// Offer → Excel frontend
(() => {
  const $ = (id) => document.getElementById(id);
  const sections = {
    upload: $("s-upload"),
    processing: $("s-processing"),
    result: $("s-result"),
  };
  const show = (name) => {
    for (const [k, el] of Object.entries(sections)) el.classList.toggle("hidden", k !== name);
  };

  let state = { jobId: null, data: null };

  // ── Upload ──
  const fileInput = $("file-input");
  const dropZone = $("drop-zone");
  $("browse-btn").addEventListener("click", () => fileInput.click());
  fileInput.addEventListener("change", (e) => e.target.files[0] && upload(e.target.files[0]));
  ["dragenter", "dragover"].forEach((ev) =>
    dropZone.addEventListener(ev, (e) => { e.preventDefault(); dropZone.classList.add("drag-over"); }));
  ["dragleave", "drop"].forEach((ev) =>
    dropZone.addEventListener(ev, (e) => { e.preventDefault(); dropZone.classList.remove("drag-over"); }));
  dropZone.addEventListener("drop", (e) => e.dataTransfer.files[0] && upload(e.dataTransfer.files[0]));

  // Close any open combobox menu when clicking outside it (bound once).
  document.addEventListener("click", (e) => {
    document.querySelectorAll(".combo-menu").forEach((m) => {
      if (!m.closest(".combo-wrap").contains(e.target)) m.classList.add("hidden");
    });
  });

  async function upload(file) {
    show("processing");
    try {
      const fd = new FormData();
      fd.append("file", file);
      const r = await fetch("api/upload", { method: "POST", body: fd });
      if (!r.ok) throw new Error((await r.json()).detail || r.statusText);
      const json = await r.json();
      state.jobId = json.job_id;
      state.data = json.data || {};
      await initOrder();
      renderForm();
      show("result");
    } catch (err) {
      alert("Chyba: " + err.message);
      show("upload");
    }
  }

  // ── Render editable form ──
  function nestedField(parent, key, label, value, opts = {}) {
    const isEmpty = value === null || value === undefined || value === "";
    const cls = "inv-input" + (isEmpty ? " is-empty" : "");
    return `
      <div class="inv-field ${opts.wide ? "inv-field-wide" : ""}">
        <label class="inv-label">${escapeHtml(label)}</label>
        <input class="${cls}" data-parent="${parent}" data-key="${key}"
               type="text" value="${escapeHtmlAttr(isEmpty ? "" : value)}"
               placeholder="${escapeHtmlAttr(opts.placeholder || "—")}">
      </div>`;
  }

  function renderForm() {
    const d = state.data;
    const sup = d.supplier || {};
    const items = d.line_items || [];

    const warn = (d.is_offer === false)
      ? `<div class="offer-warn">⚠️ Tento dokument zřejmě není dodavatelská
           nabídka. Data mohou být neúplná — zkontrolujte je, nebo nahrajte
           jiný soubor.</div>`
      : "";

    const html = `
      ${warn}
      <!-- Dodavatel -->
      <div class="inv-card">
        <div class="inv-card-title">Dodavatel</div>
        <div class="inv-grid">
          ${nestedField("supplier", "name", "Jméno", sup.name, {wide: true})}
          ${nestedField("supplier", "ico", "IČO", sup.ico)}
          ${nestedField("supplier", "dic", "DIČ", sup.dic)}
          ${nestedField("supplier", "email", "Kontaktní email", sup.email)}
          ${nestedField("supplier", "address", "Adresa", sup.address, {wide: true})}
        </div>
      </div>

      <!-- Položky -->
      <div class="inv-card">
        <div class="inv-card-title">Položky (${items.length})</div>
        <div class="inv-table-wrap">
          <table class="inv-table" id="items-table">
            <thead>
              <tr>
                <th style="min-width:220px">Název zboží</th>
                <th style="width:150px">ID zboží dodavatele</th>
                <th style="width:90px">Množství</th>
                <th style="width:80px">Jednotka</th>
                <th style="width:120px">Jednotková cena</th>
                <th style="width:120px">Cena celkem</th>
                <th class="inv-row-actions"></th>
              </tr>
            </thead>
            <tbody id="items-body">
              ${items.map((it, i) => renderItemRow(it, i)).join("")}
            </tbody>
          </table>
        </div>
        <div class="inv-table-foot">
          <button class="btn-add-row" type="button" id="add-item-btn">+ Přidat položku</button>
        </div>
      </div>
      <div id="order-card-wrap">${orderCardHtml()}</div>
    `;
    $("offer-form").innerHTML = html;
    bindFieldHandlers();
    bindOrderHandlers();
    initDatePickers();
  }

