feat: user service

user/internal/service/shared/race_name.go

@@ -0,0 +1,49 @@
+package shared
+
+import (
+	"fmt"
+	"time"
+
+	"galaxy/user/internal/domain/account"
+	"galaxy/user/internal/domain/common"
+	"galaxy/user/internal/ports"
+)
+
+// BuildRaceNameReservation constructs one validated race-name reservation
+// record for userID and raceName at reservedAt.
+func BuildRaceNameReservation(
+	policy ports.RaceNamePolicy,
+	userID common.UserID,
+	raceName common.RaceName,
+	reservedAt time.Time,
+) (account.RaceNameReservation, error) {
+	if policy == nil {
+		return account.RaceNameReservation{}, fmt.Errorf("build race-name reservation: race-name policy must not be nil")
+	}
+	if err := userID.Validate(); err != nil {
+		return account.RaceNameReservation{}, fmt.Errorf("build race-name reservation: %w", err)
+	}
+	if err := raceName.Validate(); err != nil {
+		return account.RaceNameReservation{}, fmt.Errorf("build race-name reservation: %w", err)
+	}
+	if err := common.ValidateTimestamp("build race-name reservation reserved at", reservedAt); err != nil {
+		return account.RaceNameReservation{}, err
+	}
+
+	canonicalKey, err := policy.CanonicalKey(raceName)
+	if err != nil {
+		return account.RaceNameReservation{}, fmt.Errorf("build race-name reservation: %w", err)
+	}
+
+	record := account.RaceNameReservation{
+		CanonicalKey: canonicalKey,
+		UserID:       userID,
+		RaceName:     raceName,
+		ReservedAt:   reservedAt.UTC(),
+	}
+	if err := record.Validate(); err != nil {
+		return account.RaceNameReservation{}, fmt.Errorf("build race-name reservation: %w", err)
+	}
+
+	return record, nil
+}