feat: add pre-auth service

Security/Services/PreAuthService.cs

@@ -0,0 +1,42 @@
+using Mirea.Api.Security.Common.Domain;
+using Mirea.Api.Security.Common.Dto.Requests;
+using Mirea.Api.Security.Common.Dto.Responses;
+using Mirea.Api.Security.Common.Interfaces;
+using System;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Mirea.Api.Security.Services;
+
+public class PreAuthService(ICacheService cache)
+{
+    public TimeSpan Lifetime { private get; init; }
+
+    private static string GenerateFirstAuthToken() => Guid.NewGuid().ToString().Replace("-", "");
+
+    public async Task<PreAuthTokenResponse> CreateLoginTokenAsync(TokenRequest request, string userId, CancellationToken cancellation = default)
+    {
+        var firstAuthToken = GenerateFirstAuthToken();
+
+        var loginStructure = new PreAuthToken
+        {
+            Fingerprint = request.Fingerprint,
+            UserId = userId,
+            UserAgent = request.UserAgent,
+            Token = firstAuthToken
+        };
+
+        await cache.SetAsync(
+            request.Fingerprint,
+            JsonSerializer.SerializeToUtf8Bytes(loginStructure),
+            Lifetime,
+            cancellation);
+
+        return new PreAuthTokenResponse
+        {
+            Token = firstAuthToken,
+            ExpiresIn = DateTime.UtcNow.Add(Lifetime)
+        };
+    }
+}