Project/Project.Application/Services/TwoFactorAuthService.cs

using Google.Authenticator;
using Microsoft.Extensions.Options;
using Project.Application.DTOs.TwoFactorAuth;
using Project.Application.Interfaces;
using Project.Application.Options;
using Project.Infrastructure.Interfaces;

namespace Project.Application.Services
{
    public class TwoFactorAuthService : ITwoFactorAuthService
    {
        // FIELDS FOR CTOR
        private readonly TwoFactorAuthenticator _twoFactorAuthenticator;
        private readonly ITwoFactorAuthRepository _twoFactorAuthRepository;
        private readonly string _issuer;

        // CTOR
        public TwoFactorAuthService(IOptions<AuthOptions> options, ITwoFactorAuthRepository twoFactorAuthRepository)
        {
            _twoFactorAuthenticator = new TwoFactorAuthenticator();
            _twoFactorAuthRepository = twoFactorAuthRepository;
            _issuer = options.Value.Issuer;
        }

        //public void TwoFactorAuthenticatorMethods()
        //{
        //    _twoFactorAuthenticator.Equals();
        //    _twoFactorAuthenticator.GeneratePINAtInterval();
        //    _twoFactorAuthenticator.GenerateSetupCode();
        //    _twoFactorAuthenticator.GetCurrentPIN();
        //    _twoFactorAuthenticator.GetCurrentPINs();
        //    _twoFactorAuthenticator.GetHashCode();
        //    _twoFactorAuthenticator.GetType();
        //    _twoFactorAuthenticator.ToString();
        //    _twoFactorAuthenticator.ValidateTwoFactorPIN();
        //}

        // GENERATE TWO FACTOR AUTH SETUP
        public async Task<TwoFactorSetupDto> GenerateSetupCodeAsync(string userEmail)
        {
            var userSecretKey = Guid.NewGuid().ToString();

            var setupInfo = _twoFactorAuthenticator.GenerateSetupCode(
                _issuer, // Envelope.Configuration.ApplicationName
                userEmail, // user.Email
                userSecretKey,
                false,
                10);

            string manualEntryKey = setupInfo.ManualEntryKey;
            string qrCodeImageUrl = setupInfo.QrCodeSetupImageUrl;

            await _twoFactorAuthRepository.SaveSecretKeyAsync(userEmail, userSecretKey);

            return new TwoFactorSetupDto
            {
                SecretKey = userSecretKey,
                QrCodeImageUrl = qrCodeImageUrl,
                ManualEntryKey = manualEntryKey
            };
        }

        // VALIDATE OTP
        public async Task<bool> ValidateCodeAsync(string userEmail, string userInputCode)
        {
            var secretKey = await _twoFactorAuthRepository.GetSecretKeyAsync(userEmail);

            if (string.IsNullOrEmpty(secretKey))
            {
                throw new InvalidOperationException("Secret key not found!");
            }

            return _twoFactorAuthenticator.ValidateTwoFactorPIN(secretKey, userInputCode);
        }

        //// SAVE SECRET KEY
        //public async Task SaveSecretKeyAsync(string userEmail, string userSecretKey)
        //{
        //    var user = await _twoFactorAuthRepository.GetUserByEmailAsync(userEmail);

        //    if (user == null)
        //    {
        //        throw new InvalidOperationException("User not found!");
        //    }

        //    await _twoFactorAuthRepository.SaveSecretKeyAsync(userEmail, userSecretKey);
        //}

        // GET SECRET KEY
        public async Task<string> GetSecretKeyAsync(string userEmail)
        {
            var secretKey = await _twoFactorAuthRepository.GetSecretKeyAsync(userEmail);

            return secretKey;
        }
    }
}