From bcd694a75bca62064d5ef10cb5dfe47dc4f5d0f6 Mon Sep 17 00:00:00 2001
From: "nobu.maeda" <nobu.maeda@proton.me>
Date: Tue, 2 Jan 2024 23:41:36 +0800
Subject: [PATCH] Offer Reject will currently fail without Trade Engine
 Specifics. Automatically place in a placeholder in that case

---
 src/common/types.rs      | 10 ++++++++++
 src/trade_rsp/builder.rs | 19 ++++++++++++-------
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/common/types.rs b/src/common/types.rs
index 84892ef..0325c20 100644
--- a/src/common/types.rs
+++ b/src/common/types.rs
@@ -36,6 +36,16 @@ impl dyn SerdeGenericTrait {
     }
 }
 
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub(crate) struct SerdeGenericsPlaceholder {}
+
+#[typetag::serde(name = "n3xB-placeholder")]
+impl SerdeGenericTrait for SerdeGenericsPlaceholder {
+    fn any_ref(&self) -> &dyn Any {
+        self
+    }
+}
+
 #[derive(
     Serialize, Deserialize, PartialEq, Eq, Hash, Clone, Debug, EnumString, Display, IntoStaticStr,
 )]
diff --git a/src/trade_rsp/builder.rs b/src/trade_rsp/builder.rs
index 2e1b731..55b16c1 100644
--- a/src/trade_rsp/builder.rs
+++ b/src/trade_rsp/builder.rs
@@ -1,6 +1,6 @@
 use crate::common::{
     error::{N3xbError, OfferInvalidReason},
-    types::{EventIdString, SerdeGenericTrait},
+    types::{EventIdString, SerdeGenericTrait, SerdeGenericsPlaceholder},
 };
 
 use super::{TradeResponse, TradeResponseStatus};
@@ -47,11 +47,13 @@ impl TradeResponseBuilder {
 
     pub fn build(&self) -> Result<TradeResponse, N3xbError> {
         let Some(offer_event_id) = self.offer_event_id.as_ref() else {
-            return Err(N3xbError::Simple("No Offer Event ID defined".to_string()));  // TODO: Error handling?
+            return Err(N3xbError::Simple("No Offer Event ID defined".to_string()));
+            // TODO: Error handling?
         };
 
         let Some(trade_response) = self.trade_response.as_ref() else {
-            return Err(N3xbError::Simple("No Trade Response defined".to_string()));  // TODO: Error handling?
+            return Err(N3xbError::Simple("No Trade Response defined".to_string()));
+            // TODO: Error handling?
         };
 
         let trade_response = trade_response.to_owned();
@@ -60,15 +62,18 @@ impl TradeResponseBuilder {
             // TODO: Error handling?
         }
 
-        let Some(trade_engine_specifics) = self.trade_engine_specifics.as_ref() else {
-            return Err(N3xbError::Simple("No Trade Engine Specifics defined".to_string()));
-        };
+        let trade_engine_specifics =
+            if let Some(trade_engine_specifics) = self.trade_engine_specifics.as_ref() {
+                trade_engine_specifics.to_owned()
+            } else {
+                Box::new(SerdeGenericsPlaceholder {})
+            };
 
         let trade_rsp = TradeResponse {
             offer_event_id: offer_event_id.to_owned(),
             trade_response: trade_response,
             reject_reason: self.reject_reason.to_owned(),
-            trade_engine_specifics: trade_engine_specifics.to_owned(),
+            trade_engine_specifics: trade_engine_specifics,
         };
 
         Ok(trade_rsp)