changes

components/Chat/ChatLayout.tsx

@@ -33,6 +33,14 @@ import { useDisclosure } from '@mantine/hooks';
 import { getInstalledModels, type OllamaModel } from '@/app/actions/ollama';
 import { useThemeContext } from '@/components/DynamicThemeProvider';
 import { SettingsModal } from '@/components/Settings/SettingsModal';
+import {
+  addMessageToLocalChat,
+  getLocalChat,
+  getLocalChats,
+  mergeChats,
+  saveLocalChat,
+  setLocalChats,
+} from '@/lib/chatStorage';
 import { MarkdownMessage } from './MarkdownMessage';
 import classes from './ChatLayout.module.css';
 
@@ -155,22 +163,28 @@ export default function ChatLayout() {
   };
 
   const fetchChats = async () => {
+    // Load from localStorage first for instant display
+    const localChats = getLocalChats();
+    if (localChats.length > 0) {
+      setChats(localChats);
+    }
+
+    // Then fetch from database and merge
     setIsLoadingChats(true);
     try {
       const res = await fetch('/api/chats');
       if (res.ok) {
-        const data = await res.json();
-        if (Array.isArray(data)) {
-          setChats(data);
-        } else {
-          setChats([]);
+        const remoteChats = await res.json();
+        if (Array.isArray(remoteChats)) {
+          // Merge local and remote, update both state and localStorage
+          const merged = mergeChats(localChats, remoteChats);
+          setChats(merged);
+          setLocalChats(merged);
         }
-      } else {
-        setChats([]);
       }
     } catch (e) {
-      console.error('Failed to fetch chats', e);
-      setChats([]);
+      console.error('Failed to fetch chats from server:', e);
+      // Keep using local chats if server fails
     } finally {
       setIsLoadingChats(false);
     }
@@ -178,14 +192,27 @@ export default function ChatLayout() {
 
   const handleSelectChat = (chat: Chat) => {
     setActiveChatId(chat.id);
-    if (chat.messages) {
+
+    // Try to load from localStorage first (faster), fall back to passed chat data
+    const localChat = getLocalChat(chat.id);
+    if (localChat?.messages && localChat.messages.length > 0) {
+      setMessages(localChat.messages);
+    } else if (chat.messages) {
       setMessages(chat.messages);
     } else {
       setMessages([]);
     }
+
     if (mobileOpened) {
       toggleMobile();
     }
+    // Scroll to bottom after messages load
+    setTimeout(() => {
+      const viewport = scrollViewportRef.current;
+      if (viewport) {
+        viewport.scrollTop = viewport.scrollHeight;
+      }
+    }, 0);
   };
 
   const handleNewChat = () => {
@@ -274,9 +301,9 @@ export default function ChatLayout() {
         content: fullContent,
       };
 
-      // Save both user message and assistant response to database
+      // Save to both localStorage and database
       try {
-        // Save user message
+        // Save user message to database
         const userSaveRes = await fetch('/api/chats', {
           method: 'POST',
           headers: { 'Content-Type': 'application/json' },
@@ -287,13 +314,14 @@ export default function ChatLayout() {
         });
         const userSaveData = await userSaveRes.json();
         const savedChatId = userSaveData.chatId;
+        const chatTitle = userSaveData.title || userMessage.content.slice(0, 50);
 
         // Update activeChatId if this was a new chat
         if (!activeChatId && savedChatId) {
           setActiveChatId(savedChatId);
         }
 
-        // Save assistant response
+        // Save assistant response to database
         await fetch('/api/chats', {
           method: 'POST',
           headers: { 'Content-Type': 'application/json' },
@@ -303,6 +331,15 @@ export default function ChatLayout() {
           }),
         });
 
