From d6b7ecc8fd2c0ad92519c0be22de6b6f6752f035 Mon Sep 17 00:00:00 2001
From: talksik <patel.arjun50@gmail.com>
Date: Sat, 21 Mar 2026 12:46:23 -0700
Subject: [PATCH] feat: support sending and preview links

---
 js/src/components/link-preview-card.tsx       | 104 +++++++++++++++
 js/src/electron.d.ts                          |  22 +++-
 js/src/features/compose/text-compose-step.tsx | 122 +++++++++++++-----
 .../features/particles/text-particle-view.tsx |  87 ++++++++++---
 js/src/hooks/use-link-metadata.ts             |  19 +++
 js/src/lib/link-metadata.ts                   |  14 ++
 js/src/main.ts                                | 118 ++++++++++++++++-
 js/src/preload.ts                             |   5 +
 8 files changed, 431 insertions(+), 60 deletions(-)
 create mode 100644 js/src/components/link-preview-card.tsx
 create mode 100644 js/src/hooks/use-link-metadata.ts
 create mode 100644 js/src/lib/link-metadata.ts

diff --git a/js/src/components/link-preview-card.tsx b/js/src/components/link-preview-card.tsx
new file mode 100644
index 0000000..f6ef363
--- /dev/null
+++ b/js/src/components/link-preview-card.tsx
@@ -0,0 +1,104 @@
+import { Copy, ExternalLink, Globe } from "lucide-react";
+import type { LinkMetadata } from "@/lib/link-metadata";
+import { Skeleton } from "@/components/ui/skeleton";
+import { Button } from "@/components/ui/button";
+import { cn } from "@/lib/utils";
+
+interface LinkPreviewCardProps {
+  metadata: LinkMetadata;
+  compact?: boolean;
+}
+
+export function LinkPreviewCard({ metadata, compact }: LinkPreviewCardProps) {
+  const handleOpen = (e: React.MouseEvent) => {
+    e.stopPropagation();
+    window.electronLink.openExternal(metadata.url);
+  };
+
+  const handleCopy = (e: React.MouseEvent) => {
+    e.stopPropagation();
+    navigator.clipboard.writeText(metadata.url);
+  };
+
+  return (
+    <div
+      className="max-w-sm overflow-hidden rounded-2xl bg-white/10 backdrop-blur-md"
+      onClick={(e) => e.stopPropagation()}
+    >
+      {metadata.image && (
+        <img
+          src={metadata.image}
+          alt=""
+          className="h-32 w-full object-cover"
+          onError={(e) => {
+            (e.target as HTMLImageElement).style.display = "none";
+          }}
+        />
+      )}
+      <div className="flex flex-col gap-1 p-3">
+        <div className="flex items-center gap-1.5 text-xs text-white/50">
+          {metadata.favicon ? (
+            <img
+              src={metadata.favicon}
+              alt=""
+              className="size-4 rounded-sm"
+              onError={(e) => {
+                (e.target as HTMLImageElement).replaceWith(
+                  document.createElement("span"),
+                );
+              }}
+            />
+          ) : (
+            <Globe className="size-4" />
+          )}
+          <span className="truncate">{metadata.domain}</span>
+        </div>
+        {metadata.title && (
+          <p className="truncate text-sm font-semibold leading-snug text-white">
+            {metadata.title}
+          </p>
+        )}
+        {metadata.description && (
+          <p className="line-clamp-2 text-xs leading-relaxed text-white/70">
+            {metadata.description}
+          </p>
+        )}
+        {!compact && (
+          <div className="mt-1.5 flex gap-2">
+            <Button
+              variant="ghost"
+              size="xs"
+              className="text-white/70 hover:bg-white/10 hover:text-white"
+              onClick={handleOpen}
+            >
+              <ExternalLink data-icon="inline-start" />
+              Open
+            </Button>
+            <Button
+              variant="ghost"
+              size="xs"
+              className="text-white/70 hover:bg-white/10 hover:text-white"
+              onClick={handleCopy}
+            >
+              <Copy data-icon="inline-start" />
+              Copy
+            </Button>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
+
+export function LinkPreviewCardSkeleton() {
+  return (
+    <div className="max-w-sm overflow-hidden rounded-2xl bg-white/10 backdrop-blur-md">
+      <Skeleton className="h-32 w-full rounded-none bg-white/5" />
+      <div className="flex flex-col gap-2 p-3">
+        <Skeleton className="h-3 w-24 bg-white/10" />
+        <Skeleton className="h-4 w-48 bg-white/10" />
+        <Skeleton className="h-3 w-full bg-white/10" />
+      </div>
+    </div>
+  );
+}
diff --git a/js/src/electron.d.ts b/js/src/electron.d.ts
index 7511eef..6da0a30 100644
--- a/js/src/electron.d.ts
+++ b/js/src/electron.d.ts
@@ -1,7 +1,17 @@
-interface Window {
-  electronWindow: {
-    minimize: () => void;
-    maximize: () => void;
-    close: () => void;
-  };
+import type { LinkMetadata } from './lib/link-metadata';
+
+declare global {
+  interface Window {
+    electronWindow: {
+      minimize: () => void;
+      maximize: () => void;
+      close: () => void;
+    };
+    electronLink: {
+      fetchMetadata: (url: string) => Promise<LinkMetadata | null>;
+      openExternal: (url: string) => Promise<void>;
+    };
+  }
 }
+
+export {};
diff --git a/js/src/features/compose/text-compose-step.tsx b/js/src/features/compose/text-compose-step.tsx
index c3fcfe8..27144b8 100644
--- a/js/src/features/compose/text-compose-step.tsx
+++ b/js/src/features/compose/text-compose-step.tsx
@@ -1,5 +1,10 @@
-import { useEffect, useRef, useCallback } from "react";
+import { useEffect, useRef, useCallback, useState } from "react";
 import { cn } from "@/lib/utils";
+import { useFirstLinkMetadata } from "@/hooks/use-link-metadata";
+import {
+  LinkPreviewCard,
+  LinkPreviewCardSkeleton,
+} from "@/components/link-preview-card";
 
