Zero aggregations should have the previous price

ops/aggregation_validator.go

@@ -154,15 +154,29 @@ func (a *AggregationValidator) checkZero(product string, interval time.Duration)
 		return
 	}
 
-	var i int
 	for missing.Next() {
-		i++
 		agg := missing.Value().(tacitus.Aggregation)
 		agg.Interval = int(interval.Seconds())
 
+		last := agg.Timestamp.Add(-interval)
+
+		previous, err := a.Database.AggregationService().
+			Aggregation(int(interval.Seconds()), product, last)
+		if err != nil {
+			a.Logger.Info("aggregation validator: FAIL missing aggregations. "+
+				"product: %v. interval: %v", product, interval)
+
+			missing.Close()
+			return
+		}
+
+		agg.Price = previous.Price
+
 		a.Database.AggregationService().CreateAggregation(agg)
 	}
 
+	missing.Close()
+
 	a.Logger.Info("aggregation validator: DONE missing aggregations. "+
 		"product: %v. interval: %v", product, interval)
 }