Validate login request and refactor login handling

API/Contracts/Profiles/Requests/LoginRequest.cs

@@ -1,12 +1,22 @@
-using RecNet.Domain.Common;
+using System.ComponentModel.DataAnnotations;
+using RecNet.Domain.Common;
 
 namespace API.Contracts.Profiles.Requests;
 
 public class LoginRequest
 {
+    [Required]
     public required string AppVersion { get; set; }
+    
+    [Required, StringLength(128, MinimumLength = 1)]
     public required string DeviceId { get; set; }
+    
+    [Required]
     public required string PlatformAuthentication { get; set; }
+    
+    [Required, StringLength(50, MinimumLength = 1)]
     public required string PlatformId { get; set; }
+    
+    [EnumDataType(typeof(PlatformType))]
     public PlatformType PlatformType { get; set; }
 }

RecNet.Application/Profiles/ProfileService.cs

@@ -68,10 +68,7 @@ public class ProfileService(
         if (profile.IsBanned)
             return LoginProfileResult.Fail("Profile is banned");
         
-        if (auth.Name is not null && profile.Name != auth.Name)
-            profile.SetName(auth.Name);
-
-        profile.AddDeviceId(command.DeviceId);
+        profile.RecordSuccessfulLogin(command.DeviceId, auth.Name);
 
         await profileRepository.SaveChangesAsync(ct);
 

RecNet.Domain/Profiles/Profile.cs

@@ -61,6 +61,14 @@ public class Profile
         DeviceIds.Add(deviceId);
     }
 
+    public void RecordSuccessfulLogin(string deviceId, string? platformName)
+    {
+        if (!string.IsNullOrWhiteSpace(platformName) && Name != platformName)
+            SetName(platformName);
+
+        AddDeviceId(deviceId);
+    }
+
     public void Ban()
         => IsBanned = true;
 

RecNet.Infrastructure/Services/Steam/SteamAuthValidator.cs

@@ -16,8 +16,18 @@ public class SteamAuthValidator(ISteamAuthService steamAuthService) : IPlatformA
         string platformId,
         CancellationToken ct = default)
     {
-        var steamParams = JsonSerializer.Deserialize<SteamPlatformAuth>(platformAuthentication);
-        if (steamParams == null)
+        SteamPlatformAuth? steamParams;
+
+        try
+        {
+            steamParams = JsonSerializer.Deserialize<SteamPlatformAuth>(platformAuthentication);
+        }
+        catch (JsonException)
+        {
+            return PlatformAuthResult.Failure("Invalid authentication");
+        }
+
+        if (steamParams?.AppId is null || string.IsNullOrWhiteSpace(steamParams.Ticket))
             return PlatformAuthResult.Failure("Invalid authentication");
         
         var result = await steamAuthService.AuthorizeAsync(steamParams.Ticket, steamParams.AppId.AppId, ct);