 interface TextComposeStepProps {
   textContent: string;
@@ -8,11 +13,12 @@ interface TextComposeStepProps {
   onCancel: () => void;
 }
 
-function getTextStyle(length: number) {
-  if (length < 50) return { size: "text-5xl", weight: "font-semibold" };
-  if (length < 150) return { size: "text-3xl", weight: "font-semibold" };
-  if (length < 300) return { size: "text-2xl", weight: "font-normal" };
-  return { size: "text-lg", weight: "font-normal" };
+const IMMERSIVE_CHAR_LIMIT = 120;
+
+function getImmersiveTextStyle(length: number) {
+  if (length < 30) return { size: "text-5xl", weight: "font-semibold" };
+  if (length < 70) return { size: "text-3xl", weight: "font-semibold" };
+  return { size: "text-2xl", weight: "font-normal" };
 }
 
 export function TextComposeStep({
@@ -23,6 +29,14 @@ export function TextComposeStep({
 }: TextComposeStepProps) {
   const textareaRef = useRef<HTMLTextAreaElement>(null);
 
+  // Debounce URL detection to avoid fetching on every keystroke
+  const [debouncedText, setDebouncedText] = useState(textContent);
+  useEffect(() => {
+    const t = setTimeout(() => setDebouncedText(textContent), 500);
+    return () => clearTimeout(t);
+  }, [textContent]);
+  const { data: metadata, isLoading, url: firstUrl } = useFirstLinkMetadata(debouncedText);
+
   useEffect(() => {
     textareaRef.current?.focus();
   }, []);
@@ -40,37 +54,79 @@ export function TextComposeStep({
     [onCancel, onAdvance, textContent],
   );
 
