WIP making ClientCreate endpoint

IdentityShroud.Core/Services/ClientService.cs

@@ -0,0 +1,54 @@
+using System.Security.Cryptography;
+using IdentityShroud.Core.Contracts;
+using IdentityShroud.Core.Model;
+using Microsoft.EntityFrameworkCore;
+
+namespace IdentityShroud.Core.Services;
+
+public class ClientService(
+    Db db,
+    IEncryptionService cryptor,
+    IClock clock) : IClientService
+{
+    public async Task<Result<Client>> Create(Guid realmId, ClientCreateRequest request, CancellationToken ct = default)
+    {
+        Client client = new()
+        {
+            Id = Guid.NewGuid(),
+            RealmId = realmId,
+            ClientId = request.ClientId,
+            Name = request.Name,
+            Description = request.Description,
+            SignatureAlgorithm = request.SignatureAlgorithm,
+            AllowClientCredentialsFlow = request.AllowClientCredentialsFlow ?? false,
+            CreatedAt = clock.UtcNow(),
+        };
+        
+        if (client.AllowClientCredentialsFlow)
+        {
+            client.Secrets.Add(CreateSecret());
+        }
+
+        await db.AddAsync(client, ct);
+        await db.SaveChangesAsync(ct);
+
+        return client;
+    }
+
+    public async Task<Client?> GetByClientId(string clientId, CancellationToken ct = default)
+    {
+        return await db.Clients.FirstOrDefaultAsync(c => c.ClientId == clientId, ct);
+    }
+
+    private ClientSecret CreateSecret()
+    {
+        byte[] secret = RandomNumberGenerator.GetBytes(24);
+
+        return new ClientSecret()
+        {
+            CreatedAt = clock.UtcNow(),
+            SecretEncrypted = cryptor.Encrypt(secret),
+        };
+
+    }
+}