// app.js — the client half of vrsite. Everything here works in the static
// export too; htmx only takes over the parts that need a server (filters,
// comments, live activity, jj queries).
"use strict";

const root = document.documentElement;
const live = root.dataset.live === "1";

// ── focus: trace or notes, never both ─────────────────────────────────────
// Coverage and notes want the same pixels (line background, gutter color,
// tree markers), so the whole UI switches between them instead of layering.
function setMode(m) {
  root.dataset.mode = m;
  localStorage.setItem("vrsite-mode", m);
  for (const b of document.querySelectorAll(".mode"))
    b.setAttribute("aria-pressed", String(b.dataset.mode === m));
}
for (const b of document.querySelectorAll(".mode"))
  b.addEventListener("click", () => setMode(b.dataset.mode));
setMode(root.dataset.mode || "trace");

const typing = e =>
  /^(INPUT|TEXTAREA|SELECT)$/.test(e.target.tagName) || e.target.isContentEditable;

document.addEventListener("keydown", e => {
  if (e.metaKey || e.ctrlKey || e.altKey || typing(e)) return;
  if (e.key === "t") setMode(root.dataset.mode === "notes" ? "trace" : "notes");
  if (e.key === "/") {
    const f = document.getElementById("filefind");
    if (f) { e.preventDefault(); f.focus(); f.select(); }
  }
});

// ── theme ─────────────────────────────────────────────────────────────────
const themesel = document.getElementById("themesel");
if (themesel) {
  themesel.value = localStorage.getItem("vrsite-theme") || "system";
  themesel.addEventListener("change", () => {
    localStorage.setItem("vrsite-theme", themesel.value);
    if (themesel.value === "system") delete root.dataset.theme;
    else root.dataset.theme = themesel.value;
  });
}

// ── nav tree ──────────────────────────────────────────────────────────────
const nav = document.getElementById("nav");
const tree = document.getElementById("tree");
const state = JSON.parse(localStorage.getItem("vrsite-tree") || "{}");

if (nav && tree) {
  const base = nav.dataset.root, cur = nav.dataset.current;
  fetch(nav.dataset.tree).then(r => r.text()).then(t => {
    tree.innerHTML = t.replaceAll('href="@@', 'href="' + base);
    for (const d of tree.querySelectorAll("details"))
      if (d.dataset.path in state) d.open = !!state[d.dataset.path];
    if (cur)
      for (const a of tree.querySelectorAll("a.file"))
        if (a.dataset.path === cur) {
          a.setAttribute("aria-current", "page");
          for (let e = a.parentElement; e && e !== tree; e = e.parentElement)
            if (e.tagName === "DETAILS") e.open = true;
          a.scrollIntoView({block: "center"});
          break;
        }
    tree.addEventListener("toggle", e => {
      if (tree.classList.contains("filtering")) return; // filter drives open state
      state[e.target.dataset.path] = e.target.open ? 1 : 0;
      localStorage.setItem("vrsite-tree", JSON.stringify(state));
    }, true);
  }).catch(() => {
    tree.innerHTML = '<p class="meta">tree needs http — use the <a href="' +
      base + 'files.html">file index</a></p>';
  });
}

// ── find a file ───────────────────────────────────────────────────────────
const find = document.getElementById("filefind");
if (find && tree) {
  const apply = () => {
    const q = find.value.trim().toLowerCase();
    tree.classList.toggle("filtering", q !== "");
    for (const a of tree.querySelectorAll("a.file")) {
      const hit = !q || a.dataset.path.toLowerCase().includes(q);
      a.closest("li").hidden = !hit;
      a.classList.toggle("hit", !!q && hit);
    }
    for (const d of tree.querySelectorAll("details")) {
      const any = d.querySelector("li:not([hidden])");
      d.hidden = !!q && !any;
      d.open = q ? !!any : !!state[d.dataset.path];
    }
  };
  find.addEventListener("input", apply);
  find.addEventListener("search", apply);
  find.addEventListener("keydown", e => {
    if (e.key === "Escape") { find.value = ""; apply(); find.blur(); }
    if (e.key === "Enter") {
      const first = tree.querySelector("li:not([hidden]) a.file");
      if (first) first.click();
    }
  });
}

