network-resurrector/NetworkResurrector.Application/Services/UserService.cs

using NetworkResurrector.Application.Stores;
using NetworkResurrector.Domain.Entities;
using NetworkResurrector.Domain.Models;
using NetworkResurrector.Domain.Services;
using System;
using System.Linq;
using System.Threading.Tasks;

namespace NetworkResurrector.Application.Services
{
    public interface IUserService
    {
        Task<SecurityToken> Login(string userName, string password);
        Task<User> Authenticate(string token);
    }

    public class UserService : IUserService
    {
        private readonly IParamProvider _paramProvider;
        private readonly ISecurityStore _securityStore;

        public UserService(IParamProvider paramProvider, ISecurityStore securityStore)
        {
            _paramProvider = paramProvider;
            _securityStore = securityStore;
        }

        public async Task<SecurityToken> Login(string userName, string password)
        {
            var user = _paramProvider.Users.FirstOrDefault(z => z.UserName == userName && z.Password == password);
            if (user == null)
                return null;

            var token = $"{Guid.NewGuid()}-{Guid.NewGuid()}-{user.UserId}";
            _securityStore.SetToken(token, user.UserId);

            var securityToken = new SecurityToken() { UserId = user.UserId, Token = token };
            return securityToken;
        }

        public async Task<User> Authenticate(string token)
        {
            var tokenValidation = _securityStore.ValidateToken(token);
            if (tokenValidation.Success)
            {
                var user = _paramProvider.Users.FirstOrDefault(z => z.UserId == tokenValidation.UserId);
                if (user != null)
                    return user;
            }

            return null;
        }
    }
}