Persist the dialogue session so a restart keeps the conversation

Vikunja #363. The follow-up session was a plain in-memory map, so any mavend restart dropped the thread. It now mirrors to a small TTL-pruned sqlite table and is loaded on startup; expired sessions are deleted on load, not revived. Clarify's pending question is untouched. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01CGeSZxh1DCtRxmFVSYVGvJ
2026-07-31 13:20:30 +04:00
parent 1bd2acdc2a
commit c668310b3e
5 changed files with 287 additions and 1 deletions
@@ -1,8 +1,12 @@
 package dialogue

 import (
+	"context"
+	"encoding/json"
 	"sync"
 	"time"
+
+	"github.com/kami/maven/internal/store"
 )

 type Intent string
@@ -50,10 +54,22 @@ func (s *Session) IsExpired(now time.Time) bool {
 	return now.After(s.Timestamp.Add(s.TTL))
 }

+// SessionPersister — the bit of the store the session needs, as an interface
+// so tests can swap it out. Data is an opaque blob: the store never looks
+// inside, we encode the session as JSON here.
+type SessionPersister interface {
+	SaveDialogueSession(ctx context.Context, id string, data []byte, ts time.Time, ttl time.Duration) error
+	DeleteDialogueSession(ctx context.Context, id string) error
+	LoadDialogueSessions(ctx context.Context, now time.Time) ([]store.DialogueSessionRow, error)
+}
+
+// SessionStore keeps the live sessions in a map (the fast path) and mirrors
+// every write to the persister, so a daemon restart can load them back.
 type SessionStore struct {
 	mu         sync.RWMutex
 	sessions   map[string]*Session
 	defaultTTL time.Duration
+	persist    SessionPersister // may be nil: memory only (tests, no-store paths)
 }

 func NewSessionStore(defaultTTL time.Duration) *SessionStore {
@@ -66,6 +82,43 @@ func NewSessionStore(defaultTTL time.Duration) *SessionStore {
 	}
 }

+// NewPersistentSessionStore — same store, but writes also go to the DB.
+// Call Load once after this to bring back sessions from a previous run.
+func NewPersistentSessionStore(defaultTTL time.Duration, p SessionPersister) *SessionStore {
+	s := NewSessionStore(defaultTTL)
+	s.persist = p
+	return s
+}
+
+// Load — read the saved sessions back into memory. Anything past its TTL is
+// dropped (and deleted from the DB by the store), never revived.
+func (s *SessionStore) Load(ctx context.Context, now time.Time) error {
+	if s.persist == nil {
+		return nil
+	}
+	rows, err := s.persist.LoadDialogueSessions(ctx, now)
+	if err != nil {
+		return err
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for _, r := range rows {
+		var sess Session
+		if err := json.Unmarshal(r.Data, &sess); err != nil {
+			// A blob we can't read is not worth failing a startup over.
+			continue
+		}
+		if sess.TTL <= 0 {
+			sess.TTL = r.TTL
+		}
+		if sess.IsExpired(now) {
+			continue
+		}
+		s.sessions[r.ID] = &sess
+	}
+	return nil
+}
+
 func (s *SessionStore) Get(id string, now time.Time) *Session {
 	s.mu.RLock()
 	sess, ok := s.sessions[id]
@@ -87,12 +140,33 @@ func (s *SessionStore) Put(id string, sess *Session) {
 	s.mu.Lock()
 	s.sessions[id] = sess
 	s.mu.Unlock()
+	s.save(id, sess)
 }

 func (s *SessionStore) Delete(id string) {
 	s.mu.Lock()
 	delete(s.sessions, id)
 	s.mu.Unlock()
+	if s.persist != nil {
+		_ = s.persist.DeleteDialogueSession(context.Background(), id)
+	}
+}
+
+// save — mirror one session to the DB. Best effort: memory already has it, so
+// a write error costs us the restart safety net, not the current turn.
+func (s *SessionStore) save(id string, sess *Session) {
+	if s.persist == nil {
+		return
+	}
+	data, err := json.Marshal(sess)
+	if err != nil {
+		return
+	}
+	ts := sess.Timestamp
+	if ts.IsZero() {
+		ts = time.Now()
+	}
+	_ = s.persist.SaveDialogueSession(context.Background(), id, data, ts, sess.TTL)
 }

