Apply a timeshift from the server when initializing IntentSender to better resolve time out of sync error (#219)

Author: BellringerQuinn

Assets/SequenceSDK/WaaS/Tests/IntentSenderTests.cs

@@ -164,6 +164,11 @@ public async Task<T2> SendRequest<T, T2>(string path, T args, Dictionary<string,
                 string responseJson = JsonConvert.SerializeObject(response);
                 return JsonConvert.DeserializeObject<T2>(responseJson);
             }
+
+            public async Task<TimeSpan> GetTimeShift()
+            {
+                return TimeSpan.Zero;
+            }
         }
 
         private class MockHttpClientReturnsUnknownCode : IHttpClient
@@ -177,6 +182,11 @@ public async Task<T2> SendRequest<T, T2>(string path, T args, Dictionary<string,
                 string responseJson = JsonConvert.SerializeObject(response);
                 return JsonConvert.DeserializeObject<T2>(responseJson);
             }
+
+            public async Task<TimeSpan> GetTimeShift()
+            {
+                return TimeSpan.Zero;
+            }
         }
 
         private class MockHttpClientReturnsSuccessfulTransaction : IHttpClient
@@ -190,6 +200,11 @@ public async Task<T2> SendRequest<T, T2>(string path, T args, Dictionary<string,
                 string responseJson = JsonConvert.SerializeObject(response);
                 return JsonConvert.DeserializeObject<T2>(responseJson);
             }
+
+            public async Task<TimeSpan> GetTimeShift()
+            {
+                return TimeSpan.Zero;
+            }
         }
 
         [Serializable]

Packages/Sequence-Unity/Sequence/SequenceSDK/EmbeddedWallet/DataTypes/ParameterTypes/IntentPayload.cs

@@ -11,15 +11,15 @@ namespace Sequence.EmbeddedWallet
     public class IntentPayload
     {
         public JObject data;
-        public uint expiresAt;
-        public uint issuedAt;
+        public ulong expiresAt;
+        public ulong issuedAt;
         public string name;
         public Signature[] signatures;
         public string version;
 
         [Preserve]
         [JsonConstructor]
-        public IntentPayload(string version, string name, uint expiresAt, uint issuedAt, JObject data, Signature[] signatures)
+        public IntentPayload(string version, string name, ulong expiresAt, ulong issuedAt, JObject data, Signature[] signatures)
         {
             this.version = version;
             this.name = name;
@@ -29,7 +29,7 @@ public IntentPayload(string version, string name, uint expiresAt, uint issuedAt,
             this.signatures = signatures;
         }
 
-        public IntentPayload(string version, IntentType name, uint expiresAt, uint issuedAt, JObject data, Signature[] signatures)
+        public IntentPayload(string version, IntentType name, ulong expiresAt, ulong issuedAt, JObject data, Signature[] signatures)
         {
             this.version = version;
             this.name = IntentNames[name];
@@ -39,7 +39,7 @@ public IntentPayload(string version, IntentType name, uint expiresAt, uint issue
             this.signatures = signatures;
         }
 
-        public IntentPayload(string version, IntentType type, JObject data, Signature[] signatures, uint timeBeforeExpiryInSeconds = 30, uint currentTime = 0)
+        public IntentPayload(string version, IntentType type, JObject data, Signature[] signatures, uint timeBeforeExpiryInSeconds = 30, ulong currentTime = 0)
         {
             this.version = version;
             this.name = IntentNames[type];

Packages/Sequence-Unity/Sequence/SequenceSDK/EmbeddedWallet/HttpClient.cs

@@ -238,6 +238,30 @@ public async Task<T2> SendRequest<T, T2>(string path, T args, [CanBeNull] Dictio
             }
         }
 
