refactor: 自定义业务错误

backend/internal/repository/error_translate.go

@@ -0,0 +1,40 @@
+package repository
+
+import (
+	"errors"
+	"strings"
+
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/infrastructure/errors"
+	"gorm.io/gorm"
+)
+
+func translatePersistenceError(err error, notFound, conflict *infraerrors.ApplicationError) error {
+	if err == nil {
+		return nil
+	}
+
+	if notFound != nil && errors.Is(err, gorm.ErrRecordNotFound) {
+		return notFound.WithCause(err)
+	}
+
+	if conflict != nil && isUniqueConstraintViolation(err) {
+		return conflict.WithCause(err)
+	}
+
+	return err
+}
+
+func isUniqueConstraintViolation(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	if errors.Is(err, gorm.ErrDuplicatedKey) {
+		return true
+	}
+
+	msg := strings.ToLower(err.Error())
+	return strings.Contains(msg, "duplicate key") ||
+		strings.Contains(msg, "unique constraint") ||
+		strings.Contains(msg, "duplicate entry")
+}