ana register to contributions

ana/predictor.go

@@ -39,10 +39,31 @@ func NewInterestPredictor(namePattern string, currencyPattern string, apy float6
 
 func NewContributionPredictor(reg ledger.Register) Predictor {
 	monthlyRate := getMonthlyContributionRate(reg)
+	_ = monthlyRate
 	return func(given ledger.Balances, delta time.Duration) ledger.Balances {
 		panic(nil)
 	}
 }
 
 func getMonthlyContributionRate(reg ledger.Register) map[string]ledger.Balance {
+	panic(nil)
+}
+
+func getRecentContributions(reg ledger.Register) map[string][]ledger.Balance {
+	return getContributions(reg.Between(time.Now().Add(-1*time.Hour*365/2), time.Now()))
+}
+
+func getContributions(reg ledger.Register) map[string][]ledger.Balance {
+	contributions := make(map[string][]ledger.Balance)
+	for _, date := range reg.Dates() {
+		for name := range reg[date] {
+			contributions[name] = append(contributions[name], maps.Clone(reg[date][name]))
+			if a := contributions[name]; len(a) > 1 {
+				for k := range a[len(a)-2] {
+					a[len(a)-1][k] -= a[len(a)-2][k]
+				}
+			}
+		}
+	}
+	return contributions
 }