const $ = (sel) => document.querySelector(sel);
const $$ = (sel) => document.querySelectorAll(sel);

let libraries = [];
const LANGUAGE_NAMES = { german: "Deutsch", english: "Englisch" };

async function api(path, opts = {}) {
  const resp = await fetch(path, {
    headers: { "Content-Type": "application/json" },
    ...opts,
  });
  if (!resp.ok) {
    let msg = resp.statusText;
    try { msg = (await resp.json()).detail || msg; } catch {}
    const err = new Error(msg);
    err.status = resp.status;
    throw err;
  }
  return resp.json();
}

// create a request; on a duplicate warning (409) ask the user before retrying
async function createRequest(body) {
  try {
    return await api("/api/requests", { method: "POST", body: JSON.stringify(body) });
  } catch (err) {
    if (err.status === 409 && confirm(err.message + "\nTrotzdem anlegen?")) {
      return api("/api/requests?allow_duplicate=true", {
        method: "POST", body: JSON.stringify(body),
      });
    }
    throw err;
  }
}

function toast(msg, isError = false) {
  const t = $("#toast");
  t.textContent = msg;
  t.className = isError ? "error" : "";
  t.hidden = false;
  setTimeout(() => (t.hidden = true), 4000);
}

function esc(s) {
  const d = document.createElement("div");
  d.textContent = s ?? "";
  return d.innerHTML;
}

// last used library per media type (per-browser convenience)
function getLastLib(type) {
  try { return localStorage.getItem("wordarr.lastLib." + type); } catch { return null; }
}
function setLastLib(type, id) {
  try { localStorage.setItem("wordarr.lastLib." + type, String(id)); } catch {}
}
function libOptions(mediaType) {
  const last = getLastLib(mediaType);
  return libraries
    .filter((l) => l.media_type === mediaType)
    .map((l) => `<option value="${l.id}" ${String(l.id) === last ? "selected" : ""}>${esc(l.name)}</option>`)
    .join("");
}

// ---- missing badge ----
async function refreshMissingBadge() {
  try {
    const reqs = await api("/api/requests?status=missing");
    const badge = $("#missing-badge");
    badge.textContent = reqs.length;
    badge.hidden = reqs.length === 0;
  } catch {}
}

// ---- navigation ----
$$("nav button").forEach((btn) =>
  btn.addEventListener("click", () => {
    $$("nav button").forEach((b) => b.classList.remove("active"));
    btn.classList.add("active");
    $$("main > section").forEach((s) => (s.hidden = true));
    $("#view-" + btn.dataset.view).hidden = false;
    if (btn.dataset.view === "missing") loadRequests("missing");
    if (btn.dataset.view === "imported") loadRequests("imported");
    if (btn.dataset.view === "settings") loadLibraries();
  })
);

// ---- libraries ----
async function loadLibraries() {
  libraries = await api("/api/libraries");
  const tbody = $("#lib-table tbody");
  tbody.innerHTML = libraries
    .map(
      (l) => `<tr>
        <td>${esc(l.name)}</td><td>${esc(l.media_type)}</td><td>${esc(l.root_path)}</td>
        <td class="mono">${esc(l.folder_template)}</td><td class="mono">${esc(l.file_template)}</td>
        <td>${l.language ? esc(LANGUAGE_NAMES[l.language] || l.language) : "—"}</td>
        <td class="row">
          <button class="secondary" data-edit-lib="${l.id}">Bearbeiten</button>
          <button class="danger" data-del-lib="${l.id}">Löschen</button>
        </td>
      </tr>`
    )
    .join("");
  tbody.querySelectorAll("[data-edit-lib]").forEach((b) =>
    b.addEventListener("click", () => startLibraryEdit(parseInt(b.dataset.editLib)))
  );
  tbody.querySelectorAll("[data-del-lib]").forEach((b) =>
    b.addEventListener("click", async () => {
      if (!confirm("Library löschen?")) return;
      try {
        await api("/api/libraries/" + b.dataset.delLib, { method: "DELETE" });
        loadLibraries();
      } catch (e) { toast(e.message, true); }
    })
  );
  const filter = $("#missing-filter-library");
  filter.innerHTML =
    '<option value="">Alle Libraries</option>' +
    libraries.map((l) => `<option value="${l.id}">${esc(l.name)}</option>`).join("");
}

function startLibraryEdit(id) {
  const lib = libraries.find((l) => l.id === id);
  if (!lib) return;
  const form = $("#lib-form");
  form.name.value = lib.name;
  form.media_type.value = lib.media_type;
  form.root_path.value = lib.root_path;
  form.folder_template.value = lib.folder_template;
  form.file_template.value = lib.file_template;
  form.language.value = lib.language || "";
  form.dataset.editId = lib.id;
  $("#lib-form-title").textContent = `Library „${lib.name}“ bearbeiten`;
  $("#lib-form-submit").textContent = "Speichern";
  $("#lib-form-cancel").hidden = false;
  form.scrollIntoView({ behavior: "smooth" });
}

function endLibraryEdit() {
  const form = $("#lib-form");
  form.reset();
  delete form.dataset.editId;
  $("#lib-form-title").textContent = "Neue Library";
  $("#lib-form-submit").textContent = "Anlegen";
  $("#lib-form-cancel").hidden = true;
}
$("#lib-form-cancel").addEventListener("click", endLibraryEdit);

$("#lib-form").addEventListener("submit", async (e) => {
  e.preventDefault();
  const data = Object.fromEntries(new FormData(e.target));
  if (!data.folder_template) delete data.folder_template;
  if (!data.file_template) delete data.file_template;
  const editId = e.target.dataset.editId;
  try {
    if (editId) {
      await api("/api/libraries/" + editId, { method: "PUT", body: JSON.stringify(data) });
      toast("Library gespeichert — gilt für künftige Importe");
    } else {
      await api("/api/libraries", { method: "POST", body: JSON.stringify(data) });
      toast("Library angelegt");
    }
    endLibraryEdit();
    loadLibraries();
  } catch (err) { toast(err.message, true); }
});

// path autocompletion for the library form
{
  const pathInput = document.querySelector('#lib-form [name=root_path]');
  const datalist = $("#path-suggestions");
  let pathTimer;
  pathInput.addEventListener("input", () => {
    clearTimeout(pathTimer);
    const value = pathInput.value;
    if (!value.startsWith("/")) return;
    pathTimer = setTimeout(async () => {
      try {
        const res = await api("/api/fs/browse?path=" + encodeURIComponent(value));
        datalist.innerHTML = res.dirs.map((d) => `<option value="${esc(d)}">`).join("");
      } catch {}
    }, 150);
  });
}

// ---- search & request ----
const EMPTY_HINTS = {
  ebook: "Keine Treffer. Tipp: ISBN ohne Bindestriche oder Titel + Autor versuchen.",
  audiobook: "Keine Treffer. Tipp: EAN/ISBN funktioniert bei Audible nicht — nach Titel/Autor suchen.",
  comic: "Keine Treffer bei AniList (Manga). Westliche Comics per „Manuell anlegen“ erfassen.",
};

$("#search-type").addEventListener("change", () => ($("#search-results").innerHTML = ""));