  function rerenderOrderCard() {
    const wrap = $("order-card-wrap");
    if (!wrap) return;
    wrap.innerHTML = orderCardHtml();
    bindOrderHandlers();
    initDatePickers();
  }

  function initDatePickers() {
    if (typeof flatpickr === "undefined") return;
    if (flatpickr.l10ns && flatpickr.l10ns.cs) flatpickr.localize(flatpickr.l10ns.cs);
    document.querySelectorAll(".fp-date").forEach((el) => {
      if (el._flatpickr) return;
      flatpickr(el, {
        dateFormat: "d.m.Y",      // matches the PDF / store format
        allowInput: true,
        disableMobile: true,
        onChange: () => {
          state.order[el.dataset.order] = el.value;
          el.classList.toggle("is-empty", el.value === "");
        },
      });
    });
  }

  function renderItemRow(item, i) {
    return `
      <tr data-row="${i}">
        <td><input data-field="name" type="text" value="${escapeHtmlAttr(item.name || "")}"></td>
        <td><input data-field="supplier_id" type="text" value="${escapeHtmlAttr(item.supplier_id || "")}"></td>
        <td class="num"><input data-field="quantity" type="text" value="${fmtNum(item.quantity)}"></td>
        <td><input data-field="unit" type="text" value="${escapeHtmlAttr(item.unit || "")}"></td>
        <td class="num"><input data-field="unit_price" type="text" value="${fmtNum(item.unit_price)}"></td>
        <td class="num"><input data-field="total_price" type="text" value="${fmtNum(item.total_price)}"></td>
        <td class="inv-row-actions"><button class="inv-row-delete" type="button" data-action="delete-item" title="Smazat">×</button></td>
      </tr>`;
  }

  function bindFieldHandlers() {
    $("offer-form").querySelectorAll("input[data-key]").forEach((el) => {
      el.addEventListener("input", () => {
        const key = el.dataset.key;
        const parent = el.dataset.parent;
        if (parent) {
          if (!state.data[parent]) state.data[parent] = {};
          state.data[parent][key] = el.value;
        } else {
          state.data[key] = el.value;
        }
        el.classList.toggle("is-empty", el.value === "");
      });
    });

    const itemsBody = $("items-body");
    if (itemsBody) {
      itemsBody.addEventListener("input", (e) => {
        const inp = e.target.closest("input");
        if (!inp) return;
        const i = +inp.closest("tr").dataset.row;
        const field = inp.dataset.field;
        if (!state.data.line_items) state.data.line_items = [];
        if (!state.data.line_items[i]) state.data.line_items[i] = {};
        const numFields = ["quantity", "unit_price", "total_price"];
        state.data.line_items[i][field] =
          numFields.includes(field) ? parseNum(inp.value) : inp.value;
      });
      itemsBody.addEventListener("click", (e) => {
        const btn = e.target.closest('[data-action="delete-item"]');
        if (!btn) return;
        const i = +btn.closest("tr").dataset.row;
        state.data.line_items.splice(i, 1);
        renderForm();
      });
    }
    const addItem = $("add-item-btn");
    if (addItem) {
      addItem.addEventListener("click", () => {
        if (!state.data.line_items) state.data.line_items = [];
        state.data.line_items.push({name: "", supplier_id: "", quantity: null,
          unit: "", unit_price: null, total_price: null});
        renderForm();
      });
    }
  }

  function parseNum(s) {
    if (s === "" || s == null) return null;
    const n = parseFloat(String(s).replace(",", ".").replace(/\s/g, ""));
    return Number.isFinite(n) ? n : null;
  }
  function fmtNum(v) {
    if (v === null || v === undefined || v === "") return "";
    return String(v);
  }

  // ── Export ──
  $("export-btn").addEventListener("click", async () => {
    if (!state.jobId) return;
    await fetch(`api/save/${state.jobId}`, {
      method: "POST",
      headers: {"Content-Type": "application/json"},
      body: JSON.stringify({data: state.data}),
    }).catch(() => {});
    window.location.href = `api/export/${state.jobId}`;
  });

  $("restart-btn").addEventListener("click", () => {
    state = { jobId: null, data: null };
    fileInput.value = "";
    $("offer-form").innerHTML = "";
    show("upload");
  });

