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

let libraries = [];

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 {}
    throw new Error(msg);
  }
  return resp.json();
}

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;
}

// ---- 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><button class="danger" data-del-lib="${l.id}">Löschen</button></td>
      </tr>`
    )
    .join("");
  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("");
}

$("#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;
  try {
    await api("/api/libraries", { method: "POST", body: JSON.stringify(data) });
    e.target.reset();
    loadLibraries();
    toast("Library angelegt");
  } catch (err) { toast(err.message, true); }
});

function libOptions(mediaType) {
  return libraries
    .filter((l) => l.media_type === mediaType)
    .map((l) => `<option value="${l.id}">${esc(l.name)}</option>`)
    .join("");
}

// ---- search & request ----
$("#search-form").addEventListener("submit", async (e) => {
  e.preventDefault();
  const type = $("#search-type").value;
  const q = $("#search-q").value;
  const box = $("#search-results");
  box.innerHTML = "<p class='muted'>Suche läuft…</p>";
  try {
    const results = await api(`/api/search?media_type=${type}&q=${encodeURIComponent(q)}`);
    if (!results.length) { box.innerHTML = "<p class='muted'>Keine Treffer.</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="">` : '<div class="nocover">?</div>'}
          <div class="card-body">
            <strong>${esc(r.title)}</strong>
            <span>${esc(r.authors)}</span>
            <span class="muted">${r.year ?? ""} ${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="${i}">Anfragen</button>
            </div>
          </div>
        </div>`
      )
      .join("");
    box.querySelectorAll("[data-req]").forEach((btn) =>
      btn.addEventListener("click", async () => {
        const i = btn.dataset.req;
        const r = results[i];
        const libId = box.querySelector(`[data-lib="${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 api("/api/requests", {
            method: "POST",
            body: JSON.stringify({
              library_id: parseInt(libId),
              title: r.title, authors: r.authors, external_id: r.external_id,
              year: r.year, series: r.series, cover_url: r.cover_url,
              volume: volInput && volInput.value ? parseInt(volInput.value) : null,
            }),
          });
          btn.textContent = "✓ Angefragt";
          btn.disabled = true;
        } catch (err) { toast(err.message, true); }
      })
    );
  } catch (err) {
    box.innerHTML = "";
    toast(err.message, true);
  }
});

// ---- 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 {
    await api("/api/requests", {
      method: "POST",
      body: JSON.stringify({
        library_id: parseInt(data.library_id),
        title: data.title, authors: data.authors, series: data.series,
        external_id: data.external_id,
        year: data.year ? parseInt(data.year) : null,
        volume: data.volume ? parseInt(data.volume) : null,
      }),
    });
    e.target.reset();
    toast("Anfrage angelegt");
  } catch (err) { toast(err.message, true); }
});

// ---- missing / imported lists ----
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);
  }
  const reqs = await api("/api/requests?" + params);
  const box = status === "missing" ? $("#missing-list") : $("#imported-list");
  if (!reqs.length) { box.innerHTML = "<p class='muted'>Nichts hier.</p>"; return; }
  box.innerHTML = reqs
    .map(
      (r) => `<div class="card">
        ${r.cover_url ? `<img src="${esc(r.cover_url)}" alt="">` : '<div class="nocover">?</div>'}
        <div class="card-body">
          <strong>${esc(r.title)}${r.volume != null ? " · Band " + r.volume : ""}</strong>
          <span>${esc(r.authors)}</span>
          <span class="muted">${esc(r.media_type)} → ${esc(r.library_name)}</span>
          ${status === "imported" ? `<span class="muted mono">${esc(r.imported_path)}</span>` : ""}
          <div class="row"><button class="danger" data-del-req="${r.id}">Entfernen</button></div>
        </div>
      </div>`
    )
    .join("");
  box.querySelectorAll("[data-del-req]").forEach((b) =>
    b.addEventListener("click", async () => {
      if (!confirm("Anfrage entfernen?")) return;
      await api("/api/requests/" + b.dataset.delReq, { method: "DELETE" });
      loadRequests(status);
    })
  );
}
$("#missing-filter-type").addEventListener("change", () => loadRequests("missing"));
$("#missing-filter-library").addEventListener("change", () => loadRequests("missing"));

// ---- import ----
let scanItems = [];
let missingReqs = [];

$("#scan-btn").addEventListener("click", async () => {
  $("#scan-info").textContent = "Scanne…";
  try {
    const [scan, reqs] = await Promise.all([
      api("/api/import/scan"),
      api("/api/requests?status=missing"),
    ]);
    scanItems = scan.items;
    missingReqs = reqs;
    $("#scan-info").textContent = `${scan.items.length} Kandidat(en) in ${scan.download_dir}`;
    renderImportTable();
  } catch (err) {
    $("#scan-info").textContent = "";
    toast(err.message, true);
  }
});

function renderImportTable() {
  const table = $("#import-table");
  const tbody = table.querySelector("tbody");
  if (!scanItems.length) { table.hidden = true; $("#import-btn").hidden = true; return; }
  tbody.innerHTML = scanItems
    .map((item, i) => {
      const opts = missingReqs
        .filter((r) => r.media_type === item.media_type)
        .map(
          (r) =>
            `<option value="${r.id}" ${r.id === item.suggested_request_id ? "selected" : ""}>
              ${esc(r.title)} — ${esc(r.authors)} (${esc(r.library_name)})</option>`
        )
        .join("");
      return `<tr>
        <td><input type="checkbox" data-check="${i}" ${item.suggested_request_id ? "checked" : ""}></td>
        <td class="mono">${esc(item.name)}${item.is_dir ? " 📁" : ""}</td>
        <td>${esc(item.media_type)}</td>
        <td><select data-select="${i}"><option value="">— überspringen —</option>${opts}</select></td>
        <td>${item.suggested_request_id ? item.score : "—"}</td>
      </tr>`;
    })
    .join("");
  table.hidden = false;
  $("#import-btn").hidden = false;
}

$("#import-btn").addEventListener("click", async () => {
  const items = [];
  scanItems.forEach((item, i) => {
    const checked = document.querySelector(`[data-check="${i}"]`).checked;
    const reqId = document.querySelector(`[data-select="${i}"]`).value;
    if (checked && reqId) {
      items.push({ path: item.path, is_dir: item.is_dir, files: item.files, request_id: parseInt(reqId) });
    }
  });
  if (!items.length) { toast("Nichts ausgewählt", true); return; }
  try {
    const res = await api("/api/import", { method: "POST", body: JSON.stringify({ items }) });
    $("#import-results").innerHTML = res.results
      .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("");
    $("#scan-btn").click();
  } catch (err) { toast(err.message, true); }
});

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