oyaegeli98668
1d5f775d33
- 迁移 0007: 新增 product_barcode 表（一品多码），回填旧 product.gtin 为主码， 全局唯一索引保证「一码一品」，每品至多一个主码 - internal/gtin: GS1 GTIN-8/12/13/14 校验（校验位 + 拒收店内码/变量重量码/优惠券码） - 公开只读 API: 任一条码命中商品、详情返回 barcodes、搜索匹配条码 - adminstore: 商品详情含 barcodes；新增 AddBarcode/DeleteBarcode/SetPrimaryBarcode， 一码命中其他商品返回 ConflictError 供后台去重 待办（按用户要求暂停）: 后台 handler 路由、投稿/审核多条码、前后端 UI Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
111 lines
2.7 KiB
Go
111 lines
2.7 KiB
Go
// Package gtin validates and normalizes GS1 trade item numbers (GTIN-8/12/13/14).
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// Only globally-unique GS1 codes are accepted: store-internal / variable-weight /
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// coupon codes (which are not globally unique) are rejected on purpose.
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package gtin
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import (
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"errors"
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"strings"
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)
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// Validation errors.
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var (
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ErrEmpty = errors.New("条码不能为空")
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ErrFormat = errors.New("条码必须为 8/12/13/14 位数字")
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ErrCheck = errors.New("条码校验位不正确")
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ErrRestricted = errors.New("店内码/变量重量码/优惠券码等非全球唯一码，不予收录")
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)
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// Normalize trims and validates a GTIN, returning the cleaned digit string.
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// It enforces length, the GS1 mod-10 check digit, and rejects restricted
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// (non-globally-unique) number ranges.
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func Normalize(raw string) (string, error) {
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s := strings.TrimSpace(raw)
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if s == "" {
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return "", ErrEmpty
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}
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for _, c := range s {
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if c < '0' || c > '9' {
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return "", ErrFormat
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}
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}
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switch len(s) {
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case 8, 12, 13, 14:
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default:
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return "", ErrFormat
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}
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if !validCheckDigit(s) {
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return "", ErrCheck
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}
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if restricted(s) {
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return "", ErrRestricted
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}
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return s, nil
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}
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// InferType returns the conventional GTIN type label for a normalized code.
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func InferType(s string) string {
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switch len(s) {
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case 8:
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return "EAN8"
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case 12:
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return "UPC"
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case 14:
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return "GTIN14"
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default:
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return "EAN13"
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}
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}
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// validCheckDigit verifies the trailing GS1 mod-10 check digit. The digit
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// immediately left of the check digit carries weight 3, then weights alternate.
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func validCheckDigit(s string) bool {
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n := len(s)
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sum := 0
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for i := 0; i < n-1; i++ {
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d := int(s[i] - '0')
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if (n-1-i)%2 == 1 {
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sum += d * 3
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} else {
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sum += d
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}
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}
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check := (10 - (sum % 10)) % 10
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return check == int(s[n-1]-'0')
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}
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// restricted reports whether a (length/check-digit valid) code falls in a
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// number range reserved for non-globally-unique use.
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func restricted(s string) bool {
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switch len(s) {
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case 13:
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p2 := s[:2]
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switch {
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case s[0] == '2': // 20-29 restricted distribution / in-store
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return true
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case p2 == "02": // 020-029 variable-measure within a store
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return true
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case p2 == "04": // 040-049 restricted circulation within a company
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return true
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case p2 == "05": // 050-059 coupons
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return true
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case p2 == "98" || p2 == "99": // 980-989/99 coupons & refund receipts
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return true
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}
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case 12: // UPC-A: leading number-system digit
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switch s[0] {
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case '2': // in-store / random weight
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return true
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case '4': // unrestricted in-store use
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return true
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case '5': // coupons
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return true
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}
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case 8: // EAN-8: 0/2 prefixes reserved for in-store use
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if s[0] == '0' || s[0] == '2' {
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return true
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}
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}
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return false
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}
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