+        // Save to localStorage
+        const finalMessages = [...newMessages, responseMessage];
+        saveLocalChat({
+          id: savedChatId,
+          title: chatTitle,
+          updatedAt: new Date().toISOString(),
+          messages: finalMessages,
+        });
+
         // Refresh chat list
         fetchChats();
       } catch (saveError) {

lib/chatStorage.ts

@@ -0,0 +1,135 @@
+/**
+ * Local storage utilities for chat persistence
+ * Provides fast local access while syncing with the database
+ */
+
+interface Message {
+  id: string;
+  role: 'user' | 'assistant';
+  content: string;
+}
+
+interface Chat {
+  id: string;
+  title: string;
+  updatedAt: string;
+  messages: Message[];
+}
+
+const CHATS_STORAGE_KEY = 'chat-gpz-chats';
+
+/**
+ * Get all chats from localStorage
+ */
+export function getLocalChats(): Chat[] {
+  if (typeof window === 'undefined') {
+    return [];
+  }
+  try {
+    const stored = localStorage.getItem(CHATS_STORAGE_KEY);
+    if (!stored) {
+      return [];
+    }
+    return JSON.parse(stored) as Chat[];
+  } catch (e) {
+    console.error('Failed to parse local chats:', e);
+    return [];
+  }
+}
+
+/**
+ * Save all chats to localStorage
+ */
+export function setLocalChats(chats: Chat[]): void {
+  if (typeof window === 'undefined') {
+    return;
+  }
+  try {
+    localStorage.setItem(CHATS_STORAGE_KEY, JSON.stringify(chats));
+  } catch (e) {
+    console.error('Failed to save local chats:', e);
+  }
+}
+
+/**
+ * Get a single chat by ID from localStorage
+ */
+export function getLocalChat(chatId: string): Chat | null {
+  const chats = getLocalChats();
+  return chats.find((c) => c.id === chatId) || null;
+}
+
+/**
+ * Save or update a single chat in localStorage
+ */
+export function saveLocalChat(chat: Chat): void {
+  const chats = getLocalChats();
+  const existingIndex = chats.findIndex((c) => c.id === chat.id);
+
+  if (existingIndex >= 0) {
+    chats[existingIndex] = chat;
+  } else {
+    chats.unshift(chat); // Add to beginning (most recent)
+  }
+
+  setLocalChats(chats);
+}
+
+/**
+ * Add a message to an existing chat in localStorage
+ */
+export function addMessageToLocalChat(chatId: string, message: Message): void {
+  const chats = getLocalChats();
+  const chat = chats.find((c) => c.id === chatId);
+
+  if (chat) {
+    chat.messages.push(message);
+    chat.updatedAt = new Date().toISOString();
+    setLocalChats(chats);
+  }
+}
+
+/**
+ * Delete a chat from localStorage
+ */
+export function deleteLocalChat(chatId: string): void {
+  const chats = getLocalChats();
+  const filtered = chats.filter((c) => c.id !== chatId);
+  setLocalChats(filtered);
+}
+
+/**
+ * Merge remote chats with local chats
+ * Remote chats take precedence for conflicts (based on updatedAt)
+ */
+export function mergeChats(localChats: Chat[], remoteChats: Chat[]): Chat[] {
+  const chatMap = new Map<string, Chat>();
+
+  // Add local chats first
+  for (const chat of localChats) {
+    chatMap.set(chat.id, chat);
+  }
+
+  // Override with remote chats (they're the source of truth)
+  for (const chat of remoteChats) {
+    const local = chatMap.get(chat.id);
+    if (!local || new Date(chat.updatedAt) >= new Date(local.updatedAt)) {
+      chatMap.set(chat.id, chat);
+    }
+  }
+
+  // Sort by updatedAt descending
+  return Array.from(chatMap.values()).sort(
+    (a, b) => new Date(b.updatedAt).getTime() - new Date(a.updatedAt).getTime()
+  );
+}
+
+/**
+ * Clear all local chats (useful for logout)
+ */
+export function clearLocalChats(): void {
+  if (typeof window === 'undefined') {
+    return;
+  }
+  localStorage.removeItem(CHATS_STORAGE_KEY);
+}