Initial aishare service

src/url.ts

@@ -0,0 +1,21 @@
+export function validateChatGptShareUrl(raw: string): string {
+  let url: URL;
+  try {
+    url = new URL(raw);
+  } catch {
+    throw new Error("Enter a valid public ChatGPT share URL.");
+  }
+
+  if (url.protocol !== "https:") {
+    throw new Error("Only HTTPS ChatGPT share URLs are accepted.");
+  }
+
+  const host = url.hostname.toLowerCase();
+  const allowedHost = host === "chatgpt.com" || host === "chat.openai.com";
+  if (!allowedHost || !url.pathname.startsWith("/share/")) {
+    throw new Error("Only public ChatGPT share URLs under /share/ are accepted.");
+  }
+
+  url.hash = "";
+  return url.toString();
+}