Add average fee delta to pool ranking

Co-authored-by: mononaut <83316221+mononaut@users.noreply.github.com>

backend/src/api/mining/mining.ts

@@ -106,6 +106,7 @@ class Mining {
         emptyBlocks: emptyBlocksCount.length > 0 ? emptyBlocksCount[0]['count'] : 0,
         slug: poolInfo.slug,
         avgMatchRate: poolInfo.avgMatchRate !== null ? Math.round(100 * poolInfo.avgMatchRate) / 100 : null,
+        avgFeeDelta: poolInfo.avgFeeDelta,
       };
       poolsStats.push(poolStat);
     });

backend/src/mempool.interfaces.ts

@@ -19,6 +19,7 @@ export interface PoolInfo {
   blockCount: number;
   slug: string;
   avgMatchRate: number | null;
+  avgFeeDelta: number | null;
 }
 
 export interface PoolStats extends PoolInfo {

backend/src/repositories/PoolsRepository.ts

@@ -39,7 +39,8 @@ class PoolsRepository {
           pools.name AS name,
           pools.link AS link,
           slug,
-          AVG(blocks_audits.match_rate) AS avgMatchRate
+          AVG(blocks_audits.match_rate) AS avgMatchRate,
+          AVG((CAST(blocks.fees as SIGNED) - CAST(blocks_audits.expected_fees as SIGNED)) / NULLIF(CAST(blocks_audits.expected_fees as SIGNED), 0)) AS avgFeeDelta
       FROM blocks
       JOIN pools on pools.id = pool_id
       LEFT JOIN blocks_audits ON blocks_audits.height = blocks.height