+        public async Task<TimeSpan> GetTimeShift()
+        {
+            UnityWebRequest request = UnityWebRequest.Get(_waasUrl.AppendTrailingSlashIfNeeded() + "status");
+            request.method = UnityWebRequest.kHttpVerbGET;
+
+            try
+            {
+                await request.SendWebRequest();
+                DateTime serverTime = DateTime.Parse(request.GetResponseHeader("date")).ToUniversalTime();
+                DateTime localTime = DateTime.UtcNow;
+                TimeSpan timeShift = serverTime - localTime;
+                return timeShift;
+            }
+            catch (Exception e)
+            {
+                Debug.LogError("Error getting time shift: " + e.Message);
+                return TimeSpan.Zero;
+            }
+            finally
+            {
+                request.Dispose();
+            }
+        }
+
         private string GetRequestErrorIfAvailable(UnityWebRequest request)
         {
             if (request.downloadHandler != null && request.downloadHandler.data != null)

Packages/Sequence-Unity/Sequence/SequenceSDK/EmbeddedWallet/IHttpClient.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
@@ -8,5 +9,7 @@ public interface IHttpClient
     {
         public Task<T2> SendRequest<T, T2>(string path, T args,
             [CanBeNull] Dictionary<string, string> headers = null, string overrideUrl = null);
+
+        public Task<TimeSpan> GetTimeShift();
     }
 }

Packages/Sequence-Unity/Sequence/SequenceSDK/EmbeddedWallet/IntentSender.cs

@@ -19,6 +19,8 @@ public class IntentSender : IIntentSender
         private int _waasProjectId;
         private string _waasVersion;
         private string _sessionId;
+        private TimeSpan _timeshift;
+        private bool _ready = false;
 
         private JsonSerializerSettings serializerSettings = new JsonSerializerSettings
         {
@@ -33,6 +35,13 @@ public IntentSender(IHttpClient httpClient, Sequence.Wallet.IWallet sessionWalle
             _waasProjectId = waasProjectId;
             _waasVersion = waasVersion;
             _sessionId = IntentDataOpenSession.CreateSessionId(_sessionWallet.GetAddress());
+            GetTimeShift().ConfigureAwait(false);
+        }
+        
+        private async Task GetTimeShift()
+        {
+            _timeshift = await _httpClient.GetTimeShift();
+            _ready = true;
         }
 
         public async Task<T> SendIntent<T, T2>(T2 args, IntentType type, uint timeBeforeExpiryInSeconds = 30, uint currentTime = 0)
@@ -68,11 +77,11 @@ public async Task<T> SendIntent<T, T2>(T2 args, IntentType type, uint timeBefore
                 long currentTimeAccordingToIntent = 0;
                 if (intentPayload is IntentPayload intent)
                 {
-                    currentTimeAccordingToIntent = intent.issuedAt;
+                    currentTimeAccordingToIntent = (long)intent.issuedAt;
                 }
                 else if (intentPayload is RegisterSessionIntent registerSessionIntent)
                 {
-                    currentTimeAccordingToIntent = registerSessionIntent.intent.issuedAt;
+                    currentTimeAccordingToIntent = (long)registerSessionIntent.intent.issuedAt;
                 }
                 else
                 {
@@ -116,8 +125,17 @@ private string AssemblePayloadJson<T>(T args)
             return JsonConvert.SerializeObject(args, serializerSettings);
         }
 
-        private async Task<object> AssembleIntentPayload(string payload, IntentType type, uint timeToLiveInSeconds, uint currentTime)
+        private async Task<object> AssembleIntentPayload(string payload, IntentType type, uint timeToLiveInSeconds, ulong currentTime)
         {
+            while (!_ready)
+            {
+                await Task.Yield();
+            }
+
+            if (currentTime == 0)
+            {
+                currentTime = (ulong)DateTimeOffset.UtcNow.Add(_timeshift).ToUnixTimeSeconds();
+            }
             JObject packet = JsonConvert.DeserializeObject<JObject>(payload);
             IntentPayload toSign = new IntentPayload(_waasVersion, type, packet, null, timeToLiveInSeconds, currentTime);
             string toSignJson = JsonConvert.SerializeObject(toSign, serializerSettings);