-  const style = getTextStyle(textContent.length);
+  const immersive = textContent.length < IMMERSIVE_CHAR_LIMIT;
+  const showPreview = firstUrl && (isLoading || metadata);
+
+  const linkPreview = (
+    <>
+      {firstUrl && isLoading && <LinkPreviewCardSkeleton />}
+      {firstUrl && metadata && <LinkPreviewCard metadata={metadata} compact />}
+    </>
+  );
+
+  const keyboardHints = (
+    <div className="absolute bottom-8 flex items-center gap-4 text-sm text-white/50">
+      <span>
+        <kbd className="rounded bg-white/10 px-1.5 py-0.5 font-mono text-xs">
+          Esc
+        </kbd>{" "}
+        cancel
+      </span>
+      <span>
+        <kbd className="rounded bg-white/10 px-1.5 py-0.5 font-mono text-xs">
+          ⌘+Enter
+        </kbd>{" "}
+        next
+      </span>
+    </div>
+  );
+
+  if (immersive) {
+    const style = getImmersiveTextStyle(textContent.length);
+    return (
+      <div className="absolute inset-0 z-50 flex items-center justify-center bg-black/90">
+        <div
+          className={cn(
+            "flex w-full items-center justify-center gap-6 px-6",
+            showPreview ? "flex-row" : "flex-col",
+          )}
+        >
+          <textarea
+            ref={textareaRef}
+            value={textContent}
+            onChange={(e) => onTextChange(e.target.value)}
+            onKeyDown={handleKeyDown}
+            placeholder="Type a message..."
+            className={cn(
+              "flex-1 resize-none border-none bg-transparent p-8 text-white placeholder-white/40 outline-none",
+              showPreview ? "text-left" : "text-center",
+              style.size,
+              style.weight,
+            )}
+            rows={4}
+          />
+          {showPreview && <div className="shrink-0">{linkPreview}</div>}
+        </div>
+        {keyboardHints}
+      </div>
+    );
+  }
 
   return (
     <div className="absolute inset-0 z-50 flex items-center justify-center bg-black/90">
-      <textarea
-        ref={textareaRef}
-        value={textContent}
-        onChange={(e) => onTextChange(e.target.value)}
-        onKeyDown={handleKeyDown}
-        placeholder="Type a message..."
-        className={cn(
-          "w-full max-w-2xl resize-none border-none bg-transparent p-8 text-center text-white placeholder-white/40 outline-none",
-          style.size,
-          style.weight,
-        )}
-        rows={4}
-      />
-      <div className="absolute bottom-8 flex items-center gap-4 text-sm text-white/50">
-        <span>
-          <kbd className="rounded bg-white/10 px-1.5 py-0.5 font-mono text-xs">
-            Esc
-          </kbd>{" "}
-          cancel
-        </span>
-        <span>
-          <kbd className="rounded bg-white/10 px-1.5 py-0.5 font-mono text-xs">
-            ⌘+Enter
-          </kbd>{" "}
-          next
-        </span>
+      <div className="flex max-h-[calc(100%-6rem)] max-w-md flex-col gap-4 overflow-y-auto rounded-2xl bg-white/10 p-5 backdrop-blur-md">
+        <textarea
+          ref={textareaRef}
+          value={textContent}
+          onChange={(e) => onTextChange(e.target.value)}
+          onKeyDown={handleKeyDown}
+          placeholder="Type a message..."
+          className="w-full resize-none border-none bg-transparent text-base leading-relaxed text-white placeholder-white/40 outline-none"
+          rows={6}
+        />
+        {showPreview && linkPreview}
       </div>
+      {keyboardHints}
     </div>
   );
 }
diff --git a/js/src/features/particles/text-particle-view.tsx b/js/src/features/particles/text-particle-view.tsx
index da8ff2e..f03de38 100644
--- a/js/src/features/particles/text-particle-view.tsx
+++ b/js/src/features/particles/text-particle-view.tsx
@@ -1,6 +1,11 @@
 import { useEffect, useRef } from "react";
 import type { Particle } from "@/api/types";
 import { cn } from "@/lib/utils";
+import { useFirstLinkMetadata } from "@/hooks/use-link-metadata";
+import {
+  LinkPreviewCard,
+  LinkPreviewCardSkeleton,
+} from "@/components/link-preview-card";
 
 type TextParticle = Extract<Particle, { type: "text" }>;
 
