Add logging for /v2/apr and handle Inf values (#432)

Author: kirugan

internal/v2/service/stats.go

@@ -160,6 +160,11 @@ func (s *V2Service) GetStakingAPR(ctx context.Context, satoshisStaked, ubbnStake
 }
 
 func (s *V2Service) calculateCoStakingAPR(ctx context.Context, babyPrice, btcPrice float64, totalScore int64) (float64, error) {
+	if totalScore == 0 {
+		log.Ctx(ctx).Info().Msg("empty total score")
+		return 0, nil
+	}
+
 	const (
 		totalInflation         = 5.5
 		coStakingInflationPart = 2.35
@@ -170,6 +175,13 @@ func (s *V2Service) calculateCoStakingAPR(ctx context.Context, babyPrice, btcPri
 		return 0, err
 	}
 
+	log.Ctx(ctx).Info().
+		Float64("annualProvisions", annualProvisions).
+		Float64("babyPrice", babyPrice).
+		Float64("btcPrice", btcPrice).
+		Int64("totalScore", totalScore).
+		Msg("values for costaking apr calculation")
+
 	// annualProvisions * (coStakingInflationPart / totalInflation) * babyPrice / (total_score / satoshisPerBTC * btcPrice) / ubbnPerBaby
 	// if you need percentage multiply final value by 100 (done on frontend)
 	apr := annualProvisions * (coStakingInflationPart / totalInflation) * babyPrice / ((float64(totalScore) / pkg.SatoshiPerBTC) * btcPrice) / pkg.UbbnPerBaby