feat(composer): persist text + reply target per chat across restarts

apps/desktop/src/App.tsx

@@ -1,4 +1,4 @@
-import { lazy, Suspense } from 'react';
+import { lazy, Suspense, useEffect } from 'react';
 import { HashRouter, Navigate, Outlet, Route, Routes, useParams } from 'react-router-dom';
 
 import { AppShell } from './components/AppShell';
@@ -13,6 +13,7 @@ import { CallProvider } from './context/CallContext';
 import { ConversationsProvider } from './context/ConversationsContext';
 import { FriendshipsProvider } from './context/FriendshipsContext';
 import { ThemeProvider } from './context/ThemeContext';
+import { hydrateDrafts } from './lib/composerDraftStore';
 import { AuthPage } from './pages/AuthPage';
 import { ChatsEmptyState, ChatsPage } from './pages/ChatsPage';
 import { ConversationPage } from './pages/ConversationPage';
@@ -73,6 +74,10 @@ function ConversationRoute() {
 }
 
 export function App() {
+  useEffect(() => {
+    void hydrateDrafts();
+  }, []);
+
   return (
     <ErrorBoundary scope="root">
       <ThemeProvider>

apps/desktop/src/lib/composerDraftStore.test.ts

@@ -0,0 +1,79 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import {
+  __resetForTests,
+  clearDraft,
+  getDraftSync,
+  hasDraft,
+  hydrateDrafts,
+  setDraft,
+} from './composerDraftStore';
+
+const sqlExecuteMock = vi.fn().mockResolvedValue(undefined);
+const sqlSelectMock = vi.fn().mockResolvedValue([]);
+const sqlLoadMock = vi.fn().mockResolvedValue('mock-handle');
+
+vi.stubGlobal('window', {
+  electronAPI: {
+    platform: 'electron-chatapp-v1',
+    sqlLoad: sqlLoadMock,
+    sqlExecute: sqlExecuteMock,
+    sqlSelect: sqlSelectMock,
+  },
+});
+
+describe('composerDraftStore', () => {
+  beforeEach(() => {
+    sqlExecuteMock.mockClear();
+    sqlSelectMock.mockClear();
+    sqlLoadMock.mockClear();
+    __resetForTests();
+  });
+
+  afterEach(() => {
+    __resetForTests();
+  });
+
+  it('returns null for an unknown conversation', () => {
+    expect(getDraftSync('unknown')).toBeNull();
+    expect(hasDraft('unknown')).toBe(false);
+  });
+
+  it('stores and returns a draft synchronously after set', () => {
+    setDraft('a', { text: 'hi', replyToId: null });
+    const draft = getDraftSync('a');
+    expect(draft).not.toBeNull();
+    expect(draft?.text).toBe('hi');
+    expect(draft?.replyToId).toBeNull();
+    expect(hasDraft('a')).toBe(true);
+  });
+
+  it('isolates drafts per conversation', () => {
+    setDraft('a', { text: 'one', replyToId: null });
+    setDraft('b', { text: 'two', replyToId: 'msg-9' });
+    expect(getDraftSync('a')?.text).toBe('one');
+    expect(getDraftSync('b')?.replyToId).toBe('msg-9');
+  });
+
+  it('clearDraft removes the draft from memory', () => {
+    setDraft('a', { text: 'one', replyToId: null });
+    clearDraft('a');
+    expect(getDraftSync('a')).toBeNull();
+    expect(hasDraft('a')).toBe(false);
+  });
+
+  it('treats an empty-string text + null reply as "no draft"', () => {
+    setDraft('a', { text: '', replyToId: null });
+    expect(getDraftSync('a')).toBeNull();
+    expect(hasDraft('a')).toBe(false);
+  });
+
+  it('hydrateDrafts populates the in-memory map from SQLite rows', async () => {
+    sqlSelectMock.mockResolvedValueOnce([
+      { conversation_id: 'a', text: 'persisted', reply_to_id: 'msg-1', updated_at: '2026-05-17T00:00:00Z' },
+    ]);
+    await hydrateDrafts();
+    expect(getDraftSync('a')?.text).toBe('persisted');
+    expect(getDraftSync('a')?.replyToId).toBe('msg-1');
+  });
+});

