Combat: auto-play timed-out turn-based sessions to a real win/loss

A combat session abandoned past its 1h TTL is now resumed from persisted
mid-state and auto-played through the shared resolver to a real win or
loss, rather than flatly marked as a retreat. The bulk-UPDATE sweep is
replaced by listExpiredCombatSessions plus a reaper that locks the user,
auto-plays the fight, runs the normal close-out, and DMs the outcome.
markCombatSessionExpired remains the terminal fallback for sessions that
can't be reconstructed. Wired into eventTicker.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/plugin/adventure_events.go

@@ -53,6 +53,9 @@ func (p *AdventurePlugin) eventTicker() {
 			// Expire stale pending events every tick
 			expireAdvPendingEvents()
 
+			// Auto-play any combat sessions past their 1h timeout.
+			p.reapExpiredCombatSessions()
+
 			advEventScheduleMu.Lock()
 			if advEventScheduleDay != dateKey {
 				advEventSchedule = make(map[string]int)

internal/plugin/combat_reaper.go

@@ -0,0 +1,98 @@
+package plugin
+
+import (
+	"fmt"
+	"log/slog"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// Phase 13 — turn-based combat timeout reaper.
+//
+// A CombatSession expires 1h after its last action (combatSessionTTL). Per the
+// 2026-05-13 timeout decision, an abandoned fight is not flatly marked as a
+// retreat — the reaper resumes it from persisted mid-state and auto-plays the
+// rest of the fight through the same shared resolver a live !attack uses,
+// landing on a real win or loss. The player is DM'd the outcome.
+//
+// Sessions that cannot be reconstructed (zone run deleted, enemy no longer in
+// the bestiary) or that fail to converge within reaperRoundCap fall back to the
+// terminal 'expired' status with no fatal-blow side effects — see
+// markCombatSessionExpired.
+
+// reaperRoundCap bounds the auto-play loop. A turn-based round always lands at
+// least one damage roll eventually, so a real fight converges well within this;
+// the cap only guards against a pathological non-terminating session.
+const reaperRoundCap = 300
+
+// reapExpiredCombatSessions is the timeout reaper, driven off eventTicker (one
+// pass per minute). It auto-plays every stale session to a terminal status.
+func (p *AdventurePlugin) reapExpiredCombatSessions() {
+	expired, err := listExpiredCombatSessions()
+	if err != nil {
+		slog.Error("combat: reaper failed to list expired sessions", "err", err)
+		return
+	}
+	for _, sess := range expired {
+		p.reapCombatSession(sess.UserID, sess.SessionID)
+	}
+}
+
+// reapCombatSession auto-plays a single stale session under the player's lock.
+// It re-fetches the session after locking: the player may have finished the
+// fight in the window between listing and locking, in which case there is
+// nothing to do.
+func (p *AdventurePlugin) reapCombatSession(userIDStr, sessionID string) {
+	userID := id.UserID(userIDStr)
+	userMu := p.advUserLock(userID)
+	userMu.Lock()
+	defer userMu.Unlock()
+
+	sess, err := getActiveCombatSession(userID)
+	if err != nil {
+		slog.Error("combat: reaper failed to reload session", "user", userID, "err", err)
+		return
+	}
+	// Gone, replaced, or no longer the stale one — the player acted first.
+	if sess == nil || sess.SessionID != sessionID {
+		return
+	}
+
+	player, enemy, err := p.combatantsForSession(sess)
+	if err != nil {
+		// Can't reconstruct the fight — park it terminal so it isn't retried
+		// every minute forever.
+		slog.Warn("combat: reaper cannot rebuild session, marking expired",
+			"user", userID, "session", sess.SessionID, "err", err)
+		if merr := markCombatSessionExpired(sess.SessionID); merr != nil {
+			slog.Error("combat: reaper failed to mark session expired", "session", sess.SessionID, "err", merr)
+		}
+		return
+	}
+
+	rounds := 0
+	for sess.IsActive() {
+		if rounds >= reaperRoundCap {
+			slog.Warn("combat: reaper hit round cap, marking expired",
+				"user", userID, "session", sess.SessionID)
+			if merr := markCombatSessionExpired(sess.SessionID); merr != nil {
+				slog.Error("combat: reaper failed to mark session expired", "session", sess.SessionID, "err", merr)
+			}
+			return
+		}
+		if _, rerr := runCombatRound(sess, &player, &enemy, PlayerAction{Kind: ActionAttack}); rerr != nil {
+			slog.Error("combat: reaper round failed", "user", userID, "session", sess.SessionID, "err", rerr)
+			if merr := markCombatSessionExpired(sess.SessionID); merr != nil {
+				slog.Error("combat: reaper failed to mark session expired", "session", sess.SessionID, "err", merr)
+			}
+			return
+		}
+		rounds++
+	}
+
+	outcome := p.finishCombatSession(userID, sess, enemy)
+	preamble := fmt.Sprintf("⏳ Your fight with **%s** timed out — TwinBee finished it for you.\n\n", enemy.Name)
+	if err := p.SendDM(userID, preamble+outcome); err != nil {
+		slog.Error("combat: reaper failed to DM outcome", "user", userID, "err", err)
+	}
+}

internal/plugin/combat_session.go

@@ -249,23 +249,42 @@ func saveCombatSession(s *CombatSession) error {
 	return nil
 }
 