// ── code lines: jump to a note, pick a range to comment on ────────────────
const codeLines = document.querySelectorAll("ol.code li");
const nstart = document.getElementById("nstart"), nend = document.getElementById("nend");
let anchor = 0;

function lineNo(li) { return parseInt(li.id.slice(1), 10) || 0; }

function markSelection(a, b) {
  const lo = Math.min(a, b), hi = Math.max(a, b);
  for (const li of codeLines) {
    const n = lineNo(li);
    li.classList.toggle("sel", n >= lo && n <= hi);
  }
  if (nstart) nstart.value = lo;
  if (nend) nend.value = hi > lo ? hi : "";
}

for (const li of codeLines) {
  li.addEventListener("click", e => {
    const note = li.dataset.note && document.getElementById(li.dataset.note);
    if (note && root.dataset.mode === "notes") {
      note.scrollIntoView({behavior: "smooth", block: "center"});
      note.classList.remove("flash"); void note.offsetWidth; note.classList.add("flash");
    }
    if (!live || root.dataset.mode !== "notes") return;
    const n = lineNo(li);
    if (e.shiftKey && anchor) markSelection(anchor, n);
    else { anchor = n; markSelection(n, n); }
  });
}

// ⌘/ctrl+enter posts the note form from inside the textarea
for (const ta of document.querySelectorAll(".notform textarea"))
  ta.addEventListener("keydown", e => {
    if (e.key === "Enter" && (e.metaKey || e.ctrlKey)) ta.form.requestSubmit();
  });

// ── conversation ──────────────────────────────────────────────────────────
// A session page opened from a note lands on that note, flashed the same way
// clicking a noted line flashes it.
const conv = document.querySelector(".conv[data-anchor]");
if (conv && conv.dataset.anchor) {
  const here = document.getElementById(conv.dataset.anchor);
  if (here) {
    here.scrollIntoView({block: "start"});
    here.classList.remove("flash"); void here.offsetWidth; here.classList.add("flash");
  }
}

// The trip back: a note in a conversation opens the code it was written
// about. The card is the target, so aim anywhere on it — except at the links
// it already carries.
const goTo = w => { location.href = w.dataset.href; };
for (const w of document.querySelectorAll(".notewrap[data-href]")) {
  w.addEventListener("click", e => { if (!e.target.closest("a")) goTo(w); });
  w.addEventListener("keydown", e => {
    if (e.key === "Enter" || e.key === " ") { e.preventDefault(); goTo(w); }
  });
}

// ── arriving at a note ────────────────────────────────────────────────────
// ?note=N means someone followed a note here rather than opening the file:
// show what they came for — notes focus (coverage hides the note), the card
// flashed in the pane, the lines it covers marked.
const want = new URLSearchParams(location.search).get("note");
if (want && document.body.dataset.kind === "file" && /^\d+$/.test(want)) {
  setMode("notes");
  const card = document.getElementById("note-" + want);
  if (card) {
    // the card's own range, not the lines' data-note: a line belongs to the
    // first note that claimed it, so overlapping notes would mark nothing
    const from = +card.dataset.start, to = +card.dataset.end || +card.dataset.start;
    let first = null;
    for (let n = from; n > 0 && n <= to; n++) {
      const li = document.getElementById("L" + n);
      if (!li) continue;
      li.classList.add("focus");
      first = first || li;
    }
    // after the browser has had its own go at the #L anchor
    if (first) requestAnimationFrame(() => first.scrollIntoView({block: "center"}));
    card.scrollIntoView({block: "nearest"});
    card.classList.remove("flash"); void card.offsetWidth; card.classList.add("flash");
  }
}

// ── note filters ──────────────────────────────────────────────────────────
// Live pages let the server filter (htmx); the static export filters the
// rendered list in place, so the same form works either way.
const filters = document.getElementById("notefilters");
if (filters) {
  const count = document.getElementById("notecount");
  const val = n => (filters.elements[n] ? filters.elements[n].value.trim().toLowerCase() : "");
  const applyLocal = () => {
    const text = val("text"), file = val("file"), agent = val("agent"),
          model = val("model"), session = val("session"), kind = val("kind"),
          from = val("from"), to = val("to");
    let shown = 0;
    for (const art of document.querySelectorAll("#notelist .note")) {
      const d = art.dataset, body = art.querySelector("p").textContent.toLowerCase();
      const ok =
        (!text || body.includes(text)) &&
        (!file || (d.file || "").toLowerCase().includes(file)) &&
        (!agent || d.agent === filters.elements.agent.value) &&
        (!model || d.model === filters.elements.model.value) &&
        (!session || d.session === filters.elements.session.value) &&
        (!kind || d.kind === filters.elements.kind.value) &&
        (!from || (d.date && d.date >= from)) &&
        (!to || (d.date && d.date <= to));
      art.hidden = !ok;
      if (ok) shown++;
    }
    if (count) count.textContent = shown;
  };
  if (!live) {
    filters.addEventListener("input", applyLocal);
    filters.addEventListener("change", applyLocal);
    filters.addEventListener("submit", e => { e.preventDefault(); applyLocal(); });
  }
  const clear = document.getElementById("clearfilters");
  if (clear) clear.addEventListener("click", () => {
    filters.reset();
    for (const el of filters.elements) if (el.name) el.value = "";
    if (live) window.htmx && htmx.trigger(filters, "change");
    else applyLocal();
  });
}