From 1170e2f093ec2a2f70a56eda22d3721c6063ddc4 Mon Sep 17 00:00:00 2001
From: goncalo-frade-iohk
 <87179681+goncalo-frade-iohk@users.noreply.github.com>
Date: Mon, 19 Dec 2022 12:43:09 +0000
Subject: [PATCH] feat(mercury): forward messaging to mediator (#264)

* feat(mercury): forward messaging to mediator

* Update mercury/mercury-library/agent-didcommx/src/main/scala/io/iohk/atala/mercury/MessagingService.scala

Co-authored-by: Yurii Shynbuiev - IOHK <102033808+yshyn-iohk@users.noreply.github.com>

Co-authored-by: Fabio Pinheiro <fabiomgpinheiro@gmail.com>
Co-authored-by: Yurii Shynbuiev - IOHK <102033808+yshyn-iohk@users.noreply.github.com>
---
 .../iohk/atala/mercury/MessagingService.scala | 57 +++++++++++++++----
 .../mercury/model/AttachmentDescriptor.scala  |  9 +++
 2 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/mercury/mercury-library/agent-didcommx/src/main/scala/io/iohk/atala/mercury/MessagingService.scala b/mercury/mercury-library/agent-didcommx/src/main/scala/io/iohk/atala/mercury/MessagingService.scala
index 60aed93aed..b5664f75c6 100644
--- a/mercury/mercury-library/agent-didcommx/src/main/scala/io/iohk/atala/mercury/MessagingService.scala
+++ b/mercury/mercury-library/agent-didcommx/src/main/scala/io/iohk/atala/mercury/MessagingService.scala
@@ -3,8 +3,13 @@ package io.iohk.atala.mercury
 import scala.jdk.CollectionConverters.*
 import zio._
 
+import io.circe._
+import io.circe.Json._
+import io.circe.parser._
+import io.circe.JsonObject
 import io.iohk.atala.mercury.model._
 import io.iohk.atala.mercury.model.error._
+import io.iohk.atala.mercury.protocol.routing._
 import io.iohk.atala.resolvers.DIDResolver
 import org.didcommx.didcomm.common.VerificationMethodType
 import org.didcommx.didcomm.common.VerificationMaterialFormat
@@ -14,6 +19,31 @@ case class ServiceEndpoint(uri: HttpOrDID, accept: Option[Seq[String]], routingK
 
 object MessagingService {
 
+  def isForwardMessage[Service <: DidComm, Resolver <: DIDResolver](
+    didCommService:  Service,
+    resolver: Resolver,
+    didCommServiceEndpoint: ServiceEndpoint,
+    message: Message, 
+    encrypted: EncryptedMessage): ZIO[Any, Throwable, EncryptedMessage] = {
+  if (didCommServiceEndpoint.uri.startsWith("did:")) {
+for { 
+    _ <- Console.printLine("RoutingDID:" + DidId(didCommServiceEndpoint.uri))
+    forwardMessage <- didCommService.packEncrypted(
+        ForwardMessage(
+          from = message.from.get,
+          to = DidId(didCommServiceEndpoint.uri),
+          expires_time = None,
+          body = ForwardBody(next = message.to.head), // TODO check msg header
+          attachments = Seq(AttachmentDescriptor.buildJsonAttachment(payload = encrypted.asJson)),
+        ).asMessage,
+        to = DidId(didCommServiceEndpoint.uri)
+      )
+} yield forwardMesage
+  } else {
+    ZIO.succeed(encrypted)
+  }
+}
+
   /** Encrypt and send a Message via HTTP
     *
     * TODO Move this method to another model
@@ -30,11 +60,10 @@ object MessagingService {
         case head +: tail => // TODO support for multiple destinations
           ZIO.fail(new RuntimeException("TODO multiple destinations"))
       }
+      _ <- Console.printLine("Encrypted Message")
+      encryptedMessage <- didCommService.packEncrypted(msg, to = msg.to.head) // TODO head
 
-      encryptedForwardMessage <- didCommService.packEncryptedForward(msg, to = msg.to.head) // TODO head
-      jsonString = encryptedForwardMessage.string
-
-      didCommService <- resolver
+      didCommServiceUrl <- resolver
         .didCommServices(sendToDID) /* Seq[DIDCommService] */
         .flatMap {
           case Seq() =>
@@ -57,14 +86,18 @@ object MessagingService {
                 )
               )
         }
-      serviceEndpoint <-
-        if (didCommService.uri.startsWith("did:"))
-          resolver
-            .didCommServices(DidId(didCommService.uri))
-            .map(_.toSeq.head.getServiceEndpoint()) // TODO this is not safe and also need to be recursive
-        else ZIO.succeed(didCommService.uri)
-
-      _ <- Console.printLine("Sending to " + serviceEndpoint)
+       _ <- Console.printLine("Forward message")
+      sendMsg = isForwardMessage(didCommService, resolver, didCommServiceUrl, msg, encryptedMessage)
+      jsonString <- sendMsg.map(_.string)
+
+      serviceEndpoint <- if (didCommServiceUrl.uri.startsWith("did:"))
+           resolver
+             .didCommServices(DidId(didCommServiceUrl.uri))
+             .map(_.toSeq.head.getServiceEndpoint()) // TODO this is not safe and also need to be recursive
+         else ZIO.succeed(didCommServiceUrl.uri)
+
+      _ <- Console.printLine("Sending to" + serviceEndpoint)
+
       res <- HttpClient.postDIDComm(serviceEndpoint, jsonString)
     } yield (res)
   }.catchAll { case ex =>
diff --git a/mercury/mercury-library/models/src/main/scala/io/iohk/atala/mercury/model/AttachmentDescriptor.scala b/mercury/mercury-library/models/src/main/scala/io/iohk/atala/mercury/model/AttachmentDescriptor.scala
index a6031e4725..d7b676521b 100644
--- a/mercury/mercury-library/models/src/main/scala/io/iohk/atala/mercury/model/AttachmentDescriptor.scala
+++ b/mercury/mercury-library/models/src/main/scala/io/iohk/atala/mercury/model/AttachmentDescriptor.scala
@@ -111,6 +111,15 @@ object AttachmentDescriptor {
     AttachmentDescriptor(id, mediaType, Base64(encoded)) // use JsonData or Base64 by default?
   }
 
+  def buildJsonAttachment[A](
+      id: String = java.util.UUID.randomUUID.toString,
+      payload: A,
+      mediaType: Option[String] = Some("application/json")
+  )(using Encoder[A]): AttachmentDescriptor = {
+    val jsonObject = payload.asJson.asObject.getOrElse(JsonObject.empty)
+    AttachmentDescriptor(id, mediaType, JsonData(jsonObject)) // use JsonData or Base64 by default?
+  }
+
   given attachmentDescriptorEncoderV1: Encoder[AttachmentDescriptor] = (a: AttachmentDescriptor) => {
     Json.obj(
       "@id" -> a.id.asJson,