$("#search-form").addEventListener("submit", async (e) => {
  e.preventDefault();
  const type = $("#search-type").value;
  const q = $("#search-q").value;
  const box = $("#search-results");
  const searchBtn = $("#search-btn");
  searchBtn.disabled = true;
  searchBtn.innerHTML = '<span class="spinner"></span> Suche…';
  try {
    const language = $("#search-language").value;
    const results = await api(
      `/api/search?media_type=${type}&q=${encodeURIComponent(q)}&language=${language}`
    );
    if (!results.length) {
      box.innerHTML = `<p class='muted'>${EMPTY_HINTS[type]}</p>`;
      return;
    }
    const opts = libOptions(type);
    box.innerHTML = results
      .map(
        (r, i) => `<div class="card">
          ${r.cover_url ? `<img src="${esc(r.cover_url)}" alt="" loading="lazy">` : '<div class="nocover">?</div>'}
          <div class="card-body">
            <strong>${esc(r.title)}</strong>
            <span>${esc(r.authors)}</span>
            ${r.narrator ? `<span class="muted">🎙 ${esc(r.narrator)}</span>` : ""}
            ${r.series && r.media_type ? `<span class="muted">📚 ${esc(r.series)}${r.volume != null ? " #" + r.volume : ""}</span>` : ""}
            <span class="muted">${r.year ?? ""} ${r.language ? "· " + esc(LANGUAGE_NAMES[r.language] || r.language) : ""} ${r.external_id ? "· " + esc(r.external_id) : ""}</span>
            ${type === "comic" ? `<input type="number" min="0" placeholder="Band" class="volume" data-vol="${i}">` : ""}
            <div class="row">
              <select data-lib="${i}">${opts || "<option value=''>— keine Library —</option>"}</select>
              <button data-req="${i}">Anfragen</button>
              ${r.series_id ? `<button class="secondary" data-series="${i}">Ganze Serie…</button>` : ""}
            </div>
          </div>
        </div>`
      )
      .join("");
    box.querySelectorAll("[data-series]").forEach((btn) =>
      btn.addEventListener("click", () => openSeriesDialog(results[btn.dataset.series]))
    );
    box.querySelectorAll("[data-req]").forEach((btn) =>
      btn.addEventListener("click", async () => {
        const i = btn.dataset.req;
        const r = results[i];
        const libId = box.querySelector(`[data-lib="${i}"]`).value;
        if (!libId) { toast("Erst eine Library für diesen Typ anlegen (Tab Libraries)", true); return; }
        const volInput = box.querySelector(`[data-vol="${i}"]`);
        try {
          await createRequest({
              library_id: parseInt(libId),
              title: r.title, authors: r.authors, narrator: r.narrator || "",
              external_id: r.external_id,
              year: r.year, series: r.series, cover_url: r.cover_url,
              volume: volInput && volInput.value ? parseInt(volInput.value) : (r.volume ?? null),
          });
          setLastLib(type, libId);
          btn.textContent = "✓ Angefragt";
          btn.disabled = true;
          refreshMissingBadge();
        } catch (err) { toast(err.message, true); }
      })
    );
  } catch (err) {
    box.innerHTML = "";
    toast(err.message, true);
  } finally {
    searchBtn.disabled = false;
    searchBtn.textContent = "Suchen";
  }
});

// ---- request a whole series ----
let seriesEpisodes = [];

function renderSeriesList() {
  const from = parseInt($("#series-from").value);
  const to = parseInt($("#series-to").value);
  const inRange = (e) =>
    (isNaN(from) || (e.volume != null && e.volume >= from)) &&
    (isNaN(to) || (e.volume != null && e.volume <= to));
  let previous = null;
  $("#series-list").innerHTML = seriesEpisodes
    .map((e, i) => {
      // make holes in the numbering visible - the crawl cannot reach every episode
      let gap = "";
      if (e.volume != null && previous != null && e.volume > previous + 1) {
        const missing = e.volume - previous - 1;
        gap = `<div class="gap">… ${missing} Folge${missing > 1 ? "n" : ""} nicht bei Audible gefunden (${previous + 1}–${e.volume - 1})</div>`;
      }
      if (e.volume != null) previous = e.volume;
      return `${gap}<label>
        <input type="checkbox" data-ep="${i}" ${inRange(e) ? "checked" : ""}>
        <span class="num">${e.volume ?? "—"}</span>
        <span>${esc(e.title)}</span>
      </label>`;
    })
    .join("");
  updateSeriesCount();
}

function seriesChecked() {
  return [...$("#series-list").querySelectorAll("input:checked")].map(
    (c) => seriesEpisodes[c.dataset.ep]
  );
}

function updateSeriesCount() {
  const n = seriesChecked().length;
  const btn = $("#series-submit");
  btn.textContent = n ? `${n} anfragen` : "Anfragen";
  btn.disabled = n === 0;
}

async function openSeriesDialog(result) {
  const dlg = $("#series-dialog");
  $("#series-title").textContent = result.series || "Serie";
  $("#series-info").innerHTML = '<span class="spinner"></span> Folgen werden gesucht…';
  $("#series-list").innerHTML = "";
  $("#series-from").value = "";
  $("#series-to").value = "";
  $("#series-library").innerHTML = libOptions("audiobook") || "<option value=''>— keine Library —</option>";
  $("#series-submit").disabled = true;
  dlg.showModal();
  try {
    seriesEpisodes = await api(
      `/api/search/series?series_id=${encodeURIComponent(result.series_id)}` +
        `&title=${encodeURIComponent(result.series || result.title)}`
    );
  } catch (err) {
    $("#series-info").textContent = err.message;
    return;
  }
  const numbered = seriesEpisodes.filter((e) => e.volume != null);
  $("#series-info").textContent =
    `${seriesEpisodes.length} Folgen gefunden` +
    (numbered.length ? ` (Nr. ${numbered[0].volume}–${numbered[numbered.length - 1].volume})` : "") +
    ". Audible hat keine Serien-Abfrage — einzelne Folgen können fehlen.";
  renderSeriesList();
}

$("#series-from").addEventListener("input", renderSeriesList);
$("#series-to").addEventListener("input", renderSeriesList);
$("#series-list").addEventListener("change", updateSeriesCount);
$("#series-all").addEventListener("click", () => {
  $("#series-list").querySelectorAll("input").forEach((c) => (c.checked = true));
  updateSeriesCount();
});
$("#series-none").addEventListener("click", () => {
  $("#series-list").querySelectorAll("input").forEach((c) => (c.checked = false));
  updateSeriesCount();
});
$("#series-cancel").addEventListener("click", () => $("#series-dialog").close());

$("#series-submit").addEventListener("click", async () => {
  const libId = $("#series-library").value;
  if (!libId) { toast("Erst eine Audiobook-Library anlegen (Tab Libraries)", true); return; }
  const items = seriesChecked().map((e) => ({
    title: e.title, authors: e.authors, narrator: e.narrator || "",
    external_id: e.external_id, year: e.year, series: e.series,
    volume: e.volume, cover_url: e.cover_url,
  }));
  const btn = $("#series-submit");
  btn.disabled = true;
  btn.innerHTML = '<span class="spinner"></span> Lege an…';
  try {
    const res = await api("/api/requests/bulk-items", {
      method: "POST",
      body: JSON.stringify({ library_id: parseInt(libId), items }),
    });
    setLastLib("audiobook", libId);
    toast(
      `${res.created.length} Anfragen angelegt` +
        (res.skipped ? `, ${res.skipped} bereits vorhanden` : "")
    );
    $("#series-dialog").close();
    refreshMissingBadge();
  } catch (err) {
    toast(err.message, true);
  } finally {
    btn.disabled = false;
    updateSeriesCount();
  }
});

