/**
 * Copy `text` to the system clipboard.
 *
 * The modern `navigator.clipboard.writeText()` only works in secure
 * contexts (HTTPS / localhost / file://). This deployment runs over
 * plain HTTP on the internal network, where that API is gated, so we
 * fall back to the legacy `textarea + execCommand("copy")` pattern.
 * `execCommand` is deprecated but every shipping browser still
 * implements it for the copy command, and it works in non-secure
 * contexts where the modern API doesn't.
 *
 * Returns true on success, false if both paths fail.
 */
export async function copyToClipboard(text: string): Promise<boolean> {
  if (typeof navigator !== "undefined" && navigator.clipboard?.writeText) {
    try {
      await navigator.clipboard.writeText(text);
      return true;
    } catch {
      // Fall through to legacy path — secure-context block, permission
      // denial, or any other modern-API failure.
    }
  }

  if (typeof document === "undefined") return false;
  const ta = document.createElement("textarea");
  ta.value = text;
  ta.setAttribute("readonly", "");
  // Position offscreen but still focusable; some browsers refuse to
  // copy from elements that are display:none or visibility:hidden.
  ta.style.position = "fixed";
  ta.style.top = "0";
  ta.style.left = "0";
  ta.style.opacity = "0";
  ta.style.pointerEvents = "none";
  document.body.appendChild(ta);
  try {
    ta.focus();
    ta.select();
    return document.execCommand("copy");
  } catch {
    return false;
  } finally {
    document.body.removeChild(ta);
  }
}