add rate limit for refresh

main.go

@@ -11,6 +11,7 @@ import (
 var (
 	configuredProviders []AccountProvider // Any account providers that are successfully configured get added to this slice
 	ynabClient          *ynab.Client      // YNAB HTTP client
+	lastRefresh         time.Time
 )
 
 // Called at program startup or if SIGHUP is received
@@ -61,6 +62,14 @@ func main() {
 }
 
 func refreshData() {
+
+	// Only allow a refresh at most once every 5 minutes
+	if time.Now().Before(lastRefresh.Add(time.Minute * 5)) {
+		log.Printf("refresh rate limited")
+		return
+	}
+	lastRefresh = time.Now()
+
 	// Loop through each configured account provider and attempt to get the account balances, and update YNAB
 	for _, p := range configuredProviders {
 		balances, accountIDs, err := p.GetBalances()