// ---- manual request ----
$("#manual-btn").addEventListener("click", () => {
  const dlg = $("#manual-dialog");
  const typeSel = dlg.querySelector("[name=media_type]");
  const updateLibs = () => {
    $("#manual-library").innerHTML = libOptions(typeSel.value) || "<option value=''>— keine Library —</option>";
  };
  typeSel.onchange = updateLibs;
  updateLibs();
  dlg.showModal();
});

$("#manual-form").addEventListener("submit", async (e) => {
  if (e.submitter && e.submitter.value === "cancel") return;
  const data = Object.fromEntries(new FormData(e.target));
  if (!data.library_id) { toast("Keine Library gewählt", true); return; }
  try {
    if (data.volume_to) {
      if (!data.volume) {
        toast("Für Bulk bitte Start-Band angeben", true);
        return;
      }
      const created = await api("/api/requests/bulk", {
        method: "POST",
        body: JSON.stringify({
          library_id: parseInt(data.library_id),
          series: data.series || data.title, authors: data.authors,
          narrator: data.narrator || "",
          volume_from: parseInt(data.volume),
          volume_to: parseInt(data.volume_to),
          year: data.year ? parseInt(data.year) : null,
        }),
      });
      toast(`${created.length} Anfragen angelegt`);
    } else {
      await createRequest({
        library_id: parseInt(data.library_id),
        title: data.title, authors: data.authors, series: data.series,
        narrator: data.narrator || "",
        external_id: data.external_id,
        year: data.year ? parseInt(data.year) : null,
        volume: data.volume ? parseInt(data.volume) : null,
      });
      toast("Anfrage angelegt");
    }
    setLastLib(data.media_type, data.library_id);
    e.target.reset();
    refreshMissingBadge();
  } catch (err) { toast(err.message, true); }
});

// ---- missing / imported lists ----
let currentRequests = { missing: [], imported: [] };

// view mode (Liste / kleine / große Symbole), shared by both lists
function getViewMode() {
  try { return localStorage.getItem("wordarr.viewMode") || "small"; } catch { return "small"; }
}
function applyViewMode(mode) {
  try { localStorage.setItem("wordarr.viewMode", mode); } catch {}
  ["#missing-list", "#imported-list"].forEach((sel) => {
    const box = $(sel);
    box.classList.remove("view-list", "view-small", "view-large");
    box.classList.add("view-" + mode);
  });
  $$(".view-toggle button").forEach((b) =>
    b.classList.toggle("active", b.dataset.viewmode === mode)
  );
}
$$(".view-toggle button").forEach((b) =>
  b.addEventListener("click", () => applyViewMode(b.dataset.viewmode))
);
applyViewMode(getViewMode());

function requestMatchesFilter(r, text) {
  if (!text) return true;
  const hay = `${r.title} ${r.authors} ${r.series} ${r.narrator}`.toLowerCase();
  return hay.includes(text.toLowerCase());
}

async function loadRequests(status) {
  const params = new URLSearchParams({ status });
  if (status === "missing") {
    const t = $("#missing-filter-type").value;
    const l = $("#missing-filter-library").value;
    if (t) params.set("media_type", t);
    if (l) params.set("library_id", l);
  }
  currentRequests[status] = await api("/api/requests?" + params);
  renderRequests(status);
  if (status === "missing") refreshMissingBadge();
}

function renderRequests(status) {
  const text = status === "missing" ? $("#missing-search").value : $("#imported-search").value;
  const reqs = currentRequests[status].filter((r) => requestMatchesFilter(r, text));
  const box = status === "missing" ? $("#missing-list") : $("#imported-list");
  const bulkBtn = status === "missing" ? $("#missing-bulk-delete") : $("#imported-bulk-delete");
  if (!reqs.length) {
    box.innerHTML = "<p class='muted'>Nichts hier.</p>";
    bulkBtn.hidden = true;
    return;
  }
  box.innerHTML = reqs
    .map(
      (r) => `<div class="card clickable" data-detail="${r.id}">
        ${r.cover_url ? `<img src="${esc(r.cover_url)}" alt="" loading="lazy">` : '<div class="nocover">?</div>'}
        <div class="card-body">
          <strong>${esc(r.title)}${r.volume != null ? " · Band " + r.volume : ""}</strong>
          <span>${esc(r.authors)}</span>
          ${r.narrator ? `<span class="muted">🎙 ${esc(r.narrator)}</span>` : ""}
          <span class="muted">${esc(r.media_type)} → ${esc(r.library_name)}</span>
          ${status === "imported" ? `<span class="muted mono">${esc(r.imported_path)}</span>` : ""}
        </div>
        <input type="checkbox" class="card-check" data-sel-req="${r.id}">
      </div>`
    )
    .join("");
  box.querySelectorAll("[data-detail]").forEach((card) =>
    card.addEventListener("click", (ev) => {
      if (ev.target.closest("input,button,select,a")) return;
      openDetail(parseInt(card.dataset.detail), status);
    })
  );
  const updateBulkBtn = () => {
    const n = box.querySelectorAll("[data-sel-req]:checked").length;
    bulkBtn.hidden = n === 0;
    bulkBtn.textContent = `Ausgewählte entfernen (${n})`;
  };
  box.querySelectorAll("[data-sel-req]").forEach((c) =>
    c.addEventListener("change", updateBulkBtn)
  );
  updateBulkBtn();
}

async function bulkDeleteRequests(status) {
  const box = status === "missing" ? $("#missing-list") : $("#imported-list");
  const ids = [...box.querySelectorAll("[data-sel-req]:checked")].map((c) => c.dataset.selReq);
  if (!ids.length) return;
  const hint = status === "imported"
    ? `${ids.length} Eintrag/Einträge entfernen? Die importierten Dateien in der Library bleiben erhalten.`
    : `${ids.length} Anfrage(n) entfernen?`;
  if (!confirm(hint)) return;
  for (const id of ids) {
    try { await api("/api/requests/" + id, { method: "DELETE" }); }
    catch (err) { toast(err.message, true); }
  }
  toast(`${ids.length} entfernt`);
  loadRequests(status);
}

$("#imported-bulk-delete").addEventListener("click", () => bulkDeleteRequests("imported"));

function selectAllRequests(status) {
  const box = status === "missing" ? $("#missing-list") : $("#imported-list");
  const checks = [...box.querySelectorAll("[data-sel-req]")];
  const allChecked = checks.length && checks.every((c) => c.checked);
  checks.forEach((c) => (c.checked = !allChecked));
  if (checks.length) checks[0].dispatchEvent(new Event("change"));
}
$("#missing-select-all").addEventListener("click", () => selectAllRequests("missing"));
$("#imported-select-all").addEventListener("click", () => selectAllRequests("imported"));

