draft

backend/pkg/sequence/sequence.go

@@ -0,0 +1,50 @@
+package sequence
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"pay-bridge/internal/model"
+	"pay-bridge/internal/repository"
+)
+
+// Service 订单编码服务
+type Service struct {
+	repo *repository.SequenceRepository
+}
+
+func NewService(repo *repository.SequenceRepository) *Service {
+	return &Service{repo: repo}
+}
+
+// NextTradeNo 生成下一个交易号，格式：PAY{yyMMdd}{8位序号}
+func (s *Service) NextTradeNo(ctx context.Context, appID string) (string, error) {
+	return s.next(ctx, appID, model.SeqTypeTrade)
+}
+
+// NextRefundNo 生成下一个退款单号，格式：REF{yyMMdd}{8位序号}
+func (s *Service) NextRefundNo(ctx context.Context, appID string) (string, error) {
+	return s.next(ctx, appID, model.SeqTypeRefund)
+}
+
+// NextSharingNo 生成下一个分润单号，格式：SHA{yyMMdd}{8位序号}
+func (s *Service) NextSharingNo(ctx context.Context, appID string) (string, error) {
+	return s.next(ctx, appID, model.SeqTypeSharing)
+}
+
+func (s *Service) next(ctx context.Context, appID string, seqType model.SeqType) (string, error) {
+	val, err := s.repo.IncrAndGet(ctx, appID, seqType)
+	if err != nil {
+		return "", err
+	}
+
+	prefix, err := s.repo.GetPrefix(ctx, appID, seqType)
+	if err != nil {
+		return "", err
+	}
+
+	date := time.Now().Format("060102") // yyMMdd
+	seq := fmt.Sprintf("%08d", val%100_000_000) // 8 位，溢出归零（每日最多1亿笔）
+	return prefix + date + seq, nil
+}