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

  let state = {
    jobId: null,
    checklist: [],
    analysis: null,
    pendingFile: null,  // File chosen by user but not yet uploaded
  };
  let nextCustomId = 1;

  // ── Load default checklist ──
  async function loadChecklist() {
    try {
      const r = await fetch("api/checklist");
      const data = await r.json();
      state.checklist = (data.items || []).map((it) => ({
        ...it,
        checked: it.default !== false,
      }));
      renderChecklist();
    } catch (err) {
      alert("Nepodařilo se načíst kontrolní seznam: " + err.message);
    }
  }

  function renderChecklist() {
    const c = $("checklist");
    c.innerHTML = "";
    for (const item of state.checklist) {
      const div = document.createElement("label");
      div.className = "checklist-item" + (item.custom ? " custom" : "");
      div.innerHTML = `
        <input type="checkbox" ${item.checked ? "checked" : ""}>
        <div class="checklist-item-body">
          <div class="checklist-item-label">${escapeHtml(item.label)}</div>
          ${item.hint ? `<div class="checklist-item-hint">${escapeHtml(item.hint)}</div>` : ""}
        </div>
        ${item.custom ? `<button class="checklist-remove" type="button" title="Odstranit">×</button>` : ""}
      `;
      const cb = div.querySelector("input");
      cb.addEventListener("change", () => {
        item.checked = cb.checked;
        updateRunButton();
      });
      const rm = div.querySelector(".checklist-remove");
      if (rm) {
        rm.addEventListener("click", (e) => {
          e.preventDefault();
          state.checklist = state.checklist.filter((x) => x.id !== item.id);
          renderChecklist();
          updateRunButton();
        });
      }
      c.appendChild(div);
    }
    updateRunButton();
  }

  $("check-all-btn").addEventListener("click", () => {
    for (const it of state.checklist) it.checked = true;
    renderChecklist();
  });
  $("uncheck-all-btn").addEventListener("click", () => {
    for (const it of state.checklist) it.checked = false;
    renderChecklist();
  });

  $("add-item-form").addEventListener("submit", (e) => {
    e.preventDefault();
    const input = $("add-item-input");
    const label = input.value.trim();
    if (!label) return;
    state.checklist.push({
      id: `custom_${nextCustomId++}`,
      label,
      hint: "",
      checked: true,
      custom: true,
    });
    input.value = "";
    renderChecklist();
  });

  // ── File selection (just stores the file, doesn't upload yet) ──
  const fileInput = $("file-input");
  const dropZone = $("drop-zone");
  $("browse-btn").addEventListener("click", () => fileInput.click());
  fileInput.addEventListener("change", (e) => e.target.files[0] && setFile(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] && setFile(e.dataTransfer.files[0]));

  function setFile(file) {
    state.pendingFile = file;
    $("file-info-name").textContent = file.name;
    $("file-info").classList.remove("hidden");
    dropZone.classList.add("compact");
    updateRunButton();
  }

  $("file-info-clear").addEventListener("click", () => {
    state.pendingFile = null;
    fileInput.value = "";
    $("file-info").classList.add("hidden");
    dropZone.classList.remove("compact");
    updateRunButton();
  });

  function updateRunButton() {
    const hasFile = !!state.pendingFile;
    const selectedCount = state.checklist.filter((it) => it.checked).length;
    const btn = $("run-btn");
    const hint = $("run-hint");
    // run-hint only exists after a file is selected (lives in the file-info strip)
    if (!hasFile) {
      btn.disabled = true;
      return;
    }
    if (selectedCount === 0) {
      btn.disabled = true;
      if (hint) hint.textContent = "Vyberte alespoň jednu položku ke kontrole níže.";
    } else {
      btn.disabled = false;
      if (hint) hint.textContent = `Připraveno spustit kontrolu ${selectedCount} bodů.`;
    }
  }

  $("run-btn").addEventListener("click", async () => {
    if (!state.pendingFile) return;
    const selected = state.checklist.filter((it) => it.checked);
    if (!selected.length) return;
    show("processing");
    $("processing-title").textContent = "Nahrávám smlouvu…";
    try {
      const fd = new FormData();
      fd.append("file", state.pendingFile);
      const ur = await fetch("api/upload", { method: "POST", body: fd });
      if (!ur.ok) throw new Error((await ur.json()).detail || ur.statusText);
      const upJson = await ur.json();
      state.jobId = upJson.job_id;

      $("processing-title").textContent = `Analyzuji smlouvu (${selected.length} bodů)…`;
      const ar = await fetch(`api/analyze/${state.jobId}`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          items: selected.map((it) => ({
            id: it.id,
            label: it.label,
            hint: it.hint || "",
          })),
        }),
      });
      if (!ar.ok) throw new Error((await ar.json()).detail || ar.statusText);
      state.analysis = await ar.json();
      renderResults();
      show("results");
    } catch (err) {
      alert("Chyba: " + err.message);
      show("setup");
    }
  });

  function renderResults() {
    const a = state.analysis;
    const items = a.items || [];
    const usedOcr = !!a._used_ocr;
    const counts = items.reduce((acc, it) => {
      acc[it.status || "warning"] = (acc[it.status || "warning"] || 0) + 1;
      return acc;
    }, {});
    $("results-meta").textContent =
      `Vyhodnoceno ${items.length} bodů. ` +
      `OK: ${counts.ok || 0}, Pozor: ${counts.warning || 0}, ` +
      `Problém: ${counts.problem || 0}, Chybí: ${counts.missing || 0}.`;

