Implement fromchat.ru/@username and fromchat.ru/?u=userId links, mentions

frontend/src/App.tsx

@@ -1,10 +1,11 @@
-import { BrowserRouter, Routes, Route } from "react-router-dom";
+import { BrowserRouter, Routes, Route, useNavigate, matchRoutes, type RouteObject } from "react-router-dom";
 import { ElectronTitleBar } from "./Electron";
 import { useAppState } from "./pages/chat/state";
-import { useEffect, useState, lazy } from "react";
-import ProtectedRoute from "./pages/ProtectedRoute";
-import NotFoundPage from "./pages/not-found/NotFoundPage";
-import DownloadAppPage from "./pages/download-app/DownloadAppPage";
+import { lazy, useEffect, useState } from "react";
+import { parseProfileLink } from "./core/profileLinks.ts";
+import NotFoundPage from "./pages/not-found/NotFoundPage.tsx";
+import ProtectedRoute from "./pages/ProtectedRoute.tsx";
+import DownloadAppPage from "./pages/download-app/DownloadAppPage.tsx";
 
 // Lazy load route components
 const HomePage = lazy(() => import("./pages/home/HomePage"));
@@ -12,11 +13,63 @@ const LoginPage = lazy(() => import("./pages/auth/LoginPage"));
 const RegisterPage = lazy(() => import("./pages/auth/RegisterPage"));
 const ChatPage = lazy(() => import("./pages/chat/ui/ChatPage"));
 
+const routeConfig: RouteObject[] = [
+    { path: "/", element: <HomePage /> },
+    { path: "/login", element: <LoginPage /> },
+    { path: "/register", element: <RegisterPage /> },
+    { path: "/download-app", element: <DownloadAppPage /> },
+    {
+        path: "/chat", 
+        element: (
+            <ProtectedRoute>
+                <ChatPage />
+            </ProtectedRoute>
+        ) 
+    },
+    { path: "*", element: <SmartCatchAll /> }
+];
+
+function SmartCatchAll() {
+    const navigate = useNavigate();
+    const [showNotFound, setShowNotFound] = useState(false);
+
+    function isValidRoute(path: string): boolean {
+        const validRoutes = routeConfig.filter(route => route.path !== "*");
+        const matches = matchRoutes(validRoutes, path);
+        
+        return Boolean(matches && matches.length > 0);
+    }
+
+    useEffect(() => {
+        if (isValidRoute(location.pathname)) {
+            setShowNotFound(false);
+            return;
+        }
+        
+        // Check if it's a profile link
+        const profileInfo = parseProfileLink(); // no url specified intentionally to let it use the current url
+        
+        if (profileInfo) {
+            setShowNotFound(false);
+            navigate("/chat", { 
+                replace: true,
+                state: { profileInfo }
+            });
+        } else {
+            setShowNotFound(true);
+        }
+    }, [navigate]);
+
+    // Show 404 page
+    if (showNotFound) {
+        return <NotFoundPage />;
+    }
+}
+
 export default function App() {
     const { restoreUserFromStorage } = useAppState();
     const [authReady, setAuthReady] = useState(false);
 
-    // Restore user from localStorage on app initialization
     useEffect(() => {
         restoreUserFromStorage().finally(() => {
             setAuthReady(true);
@@ -28,18 +81,9 @@ export default function App() {
             <ElectronTitleBar />
             <div id="main-wrapper">
                 <Routes>
-                    <Route path="/" element={<HomePage />} />
-                    <Route path="/login" element={<LoginPage />} />
-                    <Route path="/register" element={<RegisterPage />} />
-                    <Route path="/download-app" element={<DownloadAppPage />} />
-                    <Route path="/">
-                        <Route path="chat" element={
-                            <ProtectedRoute>
-                                <ChatPage />
-                            </ProtectedRoute>
-                        } />
-                    </Route>
-                    <Route path="*" element={<NotFoundPage />} />
+                    {routeConfig.map((route, index) => (
+                        <Route key={index} path={route.path} element={route.element} />
+                    ))}
                 </Routes>
             </div>
         </BrowserRouter>

