Handle V3 error response (#144)

Author: Gekctek

src/Agent/API.xml

@@ -103,13 +103,25 @@ public async Task<CandidArg> CallAsync(
 			byte[] cborBytes = await httpResponse.GetContentAsync();
 			var reader = new CborReader(cborBytes);
 			V3CallResponse v3CallResponse = V3CallResponse.ReadCbor(reader);
+			Certificate certificate;
+			switch (v3CallResponse.Status)
+			{
+				case V3CallResponse.StatusType.Replied:
+					certificate = v3CallResponse.AsReplied();
+					break;
+				case V3CallResponse.StatusType.NonReplicatedRejection:
+					CallRejectedResponse callRejectedResponse = v3CallResponse.AsNonReplicatedRejection();
+					throw new CallRejectedException(callRejectedResponse.Code, callRejectedResponse.Message, callRejectedResponse.ErrorCode);
+				default:
+					throw new NotImplementedException($"Invalid v3 call response status '{v3CallResponse.Status}'");
+			}
 
 			SubjectPublicKeyInfo rootPublicKey = await this.GetRootKeyAsync(cancellationToken);
-			if (!v3CallResponse.Certificate.IsValid(this.bls, rootPublicKey))
+			if (!certificate.IsValid(this.bls, rootPublicKey))
 			{
 				throw new InvalidCertificateException("Certificate signature does not match the IC public key");
 			}
-			HashTree? requestStatusData = v3CallResponse.Certificate.Tree.GetValueOrDefault(StatePath.FromSegments("request_status", requestId.RawValue));
+			HashTree? requestStatusData = certificate.Tree.GetValueOrDefault(StatePath.FromSegments("request_status", requestId.RawValue));
 			RequestStatus? requestStatus = ParseRequestStatus(requestStatusData);
 			switch (requestStatus?.Type)
 			{

src/Agent/Agents/HttpAgent.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Formats.Cbor;
 using EdjCase.ICP.Agent.Models;
@@ -9,35 +10,63 @@ namespace EdjCase.ICP.Agent.Responses
 	/// <summary>
 	/// Model for a reponse to a read state request
 	/// </summary>
-	public class V3CallResponse
+	internal class V3CallResponse
 	{
+		public enum StatusType
+		{
+			/// <summary>
+			/// The request has been processed and it has reply data
+			/// </summary>
+			Replied,
+			NonReplicatedRejection
+		}
+
+
 		/// <summary>
-		/// The status of the call ('replied', 'rejected', 'done)
+		/// The status of the call ('replied', 'non_replicated_rejection')
 		/// </summary>
-		public string Status { get; }
+		public StatusType Status { get; }
+
+		private object? value { get; }
+
+		/// <param name="status">The status of the call ('replied', 'non_replicated_rejection')</param>
+		/// <param name="value">The certificate data of the current canister state</param>
+		private V3CallResponse(StatusType status, object? value)
+		{
+			this.Status = status;
+			this.value = value;
+		}
+
 		/// <summary>
-		/// The certificate data of the current canister state
+		///	Returns the 'replied' certificate IF the status is 'replied', otherwise throws exception
 		/// </summary>
-		public Certificate Certificate { get; }
+		public Certificate AsReplied()
+		{
+			this.ValidateType(StatusType.Replied);
+			return (Certificate)this.value!;
+		}
 
-		/// <param name="status">The status of the call ('replied', 'rejected', 'done)</param>
-		/// <param name="certificate">The certificate data of the current canister state</param>
-		/// <exception cref="ArgumentNullException"></exception>
-		public V3CallResponse(string status, Certificate certificate)
+		public CallRejectedResponse AsNonReplicatedRejection()
 		{
-			this.Status = status ?? throw new ArgumentNullException(nameof(status));
-			this.Certificate = certificate ?? throw new ArgumentNullException(nameof(certificate));
+			this.ValidateType(StatusType.NonReplicatedRejection);
+			return (CallRejectedResponse)this.value!;
 		}
 
+		private void ValidateType(StatusType type)
+		{
+			if (this.Status != type)
+			{
+				throw new InvalidOperationException($"Expected status '{type}' but was '{this.Status}'");
+			}
+		}
 
 		internal static V3CallResponse ReadCbor(CborReader reader)
 		{
 			if (reader.ReadTag() != CborTag.SelfDescribeCbor)
 			{
 				throw new CborContentException("Expected self describe tag");
 			}
-			Certificate? certificate = null;
-			string? status = null;
+			Dictionary<string, object> map = new ();
 			reader.ReadStartMap();
 			while (reader.PeekState() != CborReaderState.EndMap)
 			{
@@ -46,10 +75,19 @@ internal static V3CallResponse ReadCbor(CborReader reader)
 				{
 					case "certificate":
 						var certReader = new CborReader(reader.ReadByteString());
-						certificate = Certificate.FromCbor(certReader);
+						map["certificate"] = Certificate.FromCbor(certReader);
 						break;
 					case "status":
-						status = reader.ReadTextString();
+						map["status"] = reader.ReadTextString();
+						break;
+					case "reject_code":
+						map["reject_code"] = (RejectCode)reader.ReadUInt64();
+						break;
+					case "reject_message":
+						map["reject_message"] = reader.ReadTextString();
+						break;
+					case "error_code":
+						map["error_code"] = reader.ReadTextString();
 						break;
 					default:
 						Debug.WriteLine($"Unknown field '{field}' in v3 call response");
@@ -59,17 +97,30 @@ internal static V3CallResponse ReadCbor(CborReader reader)
 			}
 			reader.ReadEndMap();
 
-			if (status == null)
+			if (map["status"] == null)
 			{
 				throw new CborContentException("Missing field: status");
 			}
+			StatusType status = Enum.Parse<StatusType>((string)map["status"], true);
 
-			if (certificate == null)
+			switch (status)
 			{
-				throw new CborContentException("Missing field: certificate");
+				case StatusType.Replied:
+					Certificate? certificate = map["certificate"] as Certificate;
+					if (certificate == null)
+					{
+						throw new CborContentException("Missing field: certificate");
+					}
+					return new V3CallResponse(status, certificate);
+				case StatusType.NonReplicatedRejection:
+					RejectCode rejectCode = (RejectCode)(map["reject_code"] ?? throw new CborContentException("Missing field: reject_code"));
+					string message = (string)(map["reject_message"] ?? throw new CborContentException("Missing field: reject_message"));
+					string? errorCode = (string?)map["error_code"];
+					CallRejectedResponse? rejectedResponse = new CallRejectedResponse(rejectCode, message, errorCode);
+					return new V3CallResponse(status, rejectedResponse);
+				default:
+					throw new NotImplementedException($"Unknown status '{status}' in v3 call response");
 			}
-
-			return new V3CallResponse(status, certificate);
 		}
 	}
-}
+}