const COPY = "Sao chép";
const COPIED = "Đã chép";
const FAILED = "Lỗi";

if (navigator.clipboard) {
  for (const pre of document.querySelectorAll("pre")) {
    const code = pre.querySelector("code");
    if (!code) continue;
    const btn = document.createElement("button");
    btn.type = "button";
    btn.className = "code-copy";
    btn.setAttribute("aria-label", COPY);
    btn.textContent = COPY;
    pre.appendChild(btn);
    btn.addEventListener("click", async () => {
      try {
        await navigator.clipboard.writeText(code.innerText);
        btn.textContent = COPIED;
      } catch {
        btn.textContent = FAILED;
      }
      setTimeout(() => { btn.textContent = COPY; }, 1500);
    });
  }
}