  // ── Objednávka (order form) ──────────────────────────────────
  function sumTotals() {
    return (state.data.line_items || []).reduce(
      (a, it) => a + (Number(it.total_price) || 0), 0);
  }

  async function initOrder() {
    const d = state.data;
    const offerNo = d.offer_number || "";
    state.order = {
      objednavka_number: "",
      kod_zakazky: "",
      nazev_zakazky: "",
      dodavatel: d.supplier || {},
      text: "Objednáváme u vás zboží dle cenové nabídky " + offerNo,
      prilohy: offerNo,
      termin_dodani_text: "Co nejdříve",
      misto_dodani: "",
      kontaktni_osoba: "",
      splatnost: "dle VNP nebo VSP",
      zaruka: "",
      poznamka: "",
      vystavil: "",
      popis: "",
      zpusob_platby: "Bankovním převodem",
      zpusob_odberu: "-",
      zpusob_dopravy: "-",
      forma_objednavky: "mailem",
      termin_dodani: "",
      fakturujte: "s DPH",
    };
    state.projects = [];
    state.orderHistory = {};
    try {
      const r = await fetch("api/projects");
      if (r.ok) {
        const j = await r.json();
        state.projects = j.projects || [];
        if (j.next_order_number) state.order.objednavka_number = j.next_order_number;
      }
    } catch (_) {}
  }

  // Body fields. `hist` = remembered per project, shown with a history
  // quick-pick (most-used first).
  const ORDER_FIELDS = [
    ["text", "Text", true, false],
    ["termin_dodani_text", "Termín dodání (text)", false, false],
    ["misto_dodani", "Místo dodání", true, true],
    ["kontaktni_osoba", "Kontaktní osoba v místě dodání", true, true],
    ["splatnost", "Splatnost", false, true],
    ["zaruka", "Záruka", false, true],
    ["poznamka", "Poznámka", false, false],
    ["prilohy", "Přílohy", false, false],
    ["vystavil", "Vystavil", false, true],
    ["popis", "Popis", false, true],
  ];

  function fieldHtml(key, label, wide, hist) {
    return hist ? historyField(key, label, wide) : textField(key, label, wide);
  }

  // ── date helpers (PDF/store use DD.MM.YYYY, <input type=date> uses ISO) ──
  function toDateInput(s) {
    s = (s == null ? "" : String(s)).trim();
    let m = s.match(/^(\d{1,2})\.(\d{1,2})\.(\d{4})$/);
    if (m) return `${m[3]}-${m[2].padStart(2,"0")}-${m[1].padStart(2,"0")}`;
    if (/^\d{4}-\d{2}-\d{2}$/.test(s)) return s;
    return "";
  }
  function fromDateInput(s) {
    const m = (s || "").match(/^(\d{4})-(\d{2})-(\d{2})$/);
    return m ? `${+m[3]}.${+m[2]}.${m[1]}` : (s || "");
  }

  // Combobox: type freely OR pick a previously-used value from a themed
  // dropdown attached to the field; each option can be deleted from history.
  function comboMenuHtml(key, filter) {
    const hist = (state.orderHistory && state.orderHistory[key]) || [];
    const f = (filter || "").toLowerCase();
    const items = hist.filter((h) => !f || String(h.value).toLowerCase().includes(f));
    if (!items.length) return '<div class="combo-empty">Žádné dříve použité</div>';
    return items.map((h) => `
      <div class="combo-opt" data-val="${escapeHtmlAttr(h.value)}">
        <span class="combo-opt-text">${escapeHtml(h.value)}
          <span class="combo-opt-count">${h.count}×</span></span>
        <button class="combo-del" type="button" title="Smazat z historie">×</button>
      </div>`).join("");
  }

  function historyField(key, label, wide) {
    const v = state.order[key];
    const cur = v == null ? "" : String(v);
    const hasHist = ((state.orderHistory && state.orderHistory[key]) || []).length > 0;
    return `
      <div class="inv-field ${wide ? "inv-field-wide" : ""}">
        <label class="inv-label">${escapeHtml(label)}</label>
        <div class="combo-wrap" data-combo="${key}">
          <input class="inv-input combo-input${cur === "" ? " is-empty" : ""}" data-order="${key}"
                 type="text" autocomplete="off" value="${escapeHtmlAttr(cur)}">
          ${hasHist ? '<button class="combo-toggle" type="button" tabindex="-1" aria-label="Dříve použité">⌄</button>' : ""}
          <div class="combo-menu hidden">${comboMenuHtml(key)}</div>
        </div>
      </div>`;
  }

