[#28] Client: Apply code optimizations

Signed-off-by: Pavel Gross <p.gross@yadro.com>

src/FrostFS.SDK.Client/Models/Session/FrostFsSessionToken.cs

@@ -1,9 +1,117 @@
 using System;
 
+using FrostFS.Refs;
+
+using FrostFS.SDK.Client;
+using FrostFS.SDK.Cryptography;
+using FrostFS.Session;
+
+using Google.Protobuf;
+
 namespace FrostFS.SDK;
 
-public class FrostFsSessionToken(byte[] token, Guid id)
+public class FrostFsSessionToken
 {
-    public Guid Id { get; private set; } = id;
-    public byte[] Token { get; private set; } = token;
+    private Guid _id;
+    private ReadOnlyMemory<byte> _sessionKey;
+    private readonly SessionToken.Types.Body _body;
+
+    private FrostFsSessionToken()
+    {
+        ProtoId = ByteString.Empty;
+        ProtoSessionKey = ByteString.Empty;
+        _body = new SessionToken.Types.Body();
+    }
+
+    internal FrostFsSessionToken(SessionToken token)
+    {
+        ProtoId = token.Body.Id;
+        ProtoSessionKey = token.Body.SessionKey;
+
+        _body = token.Body;
+    }
+
+    public Guid Id
+    {
+        get
+        {
+            if (_id == Guid.Empty)
+                _id = ProtoId.ToUuid();
+
+            return _id;
+        }
+    }
+
+    public ReadOnlyMemory<byte> SessionKey
+    {
+        get
+        {
+            if (_sessionKey.IsEmpty)
+                _sessionKey = ProtoSessionKey.Memory;
+
+            return _sessionKey;
+        }
+    }
+
+    internal ByteString ProtoId { get; }
+
+    internal ByteString ProtoSessionKey { get; }
+
+    public SessionToken CreateContainerToken(ContainerID? containerId, ContainerSessionContext.Types.Verb verb, ClientKey key)
+    {
+        if (key is null)
+        {
+            throw new ArgumentNullException(nameof(key));
+        }
+
+        SessionToken sessionToken = new() { Body = _body.Clone() };
+
+        sessionToken.Body.Container = new() { Verb = verb };
+
+        if (containerId != null)
+            sessionToken.Body.Container.ContainerId = containerId;
+        else
+            sessionToken.Body.Container.Wildcard = true;
+
+        sessionToken.Body.SessionKey = key.PublicKeyProto;
+
+        sessionToken.Signature = key.ECDsaKey.SignMessagePart(sessionToken.Body);
+
+        return sessionToken;
+    }
+
+    public SessionToken CreateObjectTokenContext(Address address, ObjectSessionContext.Types.Verb verb, ClientKey key)
+    {
+        if (address is null)
+        {
+            throw new ArgumentNullException(nameof(address));
+        }
+
+        if (key is null)
+        {
+            throw new ArgumentNullException(nameof(key));
+        }
+
+        SessionToken sessionToken = new()
+        {
+            Body = _body.Clone()
+        };
+
+        ObjectSessionContext.Types.Target target = new() { Container = address.ContainerId };
+
+        if (address.ObjectId != null)
+            target.Objects.Add(address.ObjectId);
+
+        sessionToken.Body.Object = new()
+        {
+            Target = target,
+            Verb = verb
+        };
+
+        sessionToken.Body.SessionKey = key.PublicKeyProto;
+
+        sessionToken.Signature = key.ECDsaKey.SignMessagePart(sessionToken.Body);
+
+        return sessionToken;
+    }
 }