Init

internal/services/ticket_no_service.go

@@ -0,0 +1,84 @@
+package services
+
+import (
+	"cs-agent/internal/models"
+	"cs-agent/internal/repositories"
+	"fmt"
+	"strings"
+	"time"
+
+	"gorm.io/gorm"
+)
+
+var TicketNoService = newTicketNoService()
+
+func newTicketNoService() *ticketNoService {
+	return &ticketNoService{}
+}
+
+type ticketNoService struct{}
+
+func (s *ticketNoService) Next(tx *gorm.DB, now time.Time) (string, error) {
+	if tx == nil {
+		return "", fmt.Errorf("ticket number transaction is required")
+	}
+	dateKey := now.Format("20060102")
+	for attempt := 0; attempt < 20; attempt++ {
+		current := repositories.TicketNoSequenceRepository.GetByDateKey(tx, dateKey)
+		if current == nil {
+			item := &models.TicketNoSequence{
+				DateKey:   dateKey,
+				NextSeq:   2,
+				CreatedAt: now,
+				UpdatedAt: now,
+			}
+			err := repositories.TicketNoSequenceRepository.Create(tx, item)
+			if err == nil {
+				return formatTicketNo(dateKey, 1), nil
+			}
+			if !isRetriableTicketNoError(err) {
+				return "", err
+			}
+			time.Sleep(time.Duration(attempt+1) * 10 * time.Millisecond)
+			continue
+		}
+		allocated := current.NextSeq
+		ok, err := repositories.TicketNoSequenceRepository.UpdateNextSeq(tx, current.ID, current.NextSeq, current.NextSeq+1, now)
+		if err != nil {
+			if isRetriableTicketNoError(err) {
+				time.Sleep(time.Duration(attempt+1) * 10 * time.Millisecond)
+				continue
+			}
+			return "", err
+		}
+		if ok {
+			return formatTicketNo(dateKey, allocated), nil
+		}
+		time.Sleep(time.Duration(attempt+1) * 10 * time.Millisecond)
+	}
+	return "", fmt.Errorf("failed to allocate ticket number")
+}
+
+func formatTicketNo(dateKey string, seq int64) string {
+	return fmt.Sprintf("TK%s%05d", dateKey, seq)
+}
+
+func isDuplicateKeyError(err error) bool {
+	if err == nil {
+		return false
+	}
+	message := strings.ToLower(err.Error())
+	return strings.Contains(message, "duplicate") || strings.Contains(message, "unique") || strings.Contains(message, "constraint failed")
+}
+
+func isRetriableTicketNoError(err error) bool {
+	return isDuplicateKeyError(err) || isDatabaseLockedError(err)
+}
+
+func isDatabaseLockedError(err error) bool {
+	if err == nil {
+		return false
+	}
+	message := strings.ToLower(err.Error())
+	return strings.Contains(message, "database is locked") || strings.Contains(message, "database table is locked")
+}