init: initial commit

services/api/internal/portfolio/domain/money.go

@@ -0,0 +1,35 @@
+package domain
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+	"veyra/services/api/internal/platform/apperror"
+)
+
+var moneyPattern = regexp.MustCompile(`^(0|[1-9][0-9]{0,9})(\.[0-9]{1,2})?$`)
+
+// ParseMoney converts decimal text into exact cents, rejecting rounding and exponents.
+func ParseMoney(value string) (int64, error) {
+	if !moneyPattern.MatchString(value) {
+		return 0, apperror.ErrInvalidInput
+	}
+	whole, fraction, _ := strings.Cut(value, ".")
+	units, err := strconv.ParseInt(whole, 10, 64)
+	if err != nil {
+		return 0, apperror.ErrInvalidInput
+	}
+	fraction += strings.Repeat("0", 2-len(fraction))
+	cents, err := strconv.ParseInt(fraction, 10, 64)
+	if err != nil {
+		return 0, apperror.ErrInvalidInput
+	}
+	amount := units*100 + cents
+	if amount > 100000000000 {
+		return 0, apperror.ErrInvalidInput
+	}
+	return amount, nil
+}
+
+func FormatMoney(minor int64) string { return fmt.Sprintf("%d.%02d", minor/100, minor%100) }