AlayaCore/AlayaCore/Services/AuthService.cs

using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using AlayaCore.Abstractions.Interfaces;
using AlayaCore.Abstractions.Interfaces.Services;
using AlayaCore.Utilities.Enums;
using CmlLib.Core.Auth;
using CmlLib.Core.Auth.Microsoft;
using Microsoft.Identity.Client;
using XboxAuthNet.Game.Msal;
using XboxAuthNet.Game.Msal.OAuth;

namespace AlayaCore.Services
{
    public sealed class AuthService : IAuthService
    {
        private readonly IFileStore _fileStore;

        private MSession? _session;
        private IPublicClientApplication? _clientApp;
        private JELoginHandler? _loginHandler;

        public AuthService(IFileStore fileStore)
        {
            _fileStore = fileStore ?? throw new ArgumentNullException(nameof(fileStore));
        }

        public Task<bool> IsAuthenticatedAsync(CancellationToken cancellationToken = default)
        {
            cancellationToken.ThrowIfCancellationRequested();

            bool authenticated = _session != null && _session.CheckIsValid();
            return Task.FromResult(authenticated);
        }

        public async Task AuthenticateAsync(CancellationToken cancellationToken = default)
        {
            cancellationToken.ThrowIfCancellationRequested();

            JELoginHandler loginHandler = await BuildHandlerAsync().ConfigureAwait(false);

            try
            {
                _session = await loginHandler
                    .AuthenticateSilently(cancellationToken: cancellationToken)
                    .ConfigureAwait(false);
            }
            catch
            {
                _session = await loginHandler
                    .AuthenticateInteractively(cancellationToken: cancellationToken)
                    .ConfigureAwait(false);
            }

            if (_session == null || !_session.CheckIsValid())
            {
                throw new InvalidOperationException("Authentication did not produce a valid Minecraft session.");
            }
        }

        public async Task SignOutAsync(CancellationToken cancellationToken = default)
        {
            cancellationToken.ThrowIfCancellationRequested();

            JELoginHandler loginHandler = await BuildHandlerAsync().ConfigureAwait(false);

            await loginHandler.Signout(cancellationToken).ConfigureAwait(false);
            _session = null;
        }

        public async Task<MSession> GetSessionAsync(CancellationToken cancellationToken = default)
        {
            cancellationToken.ThrowIfCancellationRequested();

            if (_session != null && _session.CheckIsValid())
            {
                return _session;
            }

            await AuthenticateAsync(cancellationToken).ConfigureAwait(false);

            if (_session == null || !_session.CheckIsValid())
            {
                throw new InvalidOperationException("No valid Minecraft session is available.");
            }

            return _session;
        }

        private async Task<JELoginHandler> BuildHandlerAsync()
        {
            if (_loginHandler != null)
            {
                return _loginHandler;
            }

            string accountDirectory = _fileStore.GetOrCreate(FolderLocation.Data);
            string accountFilePath = Path.Combine(accountDirectory, "accounts.json");

            _clientApp = await MsalClientHelper
                .BuildApplicationWithCache("d91042d4-3eb5-43e4-b3ed-600e1d0760ff")
                .ConfigureAwait(false);

            _loginHandler = new JELoginHandlerBuilder()
                .WithOAuthProvider(new MsalCodeFlowProvider(_clientApp))
                .WithAccountManager(accountFilePath)
                .Build();

            return _loginHandler;
        }
    }
}