apps/desktop/src/lib/composerDraftStore.ts

@@ -0,0 +1,160 @@
+// Composer-draft persistence. Two-tier semantics:
+//   * In-memory `Map<convId, Draft>` for instant synchronous reads on
+//     mount (mirrors the `messageMemoryCache` pattern from Phase 7).
+//   * SQLite (`composer_drafts` table, schema in `messageCache.ts`) for
+//     cross-restart persistence. Writes are debounced and fire-and-forget
+//     — losing the last 400ms of typing on a hard crash is acceptable;
+//     blocking the keystroke handler is not.
+//
+// Attachments are intentionally NOT serialized:
+//   * Files don't round-trip through SQLite cleanly (binary blobs blow
+//     up the cache size).
+//   * `replyToId` IS persisted; the consuming page looks up the actual
+//     message by id at render time.
+
+import { isTauriRuntime } from './globalShortcut';
+
+const DB_NAME = 'chatapp-cache';
+const WRITE_DEBOUNCE_MS = 400;
+
+interface Draft {
+  text: string;
+  replyToId: string | null;
+}
+
+interface DraftRow {
+  conversation_id: string;
+  text: string;
+  reply_to_id: string | null;
+  updated_at: string;
+}
+
+const drafts = new Map<string, Draft>();
+const pendingWrites = new Map<string, ReturnType<typeof setTimeout>>();
+let handlePromise: Promise<string | null> | null = null;
+
+async function getHandle(): Promise<string | null> {
+  if (handlePromise) return handlePromise;
+  if (!isTauriRuntime()) {
+    handlePromise = Promise.resolve(null);
+    return handlePromise;
+  }
+  handlePromise = (async () => {
+    try {
+      const handle = await window.electronAPI.sqlLoad({ name: DB_NAME });
+      // Self-contained DDL — the same statement also runs from
+      // `messageCache.ts`'s init path, but we don't want to depend on
+      // call order. SQLite's `CREATE TABLE IF NOT EXISTS` is idempotent
+      // so the double-creation is safe.
+      await window.electronAPI.sqlExecute({
+        handle,
+        query:
+          `CREATE TABLE IF NOT EXISTS composer_drafts (
+             conversation_id TEXT PRIMARY KEY,
+             text TEXT NOT NULL,
+             reply_to_id TEXT,
+             updated_at TEXT NOT NULL
+           )`,
+        bindings: [],
+      });
+      return handle;
+    } catch (err: unknown) {
+      console.warn('composerDraftStore: sqlLoad failed', err);
+      return null;
+    }
+  })();
+  return handlePromise;
+}
+
+export function getDraftSync(conversationId: string): Draft | null {
+  const stored = drafts.get(conversationId);
+  if (!stored) return null;
+  return { text: stored.text, replyToId: stored.replyToId };
+}
+
+export function hasDraft(conversationId: string): boolean {
+  return drafts.has(conversationId);
+}
+
+export function setDraft(conversationId: string, draft: Draft): void {
+  if (draft.text.length === 0 && draft.replyToId === null) {
+    if (drafts.has(conversationId)) {
+      drafts.delete(conversationId);
+      scheduleWrite(conversationId);
+    }
+    return;
+  }
+  drafts.set(conversationId, { text: draft.text, replyToId: draft.replyToId });
+  scheduleWrite(conversationId);
+}
+
+export function clearDraft(conversationId: string): void {
+  if (!drafts.has(conversationId)) return;
+  drafts.delete(conversationId);
+  scheduleWrite(conversationId);
+}
+
+function scheduleWrite(conversationId: string): void {
+  const existing = pendingWrites.get(conversationId);
+  if (existing) clearTimeout(existing);
+  const timer = setTimeout(() => {
+    pendingWrites.delete(conversationId);
+    void flushOne(conversationId);
+  }, WRITE_DEBOUNCE_MS);
+  pendingWrites.set(conversationId, timer);
+}
+
+async function flushOne(conversationId: string): Promise<void> {
+  const handle = await getHandle();
+  if (!handle) return;
+  const draft = drafts.get(conversationId);
+  try {
+    if (draft) {
+      await window.electronAPI.sqlExecute({
+        handle,
+        query:
+          `INSERT INTO composer_drafts (conversation_id, text, reply_to_id, updated_at)
+           VALUES ($1, $2, $3, $4)
+           ON CONFLICT(conversation_id) DO UPDATE SET
+             text = excluded.text,
+             reply_to_id = excluded.reply_to_id,
+             updated_at = excluded.updated_at`,
+        bindings: [conversationId, draft.text, draft.replyToId, new Date().toISOString()],
+      });
+    } else {
+      await window.electronAPI.sqlExecute({
+        handle,
+        query: 'DELETE FROM composer_drafts WHERE conversation_id = $1',
+        bindings: [conversationId],
+      });
+    }
+  } catch (err: unknown) {
+    console.warn('composerDraftStore: flush failed', err);
+  }
+}
+
+export async function hydrateDrafts(): Promise<void> {
+  const handle = await getHandle();
+  if (!handle) return;
+  try {
+    const rows = (await window.electronAPI.sqlSelect({
+      handle,
+      query: 'SELECT conversation_id, text, reply_to_id, updated_at FROM composer_drafts',
+      bindings: [],
+    })) as unknown as DraftRow[];
+    for (const r of rows) {
+      if (!r.conversation_id || typeof r.text !== 'string') continue;
+      if (r.text.length === 0 && r.reply_to_id === null) continue;
+      drafts.set(r.conversation_id, { text: r.text, replyToId: r.reply_to_id });
+    }
+  } catch (err: unknown) {
+    console.warn('composerDraftStore: hydrate failed', err);
+  }
+}
+
+export function __resetForTests(): void {
+  for (const t of pendingWrites.values()) clearTimeout(t);
+  pendingWrites.clear();
+  drafts.clear();
+  handlePromise = null;
+}

