorization.UserCredential credential, int userIndex)
		{
			CurrentUser = await User.GetUser(credential);
			Users[userIndex] = CurrentUser.UserInfo;

			storage.Values["UserManagement.Users"] = JsonConvert.SerializeObject(Users);
			storage.Values["UserManagement.LastUser"] = userIndex;

			credential.RefreshTokenUpdated += (s, e) => UpdateToken(CurrentUser.UserInfo.Id, credential.Token.RefreshToken);
			UpdateToken(CurrentUser.UserInfo.Id, credential.Token.RefreshToken);

			UserStateUpdated?.Invoke(Users, true);
		}

		private static void UpdateToken(string id, string refreshToken)
		{
			PasswordVault passwordVault = new PasswordVault();
			PasswordCredential vaultCredential = passwordVault.Retrieve("foxtube", id);

			if (vaultCredential == null)
			{
				vaultCredential = new PasswordCredential("foxtube", CurrentUser.UserInfo.Id, refreshToken);
				passwordVault.Add(vaultCredential);
			}
			else
				vaultCredential.Password = refreshToken;
		}

		internal static void SubscriptionsChangedInvoker(User sender, Subscription subscription) =>
			SubscriptionsChanged?.Invoke(sender, subscription);
	}
}