refactor: 30-day defaults, time-based message expiry

- Change QUEUE_MAX_AGE default from 48h to 30 days (2592000s)
- Replace count-based MAX_HISTORY with time-based MESSAGE_MAX_AGE
  (default 30 days) — messages older than the configured age are
  pruned instead of keeping a fixed count per target
- Update README to reflect new defaults and time-based expiry

internal/config/config.go

@@ -38,7 +38,7 @@ type Config struct {
 	MetricsUsername    string
 	Port               int
 	SentryDSN          string
-	MaxHistory         int
+	MessageMaxAge      int
 	MaxMessageSize     int
 	QueueMaxAge        int
 	MOTD               string
@@ -69,9 +69,9 @@ func New(
 	viper.SetDefault("SENTRY_DSN", "")
 	viper.SetDefault("METRICS_USERNAME", "")
 	viper.SetDefault("METRICS_PASSWORD", "")
-	viper.SetDefault("MAX_HISTORY", "10000")
+	viper.SetDefault("MESSAGE_MAX_AGE", "2592000")
 	viper.SetDefault("MAX_MESSAGE_SIZE", "4096")
-	viper.SetDefault("QUEUE_MAX_AGE", "172800")
+	viper.SetDefault("QUEUE_MAX_AGE", "2592000")
 	viper.SetDefault("MOTD", defaultMOTD)
 	viper.SetDefault("SERVER_NAME", "")
 	viper.SetDefault("FEDERATION_KEY", "")
@@ -94,7 +94,7 @@ func New(
 		MaintenanceMode:    viper.GetBool("MAINTENANCE_MODE"),
 		MetricsUsername:    viper.GetString("METRICS_USERNAME"),
 		MetricsPassword:    viper.GetString("METRICS_PASSWORD"),
-		MaxHistory:         viper.GetInt("MAX_HISTORY"),
+		MessageMaxAge:      viper.GetInt("MESSAGE_MAX_AGE"),
 		MaxMessageSize:     viper.GetInt("MAX_MESSAGE_SIZE"),
 		QueueMaxAge:        viper.GetInt("QUEUE_MAX_AGE"),
 		MOTD:               viper.GetString("MOTD"),

internal/db/queries.go

@@ -1118,84 +1118,23 @@ func (database *Database) PruneOldQueueEntries(
 	return deleted, nil
 }
 
-// RotateChannelMessages enforces MAX_HISTORY per channel
-// by deleting the oldest messages beyond the limit for
-// each msg_to target. Returns the total number of rows
-// removed.
-func (database *Database) RotateChannelMessages(
+// PruneOldMessages deletes messages older than cutoff and
+// returns the number of rows removed.
+func (database *Database) PruneOldMessages(
 	ctx context.Context,
-	maxHistory int,
+	cutoff time.Time,
 ) (int64, error) {
-	if maxHistory <= 0 {
-		return 0, nil
-	}
-
-	// Find distinct targets that have messages.
-	rows, err := database.conn.QueryContext(ctx,
-		`SELECT msg_to, COUNT(*) AS cnt
-		 FROM messages
-		 WHERE msg_to != ''
-		 GROUP BY msg_to
-		 HAVING cnt > ?`,
-		maxHistory,
+	res, err := database.conn.ExecContext(ctx,
+		"DELETE FROM messages WHERE created_at < ?",
+		cutoff,
 	)
 	if err != nil {
 		return 0, fmt.Errorf(
-			"list targets for rotation: %w", err,
+			"prune old messages: %w", err,
 		)
 	}
 
-	defer func() { _ = rows.Close() }()
+	deleted, _ := res.RowsAffected()
 
-	type targetCount struct {
-		target string
-		count  int64
-	}
-
-	var targets []targetCount
-
-	for rows.Next() {
-		var entry targetCount
-
-		err = rows.Scan(&entry.target, &entry.count)
-		if err != nil {
-			return 0, fmt.Errorf(
-				"scan target count: %w", err,
-			)
-		}
-
-		targets = append(targets, entry)
-	}
-
-	err = rows.Err()
-	if err != nil {
-		return 0, fmt.Errorf("rows error: %w", err)
-	}
-
-	var totalDeleted int64
-
-	for _, entry := range targets {
-		res, delErr := database.conn.ExecContext(ctx,
-			`DELETE FROM messages
-			 WHERE msg_to = ?
-			   AND id NOT IN (
-			     SELECT id FROM messages
-			     WHERE msg_to = ?
-			     ORDER BY id DESC
-			     LIMIT ?
-			   )`,
-			entry.target, entry.target, maxHistory,
-		)
-		if delErr != nil {
-			return totalDeleted, fmt.Errorf(
-				"rotate messages for %s: %w",
-				entry.target, delErr,
-			)
-		}
-
-		deleted, _ := res.RowsAffected()
-		totalDeleted += deleted
-	}
-
-	return totalDeleted, nil
+	return deleted, nil
 }

internal/handlers/handlers.go

@@ -205,8 +205,7 @@ func (hdlr *Handlers) runCleanup(
 }
 
 // pruneQueuesAndMessages removes old client_queues entries
-// per QUEUE_MAX_AGE, rotates messages per MAX_HISTORY, and
-// cleans up orphaned messages.
+// per QUEUE_MAX_AGE and old messages per MESSAGE_MAX_AGE.
 func (hdlr *Handlers) pruneQueuesAndMessages(
 	ctx context.Context,
 ) {
@@ -230,18 +229,22 @@ func (hdlr *Handlers) pruneQueuesAndMessages(
 		}
 	}
 
-	maxHistory := hdlr.params.Config.MaxHistory
-	if maxHistory > 0 {
-		rotated, err := hdlr.params.Database.
-			RotateChannelMessages(ctx, maxHistory)
+	messageMaxAge := hdlr.params.Config.MessageMaxAge
+	if messageMaxAge > 0 {
+		msgCutoff := time.Now().Add(
+			-time.Duration(messageMaxAge) * time.Second,
+		)
+
+		pruned, err := hdlr.params.Database.
+			PruneOldMessages(ctx, msgCutoff)
 		if err != nil {
 			hdlr.log.Error(
-				"message rotation failed", "error", err,
+				"message pruning failed", "error", err,
 			)
-		} else if rotated > 0 {
+		} else if pruned > 0 {
 			hdlr.log.Info(
-				"rotated old messages",
-				"deleted", rotated,
+				"pruned old messages",
+				"deleted", pruned,
 			)
 		}
 	}