PalacePal/Pal.Client/Net/RemoteApi.AccountService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using Account;
using Grpc.Core;
using Grpc.Net.Client;
using Microsoft.Extensions.Logging;
using Pal.Client.Configuration;
using Pal.Client.Extensions;
using Pal.Client.Properties;

namespace Pal.Client.Net;

internal partial class RemoteApi
{
    private readonly SemaphoreSlim _connectLock = new(1, 1);

    private async Task<(bool Success, string Error)> TryConnect(CancellationToken cancellationToken,
        ILoggerFactory? loggerFactory = null, bool retry = true)
    {
        using IDisposable? logScope = _logger.BeginScope("TryConnect");

        var result = await TryConnectImpl(cancellationToken, loggerFactory);
        if (retry && result.ShouldRetry)
            result = await TryConnectImpl(cancellationToken, loggerFactory);

        return (result.Success, result.Error);
    }

    private async Task<(bool Success, string Error, bool ShouldRetry)> TryConnectImpl(
        CancellationToken cancellationToken,
        ILoggerFactory? loggerFactory)
    {
        if (_configuration.Mode != EMode.Online)
        {
            _logger.LogDebug("Not Online, not attempting to establish a connection");
            return (false, Localization.ConnectionError_NotOnline, false);
        }

        if (_channel == null ||
            !(_channel.State == ConnectivityState.Ready || _channel.State == ConnectivityState.Idle))
        {
            Dispose();

            _logger.LogInformation("Creating new gRPC channel");
            _channel = GrpcChannel.ForAddress(RemoteUrl, new GrpcChannelOptions
            {
                HttpHandler = new SocketsHttpHandler
                {
                    ConnectTimeout = TimeSpan.FromSeconds(5),
                    SslOptions = GetSslClientAuthenticationOptions(),
                },
                LoggerFactory = loggerFactory,
            });

            _logger.LogInformation("Connecting to upstream service at {Url}", RemoteUrl);
            await _channel.ConnectAsync(cancellationToken);
        }

        cancellationToken.ThrowIfCancellationRequested();

        _logger.LogTrace("Acquiring connect lock");
        await _connectLock.WaitAsync(cancellationToken);
        _logger.LogTrace("Obtained connect lock");

        try
        {
            var accountClient = new AccountService.AccountServiceClient(_channel);
            IAccountConfiguration? configuredAccount = _configuration.FindAccount(RemoteUrl);
            if (configuredAccount == null)
            {
                _logger.LogInformation("No account information saved for {Url}, creating new account", RemoteUrl);
                var createAccountReply = await accountClient.CreateAccountAsync(new CreateAccountRequest(),
                    headers: UnauthorizedHeaders(), deadline: DateTime.UtcNow.AddSeconds(10),
                    cancellationToken: cancellationToken);
                if (createAccountReply.Success)
                {
                    if (!Guid.TryParse(createAccountReply.AccountId, out Guid accountId))
                        throw new InvalidOperationException("invalid account id returned");

                    configuredAccount = _configuration.CreateAccount(RemoteUrl, accountId);
                    _logger.LogInformation("Account created with id {AccountId}", accountId.ToPartialId());

                    _configurationManager.Save(_configuration);
                }
                else
                {
                    _logger.LogError("Account creation failed with error {Error}", createAccountReply.Error);
                    if (createAccountReply.Error == CreateAccountError.UpgradeRequired && !_warnedAboutUpgrade)
                    {
                        _chat.Error(Localization.ConnectionError_OldVersion);
                        _warnedAboutUpgrade = true;
                    }

                    return (false,
                        string.Format(Localization.ConnectionError_CreateAccountFailed, createAccountReply.Error),
                        false);
                }
            }

            cancellationToken.ThrowIfCancellationRequested();