  // Dodací a platební podmínky — selectable presets (editable: type or pick).
  const TERMS_FIELDS = [
    ["zpusob_platby", "Způsob platby", ["Bankovním převodem", "Hotově", "Kartou", "Zálohově", "Dobírka"]],
    ["forma_objednavky", "Forma objednávky", ["mailem", "telefonicky", "osobně", "písemně"]],
    ["zpusob_odberu", "Způsob odběru", ["-", "Osobní odběr", "Dodání na stavbu", "Dopravcem"]],
    ["termin_dodani", "Termín dodání", []],
    ["zpusob_dopravy", "Způsob dopravy", ["-", "Dodavatel", "Vlastní", "Dopravce"]],
    ["fakturujte", "Fakturujte", ["s DPH", "bez DPH"]],
  ];

  function textField(key, label, wide) {
    const v = state.order[key];
    const isEmpty = v === null || v === undefined || v === "";
    return `
      <div class="inv-field ${wide ? "inv-field-wide" : ""}">
        <label class="inv-label">${escapeHtml(label)}</label>
        <input class="inv-input${isEmpty ? " is-empty" : ""}" data-order="${key}"
               type="text" value="${escapeHtmlAttr(isEmpty ? "" : v)}">
      </div>`;
  }

  function comboField(key, label, options) {
    const v = state.order[key];
    const cur = v == null ? "" : String(v);
    // Termín dodání → flatpickr date picker (value stays DD.MM.YYYY).
    if (key === "termin_dodani") {
      return `
        <div class="inv-field">
          <label class="inv-label">${escapeHtml(label)}</label>
          <input class="inv-input fp-date${cur === "" ? " is-empty" : ""}" data-order="${key}"
                 type="text" placeholder="dd.mm.rrrr" value="${escapeHtmlAttr(cur)}">
        </div>`;
    }
    // Real dropdown: history (most-used first) + presets + any custom value.
    const histVals = ((state.orderHistory && state.orderHistory[key]) || [])
      .map((h) => h.value);
    const vals = [];
    for (const x of [...histVals, ...(options || []), cur]) {
      if (x && !vals.includes(x)) vals.push(x);
    }
    const opts = ['<option value=""></option>']
      .concat(vals.map((o) =>
        `<option value="${escapeHtmlAttr(o)}"${o === cur ? " selected" : ""}>${escapeHtml(o)}</option>`))
      .join("");
    return `
      <div class="inv-field">
        <label class="inv-label">${escapeHtml(label)}</label>
        <select class="inv-input" data-order="${key}">${opts}</select>
      </div>`;
  }

  function projectOptions() {
    const cur = state.order.kod_zakazky || "";
    const opts = ['<option value="">— vyberte zakázku —</option>'];
    for (const p of state.projects || []) {
      const sel = p.kod === cur ? " selected" : "";
      const label = p.nazev ? `${p.kod} — ${p.nazev}` : p.kod;
      opts.push(`<option value="${escapeHtmlAttr(p.kod)}"${sel}>${escapeHtml(label)}</option>`);
    }
    return opts.join("");
  }

  function orderCardHtml() {
    return `
      <div class="inv-card">
        <div class="inv-card-title">Objednávka (vyplní se do PDF)</div>
        <p class="order-hint">Zakázku vyberte z nabídky (nebo přidejte přes
          <strong>Spravovat zakázky</strong>). Pole jako <strong>Místo dodání</strong>,
          kontaktní osoba či Vystavil se pamatují podle zakázky. Číslo objednávky
          se předvyplní jako poslední&nbsp;+&nbsp;1. Cena celkem z položek:
          ${fmtCzk(sumTotals())}.</p>
        <div class="inv-grid">
          ${textField("objednavka_number", "Číslo objednávky", false)}
          <div class="inv-field">
            <label class="inv-label">Kód zakázky / NS</label>
            <div class="proj-row">
              <select class="inv-input" id="proj-select">${projectOptions()}</select>
              <button class="btn btn-secondary btn-sm" id="proj-manage" type="button">Spravovat</button>
            </div>
          </div>
          ${textField("nazev_zakazky", "Název zakázky", true)}
          ${ORDER_FIELDS.map(([k, l, w, h]) => fieldHtml(k, l, w, h)).join("")}
        </div>
        <div class="terms-subtitle">Dodací a platební podmínky</div>
        <div class="inv-grid">
          ${TERMS_FIELDS.map(([k, l, o]) => comboField(k, l, o)).join("")}
        </div>
        <div class="proj-panel hidden" id="proj-panel"></div>
      </div>`;
  }