frontend/src/core/profileLinks.ts

@@ -0,0 +1,39 @@
+/**
+ * @fileoverview Utility functions for handling profile links
+ * @description Functions to parse and handle profile links in markdown content.
+ * Supports two formats:
+ * - fromchat.ru/@username (e.g., fromchat.ru/@john_doe)
+ * - fromchat.ru/?u=<userId> (e.g., fromchat.ru/?u=123)
+ * @author Cursor
+ * @version 1.0.0
+ */
+
+import escapeStringRegexp from "escape-string-regexp";
+
+/**
+ * Parses a profile link URL and extracts user information
+ * @param url - The URL to parse
+ * @returns Object with user ID and username if it's a valid profile link, null otherwise
+ */
+export function parseProfileLink(url: string = location.pathname): { userId?: number; username?: string } | null {
+    try {
+        let host: string = url.startsWith("@") ? "" : !url.startsWith("/") ? "https://fromchat.ru/" : "/";
+
+        // Handle fromchat.ru/@username format
+        const usernameMatch = url.match(new RegExp(`${escapeStringRegexp(host)}@([a-zA-Z0-9_-]+)`));
+        if (usernameMatch) {
+            return { username: usernameMatch[1] };
+        }
+
+        // Handle fromchat.ru/?u=<userId> format
+        const userIdMatch = url.match(new RegExp(`${escapeStringRegexp(host)}\\?u=(\\d+)`));
+        if (userIdMatch) {
+            return { userId: Number(userIdMatch[1]) };
+        }
+
+        return null;
+    } catch (error) {
+        console.error('Error parsing profile link:', error);
+        return null;
+    }
+}

frontend/src/pages/chat/css/_message.scss

@@ -375,3 +375,25 @@
         justify-content: center;
     }
 }
+
+// Mention link styling
+.message-content {
+    .mention-link {
+        color: $color-dark-primary;
+        text-decoration: none;
+        font-weight: 500;
+        border-radius: 4px;
+        padding: 2px 4px;
+        transition: all 0.2s ease;
+        background-color: rgba(145, 206, 244, 0.1); // TODO adjust
+        
+        &:hover {
+            background-color: rgba(145, 206, 244, 0.2); // TODO adjust
+            transform: translateY(-1px);
+        }
+        
+        &:active {
+            transform: translateY(0);
+        }
+    }
+}

frontend/src/pages/chat/ui/ChatPage.tsx

@@ -3,9 +3,69 @@ import { RightPanel } from "./right/RightPanel";
 import "@/pages/chat/css/chat.scss";
 import useDownloadAppScreen from "@/core/hooks/useDownloadAppScreen";
 import { CallWindow } from "./right/calls/CallWindow";
+import { useEffect, useRef } from "react";
+import { useLocation, useNavigate } from "react-router-dom";
+import { useAppState } from "@/pages/chat/state";
+import { fetchUserProfileById, fetchUserProfile } from "@/core/api/profileApi";
 
 export default function ChatPage() {
     const { navigate: navigateDownloadApp } = useDownloadAppScreen();
+    const location = useLocation();
+    const navigate = useNavigate();
+    const { user, setProfileDialog } = useAppState();
+    const processedProfile = useRef<string | null>(null);
+
+    // Handle profile links ONLY from navigation state (from SmartCatchAll)
+    useEffect(() => {
+        async function handleProfileLink() {
+            if (!user.authToken) return;
+
+            // Only process profile links that come from navigation state (SmartCatchAll)
+            // This prevents re-processing on page refresh
+            if (!location.state?.profileInfo) return;
+
+            const profileInfo = location.state.profileInfo;
+            
+            // Create a unique key for this profile
+            const profileKey = profileInfo.userId 
+                ? `user_${profileInfo.userId}` 
+                : `username_${profileInfo.username}`;
+            
+            // Skip if we've already processed this exact profile
+            if (processedProfile.current === profileKey) return;
+            
+            processedProfile.current = profileKey; // Mark this specific profile as processed
+            
+            try {
+                let userProfile;
+                
+                if (profileInfo.userId) {
+                    // Fetch by user ID
+                    userProfile = await fetchUserProfileById(user.authToken, profileInfo.userId);
+                } else if (profileInfo.username) {
+                    // Fetch by username
+                    userProfile = await fetchUserProfile(user.authToken, profileInfo.username);
+                }
+                
+                if (userProfile) {
+                    setProfileDialog({
+                        ...userProfile,
+                        userId: userProfile.id,
+                        memberSince: userProfile.created_at,
+                        isOwnProfile: userProfile.id === user.currentUser?.id
+                    });
+                }
+                
+                // Clear the navigation state to prevent re-processing on refresh
+                navigate(location.pathname, { replace: true, state: null });
+            } catch (error) {
+                console.error("Failed to fetch user profile from URL:", error);
+            }
+        }
+
+        handleProfileLink();
+    }, [location.state, user.authToken, user.currentUser?.id, setProfileDialog, navigate, location.pathname]);
+
     if (navigateDownloadApp) return navigateDownloadApp;
 
     return (

frontend/src/pages/chat/ui/right/Message.tsx

@@ -10,10 +10,11 @@ import { ecdhSharedSecret, deriveWrappingKey } from "@/utils/crypto/asymmetric";
 import { importAesGcmKey, aesGcmDecrypt } from "@/utils/crypto/symmetric";
 import { getAuthHeaders } from "@/core/api/authApi";
 import { useAppState } from "@/pages/chat/state";
-import { fetchUserProfileById } from "@/core/api/profileApi";
+import { fetchUserProfileById, fetchUserProfile } from "@/core/api/profileApi";
 import { ub64 } from "@/utils/utils";
 import { useImmer } from "use-immer";
 import { createPortal } from "react-dom";
+import { parseProfileLink } from "@/core/profileLinks";
 
