massive work on user auth

SurveyBackend/SurveyBackend.Infrastructure/Helpers/TokenHelper.cs

@@ -0,0 +1,31 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Claims;
+using Microsoft.IdentityModel.Tokens;
+using SurveyBackend.Core.Models;
+
+namespace SurveyBackend.Infrastructure.Helpers;
+
+public class TokenHelper
+{
+    public static string GetAuthToken(User user)
+    {
+        var userId = user.Id.ToString();
+
+        var claims = new List<Claim>
+        {
+            new(ClaimTypes.NameIdentifier, userId)
+        };
+
+        var jwt = new JwtSecurityToken(
+            claims: claims,
+            issuer: AuthOptions.Issuer,
+            audience: AuthOptions.Audience,
+            expires: DateTime.UtcNow + AuthOptions.TokenLifetime,
+            signingCredentials: new SigningCredentials(AuthOptions.SymmetricSecurityKey, SecurityAlgorithms.HmacSha256)
+        );
+
+        var token = new JwtSecurityTokenHandler().WriteToken(jwt);
+
+        return token;
+    }
+}