$("#missing-filter-type").addEventListener("change", () => loadRequests("missing"));
$("#missing-filter-library").addEventListener("change", () => loadRequests("missing"));
$("#missing-search").addEventListener("input", () => renderRequests("missing"));
$("#imported-search").addEventListener("input", () => renderRequests("imported"));

$("#missing-bulk-delete").addEventListener("click", () => bulkDeleteRequests("missing"));

// ---- request detail dialog ----
let detailRequest = null;

function openDetail(id, status) {
  const r = currentRequests[status].find((x) => x.id === id);
  if (!r) return;
  detailRequest = r;
  const form = $("#detail-form");
  form.title.value = r.title;
  form.authors.value = r.authors || "";
  form.narrator.value = r.narrator || "";
  form.series.value = r.series || "";
  form.volume.value = r.volume ?? "";
  form.year.value = r.year ?? "";
  form.external_id.value = r.external_id || "";
  $("#detail-library").innerHTML = libraries
    .filter((l) => l.media_type === r.media_type)
    .map((l) => `<option value="${l.id}" ${l.id === r.library_id ? "selected" : ""}>${esc(l.name)}</option>`)
    .join("");
  $("#detail-title").textContent = r.title;
  $("#detail-status").textContent =
    `${r.media_type} · ${r.status === "missing" ? "fehlt noch" : "importiert"}`;
  $("#detail-path").textContent = r.imported_path || "";
  const img = $("#detail-cover");
  img.hidden = !r.cover_url;
  $("#detail-nocover").hidden = !!r.cover_url;
  if (r.cover_url) img.src = r.cover_url;
  $("#detail-retag").hidden = !(r.status === "imported" && r.media_type === "audiobook");
  $("#detail-relocate").hidden = r.status !== "imported";
  $("#detail-dialog").showModal();
}

async function saveDetail(form) {
  await api("/api/requests/" + detailRequest.id, {
    method: "PUT",
    body: JSON.stringify({
      library_id: parseInt(form.library_id.value),
      title: form.title.value,
      authors: form.authors.value,
      narrator: form.narrator.value,
      series: form.series.value,
      volume: form.volume.value ? parseInt(form.volume.value) : null,
      year: form.year.value ? parseInt(form.year.value) : null,
      external_id: form.external_id.value,
      cover_url: detailRequest.cover_url || "",
    }),
  });
}

// after correcting series/title/author the files are still filed under the old
// name - this re-applies the library's scheme to what is already on disk
$("#detail-relocate").addEventListener("click", async () => {
  if (!detailRequest) return;
  const btn = $("#detail-relocate");
  btn.disabled = true;
  btn.innerHTML = '<span class="spinner"></span> Lege ab…';
  try {
    await saveDetail($("#detail-form"));
    const res = await api(`/api/requests/${detailRequest.id}/relocate`, { method: "POST" });
    toast(res.moved ? `Neu abgelegt: ${res.dest}` : "Liegt bereits richtig");
    $("#detail-dialog").close();
    loadRequests(detailRequest.status);
  } catch (err) { toast(err.message, true); }
  finally {
    btn.disabled = false;
    btn.textContent = "Speichern & neu ablegen";
  }
});

$("#detail-retag").addEventListener("click", async () => {
  if (!detailRequest) return;
  const btn = $("#detail-retag");
  btn.disabled = true;
  btn.innerHTML = '<span class="spinner"></span> Tagge…';
  try {
    await saveDetail($("#detail-form"));
    const res = await api(`/api/requests/${detailRequest.id}/retag`, { method: "POST" });
    toast(`${res.files} Datei(en) neu getaggt`);
    $("#detail-dialog").close();
    loadRequests(detailRequest.status);
  } catch (err) { toast(err.message, true); }
  finally {
    btn.disabled = false;
    btn.textContent = "Speichern & neu taggen";
  }
});

$("#detail-form").addEventListener("submit", async (e) => {
  if (e.submitter && e.submitter.value === "cancel") return;
  if (!detailRequest) return;
  try {
    await saveDetail(e.target);
    toast("Anfrage gespeichert");
    loadRequests(detailRequest.status);
  } catch (err) { toast(err.message, true); }
});

// ---- import ----
let scanItems = [];
let missingReqs = [];
let importedReqs = [];
let skippedConflicts = 0;
let orphanedIds = new Set();   // imported, but their files are gone from the library
let viewIdx = []; // indices into scanItems after filter/sort
let importPage = 0;
const IMPORT_PAGE_SIZE = 25;

$("#scan-btn").addEventListener("click", async () => {
  const scanBtn = $("#scan-btn");
  scanBtn.disabled = true;
  $("#scan-info").innerHTML = '<span class="spinner"></span> Scanne…';
  try {
    const split = $("#split-dirs").checked;
    const [scan, reqs, done] = await Promise.all([
      api("/api/import/scan?split_dirs=" + split),
      api("/api/requests?status=missing"),
      api("/api/requests?status=imported"),
    ]);
    clearTimeout(cleanupTimer);
    scanItems = scan.items;
    // selection state lives here, not in the DOM, so it survives paging/filtering
    scanItems.forEach((item) => {
      item.request_id = item.suggested_request_id;
      item.checked = !!item.suggested_request_id;
    });
    orphanedIds = new Set(scan.orphaned_request_ids || []);
    // an imported title whose files vanished is selectable like an open one
    missingReqs = [...reqs, ...done.filter((r) => orphanedIds.has(r.id))];
    importedReqs = done.filter((r) => !orphanedIds.has(r.id));
    importPage = 0;
    $("#scan-info").textContent = `${scan.items.length} Kandidat(en) in ${scan.download_dir}`;
    $("#import-toolbar").hidden = scanItems.length === 0;
    renderImportTable();
  } catch (err) {
    $("#scan-info").textContent = "";
    toast(err.message, true);
  } finally {
    scanBtn.disabled = false;
  }
});

function applyImportView() {
  const text = $("#import-filter-text").value.toLowerCase();
  const mode = $("#import-filter-mode").value;
  const sort = $("#import-sort").value;
  viewIdx = scanItems
    .map((_, i) => i)
    .filter((i) => {
      const item = scanItems[i];
      if (text && !(`${item.name} ${item.rel_dir || ""}`.toLowerCase().includes(text))) return false;
      if (mode === "suggested" && !item.suggested_request_id) return false;
      if (mode === "unassigned" && item.request_id) return false;
      if (mode === "conflict" && !item.conflict) return false;
      return true;
    });
  if (sort === "score") viewIdx.sort((a, b) => scanItems[b].score - scanItems[a].score);
  if (sort === "name") viewIdx.sort((a, b) => scanItems[a].name.localeCompare(scanItems[b].name));
}

function scoreCell(item) {
  if (!item.suggested_request_id) return '<td class="score-none">—</td>';
  const cls = item.score >= 80 ? "score-hi" : item.score >= 50 ? "score-mid" : "score-lo";
  return `<td class="${cls}">${item.score}</td>`;
}