 interface MessageReactionsProps {
     reactions?: Reaction[];
@@ -147,7 +148,6 @@ interface Rect {
 }
 
 export function Message({ message, isAuthor, onContextMenu, onReactionClick, isDm = false, dmRecipientPublicKey }: MessageProps) {
-    const [formattedMessage, setFormattedMessage] = useState({ __html: "" });
     const [decryptedFiles, updateDecryptedFiles] = useImmer<Map<string, string>>(new Map());
     const [loadedImages, updateLoadedImages] = useImmer<Set<string>>(new Set());
     const [downloadingPaths, updateDownloadingPaths] = useImmer<Set<string>>(new Set());
@@ -164,15 +164,29 @@ export function Message({ message, isAuthor, onContextMenu, onReactionClick, isD
     const imageRefs = useRef<Map<string, HTMLImageElement>>(new Map());
     const dmEnvelope = message.runtimeData?.dmEnvelope;
 
-    useEffect(() => {
-        (async () => {
-            setFormattedMessage({
-                __html: DOMPurify.sanitize(
-                    await parse(message.content)
-                ).trim()
+    const formattedMessage = useMemo(() => {
+        // First, temporarily replace existing fromchat.ru links to avoid conflicts
+        const linkPlaceholders: string[] = [];
+        let content = message.content.replace(/https?:\/\/fromchat\.ru\/@[a-zA-Z0-9_.-]+/g, (match) => {
+            const placeholder = `__LINK_PLACEHOLDER_${linkPlaceholders.length}__`;
+            linkPlaceholders.push(match);
+            return placeholder;
         });
-        })();
-    }, [message]);
+
+        // Now process @mentions that aren't in existing links
+        content = content.replace(/@([a-zA-Z0-9_.-]+)/g, (match, username) => {
+            return `<a href="https://fromchat.ru/@${username}" class="mention-link">${match}</a>`;
+        });
+
+        // Restore the original links
+        linkPlaceholders.forEach((link, index) => {
+            content = content.replace(`__LINK_PLACEHOLDER_${index}__`, link);
+        });
+
+        return {
+            __html: DOMPurify.sanitize(parse(content, { async: false })).trim()
+        };
+    }, [message.content]);
 
     // Auto-decrypt images in DMs
     useEffect(() => {
@@ -406,6 +420,44 @@ export function Message({ message, isAuthor, onContextMenu, onReactionClick, isD
         }
     }
 
+    async function handleLinkClick(e: React.MouseEvent<HTMLDivElement>) {
+        const target = e.target as HTMLElement;
+        
+        if (target.tagName === 'A') {
+            const profileLink = parseProfileLink((target as HTMLAnchorElement).href);
+            
+            if (profileLink) {
+                e.preventDefault();
+                e.stopPropagation();
+                
+                if (!user.authToken) return;
+                
+                try {
+                    let userProfile;
+                    
+                    if (profileLink.userId) {
+                        userProfile = await fetchUserProfileById(user.authToken, profileLink.userId);
+                    } else if (profileLink.username) {
+                        userProfile = await fetchUserProfile(user.authToken, profileLink.username);
+                    }
+                    
+                    if (userProfile) {
+                        setProfileDialog({
+                            ...userProfile,
+                            userId: userProfile.id,
+                            memberSince: userProfile.created_at,
+                            isOwnProfile: userProfile.id === user.currentUser?.id
+                        });
+                    } else {
+                        throw new Error("Invalid link: " + (target as HTMLAnchorElement).href);
+                    }
+                } catch (error) {
+                    console.error("Failed to fetch user profile from link:", error);
+                }
+            }
+        }
+    }
+
     function handleContextMenu(e: React.MouseEvent) {
         e.preventDefault();
         e.stopPropagation();
@@ -460,7 +512,11 @@ export function Message({ message, isAuthor, onContextMenu, onReactionClick, isD
                         </Quote>
                     )}
 
-                    <div className={`message-content ${isEmojiMessage ? "emoji-content" : ""} ${isSingleEmojiMessage ? "single-emoji-content" : ""}`} dangerouslySetInnerHTML={formattedMessage} />
+                    <div 
+                        className={`message-content ${isEmojiMessage ? "emoji-content" : ""} ${isSingleEmojiMessage ? "single-emoji-content" : ""}`} 
+                        dangerouslySetInnerHTML={formattedMessage}
+                        onClick={handleLinkClick}
+                    />
 
                     {message.files && message.files.length > 0 && (
                         <mdui-list className="message-attachments">

package.json

@@ -65,6 +65,7 @@
     "dependencies": {
         "dompurify": "^3.2.7",
         "electron-squirrel-startup": "^1.0.1",
+        "escape-string-regexp": "^5.0.0",
         "marked": "^16.3.0",
         "mdui": "^2.1.4",
         "react": "^19.1.1",