feat: mail service

mail/internal/adapters/redisstate/index_cleaner.go

@@ -0,0 +1,118 @@
+package redisstate
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"galaxy/mail/internal/domain/common"
+
+	"github.com/redis/go-redis/v9"
+)
+
+// CleanupReport describes the work done by IndexCleaner.
+type CleanupReport struct {
+	// ScannedIndexes stores how many secondary index keys were inspected.
+	ScannedIndexes int
+
+	// ScannedMembers stores how many index members were examined.
+	ScannedMembers int
+
+	// RemovedMembers stores how many stale members were removed.
+	RemovedMembers int
+}
+
+// IndexCleaner removes stale delivery references from the Mail Service
+// secondary indexes after primary delivery keys expire by TTL.
+type IndexCleaner struct {
+	client   *redis.Client
+	keyspace Keyspace
+}
+
+// NewIndexCleaner constructs one delivery-index cleanup helper.
+func NewIndexCleaner(client *redis.Client) (*IndexCleaner, error) {
+	if client == nil {
+		return nil, errors.New("new redis index cleaner: nil client")
+	}
+
+	return &IndexCleaner{
+		client:   client,
+		keyspace: Keyspace{},
+	}, nil
+}
+
+// CleanDeliveryIndexes scans every `mail:idx:*` key and removes members that
+// no longer have a primary delivery record.
+func (cleaner *IndexCleaner) CleanDeliveryIndexes(ctx context.Context) (CleanupReport, error) {
+	if cleaner == nil || cleaner.client == nil {
+		return CleanupReport{}, errors.New("clean delivery indexes in redis: nil cleaner")
+	}
+	if ctx == nil {
+		return CleanupReport{}, errors.New("clean delivery indexes in redis: nil context")
+	}
+
+	var (
+		report CleanupReport
+		cursor uint64
+	)
+
+	for {
+		keys, nextCursor, err := cleaner.client.Scan(ctx, cursor, cleaner.keyspace.SecondaryIndexPattern(), 0).Result()
+		if err != nil {
+			return CleanupReport{}, fmt.Errorf("clean delivery indexes in redis: %w", err)
+		}
+
+		for _, key := range keys {
+			if key == cleaner.keyspace.MalformedCommandCreatedAtIndex() {
+				continue
+			}
+
+			report.ScannedIndexes++
+
+			members, err := cleaner.client.ZRange(ctx, key, 0, -1).Result()
+			if err != nil {
+				return CleanupReport{}, fmt.Errorf("clean delivery indexes in redis: read index %q: %w", key, err)
+			}
+
+			report.ScannedMembers += len(members)
+			for _, member := range members {
+				remove, err := cleaner.shouldRemoveMember(ctx, member)
+				if err != nil {
+					return CleanupReport{}, fmt.Errorf("clean delivery indexes in redis: inspect index %q member %q: %w", key, member, err)
+				}
+				if !remove {
+					continue
+				}
+
+				if err := cleaner.client.ZRem(ctx, key, member).Err(); err != nil {
+					return CleanupReport{}, fmt.Errorf("clean delivery indexes in redis: remove index %q member %q: %w", key, member, err)
+				}
+				report.RemovedMembers++
+			}
+		}
+
+		if nextCursor == 0 {
+			return report, nil
+		}
+		cursor = nextCursor
+	}
+}
+
+func (cleaner *IndexCleaner) shouldRemoveMember(ctx context.Context, member string) (bool, error) {
+	if strings.TrimSpace(member) == "" {
+		return true, nil
+	}
+
+	deliveryID := common.DeliveryID(member)
+	if err := deliveryID.Validate(); err != nil {
+		return true, nil
+	}
+
+	exists, err := cleaner.client.Exists(ctx, cleaner.keyspace.Delivery(deliveryID)).Result()
+	if err != nil {
+		return false, err
+	}
+
+	return exists == 0, nil
+}