@@ -11,22 +16,27 @@ interface TextParticleViewProps {
   onProgress?: (ratio: number) => void;
 }
 
-const WORDS_PER_MINUTE = 200;
+// Characters per minute (~1000 cpm ≈ 200 wpm at ~5 chars/word)
+const CHARS_PER_MINUTE = 1000;
 const MIN_DURATION_S = 3;
 const MAX_DURATION_S = 15;
 const TICK_MS = 100;
+const LINK_EXTRA_DURATION_S = 3;
 
-function computeReadDuration(text: string): number {
-  const wordCount = text.trim().split(/\s+/).length;
-  const seconds = (wordCount / WORDS_PER_MINUTE) * 60;
+// Below this threshold: immersive centered display
+// Above: contained left-aligned card
+const IMMERSIVE_CHAR_LIMIT = 120;
+
+function computeReadDuration(text: string, hasLink: boolean): number {
+  const base = (text.length / CHARS_PER_MINUTE) * 60;
+  const seconds = hasLink ? base + LINK_EXTRA_DURATION_S : base;
   return Math.min(Math.max(seconds, MIN_DURATION_S), MAX_DURATION_S);
 }
 
-function getTextStyle(length: number) {
-  if (length < 50) return { size: "text-5xl", weight: "font-semibold" };
-  if (length < 150) return { size: "text-3xl", weight: "font-semibold" };
-  if (length < 300) return { size: "text-2xl", weight: "font-normal" };
-  return { size: "text-lg", weight: "font-normal" };
+function getImmersiveTextStyle(length: number) {
+  if (length < 30) return { size: "text-5xl", weight: "font-semibold" };
+  if (length < 70) return { size: "text-3xl", weight: "font-semibold" };
+  return { size: "text-2xl", weight: "font-normal" };
 }
 
 export function TextParticleView({
@@ -35,8 +45,11 @@ export function TextParticleView({
   onEnded,
   onProgress,
 }: TextParticleViewProps) {
-  const style = getTextStyle(particle.properties.content.length);
-  const durationS = computeReadDuration(particle.properties.content);
+  const content = particle.properties.content;
+  const { data: metadata, isLoading, url: firstUrl } = useFirstLinkMetadata(content);
+  const hasLink = !!firstUrl;
+  const immersive = content.length < IMMERSIVE_CHAR_LIMIT;
+  const durationS = computeReadDuration(content, hasLink);
   const elapsedRef = useRef(0);
 
   // Reset elapsed when particle changes
@@ -61,17 +74,51 @@ export function TextParticleView({
     return () => clearInterval(interval);
   }, [paused, durationS, onEnded, onProgress, particle.id]);
 