function renderImportTable() {
  applyImportView();
  const table = $("#import-table");
  const tbody = table.querySelector("tbody");
  if (!viewIdx.length) {
    table.hidden = true;
    $("#import-btn").hidden = scanItems.length === 0;
    $("#import-pager").hidden = true;
    tbody.innerHTML = "";
    if (scanItems.length) {
      $("#import-page-info").textContent = "";
    }
    return;
  }
  const pages = Math.ceil(viewIdx.length / IMPORT_PAGE_SIZE);
  importPage = Math.min(importPage, pages - 1);
  const start = importPage * IMPORT_PAGE_SIZE;
  const pageIdx = viewIdx.slice(start, start + IMPORT_PAGE_SIZE);

  tbody.innerHTML = pageIdx
    .map((i) => {
      const item = scanItems[i];
      const option = (r, suffix = "") =>
        `<option value="${r.id}" ${r.id === item.request_id ? "selected" : ""}>
          ${esc(r.title)} — ${esc(r.authors)} (${esc(r.library_name)})${suffix}</option>`;
      const opts = missingReqs
        .filter((r) => r.media_type === item.media_type)
        .map((r) => option(r, orphanedIds.has(r.id) ? " ↺" : ""))
        .join("");
      // already imported audiobooks can take further parts (a late CD, or one
      // that failed while its siblings went through)
      const appendOpts = importedReqs
        .filter((r) => r.media_type === item.media_type && r.imported_path)
        .map((r) => option(r, " ↩︎"))
        .join("");
      return `<tr class="${item.importState ? "row-" + item.importState : item.conflict ? "row-conflict" : ""}">
        <td><input type="checkbox" data-check="${i}" ${item.checked ? "checked" : ""}></td>
        <td class="mono">
          ${esc(item.name)}${item.is_dir ? " 📁" : ""}
          ${item.parts ? `<span class="tag">${item.parts.length} Teile · ${item.files.length} Dateien</span>` : ""}
          ${!item.parts && item.maybe_separate
            ? `<span class="tag warn" title="Die ${item.files.length} Dateien tragen verschiedene Titel und sind je groß genug für ein ganzes Buch — mit ✂️ aufteilen">${item.files.length} Titel?</span>`
            : ""}
          ${item.rel_dir ? `<div class="subpath">${esc(item.rel_dir)}/</div>` : ""}
        </td>
        <td>${esc(item.media_type)}</td>
        <td class="row">
          <select data-select="${i}"><option value="">— überspringen —</option>${opts}
            ${appendOpts ? `<optgroup label="Bereits importiert — Teile anhängen">${appendOpts}</optgroup>` : ""}
          </select>
          <button class="secondary" data-quick="${i}" title="Metadaten suchen und Anfrage direkt verbinden">🔍</button>
          ${item.parts || item.maybe_separate
            ? `<button class="secondary" data-split="${i}" title="${item.parts ? "Zusammenfassung wieder auflösen" : "Ordner in einzelne Titel aufteilen"}">✂️</button>`
            : ""}
        </td>
        <td>${libraryCell(item, i)}</td>
        ${item.importState ? importStateCell(item)
          : item.conflict ? '<td class="state conflict" title="Mehrere Einträge zeigen auf dieselbe Anfrage">⚠ Konflikt</td>'
          : scoreCell(item)}
      </tr>`;
    })
    .join("");
  table.hidden = false;
  $("#import-btn").hidden = false;
  const showsState = scanItems.some((it) => it.importState);
  table.querySelector("thead th:last-child").textContent = showsState ? "Status" : "Score";

  tbody.querySelectorAll("[data-quick]").forEach((b) =>
    b.addEventListener("click", () => openQuickDialog(parseInt(b.dataset.quick)))
  );
  tbody.querySelectorAll("[data-lib-for]").forEach((sel) =>
    sel.addEventListener("change", async () => {
      const item = scanItems[sel.dataset.libFor];
      const req = requestById(item.request_id);
      if (!req) return;
      const previous = req.library_id;
      req.library_id = parseInt(sel.value);
      try {
        const saved = await api("/api/requests/" + req.id, {
          method: "PUT",
          body: JSON.stringify({
            library_id: req.library_id, title: req.title, authors: req.authors,
            narrator: req.narrator || "", series: req.series, volume: req.volume,
            year: req.year, external_id: req.external_id, cover_url: req.cover_url,
          }),
        });
        Object.assign(req, saved);
        toast(`„${req.title}" → ${saved.library_name}`);
      } catch (err) {
        req.library_id = previous;
        sel.value = String(previous);
        toast(err.message, true);
      }
      renderImportTable();
    })
  );
  tbody.querySelectorAll("[data-split]").forEach((b) =>
    b.addEventListener("click", () => splitItem(parseInt(b.dataset.split)))
  );
  tbody.querySelectorAll("[data-check]").forEach((c) =>
    c.addEventListener("change", () => {
      scanItems[c.dataset.check].checked = c.checked;
      updateImportPageInfo();
    })
  );
  tbody.querySelectorAll("[data-select]").forEach((s) =>
    s.addEventListener("change", () => {
      const item = scanItems[s.dataset.select];
      item.request_id = s.value ? parseInt(s.value) : null;
      item.checked = !!item.request_id;
      const check = tbody.querySelector(`[data-check="${s.dataset.select}"]`);
      if (check) check.checked = item.checked;
      updateImportPageInfo();
    })
  );

  $("#import-pager").hidden = false;
  $("#import-prev").disabled = importPage === 0;
  $("#import-next").disabled = importPage >= pages - 1;
  updateImportPageInfo(pages);
}

// which library the assigned request writes to - visible in the row, because the
// select inside the search dialog is easy to miss
function libraryCell(item, i) {
  const req = requestById(item.request_id);
  if (!req) return '<span class="muted">—</span>';
  const opts = libraries
    .filter((l) => l.media_type === req.media_type)
    .map((l) => `<option value="${l.id}" ${l.id === req.library_id ? "selected" : ""}>${esc(l.name)}</option>`)
    .join("");
  return `<select data-lib-for="${i}" title="Ziel-Library dieser Anfrage ändern">${opts}</select>`;
}

function requestById(id) {
  if (!id) return null;
  return missingReqs.find((r) => r.id === id) || importedReqs.find((r) => r.id === id) || null;
}

function importStateCell(item) {
  if (item.importState === "running") {
    return '<td class="state running"><span class="spinner"></span> läuft…</td>';
  }
  if (item.importState === "done") return '<td class="state done">✓ importiert</td>';
  return `<td class="state failed" title="${esc(item.importError)}">✗ Fehler</td>`;
}

function updateImportPageInfo(pages) {
  pages = pages ?? Math.max(1, Math.ceil(viewIdx.length / IMPORT_PAGE_SIZE));
  const selected = scanItems.filter((it) => it.checked && it.request_id).length;
  const filtered = viewIdx.length !== scanItems.length ? ` (gefiltert: ${viewIdx.length})` : "";
  $("#import-page-info").textContent =
    `Seite ${importPage + 1}/${pages} · ${scanItems.length} Einträge${filtered} · ${selected} ausgewählt`;
}

$("#import-prev").addEventListener("click", () => { importPage--; renderImportTable(); });
$("#import-next").addEventListener("click", () => { importPage++; renderImportTable(); });
$("#import-filter-text").addEventListener("input", () => { importPage = 0; renderImportTable(); });
$("#import-filter-mode").addEventListener("change", () => { importPage = 0; renderImportTable(); });
$("#import-sort").addEventListener("change", () => { importPage = 0; renderImportTable(); });

