Link nostr entities and URLs in chat messages

Image URLs included

src/lib/linkify.ts

@@ -0,0 +1,195 @@
+import * as nip19 from "@nostr/tools/nip19";
+
+// Curated TLD list: gTLDs, popular new gTLDs, common ccTLDs
+const TLDS = [
+  "com",
+  "org",
+  "net",
+  "edu",
+  "gov",
+  "mil",
+  "int",
+  "info",
+  "biz",
+  "name",
+  "pro",
+  "io",
+  "co",
+  "app",
+  "dev",
+  "ai",
+  "sh",
+  "me",
+  "ly",
+  "tv",
+  "fm",
+  "lol",
+  "club",
+  "online",
+  "site",
+  "store",
+  "blog",
+  "tech",
+  "xyz",
+  "art",
+  "design",
+  "news",
+  "media",
+  "page",
+  "link",
+  "fun",
+  "gg",
+  "gl",
+  "st",
+  "to",
+  "run",
+  "life",
+  "world",
+  "space",
+  "cloud",
+  "email",
+  "social",
+  "chat",
+  "wtf",
+  "cafe",
+  "zone",
+  "studio",
+  "us",
+  "uk",
+  "de",
+  "fr",
+  "it",
+  "es",
+  "nl",
+  "ru",
+  "jp",
+  "cn",
+  "ca",
+  "au",
+  "br",
+  "in",
+  "mx",
+  "se",
+  "no",
+  "fi",
+  "dk",
+  "ch",
+  "at",
+  "be",
+  "pl",
+  "pt",
+  "gr",
+  "cz",
+  "ie",
+  "nz",
+  "kr",
+  "sg",
+  "hk",
+  "tw",
+  "za",
+  "cc",
+  "ws",
+  "eu",
+  "tr",
+  "ua",
+  "il",
+  "ar",
+  "cl",
+  "pe",
+].join("|");
+
+// Matches nostr entities, http(s) URLs, and bare domains
+const URL_SOURCE = `nostr:(?:npub1|nprofile1|note1|nevent1|naddr1)[a-z0-9]+|https?:\\/\\/[^\\s<>"']+|(?<![\\w@.\\/])(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+(?:${TLDS})\\b(?:[\\/?#][^\\s<>"']*)?`;
+// Trailing punctuation that is usually not part of the URL
+const TRAILING_PUNCT_RE = /[).,;:!?'"]+$/;
+
+export type ChatToken =
+  | { type: "text"; value: string }
+  | { type: "link"; href: string; label: string }
+  | { type: "mention"; pubkey: string; entity: string; fallback: string }
+  | { type: "entity"; entity: string; href: string; label: string };
+
+// Shorten a nostr entity to xxxxxxxx...xxxx
+export function shortNostrEntity(entity: string): string {
+  if (entity.length <= 12) return entity;
+  return `${entity.slice(0, 8)}...${entity.slice(-4)}`;
+}
+
+// Shorten a URL to domain.tld/...last-10-chars-of-the-final-part
+export function shortUrl(href: string): string {
+  const rest = href.replace(/^https?:\/\//i, "").replace(/\/+$/, "");
+  const slash = rest.indexOf("/");
+  if (slash === -1) return rest;
+  const host = rest.slice(0, slash);
+  const path = rest.slice(slash + 1);
+  if (path === "") return host;
+  const finalPart = path.slice(path.lastIndexOf("/") + 1);
+  const tail = finalPart.length > 10 ? finalPart.slice(-10) : finalPart;
+  return `${host}/...${tail}`;
+}
+
+function decodeEntity(entity: string): ChatToken | null {
+  try {
+    const decoded = nip19.decode(entity);
+    if (decoded.type === "npub")
+      return {
+        type: "mention",
+        pubkey: decoded.data,
+        entity,
+        fallback: shortNostrEntity(entity),
+      };
+    if (decoded.type === "nprofile")
+      return {
+        type: "mention",
+        pubkey: decoded.data.pubkey,
+        entity,
+        fallback: shortNostrEntity(entity),
+      };
+    if (decoded.type === "note" || decoded.type === "nevent" || decoded.type === "naddr")
+      return {
+        type: "entity",
+        entity,
+        href: `https://njump.me/${entity}`,
+        label: shortNostrEntity(entity),
+      };
+  } catch {
+    // Invalid bech32, fall through to text
+  }
+  return null;
+}
+
+// Tokenize a plain-text chat message into text, links, mentions and entities.
+// Image URLs are treated as plain links (never embedded).
+export function tokenizeChat(content: string): ChatToken[] {
+  const out: ChatToken[] = [];
+  let last = 0;
+  const re = new RegExp(URL_SOURCE, "gi");
+  for (const m of content.matchAll(re)) {
+    const start = m.index ?? 0;
+    let raw = m[0];
+    const isNostr = /^nostr:/i.test(raw);
+    let trailing = "";
+    if (!isNostr) {
+      const trail = raw.match(TRAILING_PUNCT_RE);
+      if (trail) {
+        trailing = trail[0];
+        raw = raw.slice(0, -trailing.length);
+      }
+    }
+    if (start > last)
+      out.push({ type: "text", value: content.slice(last, start) });
+    if (isNostr) {
+      const entity = raw.slice(6).toLowerCase();
+      const token = decodeEntity(entity);
+      out.push(token ?? { type: "text", value: m[0] });
+    } else {
+      const href = /^https?:\/\//i.test(raw) ? raw : `https://${raw}`;
+      out.push({ type: "link", href, label: shortUrl(href) });
+      if (trailing) out.push({ type: "text", value: trailing });
+    }
+    last = start + m[0].length;
+  }
+  if (last < content.length)
+    out.push({ type: "text", value: content.slice(last) });
+  return out;
+}