+  const linkPreview = (
+    <>
+      {isLoading && <LinkPreviewCardSkeleton />}
+      {metadata && <LinkPreviewCard metadata={metadata} />}
+    </>
+  );
+
+  // Content is just a bare URL with no surrounding text
+  const linkOnly = hasLink && content.trim() === firstUrl;
+
+  if (linkOnly) {
+    return (
+      <div className="flex h-full w-full items-center justify-center bg-gradient-to-b from-black/40 via-black/20 to-black/40 p-8">
+        {linkPreview}
+      </div>
+    );
+  }
+
+  if (immersive && !hasLink) {
+    const style = getImmersiveTextStyle(content.length);
+    return (
+      <div className="flex h-full w-full flex-col items-center justify-center bg-gradient-to-b from-black/40 via-black/20 to-black/40 p-8">
+        <p
+          className={cn(
+            "max-w-2xl break-words text-center leading-relaxed text-white",
+            style.size,
+            style.weight,
+          )}
+        >
+          {content}
+        </p>
+      </div>
+    );
+  }
+
   return (
     <div className="flex h-full w-full items-center justify-center bg-gradient-to-b from-black/40 via-black/20 to-black/40 p-8">
-      <p
-        className={cn(
-          "max-w-2xl text-center leading-relaxed text-white",
-          style.size,
-          style.weight,
-        )}
-      >
-        {particle.properties.content}
-      </p>
+      <div className="flex max-h-full w-full max-w-3xl items-center gap-6 px-2">
+        <div className="flex-1 overflow-y-auto rounded-2xl bg-white/10 p-5 backdrop-blur-md">
+          <p className="break-words text-base leading-relaxed text-white">
+            {content}
+          </p>
+        </div>
+        {hasLink && <div className="shrink-0">{linkPreview}</div>}
+      </div>
     </div>
   );
 }
diff --git a/js/src/hooks/use-link-metadata.ts b/js/src/hooks/use-link-metadata.ts
new file mode 100644
index 0000000..6f94982
--- /dev/null
+++ b/js/src/hooks/use-link-metadata.ts
@@ -0,0 +1,19 @@
+import { useQuery } from "@tanstack/react-query";
+import { extractUrls, type LinkMetadata } from "@/lib/link-metadata";
+
+export function useLinkMetadata(url: string | null) {
+  return useQuery<LinkMetadata | null>({
+    queryKey: ["link-metadata", url],
+    queryFn: () => window.electronLink.fetchMetadata(url!),
+    enabled: !!url,
+    staleTime: Infinity,
+    gcTime: 30 * 60 * 1000,
+    retry: 1,
+  });
+}
+
+export function useFirstLinkMetadata(text: string) {
+  const urls = extractUrls(text);
+  const firstUrl = urls[0] ?? null;
+  return { ...useLinkMetadata(firstUrl), url: firstUrl };
+}
diff --git a/js/src/lib/link-metadata.ts b/js/src/lib/link-metadata.ts
new file mode 100644
index 0000000..78b9388
--- /dev/null
+++ b/js/src/lib/link-metadata.ts
@@ -0,0 +1,14 @@
+export interface LinkMetadata {
+  url: string;
+  title: string | null;
+  description: string | null;
+  image: string | null;
+  favicon: string | null;
+  domain: string;
+}
+
+const URL_REGEX = /https?:\/\/[^\s<>"')\]]+/g;
+
+export function extractUrls(text: string): string[] {
+  return Array.from(text.matchAll(URL_REGEX), (m) => m[0]);
+}
diff --git a/js/src/main.ts b/js/src/main.ts
index 623e5a1..9963240 100644
--- a/js/src/main.ts
+++ b/js/src/main.ts
@@ -1,8 +1,10 @@
-import { app, BrowserWindow, ipcMain, session } from 'electron';
+import { app, BrowserWindow, ipcMain, session, shell } from 'electron';
 import path from 'node:path';
 import started from 'electron-squirrel-startup';
 import { updateElectronApp, UpdateSourceType } from 'update-electron-app';
 
+import type { LinkMetadata } from './lib/link-metadata';
+
 updateElectronApp({
   updateSource: {
     type: UpdateSourceType.StaticStorage,
@@ -59,6 +61,120 @@ ipcMain.on('window:close', (event) => {
   BrowserWindow.fromWebContents(event.sender)?.close();
 });
 