$("#import-select-suggested").addEventListener("click", () => {
  applyImportView();
  viewIdx.forEach((i) => {
    const item = scanItems[i];
    if (item.suggested_request_id) {
      item.request_id = item.request_id || item.suggested_request_id;
      item.checked = true;
    }
  });
  renderImportTable();
});

$("#import-select-page").addEventListener("click", () => {
  applyImportView();
  const start = importPage * IMPORT_PAGE_SIZE;
  const pageIdx = viewIdx.slice(start, start + IMPORT_PAGE_SIZE);
  // exclusive on purpose: "import what I see", not "add to what was selected"
  scanItems.forEach((it) => (it.checked = false));
  let n = 0;
  pageIdx.forEach((i) => {
    const item = scanItems[i];
    const req = item.request_id || item.suggested_request_id;
    if (!req) return;
    item.request_id = req;
    item.checked = true;
    n += 1;
  });
  renderImportTable();
  toast(n ? `${n} Einträge dieser Seite ausgewählt` : "Auf dieser Seite gibt es keine Zuordnung", !n);
});

$("#import-deselect-all").addEventListener("click", () => {
  applyImportView();
  viewIdx.forEach((i) => (scanItems[i].checked = false));
  renderImportTable();
});

// ---- multi-part episodes: import several entries as one audiobook ----
// e.g. "100 - Toteninsel Teil 1/2/3", which Audible lists as a single title
function commonPrefix(names) {
  let prefix = names[0];
  for (const n of names.slice(1)) {
    let i = 0;
    while (i < prefix.length && i < n.length && prefix[i] === n[i]) i++;
    prefix = prefix.slice(0, i);
  }
  // drop a dangling part marker: "100 - Toteninsel Teil " -> "100 - Toteninsel"
  return prefix.replace(/[\s._\-–—:]*(?:teil|part|cd|disc|folge)?[\s._\-–—:]*$/i, "").trim();
}

$("#import-merge").addEventListener("click", () => {
  const chosen = scanItems.filter((it) => it.checked);
  if (chosen.length < 2) {
    toast("Mindestens zwei Einträge auswählen", true);
    return;
  }
  if (new Set(chosen.map((it) => it.media_type)).size > 1) {
    toast("Nur Einträge desselben Typs lassen sich zusammenfassen", true);
    return;
  }
  const parents = new Set(chosen.map((it) => it.rel_dir));
  if (parents.size > 1) {
    toast("Die Einträge liegen in verschiedenen Ordnern", true);
    return;
  }
  // parts may share no prefix at all ("A - Sphinx", "B - Volk"): then the
  // folder holding them carries the real title ("100 - Toteninsel")
  const parentName = (chosen[0].rel_dir || "").split("/").filter(Boolean).pop();
  const name =
    commonPrefix(chosen.map((it) => it.name)) || parentName || chosen[0].name;
  const merged = {
    path: chosen[0].path.slice(0, chosen[0].path.length - chosen[0].name.length - 1) || chosen[0].path,
    name,
    rel_dir: chosen[0].rel_dir,
    media_type: chosen[0].media_type,
    is_dir: true,
    files: chosen.flatMap((it) => it.files),
    checked: true,
    request_id: chosen.find((it) => it.request_id)?.request_id ?? null,
    suggested_request_id: chosen.find((it) => it.suggested_request_id)?.suggested_request_id ?? null,
    score: Math.max(...chosen.map((it) => it.score ?? 0)),
    parts: chosen,
  };
  const first = scanItems.indexOf(chosen[0]);
  scanItems = scanItems.filter((it) => !chosen.includes(it));
  scanItems.splice(first, 0, merged);
  toast(`${chosen.length} Einträge als „${name}" zusammengefasst (${merged.files.length} Dateien)`);
  renderImportTable();
});

function splitItem(i) {
  const item = scanItems[i];
  if (item.parts) {          // undo a merge
    scanItems.splice(i, 1, ...item.parts);
  } else if (item.is_dir && item.files.length > 1) {
    // a folder holding one book per file (a series bought as single titles):
    // turn every file into its own entry so each can get its own request
    const parts = item.files.map((f) => ({
      path: f,
      name: f.split("/").pop().replace(/\.[^.]+$/, ""),
      rel_dir: item.rel_dir ? `${item.rel_dir}/${item.name}` : item.name,
      media_type: item.media_type,
      is_dir: false,
      files: [f],
      checked: false,
      request_id: null,
      suggested_request_id: null,
      score: null,
    }));
    scanItems.splice(i, 1, ...parts);
    toast(`„${item.name}" in ${parts.length} Einzeltitel aufgeteilt`);
  } else {
    return;
  }
  renderImportTable();
}

// ---- quick request from a scanned file ----
let quickItemIndex = null;
let quickEpisode = null;
let quickPicked = null;   // metadata hit the manual fields were filled from
let lastSeries = "";

// "017 - Titel", "Folge 17: Titel", "[003] Titel" -> episode number + rest.
// A bare number without a separator ("100 Stunden") or without a leading zero is
// left alone: there it is part of the title, not a numbering.
const EPISODE_PATTERNS = [
  /^\s*(?:folge|teil|band|nr\.?)\s*(\d{1,4})\s*(?:[-–—._:]+\s*|\s+)/i, // "Folge 124: Titel"
  /^\s*[\[(](\d{1,4})[\])]\s*(?:[-–—._:]+\s*|\s+)/,               // "[003] Titel"
  /^\s*(0\d{1,3})\s*(?:[-–—._:]+\s*|\s+)/,                        // "001 Titel"
  /^\s*(\d{1,3})\s*[-–—._:]+\s*/,                                 // "17 - Titel"
];

function splitEpisodeNumber(name) {
  for (const re of EPISODE_PATTERNS) {
    const m = name.match(re);
    if (!m) continue;
    const rest = name.slice(m[0].length).trim();
    if (!rest) break;  // the number *is* the name
    return { number: parseInt(m[1], 10), rest };
  }
  return { number: null, rest: name };
}

function cleanFileName(name) {
  return name
    .replace(/[._\-\[\]()]+/g, " ")
    .replace(/\b(mp3|m4b|flac|epub|pdf|cbz|cbr|retail|unabridged|kompl.*)\b/gi, " ")
    .replace(/\s+/g, " ")
    .trim();
}

function openQuickDialog(i) {
  quickItemIndex = i;
  const item = scanItems[i];
  // the episode number wrecks the Audible keyword search, so it is kept out of
  // the query and used as the volume instead
  const { number, rest } = splitEpisodeNumber(item.name);
  quickEpisode = number;
  $("#quick-file").textContent = (item.rel_dir ? item.rel_dir + "/" : "") + item.name;
  $("#quick-episode").textContent = number != null ? `Folge ${number} — nicht mitgesucht` : "";
  $("#quick-q").value = cleanFileName(rest);
  quickPicked = null;
  $("#quick-m-title").value = cleanFileName(rest);
  $("#quick-m-authors").value = "";
  $("#quick-m-volume").value = number ?? "";
  $("#quick-m-series").value = lastSeries;
  $("#quick-based-on").hidden = true;
  $("#quick-manual-summary").textContent = "Nicht bei Audible? Manuell anlegen";
  $("#quick-manual").open = false;
  $("#quick-library").innerHTML =
    libOptions(item.media_type) || "<option value=''>— keine Library —</option>";
  $("#quick-results").innerHTML = "";
  renderQuickOpenRequests(item);
  $("#quick-dialog").showModal();
  runQuickSearch();
}

