// COPY BUTTON:
document.addEventListener("DOMContentLoaded", function () {
  document.querySelectorAll("pre.src").forEach(function (block) {
    const button = document.createElement("button");
    button.innerText = "Copy";
    button.className = "copy-btn";

    // Append button inside <pre>
    block.appendChild(button);

    button.addEventListener("click", function () {
      const text = block.innerText.replace(button.innerText, ""); // exclude button text
      navigator.clipboard.writeText(text.trim()).then(() => {
        button.innerText = "Copied!";
        setTimeout(() => (button.innerText = "Copy"), 1500);
      });
    });
  });
});

document.addEventListener("DOMContentLoaded", () => {
  document.querySelectorAll('a.footref[href^="#fn"]').forEach(ref => {
    const sup = ref.closest("sup") || ref;
    // idempotent: don't insert twice
    if (sup.nextElementSibling && sup.nextElementSibling.classList?.contains("footnote-sidenote")) return;

    const targetId = ref.getAttribute("href").replace(/^#/, ""); // works for fn.2 or fn2

    const anchor   = document.getElementById(targetId);
    if (!anchor) return;

    const footdef = anchor.closest(".footdef") || anchor.parentElement;
    if (!footdef) return;

    // 1) Prefer leaf paragraphs to avoid div+p duplication
    let paras = footdef.querySelectorAll("p.footpara");
    if (!paras.length) {
      // fallback: any .footpara elements that don't contain another .footpara
      paras = footdef.querySelectorAll(".footpara:not(:has(.footpara))");
    }

    // 2) Build HTML, de-duplicating by text content
    let parts = [];
    if (paras.length) {
      const seen = new Set();
      parts = Array.from(paras).map(p => {
        const txt = p.textContent.trim().replace(/\s+/g, " ");
        if (seen.has(txt)) return "";
        seen.add(txt);
        return p.innerHTML.trim();
      }).filter(Boolean);
    }

    // 3) Fallback: clean full block if no paras found
    if (!parts.length) {
      const clone = footdef.cloneNode(true);
      clone.querySelectorAll("sup.footnum, a[role='doc-backlink']").forEach(n => n.remove());
      parts = [clone.innerHTML.trim()];
    }

    // 4) Insert the sidenote
    const sn = document.createElement("span");
    sn.className = "sidenote footnote-sidenote";
    sn.setAttribute("data-fn", (ref.textContent || "").trim());
    sn.innerHTML = parts.join(" ");

    sup.insertAdjacentElement("afterend", sn);
  });
});
  (function(){
    const root = document.documentElement;
    const storageKey = "theme";
    const saved = localStorage.getItem(storageKey);
    if (saved === "dark" || saved === "light") {
      root.setAttribute("data-theme", saved);
    }
    const btn = document.getElementById("theme-toggle");
    if (!btn) return;
    btn.addEventListener("click", () => {
      const current = root.getAttribute("data-theme");
      const next = current === "dark" ? "light" : "dark";
      // If no current (auto), assume we’re toggling to dark first
      const target = current ? next : "dark";
      root.setAttribute("data-theme", target);
      localStorage.setItem(storageKey, target);
    });
  })();

document.addEventListener("DOMContentLoaded", () => {
  const toc = document.querySelector("#text-table-of-contents");
  if (!toc) { console.warn("No #text-table-of-contents found"); return; }

  const links = toc.querySelectorAll('a[href^="#"]');
  if (!links.length) { console.warn("No ToC links found"); return; }

  // Map: id -> link
  const linkById = new Map();
  links.forEach(a => {
    const id = decodeURIComponent(a.getAttribute("href").slice(1));
    const el = document.getElementById(id);
    if (el) linkById.set(id, a);
  });
  if (!linkById.size) { console.warn("No matching headings with IDs"); return; }

  // Headings to observe (h2–h4 usually)
  const headings = [...document.querySelectorAll("h2[id], h3[id], h4[id]")]
    .filter(h => linkById.has(h.id));

  // Helper to mark active
  const setActive = (id) => {
    links.forEach(a => {
      const active = a.getAttribute("href") === `#${id}`;
      a.classList.toggle("is-active", active);
      if (active) a.setAttribute("aria-current", "true");
      else a.removeAttribute("aria-current");
    });
  };

  // Calculate sticky header offset in px
  const headerOffsetPx = 6.5 * parseFloat(getComputedStyle(document.documentElement).fontSize);

  // Track visible headings (id -> distance from top)
  const visible = new Map();

  const observer = new IntersectionObserver((entries) => {
    entries.forEach(entry => {
      const id = entry.target.id;
      if (entry.isIntersecting) {
        // How far from the top (after header offset)
        const dist = entry.target.getBoundingClientRect().top - headerOffsetPx;
        visible.set(id, dist);
      } else {
        visible.delete(id);
      }
    });

    if (visible.size) {
      // Choose the heading closest to the top (>= -headerOffset)
      const topMost = [...visible.entries()]
        .sort((a,b) => Math.abs(a[1]) - Math.abs(b[1]))[0][0];
      setActive(topMost);
      // console.log("Active:", topMost, visible);
    }
  }, {
    root: null,                                   // track relative to viewport
    rootMargin: `-${headerOffsetPx}px 0px -70% 0px`,
    threshold: [0, 0.01, 0.1]                     // fire as soon as it enters
  });

  headings.forEach(h => observer.observe(h));

  // Initial highlight (in case you load mid‑page)
  let bestId = null, bestDist = Infinity;
  headings.forEach(h => {
    const top = h.getBoundingClientRect().top - headerOffsetPx;
    const dist = top < 0 ? Math.abs(top) : top + 1e6;
    if (dist < bestDist) { bestDist = dist; bestId = h.id; }
  });
  if (bestId) setActive(bestId);

  // Optional: smooth-scroll ToC clicks
  toc.addEventListener("click", (e) => {
    const a = e.target.closest('a[href^="#"]');
    if (!a) return;
    const id = decodeURIComponent(a.hash.slice(1));
    const el = document.getElementById(id);
    if (!el) return;
    e.preventDefault();
    el.scrollIntoView({ behavior: "smooth", block: "start" });
    el.setAttribute("tabindex", "-1");
    el.focus({ preventScroll: true });
    history.pushState(null, "", `#${id}`);
  });
});