+// --- Link metadata ---
+
+const metadataCache = new Map<string, LinkMetadata>();
+
+function getMetaContent(html: string, property: string): string | null {
+  // Match both property="..." and name="..." attributes
+  const regex = new RegExp(
+    `<meta[^>]*(?:property|name)=["']${property}["'][^>]*content=["']([^"']*)["']|<meta[^>]*content=["']([^"']*)["'][^>]*(?:property|name)=["']${property}["']`,
+    'i',
+  );
+  const match = html.match(regex);
+  return match?.[1] ?? match?.[2] ?? null;
+}
+
+function getTitle(html: string): string | null {
+  const match = html.match(/<title[^>]*>([^<]*)<\/title>/i);
+  return match?.[1]?.trim() ?? null;
+}
+
+function getFavicon(html: string, baseUrl: string): string | null {
+  const match = html.match(/<link[^>]*rel=["'](?:shortcut )?icon["'][^>]*href=["']([^"']*)["']/i)
+    ?? html.match(/<link[^>]*href=["']([^"']*)["'][^>]*rel=["'](?:shortcut )?icon["']/i);
+  if (!match?.[1]) {
+    // Fall back to /favicon.ico
+    try {
+      const url = new URL(baseUrl);
+      return `${url.protocol}//${url.host}/favicon.ico`;
+    } catch {
+      return null;
+    }
+  }
+  try {
+    return new URL(match[1], baseUrl).href;
+  } catch {
+    return match[1];
+  }
+}
+
+function resolveUrl(src: string | null, baseUrl: string): string | null {
+  if (!src) return null;
+  try {
+    return new URL(src, baseUrl).href;
+  } catch {
+    return src;
+  }
+}
+
+async function fetchLinkMetadata(url: string): Promise<LinkMetadata | null> {
+  const cached = metadataCache.get(url);
+  if (cached) return cached;
+
+  try {
+    const controller = new AbortController();
+    const timeout = setTimeout(() => controller.abort(), 5000);
+
+    const response = await fetch(url, {
+      signal: controller.signal,
+      headers: {
+        'User-Agent': 'Mozilla/5.0 (compatible; llink/1.0)',
+        'Accept': 'text/html',
+      },
+      redirect: 'follow',
+    });
+    clearTimeout(timeout);
+
+    if (!response.ok) return null;
+
+    // Only read the first ~50KB to get <head> content
+    const reader = response.body?.getReader();
+    if (!reader) return null;
+
+    let html = '';
+    const decoder = new TextDecoder();
+    while (html.length < 50_000) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      html += decoder.decode(value, { stream: true });
+    }
+    reader.cancel();
+
+    const domain = new URL(url).hostname.replace(/^www\./, '');
+    const metadata: LinkMetadata = {
+      url,
+      title: getMetaContent(html, 'og:title') ?? getTitle(html),
+      description: getMetaContent(html, 'og:description') ?? getMetaContent(html, 'description'),
+      image: resolveUrl(getMetaContent(html, 'og:image'), url),
+      favicon: getFavicon(html, url),
+      domain,
+    };
+
+    metadataCache.set(url, metadata);
+    return metadata;
+  } catch {
+    return null;
+  }
+}
+
+ipcMain.handle('link:fetch-metadata', async (_event, url: string) => {
+  if (typeof url !== 'string') return null;
+  try {
+    new URL(url);
+  } catch {
+    return null;
+  }
+  return fetchLinkMetadata(url);
+});
+
+ipcMain.handle('link:open-external', async (_event, url: string) => {
+  if (typeof url !== 'string') return;
+  // Only allow http(s) URLs for security
+  if (!url.startsWith('http://') && !url.startsWith('https://')) return;
+  await shell.openExternal(url);
+});
+
 // This method will be called when Electron has finished
 // initialization and is ready to create browser windows.
 // Some APIs can only be used after this event occurs.
diff --git a/js/src/preload.ts b/js/src/preload.ts
index b83ab47..de492ff 100644
--- a/js/src/preload.ts
+++ b/js/src/preload.ts
@@ -7,3 +7,8 @@ contextBridge.exposeInMainWorld('electronWindow', {
   maximize: () => ipcRenderer.send('window:maximize'),
   close: () => ipcRenderer.send('window:close'),
 });
+
+contextBridge.exposeInMainWorld('electronLink', {
+  fetchMetadata: (url: string) => ipcRenderer.invoke('link:fetch-metadata', url),
+  openExternal: (url: string) => ipcRenderer.invoke('link:open-external', url),
+});