 func InheritSlots(prev, cur Slots) Slots {
@@ -0,0 +1,118 @@
+package dialogue
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/kami/maven/internal/store"
+)
+
+// openStore — a store on disk, so a second handle can reopen the same file.
+func openStore(t *testing.T, path string) *store.Store {
+	t.Helper()
+	s, err := store.Open(context.Background(), path)
+	if err != nil {
+		t.Fatalf("open store: %v", err)
+	}
+	t.Cleanup(func() { _ = s.Close() })
+	return s
+}
+
+// A session written before a restart comes back and still merges a follow-up.
+func TestSessionSurvivesRestart(t *testing.T) {
+	ctx := context.Background()
+	path := filepath.Join(t.TempDir(), "maven_test.db")
+	now := time.Now().UTC().Truncate(time.Millisecond)
+
+	first := openStore(t, path)
+	before := NewPersistentSessionStore(2*time.Minute, first)
+	before.Put("voice", &Session{
+		Intent:    IntentReminder,
+		Slots:     Slots{Text: "полить цветы", Time: now.Add(time.Hour), HasTime: true},
+		Timestamp: now,
+		TTL:       2 * time.Minute,
+	})
+	if err := first.Close(); err != nil {
+		t.Fatalf("close: %v", err)
+	}
+
+	// fresh handle, fresh in-memory map — as after a daemon restart
+	after := openStore(t, path)
+	reloaded := NewPersistentSessionStore(2*time.Minute, after)
+	if err := reloaded.Load(ctx, now.Add(10*time.Second)); err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	sess := reloaded.Get("voice", now.Add(10*time.Second))
+	if sess == nil {
+		t.Fatal("session did not survive the restart")
+	}
+	if sess.Intent != IntentReminder {
+		t.Fatalf("intent = %q, want reminder", sess.Intent)
+	}
+	// the follow-up carries no text of its own; it must inherit the old one
+	merged := InheritSlots(sess.Slots, Slots{Time: now.Add(2 * time.Hour), HasTime: true})
+	if merged.Text != "полить цветы" {
+		t.Fatalf("merged text = %q, want the earlier turn's text", merged.Text)
+	}
+	if !merged.Time.Equal(now.Add(2 * time.Hour)) {
+		t.Fatalf("merged time = %v, want the follow-up's time", merged.Time)
+	}
+}
+
+// A session past its TTL is dead: a restart must not bring it back.
+func TestExpiredSessionNotResurrected(t *testing.T) {
+	ctx := context.Background()
+	path := filepath.Join(t.TempDir(), "maven_test.db")
+	now := time.Now().UTC().Truncate(time.Millisecond)
+
+	first := openStore(t, path)
+	before := NewPersistentSessionStore(2*time.Minute, first)
+	before.Put("voice", &Session{
+		Intent:    IntentReminder,
+		Slots:     Slots{Text: "полить цветы"},
+		Timestamp: now,
+		TTL:       time.Minute,
+	})
+	if err := first.Close(); err != nil {
+		t.Fatalf("close: %v", err)
+	}
+
+	after := openStore(t, path)
+	reloaded := NewPersistentSessionStore(2*time.Minute, after)
+	later := now.Add(5 * time.Minute) // well past the 1-min TTL
+	if err := reloaded.Load(ctx, later); err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if sess := reloaded.Get("voice", later); sess != nil {
+		t.Fatalf("expired session came back: %+v", sess)
+	}
+	// and it is gone from the DB too, not just from memory
+	rows, err := after.LoadDialogueSessions(ctx, later)
+	if err != nil {
+		t.Fatalf("LoadDialogueSessions: %v", err)
+	}
+	if len(rows) != 0 {
+		t.Fatalf("expired row still in the DB: %+v", rows)
+	}
+}
+
+// Delete removes the row as well, so an ended conversation stays ended.
+func TestDeleteRemovesPersistedSession(t *testing.T) {
+	ctx := context.Background()
+	path := filepath.Join(t.TempDir(), "maven_test.db")
+	now := time.Now().UTC().Truncate(time.Millisecond)
+
+	s := openStore(t, path)
+	ss := NewPersistentSessionStore(2*time.Minute, s)
+	ss.Put("voice", &Session{Intent: IntentChat, Timestamp: now, TTL: time.Minute})
+	ss.Delete("voice")
+	rows, err := s.LoadDialogueSessions(ctx, now)
+	if err != nil {
+		t.Fatalf("LoadDialogueSessions: %v", err)
+	}
+	if len(rows) != 0 {
+		t.Fatalf("row survived Delete: %+v", rows)
+	}
+}