  function fmtCzk(n) {
    return (Number(n) || 0).toLocaleString("cs-CZ", {minimumFractionDigits: 2, maximumFractionDigits: 2}) + " Kč";
  }

  function applyOrderToInputs() {
    document.querySelectorAll('[data-order]').forEach((inp) => {
      const k = inp.dataset.order;
      if (state.order[k] != null) {
        inp.value = state.order[k];
        inp.classList.toggle("is-empty", inp.value === "");
      }
    });
    document.querySelectorAll('[data-order-date]').forEach((inp) => {
      const k = inp.dataset.orderDate;
      inp.value = toDateInput(state.order[k]);
    });
  }

  async function loadProjectDefaults(code) {
    if (!code) { state.orderHistory = {}; return; }
    try {
      const r = await fetch(`api/order-defaults?code=${encodeURIComponent(code)}`);
      if (!r.ok) return;
      const { defaults } = await r.json();
      if (defaults && Object.keys(defaults).length) {
        state.orderHistory = defaults._history || {};
        delete defaults._history;
        Object.assign(state.order, defaults);
        // Re-render so history dropdowns reflect the selected project.
        rerenderOrderCard();
      }
    } catch (_) {}
  }

  function renderProjPanel() {
    const rows = (state.projects || []).map((p) => `
      <div class="proj-item" data-kod="${escapeHtmlAttr(p.kod)}">
        <span class="proj-kod">${escapeHtml(p.kod)}</span>
        <input class="inv-input proj-nazev" value="${escapeHtmlAttr(p.nazev || "")}" placeholder="Název zakázky">
        <button class="btn btn-secondary btn-sm proj-save" type="button">Uložit</button>
        <button class="btn btn-secondary btn-sm proj-del" type="button">Smazat</button>
      </div>`).join("");
    return `
      <div class="proj-add">
        <input class="inv-input" id="proj-new-kod" placeholder="Číslo zakázky (kód/NS)">
        <input class="inv-input" id="proj-new-nazev" placeholder="Název zakázky">
        <button class="btn btn-primary btn-sm" id="proj-add-btn" type="button">Přidat</button>
      </div>
      <div class="proj-list">${rows || '<p class="order-hint">Zatím žádné zakázky.</p>'}</div>`;
  }

  async function refreshProjects(list) {
    state.projects = list || state.projects;
    const sel = $("proj-select");
    if (sel) sel.innerHTML = projectOptions();
    const panel = $("proj-panel");
    if (panel && !panel.classList.contains("hidden")) panel.innerHTML = renderProjPanel();
  }

  function bindOrderHandlers() {
    document.querySelectorAll('[data-order]').forEach((el) => {
      const upd = () => {
        state.order[el.dataset.order] = el.value;
        el.classList.toggle("is-empty", el.value === "");
      };
      el.addEventListener("input", upd);
      el.addEventListener("change", upd);  // <select> fires change
    });
    // Date pickers store DD.MM.YYYY in the order.
    document.querySelectorAll('[data-order-date]').forEach((el) => {
      el.addEventListener("change", () => {
        state.order[el.dataset.orderDate] = fromDateInput(el.value);
        el.classList.toggle("is-empty", el.value === "");
      });
    });
    // Combobox fields: open menu on focus/toggle, filter on type, pick or
    // delete a previously-used value.
    document.querySelectorAll(".combo-wrap").forEach((wrap) => {
      const key = wrap.dataset.combo;
      const input = wrap.querySelector(".combo-input");
      const menu = wrap.querySelector(".combo-menu");
      const toggle = wrap.querySelector(".combo-toggle");
      const open = () => { menu.innerHTML = comboMenuHtml(key, input.value); menu.classList.remove("hidden"); };
      const close = () => menu.classList.add("hidden");
      if (toggle) toggle.addEventListener("click", (e) => {
        e.stopPropagation();
        menu.classList.contains("hidden") ? open() : close();
      });
      input.addEventListener("focus", open);
      input.addEventListener("input", open);  // value already synced by generic handler
      menu.addEventListener("click", async (e) => {
        const del = e.target.closest(".combo-del");
        if (del) {
          e.stopPropagation();
          const val = del.closest(".combo-opt").dataset.val;
          const code = state.order.kod_zakazky;
          if (!code) { menu.querySelector(`[data-val="${CSS.escape(val)}"]`)?.remove(); return; }
          try {
            const r = await fetch("api/order-history/delete", {
              method: "POST", headers: {"Content-Type": "application/json"},
              body: JSON.stringify({ code, field: key, value: val }),
            });
            if (r.ok) {
              state.orderHistory = (await r.json()).defaults._history || {};
              menu.innerHTML = comboMenuHtml(key, input.value);
            }
          } catch (_) {}
          return;
        }
        const opt = e.target.closest(".combo-opt");
        if (opt) {
          input.value = opt.dataset.val;
          input.classList.remove("is-empty");
          state.order[key] = opt.dataset.val;
          close();
        }
      });
    });

