GreenTree.Nachtragsmanagement/GreenTree.Nachtragsmanagement.Core/Authentication/UserHelper.cs

using GreenTree.Nachtragsmanagement.Core.Domain.User;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;

namespace GreenTree.Nachtragsmanagement.Core.Authentication
{
    public class UserHelper : IUserHelper
    {
        /// <summary>
        /// Evaluates the current user from request cookies
        /// </summary>
        public User FromCookies()
        {
            return FromCookies(2);
        }

        /// <summary>
        /// Evaluates the current user from request cookies
        /// </summary>
        /// <param name="expirationHoursIncrease">The hours the authCookie will be increased if it exists.</param>
        public User FromCookies(int expirationHoursIncrease)
        {
            if (HttpContext.Current == null || HttpContext.Current.Session == null) return null;

            var authCookie = HttpContext.Current.Request.Cookies["auth"];

            if (authCookie == null)
                return null;

            var user = JsonConvert.DeserializeObject<User>(StaticHelper.DecompressString(authCookie.Value));

            if (user != null)
            {
                authCookie.Expires = DateTime.Now.AddHours(expirationHoursIncrease);

                HttpContext.Current.Response.Cookies.Set(authCookie);
            }

            return user;
        }

        /// <summary>
        /// Writes the current user to response cookies
        /// </summary>
        /// <param name="user">The current authenticated user.</param>
        /// <param name="expirationDate">The cookie expiration date.</param>
        public void ToCookies(User user, DateTime expirationDate)
        {
            if (HttpContext.Current == null || HttpContext.Current.Session == null) return;

            var authCookie = HttpContext.Current.Request.Cookies["auth"];

            var userJson = JsonConvert.SerializeObject(user);

            authCookie = new HttpCookie("auth", StaticHelper.CompressString(userJson))
            {
                Expires = expirationDate
            };

            HttpContext.Current.Response.Cookies.Set(authCookie);
        }

        /// <summary>
        /// Clears the authentication cookie
        /// </summary>
        public void ClearCookie()
        {
            if (HttpContext.Current == null || HttpContext.Current.Session == null) return;

            var authCookie = HttpContext.Current.Request.Cookies["auth"];

            authCookie.Expires = DateTime.Now.AddHours(-1);

            HttpContext.Current.Response.Cookies.Set(authCookie);
        }
    }
}