// offer linking to similar already-open requests instead of creating a duplicate
function renderQuickOpenRequests(item) {
  const box = $("#quick-open-requests");
  const tokens = cleanFileName(item.name).toLowerCase().split(" ").filter((t) => t.length > 2);
  const matches = missingReqs
    .filter((r) => r.media_type === item.media_type)
    .map((r) => {
      const hay = `${r.title} ${r.authors} ${r.series} ${r.narrator}`.toLowerCase();
      return { r, hits: tokens.filter((t) => hay.includes(t)).length };
    })
    .filter((m) => m.hits >= 2)
    .sort((a, b) => b.hits - a.hits)
    .slice(0, 3);
  if (!matches.length) { box.innerHTML = ""; return; }
  box.innerHTML =
    '<p class="muted">Passende offene Requests:</p>' +
    matches
      .map(
        ({ r }) => `<div class="row open-req">
          <span>${esc(r.title)}${r.volume != null ? " · Band " + r.volume : ""} — ${esc(r.authors)} (${esc(r.library_name)})</span>
          <button class="secondary" data-link-req="${r.id}">Verbinden</button>
        </div>`
      )
      .join("");
  box.querySelectorAll("[data-link-req]").forEach((b) =>
    b.addEventListener("click", () => {
      const i = quickItemIndex;
      scanItems[i].request_id = parseInt(b.dataset.linkReq);
      scanItems[i].checked = true;
      renderImportTable();
      $("#quick-dialog").close();
      toast("Mit bestehendem Request verbunden");
    })
  );
}

async function runQuickSearch() {
  const item = scanItems[quickItemIndex];
  const box = $("#quick-results");
  box.innerHTML = "<p class='muted'>Suche läuft…</p>";
  try {
    // the target library decides the language: an "english" library should not
    // offer the German edition of the same book
    const lib = libraries.find((l) => String(l.id) === $("#quick-library").value);
    const results = await api(
      `/api/search?media_type=${item.media_type}&q=${encodeURIComponent($("#quick-q").value)}` +
        `&language=${lib?.language || ""}`
    );
    if (!results.length) {
      box.innerHTML = `<p class='muted'>${EMPTY_HINTS[item.media_type]}</p>`;
      return;
    }
    // one compact row per hit: cover, title + a single meta line, action right
    box.innerHTML = results
      .map((r, j) => {
        const meta = [
          r.authors,
          r.narrator ? "🎙 " + r.narrator : "",
          r.series ? `📚 ${r.series}${r.volume != null ? " #" + r.volume : ""}` : "",
          r.year ?? "",
          LANGUAGE_NAMES[r.language] || r.language,
        ].filter(Boolean).map(esc).join(" · ");
        return `<div class="card">
          ${r.cover_url ? `<img src="${esc(r.cover_url)}" alt="" loading="lazy">` : '<div class="nocover">?</div>'}
          <div class="card-body">
            <strong>${esc(r.title)}</strong>
            <span class="muted">${meta}</span>
          </div>
          <button data-edit="${j}" class="secondary" title="Felder vor dem Anlegen anpassen (z.B. Serie)">✎</button>
          <button data-pick="${j}" title="Anfrage anlegen und mit diesem Eintrag verbinden">Verbinden</button>
        </div>`;
      })
      .join("");
    box.querySelectorAll("[data-pick]").forEach((btn) =>
      btn.addEventListener("click", () => pickQuickResult(results[btn.dataset.pick]))
    );
    box.querySelectorAll("[data-edit]").forEach((btn) =>
      btn.addEventListener("click", () => editBeforeRequest(results[btn.dataset.edit]))
    );
  } catch (err) {
    box.innerHTML = "";
    toast(err.message, true);
  }
}

$("#quick-search-form").addEventListener("submit", (e) => {
  e.preventDefault();
  runQuickSearch();
});
$("#quick-close").addEventListener("click", () => $("#quick-dialog").close());

// create the request and wire it to the scanned entry the dialog was opened for
async function requestAndConnect(body) {
  const libId = $("#quick-library").value;
  if (!libId) { toast("Erst eine Library für diesen Typ anlegen", true); return; }
  const i = quickItemIndex;
  try {
    const req = await createRequest({ library_id: parseInt(libId), ...body });
    setLastLib(scanItems[i].media_type, libId);
    missingReqs.push(req);
    scanItems[i].request_id = req.id;
    scanItems[i].checked = true;
    renderImportTable();
    refreshMissingBadge();
    $("#quick-dialog").close();
    toast(`„${req.title}" angefragt und verbunden`);
  } catch (err) { toast(err.message, true); }
}

function pickQuickResult(r) {
  return requestAndConnect({
    title: r.title, authors: r.authors, narrator: r.narrator || "",
    external_id: r.external_id, volume: r.volume ?? quickEpisode,
    year: r.year, series: r.series, cover_url: r.cover_url,
  });
}

// take a hit into the fields so title/author/series can be corrected before the
// request is created - Audible files Harry Potter under "Wizarding World", and
// the series ends up in the folder name
function editBeforeRequest(r) {
  quickPicked = r;
  $("#quick-m-title").value = r.title || "";
  $("#quick-m-authors").value = r.authors || "";
  $("#quick-m-series").value = r.series || "";
  $("#quick-m-volume").value = r.volume ?? quickEpisode ?? "";
  $("#quick-based-on").textContent =
    `Übernommen von Audible: „${r.title}" — Sprecher, Cover, Jahr und ASIN bleiben erhalten.`;
  $("#quick-based-on").hidden = false;
  $("#quick-manual-summary").textContent = "Felder anpassen";
  $("#quick-manual").open = true;
  $("#quick-m-title").focus();
}

$("#quick-m-submit").addEventListener("click", () => {
  const title = $("#quick-m-title").value.trim();
  if (!title) { toast("Titel angeben", true); return; }
  const volume = $("#quick-m-volume").value;
  const base = quickPicked
    ? { narrator: quickPicked.narrator || "", external_id: quickPicked.external_id,
        year: quickPicked.year, cover_url: quickPicked.cover_url }
    : {};
  return requestAndConnect({
    ...base,
    title,
    authors: $("#quick-m-authors").value.trim(),
    series: (lastSeries = $("#quick-m-series").value.trim()),
    volume: volume ? parseInt(volume) : null,
  });
});

// ---- import execution (batched, with progress) ----
const IMPORT_BATCH_SIZE = 20;
// finished rows disappear after a while: the result list below keeps the record,
// and a shrinking table makes the remaining work obvious
const IMPORT_DONE_CLEANUP_MS = 15000;
let cleanupTimer = null;

