GenFakeUPC考虑校验规则

business/jxutils/jxutils.go

@@ -409,8 +409,29 @@ func SplitSkuName(skuName string) (prefix, name, comment, specUnit, unit string,
 	return prefix, name, comment, specUnit, unit, specQuality
 }
 
+// https://my.oschina.net/hyller/blog/700414
+func CalUpcCheckSum(upc12 int64) (checkSum int) {
+	var sum [2]int
+	for i := 0; i < 12; i++ {
+		base := int64(math.Pow10(i))
+		sum[i%2] += int((upc12 / base) % 10)
+	}
+	sum[0] *= 3
+	return (10 - (sum[0]+sum[1])%10)
+}
+
+func IsUpcValid(upc string) bool {
+	if len(upc) != 13 {
+		return false
+	}
+	upcInt := utils.Str2Int64WithDefault(upc, 0)
+	checkSum := CalUpcCheckSum(upcInt / 10)
+	return int(utils.Str2Int64(upc[12:])) == checkSum
+}
+
 func GenFakeUPC(skuID int) string {
-	return fmt.Sprintf("%013d", int64(skuID)+6666000000000)
+	id := int64(skuID) + 666600000000
+	return fmt.Sprintf("%012d%d", id, CalUpcCheckSum(id))
 }
 
 func MakeValidationMapFromSlice(validValues []string, flag int) map[string]int {