    const sel = $("proj-select");
    if (sel) sel.addEventListener("change", async () => {
      const code = sel.value;
      state.order.kod_zakazky = code;
      const p = (state.projects || []).find((x) => x.kod === code);
      state.order.nazev_zakazky = p ? (p.nazev || "") : "";
      applyOrderToInputs();
      await loadProjectDefaults(code);
    });

    const manage = $("proj-manage");
    if (manage) manage.addEventListener("click", () => {
      const panel = $("proj-panel");
      panel.classList.toggle("hidden");
      if (!panel.classList.contains("hidden")) {
        panel.innerHTML = renderProjPanel();
        panel.scrollIntoView({ behavior: "smooth", block: "center" });
      }
    });

    const panel = $("proj-panel");
    if (panel) {
      panel.addEventListener("click", async (e) => {
        const addBtn = e.target.closest("#proj-add-btn");
        if (addBtn) {
          const kod = $("proj-new-kod").value.trim();
          const nazev = $("proj-new-nazev").value.trim();
          if (!kod) { alert("Zadejte číslo zakázky."); return; }
          const r = await fetch("api/projects", {method:"POST", headers:{"Content-Type":"application/json"}, body: JSON.stringify({kod, nazev})});
          if (r.ok) { refreshProjects((await r.json()).projects); }
          return;
        }
        const item = e.target.closest(".proj-item");
        if (!item) return;
        const kod = item.dataset.kod;
        if (e.target.closest(".proj-save")) {
          const nazev = item.querySelector(".proj-nazev").value.trim();
          const r = await fetch("api/projects", {method:"POST", headers:{"Content-Type":"application/json"}, body: JSON.stringify({kod, nazev})});
          if (r.ok) refreshProjects((await r.json()).projects);
        } else if (e.target.closest(".proj-del")) {
          if (!confirm(`Smazat zakázku ${kod}?`)) return;
          const r = await fetch(`api/projects/${encodeURIComponent(kod)}`, {method:"DELETE"});
          if (r.ok) refreshProjects((await r.json()).projects);
        }
      });
    }
  }

  $("order-pdf-btn").addEventListener("click", async () => {
    if (!state.jobId) return;
    const btn = $("order-pdf-btn");
    const old = btn.textContent;
    btn.disabled = true; btn.textContent = "Generuji…";
    try {
      // keep supplier in sync as dodavatel
      state.order.dodavatel = state.data.supplier || {};
      state.order.cena_celkem = sumTotals();
      const r = await fetch(`api/order-pdf/${state.jobId}`, {
        method: "POST",
        headers: {"Content-Type": "application/json"},
        body: JSON.stringify({ order: state.order, items: state.data.line_items || [] }),
      });
      if (!r.ok) throw new Error((await r.json()).detail || r.statusText);
      const cd = r.headers.get("content-disposition") || "";
      const m = cd.match(/filename="?([^"]+)"?/);
      const blob = await r.blob();
      const a = document.createElement("a");
      a.href = URL.createObjectURL(blob);
      a.download = m ? m[1] : "objednavka.pdf";
      document.body.appendChild(a); a.click(); a.remove();
      setTimeout(() => URL.revokeObjectURL(a.href), 60000);
    } catch (err) {
      alert("Chyba: " + err.message);
    } finally {
      btn.disabled = false; btn.textContent = old;
    }
  });

  function escapeHtml(s) {
    return String(s ?? "").replace(/[&<>"']/g, (c) =>
      ({"&":"&amp;","<":"&lt;",">":"&gt;",'"':"&quot;","'":"&#39;"}[c]));
  }
  function escapeHtmlAttr(s) { return escapeHtml(s); }
})();