apps/desktop/src/pages/ConversationPage.tsx

@@ -78,6 +78,7 @@ import { markRead as markMessagesReadRemote, useMessageReads } from '../lib/useM
 import { usePeerPresence } from '../lib/usePeerPresence';
 import { usePinnedMessages } from '../lib/usePinnedMessages';
 import { useTypingChannel } from '../lib/useTypingChannel';
+import { clearDraft, getDraftSync, setDraft } from '../lib/composerDraftStore';
 
 // Discriminated union for rows inside the virtualized message list. Keeping
 // pending bubbles and the "load older" tile inside the same Virtuoso
@@ -200,7 +201,10 @@ export function ConversationPage() {
     });
   }, [id, messages, myId]);
 
-  const [text, setText] = useState('');
+  const [text, setText] = useState<string>(() => {
+    if (!id) return '';
+    return getDraftSync(id)?.text ?? '';
+  });
   const [sending, setSending] = useState(false);
   const [sendError, setSendError] = useState<string | null>(null);
   const [stickToBottom, setStickToBottom] = useState(true);
@@ -304,6 +308,21 @@ export function ConversationPage() {
   const fileInputRef = useRef<HTMLInputElement>(null);
   const composerRef = useRef<HTMLTextAreaElement>(null);
 
+  useEffect(() => {
+    if (!id) return;
+    const draft = getDraftSync(id);
+    const savedReplyToId = draft?.replyToId ?? null;
+    if (!savedReplyToId) return;
+    if (replyTo?.id === savedReplyToId) return;
+    const match = messages.find((m) => m.id === savedReplyToId);
+    if (match) setReplyTo(match);
+  }, [id, messages, replyTo?.id]);
+
+  useEffect(() => {
+    if (!id) return;
+    setDraft(id, { text, replyToId: replyTo?.id ?? null });
+  }, [id, text, replyTo?.id]);
+
   useEffect(() => {
     if (firstUnreadComputedRef.current) return;
     if (!id || messages.length === 0) return;
@@ -753,6 +772,7 @@ export function ConversationPage() {
       if (fileInputRef.current) fileInputRef.current.value = '';
       setStickToBottom(true);
       notifyStopTyping();
+      if (id) clearDraft(id);
     } catch (err: unknown) {
       const code = extractErrorCode(err);
       setSendError(