// several entries on one request means one audiobook split across folders:
// importing them one by one only imports the first and fails the rest
function groupByRequest(chosen) {
  const byRequest = new Map();
  for (const item of chosen) {
    const group = byRequest.get(item.request_id);
    if (group) group.push(item);
    else byRequest.set(item.request_id, [item]);
  }
  return [...byRequest.values()];
}

function buildImportGroups(groups) {
  return groups.map((group) => ({
    parts: group,
    item: {
      path: group.length > 1 ? sharedParent(group) : group[0].path,
      is_dir: group.length > 1 ? true : group[0].is_dir,
      files: group.flatMap((it) => it.files),
      request_id: group[0].request_id,
      append: importedReqs.some((r) => r.id === group[0].request_id),  // orphans re-import
    },
  }));
}

// Several entries on one request is either a multi-part title (merge them) or a
// mismatch (skip them). The user decides once, then keeps the rest importable.
function askAboutSharedRequests(shared) {
  const dlg = $("#conflict-dialog");
  $("#conflict-intro").textContent =
    `${shared.length} Anfrage(n) sind mehreren Einträgen zugeordnet. Gehören die Einträge ` +
    "zusammen (Mehrteiler), lassen sie sich als ein Hörbuch importieren — sonst " +
    "überspringst du sie, korrigierst die Zuordnung und importierst sie später.";
  $("#conflict-list").innerHTML = shared
    .map((group) => {
      const req = missingReqs.find((r) => r.id === group[0].request_id);
      return `<label><span>${esc(req ? req.title : "#" + group[0].request_id)}</span>
        <span class="muted">← ${group.map((it) => esc(it.name)).join(" + ")}</span></label>`;
    })
    .join("");
  dlg.showModal();
  return new Promise((resolve) => {
    const done = (answer) => {
      dlg.close();
      resolve(answer);
    };
    $("#conflict-merge").onclick = () => done("merge");
    $("#conflict-skip").onclick = () => done("skip");
    $("#conflict-cancel").onclick = () => done("cancel");
  });
}

async function collapseSharedRequests(chosen) {
  const groups = groupByRequest(chosen);
  scanItems.forEach((it) => (it.conflict = false));
  skippedConflicts = 0;
  const shared = groups.filter((g) => g.length > 1);
  if (!shared.length) return buildImportGroups(groups);

  const answer = await askAboutSharedRequests(shared);
  if (answer === "cancel") return null;
  if (answer === "merge") return buildImportGroups(groups);

  // skip: mark the clashing entries, deselect them, import everything else
  const skipped = shared.flat();
  skipped.forEach((it) => {
    it.conflict = true;
    it.checked = false;
  });
  skippedConflicts = shared.length;
  return buildImportGroups(groups.filter((g) => g.length === 1));
}

// deepest folder that holds all of the group's entries
function sharedParent(group) {
  const parts = group.map((it) => it.path.split("/"));
  const first = parts[0];
  let i = 0;
  while (i < first.length - 1 && parts.every((p) => p[i] === first[i])) i++;
  return first.slice(0, i).join("/") || group[0].path;
}

$("#import-btn").addEventListener("click", async () => {
  const chosen = scanItems.filter((item) => item.checked && item.request_id);
  if (!chosen.length) { toast("Nichts ausgewählt", true); return; }
  const groups = await collapseSharedRequests(chosen);
  if (!groups) return;
  if (!groups.length) {
    $("#import-summary").innerHTML =
      `<p class="error">Nichts importiert: alle ausgewählten Einträge waren mehreren ` +
      `Anfragen zugeordnet — Filter „Nur Konflikte" zeigt sie.</p>`;
    renderImportTable();
    return;
  }

  const btn = $("#import-btn");
  btn.disabled = true;
  scanItems.forEach((it) => { it.importState = null; it.importError = ""; });
  const total = groups.length;
  const allResults = [];
  let done = 0;
  setImportProgress(0, total);

  try {
    // one request per entry: the row can only turn green once its own move came
    // back, and a batch would only report after all of its items finished
    for (const { item, parts } of groups) {
      parts.forEach((p) => (p.importState = "running"));
      // follow the running entry across pages, otherwise only the bar moves
      applyImportView();
      const pos = viewIdx.indexOf(scanItems.indexOf(parts[0]));
      if (pos >= 0) importPage = Math.floor(pos / IMPORT_PAGE_SIZE);
      renderImportTable();
      let result;
      try {
        const res = await api("/api/import", {
          method: "POST", body: JSON.stringify({ items: [item] }),
        });
        result = res.results[0];
      } catch (err) {
        result = { path: item.path, ok: false, error: err.message };
      }
      allResults.push(result);
      parts.forEach((p) => {
        p.importState = result.ok ? "done" : "failed";
        p.importError = result.ok ? "" : result.error;
        p.checked = false;
      });
      done += 1;
      setImportProgress(done, total);
      renderImportTable();
    }

    const failed = allResults.filter((r) => !r.ok);
    $("#import-summary").innerHTML =
      `<p class="${failed.length ? "error" : "ok"}"><strong>` +
      `${allResults.length - failed.length} importiert` +
      (failed.length ? `, ${failed.length} Fehler` : "") +
      `</strong></p>` +
      (skippedConflicts
        ? `<p class="error">${skippedConflicts} Anfrage(n) waren mehreren Einträgen ` +
          `zugeordnet und wurden übersprungen — Filter „Nur Konflikte" zeigt sie.</p>`
        : "");
    $("#import-results").innerHTML = [...failed, ...allResults.filter((r) => r.ok)]
      .map((r) =>
        r.ok
          ? `<p class="ok">✓ ${esc(r.path)} → ${esc(r.dest)}</p>`
          : `<p class="error">✗ ${esc(r.path)}: ${esc(r.error)}</p>`
      )
      .join("");
    toast(failed.length ? `Import fertig, ${failed.length} Fehler` : "Import fertig", failed.length > 0);
    refreshMissingBadge();
    clearTimeout(cleanupTimer);
    cleanupTimer = setTimeout(() => {
      // only the successful ones go; failures and conflicts stay to be dealt with
      const before = scanItems.length;
      scanItems = scanItems.filter((it) => it.importState !== "done");
      if (scanItems.length !== before) {
        importPage = 0;
        setImportProgress(0, 0);
        renderImportTable();
        $("#scan-info").textContent =
          `${scanItems.length} Kandidat(en) übrig — für den aktuellen Stand erneut scannen`;
      }
    }, IMPORT_DONE_CLEANUP_MS);
    // the list stays as it is, with its green and red rows - rescanning would
    // wipe exactly the feedback the user just waited for
  } finally {
    btn.disabled = false;
    btn.textContent = "Ausgewählte importieren";
  }
});

function setImportProgress(done, total) {
  const box = $("#import-progress");
  if (!total) { box.hidden = true; return; }
  if (done >= total) {
    box.hidden = done < total;
    if (done >= total) {
      box.querySelector("progress").value = total;
      box.querySelector("span").textContent = `${total}/${total} · fertig`;
    }
    return;
  }
  box.hidden = false;
  const bar = box.querySelector("progress");
  bar.max = total;
  bar.value = done;
  box.querySelector("span").textContent =
    `${done}/${total} · ${Math.round((done / total) * 100)} %`;
}

// ---- init ----
loadLibraries();
refreshMissingBadge();