Feature/downcast reward estimation (#1031)

* Downcast u128 to u64

* fmt

* Fix status

* fmt

validator-api/src/node_status_api/routes.rs

@@ -131,18 +131,28 @@ pub(crate) async fn get_mixnode_reward_estimation(
             .await
             .map_err(|err| ErrorResponse::new(err.to_string(), Status::NotFound))?;
 
-        let (estimated_total_node_reward, estimated_operator_reward, estimated_delegators_reward) =
-            epoch_reward_params.estimate_reward(&bond, uptime.u8(), status.is_active());
-
-        Ok(Json(RewardEstimationResponse {
-            estimated_total_node_reward,
-            estimated_operator_reward,
-            estimated_delegators_reward,
-            current_epoch_start: current_epoch.start_unix_timestamp(),
-            current_epoch_end: current_epoch.end_unix_timestamp(),
-            current_epoch_uptime: uptime.u8(),
-            as_at,
-        }))
+        match epoch_reward_params.estimate_reward(&bond, uptime.u8(), status.is_active()) {
+            Ok((
+                estimated_total_node_reward,
+                estimated_operator_reward,
+                estimated_delegators_reward,
+            )) => {
+                let reponse = RewardEstimationResponse {
+                    estimated_total_node_reward,
+                    estimated_operator_reward,
+                    estimated_delegators_reward,
+                    current_epoch_start: current_epoch.start_unix_timestamp(),
+                    current_epoch_end: current_epoch.end_unix_timestamp(),
+                    current_epoch_uptime: uptime.u8(),
+                    as_at,
+                };
+                Ok(Json(reponse))
+            }
+            Err(e) => Err(ErrorResponse::new(
+                e.to_string(),
+                Status::InternalServerError,
+            )),
+        }
     } else {
         Err(ErrorResponse::new(
             "mixnode bond not found",

validator-api/src/rewarding/error.rs

@@ -23,6 +23,12 @@ pub(crate) enum RewardingError {
 
     #[error("Failed to query the smart contract - {0}")]
     ValidatorClientError(ValidatorClientError),
+
+    #[error("Error downcasting u128 -> u64")]
+    DowncastingError {
+        #[from]
+        source: std::num::TryFromIntError,
+    },
 }
 
 impl From<NymdError> for RewardingError {

validator-api/src/rewarding/mod.rs

@@ -58,7 +58,7 @@ impl EpochRewardParams {
         node: &MixNodeBond,
         uptime: u8,
         in_active_set: bool,
-    ) -> (u128, u128, u128) {
+    ) -> Result<(u64, u64, u64), RewardingError> {
         let node_reward_params = NodeRewardParams::new(
             self.period_reward_pool,
             self.rewarded_set_size.into(),
@@ -76,14 +76,15 @@ impl EpochRewardParams {
         let delegators_reward =
             node.reward_delegation(node.total_delegation().amount, &node_reward_params);
 
-        (
+        Ok((
             total_node_reward
                 .reward()
-                .checked_to_num()
-                .unwrap_or_default(),
-            operator_reward,
-            delegators_reward,
-        )
+                .checked_to_num::<u128>()
+                .unwrap_or_default()
+                .try_into()?,
+            operator_reward.try_into()?,
+            delegators_reward.try_into()?,
+        ))
     }
 }
 

validator-api/validator-api-requests/src/models.rs

@@ -35,9 +35,9 @@ pub struct MixnodeStatusResponse {
 #[derive(Clone, Copy, Debug, Serialize, Deserialize)]
 #[cfg_attr(feature = "ts-rs", derive(ts_rs::TS))]
 pub struct RewardEstimationResponse {
-    pub estimated_total_node_reward: u128,
-    pub estimated_operator_reward: u128,
-    pub estimated_delegators_reward: u128,
+    pub estimated_total_node_reward: u64,
+    pub estimated_operator_reward: u64,
+    pub estimated_delegators_reward: u64,
 
     pub current_epoch_start: i64,
     pub current_epoch_end: i64,