            // ReSharper disable once ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
            if (configuredAccount == null)
            {
                _logger.LogWarning("No account to login with");
                return (false, Localization.ConnectionError_CreateAccountReturnedNoId, false);
            }

            if (!_loginInfo.IsValid)
            {
                _logger.LogInformation("Logging in with account id {AccountId}",
                    configuredAccount.AccountId.ToPartialId());
                LoginReply loginReply = await accountClient.LoginAsync(
                    new LoginRequest { AccountId = configuredAccount.AccountId.ToString() },
                    headers: UnauthorizedHeaders(), deadline: DateTime.UtcNow.AddSeconds(10),
                    cancellationToken: cancellationToken);

                if (loginReply.Success)
                {
                    _logger.LogInformation("Login successful with account id: {AccountId}",
                        configuredAccount.AccountId.ToPartialId());
                    _loginInfo = new LoginInfo(loginReply.AuthToken);

                    bool save = configuredAccount.EncryptIfNeeded();

                    List<string> newRoles = _loginInfo.Claims?.Roles.ToList() ?? new();
                    if (!newRoles.SequenceEqual(configuredAccount.CachedRoles))
                    {
                        configuredAccount.CachedRoles = newRoles;
                        save = true;
                    }

                    if (save)
                        _configurationManager.Save(_configuration);
                }
                else
                {
                    _logger.LogError("Login failed with error {Error}", loginReply.Error);
                    _loginInfo = new LoginInfo(null);
                    if (loginReply.Error == LoginError.InvalidAccountId)
                    {
                        _configuration.RemoveAccount(RemoteUrl);
                        _configurationManager.Save(_configuration);

                        _logger.LogInformation("Attempting connection retry without account id");
                        return (false, Localization.ConnectionError_InvalidAccountId, true);
                    }

                    if (loginReply.Error == LoginError.UpgradeRequired && !_warnedAboutUpgrade)
                    {
                        _chat.Error(Localization.ConnectionError_OldVersion);
                        _warnedAboutUpgrade = true;
                    }

                    return (false, string.Format(Localization.ConnectionError_LoginFailed, loginReply.Error),
                        false);
                }
            }

            if (!_loginInfo.IsValid)
            {
                _logger.LogError("Login state is loggedIn={LoggedIn}, expired={Expired}", _loginInfo.IsLoggedIn,
                    _loginInfo.IsExpired);
                return (false, Localization.ConnectionError_LoginReturnedNoToken, false);
            }

            cancellationToken.ThrowIfCancellationRequested();
            return (true, string.Empty, false);
        }
        finally
        {
            _logger.LogTrace("Releasing connectLock");
            _connectLock.Release();
        }
    }

    private async Task<bool> Connect(CancellationToken cancellationToken)
    {
        var result = await TryConnect(cancellationToken);
        return result.Success;
    }

    public async Task<string> VerifyConnection(CancellationToken cancellationToken = default)
    {
        using IDisposable? logScope = _logger.BeginScope("VerifyConnection");

        _warnedAboutUpgrade = false;

        var connectionResult = await TryConnect(cancellationToken, loggerFactory: _loggerFactory);
        if (!connectionResult.Success)
            return string.Format(Localization.ConnectionError_CouldNotConnectToServer, connectionResult.Error);

        _logger.LogInformation("Connection established, trying to verify auth token");
        var accountClient = new AccountService.AccountServiceClient(_channel);
        await accountClient.VerifyAsync(new VerifyRequest(), headers: AuthorizedHeaders(),
            deadline: DateTime.UtcNow.AddSeconds(10), cancellationToken: cancellationToken);

        _logger.LogInformation("Verification returned no errors.");
        return Localization.ConnectionSuccessful;
    }

    internal sealed class LoginInfo
    {
        public LoginInfo(string? authToken)
        {
            if (!string.IsNullOrEmpty(authToken))
            {
                IsLoggedIn = true;
                AuthToken = authToken;
                Claims = JwtClaims.FromAuthToken(authToken);
            }
            else
                IsLoggedIn = false;
        }

        public bool IsLoggedIn { get; }
        public string? AuthToken { get; }
        public JwtClaims? Claims { get; }

        private DateTimeOffset ExpiresAt =>
            Claims?.ExpiresAt.Subtract(TimeSpan.FromMinutes(5)) ?? DateTimeOffset.MinValue;

        public bool IsExpired => ExpiresAt < DateTimeOffset.UtcNow;

        public bool IsValid => IsLoggedIn && !IsExpired;
    }
}