-// sweepExpiredCombatSessions is the timeout reaper. It marks every active
-// session past its expires_at as 'expired' (a terminal status alongside
-// won/lost/fled) and parks it in the 'over' phase. Auto-playing an abandoned
-// fight to a real win/loss needs Combatant reconstruction, which lands with
-// the command-wiring PR; until then 'expired' is the safe terminal outcome —
-// no fatal-blow side effects, treated like a retreat. Returns the sweep count.
-func sweepExpiredCombatSessions() (int, error) {
-	res, err := db.Get().Exec(`
+// listExpiredCombatSessions returns every active session past its expires_at.
+// The timeout reaper (reapExpiredCombatSessions) auto-plays each of these to a
+// real win/loss from persisted mid-state — per the 2026-05-13 decision, an
+// abandoned fight is finished by the engine, not flatly marked as a retreat.
+func listExpiredCombatSessions() ([]*CombatSession, error) {
+	rows, err := db.Get().Query(`SELECT `+combatSessionCols+`
+		  FROM combat_session
+		 WHERE status = 'active'
+		   AND expires_at <= CURRENT_TIMESTAMP
+		 ORDER BY started_at ASC`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var out []*CombatSession
+	for rows.Next() {
+		s, err := scanCombatSession(rows)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, s)
+	}
+	return out, rows.Err()
+}
+
+// markCombatSessionExpired is the fallback terminal outcome for a stale session
+// the reaper cannot auto-play (zone run gone, enemy missing from the bestiary,
+// or a runaway fight that won't converge). It parks the row in 'expired'/'over'
+// with no fatal-blow side effects — treated like a retreat.
+func markCombatSessionExpired(sessionID string) error {
+	_, err := db.Get().Exec(`
 		UPDATE combat_session
 		   SET status = 'expired',
 		       phase = 'over',
 		       last_action_at = CURRENT_TIMESTAMP
-		 WHERE status = 'active'
-		   AND expires_at <= CURRENT_TIMESTAMP`)
-	if err != nil {
-		return 0, err
-	}
-	n, _ := res.RowsAffected()
-	return int(n), nil
+		 WHERE session_id = ? AND status = 'active'`, sessionID)
+	return err
 }

internal/plugin/combat_session_test.go

@@ -88,35 +88,54 @@ func TestStartCombatSession_RejectsConcurrent(t *testing.T) {
 	}
 }
 
-func TestSweepExpiredCombatSessions(t *testing.T) {
+func TestListExpiredCombatSessions(t *testing.T) {
 	setupZoneRunTestDB(t)
 	uid := id.UserID("@combat-sweep:example.org")
+	fresh := id.UserID("@combat-fresh:example.org")
 	defer cleanupCombatSessions(uid)
+	defer cleanupCombatSessions(fresh)
 
 	s, err := startCombatSession(uid, "r", "n", "boss", 60, 60, 200, 200)
 	if err != nil {
 		t.Fatal(err)
 	}
-	// Backdate expiry so the reaper considers it stale.
+	// A second, non-stale session should never show up in the list.
+	if _, err := startCombatSession(fresh, "r2", "n2", "rat", 40, 40, 20, 20); err != nil {
+		t.Fatal(err)
+	}
+	// Backdate expiry so the reaper considers the first one stale.
 	if _, err := db.Get().Exec(
 		`UPDATE combat_session SET expires_at = datetime('now', '-1 hour') WHERE session_id = ?`,
 		s.SessionID); err != nil {
 		t.Fatal(err)
 	}
-	n, err := sweepExpiredCombatSessions()
+
+	expired, err := listExpiredCombatSessions()
 	if err != nil {
-		t.Fatalf("sweep: %v", err)
+		t.Fatalf("list: %v", err)
 	}
-	if n < 1 {
-		t.Errorf("sweep count = %d, want >= 1", n)
+	if len(expired) != 1 {
+		t.Fatalf("expired count = %d, want 1", len(expired))
+	}
+	if expired[0].SessionID != s.SessionID {
+		t.Errorf("expired[0] = %q, want %q", expired[0].SessionID, s.SessionID)
+	}
+
+	// markCombatSessionExpired is the non-auto-play fallback path.
+	if err := markCombatSessionExpired(s.SessionID); err != nil {
+		t.Fatalf("mark expired: %v", err)
 	}
 	if active, _ := getActiveCombatSession(uid); active != nil {
-		t.Errorf("expected no active session after sweep, got %+v", active)
+		t.Errorf("expected no active session after mark, got %+v", active)
 	}
 	reaped, _ := getCombatSession(s.SessionID)
 	if reaped.Status != CombatStatusExpired || reaped.Phase != CombatPhaseOver {
 		t.Errorf("reaped session: status=%q phase=%q", reaped.Status, reaped.Phase)
 	}
+	// The non-stale session is untouched.
+	if again, _ := listExpiredCombatSessions(); len(again) != 0 {
+		t.Errorf("expected 0 expired after mark, got %d", len(again))
+	}
 }
 
 // ── State machine ──────────────────────────────────────────────────────────