Add /api/v1/mining/blocks/fee-rates/{interval} API

backend/src/repositories/BlocksRepository.ts

@@ -427,6 +427,41 @@ class BlocksRepository {
       throw e;
     }
   }
+
+  /**
+   * Get the historical averaged block fee rate percentiles
+   */
+   public async $getHistoricalBlockFeeRates(div: number, interval: string | null): Promise<any> {
+    let connection;
+    try {
+      connection = await DB.getConnection();
+
+      let query = `SELECT CAST(AVG(UNIX_TIMESTAMP(blockTimestamp)) as INT) as timestamp,
+        CAST(AVG(JSON_EXTRACT(fee_span, '$[0]')) as INT) as avg_fee_0,
+        CAST(AVG(JSON_EXTRACT(fee_span, '$[1]')) as INT) as avg_fee_10,
+        CAST(AVG(JSON_EXTRACT(fee_span, '$[2]')) as INT) as avg_fee_25,
+        CAST(AVG(JSON_EXTRACT(fee_span, '$[3]')) as INT) as avg_fee_50,
+        CAST(AVG(JSON_EXTRACT(fee_span, '$[4]')) as INT) as avg_fee_75,
+        CAST(AVG(JSON_EXTRACT(fee_span, '$[5]')) as INT) as avg_fee_90,
+        CAST(AVG(JSON_EXTRACT(fee_span, '$[6]')) as INT) as avg_fee_100
+      FROM blocks`;
+
+      if (interval !== null) {
+        query += ` WHERE blockTimestamp BETWEEN DATE_SUB(NOW(), INTERVAL ${interval}) AND NOW()`;
+      }
+
+      query += ` GROUP BY UNIX_TIMESTAMP(blockTimestamp) DIV ${div}`;
+
+      const [rows]: any = await connection.query(query);
+      connection.release();
+
+      return rows;
+    } catch (e) {
+      connection.release();
+      logger.err('Cannot generate block fee rates history. Reason: ' + (e instanceof Error ? e.message : e));
+      throw e;
+    }
+  }
 }
 
 export default new BlocksRepository();