feat: game lobby service

lobby/internal/adapters/redisstate/codecs_membership.go

@@ -0,0 +1,75 @@
+package redisstate
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"galaxy/lobby/internal/domain/common"
+	"galaxy/lobby/internal/domain/membership"
+)
+
+// membershipRecord stores the strict Redis JSON shape used for one
+// membership record.
+type membershipRecord struct {
+	MembershipID string            `json:"membership_id"`
+	GameID       string            `json:"game_id"`
+	UserID       string            `json:"user_id"`
+	RaceName     string            `json:"race_name"`
+	CanonicalKey string            `json:"canonical_key"`
+	Status       membership.Status `json:"status"`
+	JoinedAtMS   int64             `json:"joined_at_ms"`
+	RemovedAtMS  *int64            `json:"removed_at_ms,omitempty"`
+}
+
+// MarshalMembership encodes record into the strict Redis JSON shape used
+// for membership records. The record is re-validated before marshalling.
+func MarshalMembership(record membership.Membership) ([]byte, error) {
+	if err := record.Validate(); err != nil {
+		return nil, fmt.Errorf("marshal redis membership record: %w", err)
+	}
+
+	stored := membershipRecord{
+		MembershipID: record.MembershipID.String(),
+		GameID:       record.GameID.String(),
+		UserID:       record.UserID,
+		RaceName:     record.RaceName,
+		CanonicalKey: record.CanonicalKey,
+		Status:       record.Status,
+		JoinedAtMS:   record.JoinedAt.UTC().UnixMilli(),
+		RemovedAtMS:  optionalUnixMilli(record.RemovedAt),
+	}
+
+	payload, err := json.Marshal(stored)
+	if err != nil {
+		return nil, fmt.Errorf("marshal redis membership record: %w", err)
+	}
+
+	return payload, nil
+}
+
+// UnmarshalMembership decodes payload from the strict Redis JSON shape
+// used for membership records. The decoded record is validated before
+// returning.
+func UnmarshalMembership(payload []byte) (membership.Membership, error) {
+	var stored membershipRecord
+	if err := decodeStrictJSON("decode redis membership record", payload, &stored); err != nil {
+		return membership.Membership{}, err
+	}
+
+	record := membership.Membership{
+		MembershipID: common.MembershipID(stored.MembershipID),
+		GameID:       common.GameID(stored.GameID),
+		UserID:       stored.UserID,
+		RaceName:     stored.RaceName,
+		CanonicalKey: stored.CanonicalKey,
+		Status:       stored.Status,
+		JoinedAt:     time.UnixMilli(stored.JoinedAtMS).UTC(),
+		RemovedAt:    inflateOptionalTime(stored.RemovedAtMS),
+	}
+	if err := record.Validate(); err != nil {
+		return membership.Membership{}, fmt.Errorf("decode redis membership record: %w", err)
+	}
+
+	return record, nil
+}