support filtering transaction amount

pkg/validators/amount_filter.go

@@ -0,0 +1,54 @@
+package validators
+
+import (
+	"strings"
+
+	"github.com/go-playground/validator/v10"
+
+	"github.com/mayswind/ezbookkeeping/pkg/utils"
+)
+
+// ValidAmountFilter returns whether the given amount filter is valid
+func ValidAmountFilter(fl validator.FieldLevel) bool {
+	if value, ok := fl.Field().Interface().(string); ok {
+		if value == "" {
+			return true
+		}
+
+		amountFilterItems := strings.Split(value, ":")
+
+		if len(amountFilterItems) < 2 {
+			return false
+		}
+
+		amount1, err := utils.StringToInt64(amountFilterItems[1])
+
+		if err != nil {
+			return false
+		}
+
+		if amountFilterItems[0] == "gt" || amountFilterItems[0] == "lt" || amountFilterItems[0] == "eq" || amountFilterItems[0] == "ne" {
+			if len(amountFilterItems) != 2 {
+				return false
+			}
+		} else if amountFilterItems[0] == "bt" || amountFilterItems[0] == "nb" {
+			if len(amountFilterItems) != 3 {
+				return false
+			}
+
+			amount2, err := utils.StringToInt64(amountFilterItems[2])
+
+			if err != nil {
+				return false
+			}
+
+			if amount2 < amount1 {
+				return false
+			}
+		}
+
+		return true
+	}
+
+	return false
+}