From 483a1477f335b6f98aaed787851b83c6aa5c101e Mon Sep 17 00:00:00 2001
From: Josh <josh.hundley@gmail.com>
Date: Wed, 23 Jun 2021 13:49:52 -0700
Subject: [PATCH] Explorer: display message when block rewards not found for
 interval (#17943)

* fix: disable block not found error message and give feedback for rewards not found

* feat: add lowest available epochs for rewards

* feat: make sure current epoch is not fetched
---
 .../src/components/account/RewardsCard.tsx    | 37 +++++++++++--------
 explorer/src/providers/accounts/rewards.tsx   | 27 ++++++++++----
 2 files changed, 41 insertions(+), 23 deletions(-)

diff --git a/explorer/src/components/account/RewardsCard.tsx b/explorer/src/components/account/RewardsCard.tsx
index 39d2cb3eb5..e4d48e54bc 100644
--- a/explorer/src/components/account/RewardsCard.tsx
+++ b/explorer/src/components/account/RewardsCard.tsx
@@ -61,8 +61,8 @@ export function RewardsCard({ pubkey }: { pubkey: PublicKey }) {
       </tr>
     );
   });
-
-  const { foundOldest } = rewards.data;
+  const rewardsFound = rewardsList.some((r) => r);
+  const { foundOldest, lowestFetchedEpoch, highestFetchedEpoch } = rewards.data;
   const fetching = rewards.status === FetchStatus.Fetching;
 
   return (
@@ -76,19 +76,26 @@ export function RewardsCard({ pubkey }: { pubkey: PublicKey }) {
           </div>
         </div>
 
-        <div className="table-responsive mb-0">
-          <table className="table table-sm table-nowrap card-table">
-            <thead>
-              <tr>
-                <th className="w-1 text-muted">Epoch</th>
-                <th className="text-muted">Effective Slot</th>
-                <th className="text-muted">Reward Amount</th>
-                <th className="text-muted">Post Balance</th>
-              </tr>
-            </thead>
-            <tbody className="list">{rewardsList}</tbody>
-          </table>
-        </div>
+        {rewardsFound ? (
+          <div className="table-responsive mb-0">
+            <table className="table table-sm table-nowrap card-table">
+              <thead>
+                <tr>
+                  <th className="w-1 text-muted">Epoch</th>
+                  <th className="text-muted">Effective Slot</th>
+                  <th className="text-muted">Reward Amount</th>
+                  <th className="text-muted">Post Balance</th>
+                </tr>
+              </thead>
+              <tbody className="list">{rewardsList}</tbody>
+            </table>
+          </div>
+        ) : (
+          <div className="card-body">
+            No rewards issued between epochs {lowestFetchedEpoch} and{" "}
+            {highestFetchedEpoch}
+          </div>
+        )}
 
         <div className="card-footer">
           {foundOldest ? (
diff --git a/explorer/src/providers/accounts/rewards.tsx b/explorer/src/providers/accounts/rewards.tsx
index 4b3517ad05..32fc4a0078 100644
--- a/explorer/src/providers/accounts/rewards.tsx
+++ b/explorer/src/providers/accounts/rewards.tsx
@@ -6,6 +6,11 @@ import { ActionType } from "providers/block";
 import { FetchStatus } from "providers/cache";
 import { reportError } from "utils/sentry";
 
+const REWARDS_AVAILABLE_EPOCH = new Map<Cluster, number>([
+  [Cluster.MainnetBeta, 132],
+  [Cluster.Testnet, 43],
+]);
+
 const PAGE_SIZE = 15;
 
 export type Rewards = {
@@ -17,6 +22,8 @@ export type Rewards = {
 
 export type RewardsUpdate = {
   rewards: (InflationReward | null)[];
+  highestFetchedEpoch: number;
+  lowestFetchedEpoch: number;
   foundOldest?: boolean;
 };
 
@@ -39,8 +46,9 @@ function reconcile(
 
   return {
     rewards: combined,
-    highestFetchedEpoch: combined[0]?.epoch,
-    lowestFetchedEpoch: combined[combined.length - 1]?.epoch,
+    highestFetchedEpoch:
+      rewards?.highestFetchedEpoch || update.highestFetchedEpoch,
+    lowestFetchedEpoch: update.lowestFetchedEpoch,
     foundOldest,
   };
 }
@@ -84,12 +92,9 @@ async function fetchRewards(
     url,
   });
 
+  const lowestAvailableEpoch = REWARDS_AVAILABLE_EPOCH.get(cluster) || 0;
   const connection = new Connection(url);
 
-  if (!fromEpoch && highestEpoch) {
-    fromEpoch = highestEpoch;
-  }
-
   if (!fromEpoch) {
     try {
       const epochInfo = await connection.getEpochInfo();
@@ -106,6 +111,10 @@ async function fetchRewards(
         url,
       });
     }
+
+    if (highestEpoch && highestEpoch < fromEpoch) {
+      fromEpoch = highestEpoch;
+    }
   }
 
   const getInflationReward = async (epoch: number) => {
@@ -128,7 +137,7 @@ async function fetchRewards(
   }
 
   const results = await Promise.all(requests);
-  fromEpoch = fromEpoch - requests.length;
+  const lowestFetchedEpoch = fromEpoch - requests.length;
 
   dispatch({
     type: ActionType.Update,
@@ -137,7 +146,9 @@ async function fetchRewards(
     status: FetchStatus.Fetched,
     data: {
       rewards: results || [],
-      foundOldest: fromEpoch <= 0,
+      foundOldest: lowestFetchedEpoch <= lowestAvailableEpoch,
+      highestFetchedEpoch: fromEpoch,
+      lowestFetchedEpoch,
     },
   });
 }