refactor

ana/predictor.go

@@ -67,24 +67,32 @@ func getMonthlyContributionRates(reg ledger.Register) map[string]ledger.Balance
 	contributions := getRecentContributions(reg, window)
 	result := make(map[string]ledger.Balance)
 	for name := range contributions {
-		result[name] = getMonthlyContributionRate(contributions[name], window, name)
+		result[name] = getMonthlyContributionRate(contributions[name], window)
+	}
+	return result
+}
+
+func getMonthlyContributionRate(contributions []ledger.Balance, window time.Duration) ledger.Balance {
+	currencies := map[ledger.Currency]int{}
+	for _, balance := range contributions {
+		for currency := range balance {
+			currencies[currency] = 1
+		}
+	}
+	result := make(ledger.Balance)
+	for currency := range currencies {
+		result[currency] = getMonthlyContributionRateForCurrency(contributions, window, currency)
 	}
 	return result
 }
 
 // TODO better than average
-func getMonthlyContributionRate(contributions []ledger.Balance, window time.Duration, name string) ledger.Balance {
-	sumPerCurrency := map[ledger.Currency]float64{}
+func getMonthlyContributionRateForCurrency(contributions []ledger.Balance, window time.Duration, currency ledger.Currency) float64 {
+	sum := 0.0
 	for _, balance := range contributions {
-		for currency, v := range balance {
-			sumPerCurrency[currency] += v
-		}
+		sum += balance[currency]
 	}
-	result := make(ledger.Balance)
-	for currency, summed := range sumPerCurrency {
-		result[currency] = summed / (float64(window) / float64(time.Hour*24.0*365.0/12.0))
-	}
-	return result
+	return sum / (float64(window) / float64(time.Hour*24.0*365.0/12.0))
 }
 
 func getRecentContributions(reg ledger.Register, window time.Duration) map[string][]ledger.Balance {

ana/predictor_test.go

@@ -86,7 +86,7 @@ func TestGetMonthlyContributionRate(t *testing.T) {
 		ledger.Balance{"x": 4},
 		ledger.Balance{"y": 3},
 	}
-	got := getMonthlyContributionRate(input, time.Hour*24*365/4, "")
+	got := getMonthlyContributionRate(input, time.Hour*24*365/4)
 	if len(got) != 2 {
 		t.Error(got)
 	}