    const riskMap = {
      low: ["Nízké riziko", "risk-low"],
      medium: ["Střední riziko", "risk-medium"],
      high: ["Vysoké riziko", "risk-high"],
    };
    const r = riskMap[a.risk_level] || ["—", ""];
    const overall = $("overall-card");
    const ocrNotice = usedOcr
      ? `<div class="ocr-notice">⚙ Smlouva neměla textovou vrstvu — použito OCR (rozpoznávání textu z obrazu). Stažené PDF bude obsahovat jen souhrnnou stránku, bez zvýraznění v původním textu (kvalita OCR neumožňuje spolehlivé vyhledání citací).</div>`
      : "";
    overall.innerHTML = `
      <div class="risk-badge ${r[1]}">${r[0]}</div>
      <div class="overall-text">
        ${escapeHtml(a.overall_summary || "")}
        ${ocrNotice}
      </div>
    `;

    const findings = $("findings");
    findings.innerHTML = "";
    const labelMap = { ok: "OK", warning: "POZOR", problem: "PROBLÉM", missing: "CHYBÍ" };
    // Sort: problem > warning > missing > ok
    const order = { problem: 0, warning: 1, missing: 2, ok: 3 };
    const sorted = [...items].sort((a, b) =>
      (order[a.status] ?? 9) - (order[b.status] ?? 9)
    );
    for (const it of sorted) {
      const div = document.createElement("div");
      div.className = `finding status-${it.status || "warning"}`;
      const excerptsHtml = (it.excerpts || []).map((ex) => `
        <div class="excerpt">
          <div class="excerpt-text">
            ${ex.page ? `<span class="excerpt-page">str. ${ex.page}</span>` : ""}
            <span>„${escapeHtml(ex.text || "")}"</span>
          </div>
          ${ex.comment ? `<div class="excerpt-comment">${escapeHtml(ex.comment)}</div>` : ""}
        </div>
      `).join("");
      const canAdvise = it.status === "warning" || it.status === "problem";
      const adviceBtn = canAdvise
        ? `<button class="btn btn-secondary btn-sm advice-btn" data-id="${escapeHtmlAttr(it.id)}" type="button">Navrhnout úpravu</button>`
        : "";
      div.innerHTML = `
        <div class="finding-header">
          <span class="finding-status">${labelMap[it.status] || it.status || ""}</span>
          <span class="finding-title">${escapeHtml(it.title || it.label || it.id)}</span>
        </div>
        ${it.summary ? `<p class="finding-summary">${escapeHtml(it.summary)}</p>` : ""}
        ${excerptsHtml ? `<div class="finding-excerpts">${excerptsHtml}</div>` : ""}
        ${adviceBtn ? `<div class="finding-advice-row">${adviceBtn}</div>
          <div class="finding-advice hidden" data-advice="${escapeHtmlAttr(it.id)}"></div>` : ""}
      `;
      findings.appendChild(div);
    }
    findings.onclick = onFindingClick;
    state.supplierDone = false;
    state.supplierStatus = "checking";
    updateDownloadGate();
    renderSupplier();
    resetChat();
  }

  // ── Per-clause improvement advice ──
  async function onFindingClick(e) {
    const btn = e.target.closest(".advice-btn");
    if (!btn) return;
    const id = btn.dataset.id;
    const box = document.querySelector(`[data-advice="${CSS.escape(id)}"]`);
    if (box && !box.classList.contains("hidden") && box.dataset.loaded) {
      box.classList.toggle("hidden");  // collapse if already loaded
      return;
    }
    btn.disabled = true; const old = btn.textContent; btn.textContent = "Generuji…";
    try {
      const r = await fetch(`api/advice/${state.jobId}`, {
        method: "POST", headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ item_id: id }),
      });
      if (!r.ok) throw new Error((await r.json()).detail || r.statusText);
      const d = await r.json();
      box.innerHTML = renderAdvice(d.advice || "");
      box.dataset.loaded = "1";
      box.classList.remove("hidden");
      btn.textContent = "Skrýt návrh";
    } catch (err) {
      alert("Chyba: " + err.message);
      btn.textContent = old;
    } finally {
      btn.disabled = false;
    }
  }

  function renderAdvice(text) {
    return `<div class="advice-label">Návrh úprav</div>${mdToHtml(text)}`;
  }

  function updateDownloadGate() {
    const btn = $("download-pdf-btn");
    const note = $("download-gate-note");
    btn.disabled = !state.supplierDone;
    if (state.supplierDone) {
      btn.title = "";
      note.classList.add("hidden");
      note.textContent = "";
    } else {
      const msg = state.supplierStatus === "checking"
        ? "⏳ PDF bude k dispozici po dokončení ověření protistrany v rejstřících (probíhá…). Ověření je součástí PDF."
        : "⚠ Stažení PDF je zatím nedostupné: nejprve dokončete ověření protistrany (zadejte IČO v kartě výše). Výsledek ověření je povinnou součástí PDF.";
      btn.title = "Nejprve dokončete ověření protistrany v rejstřících";
      note.textContent = msg;
      note.classList.remove("hidden");
    }
  }

  // ── Supplier reputation (ARES + MFČR) ──
  async function renderSupplier(ico) {
    const card = $("supplier-card");
    card.innerHTML = `<div class="supplier-loading">Ověřuji protistranu v rejstřících…</div>`;
    state.supplierDone = false;
    state.supplierStatus = "checking";
    updateDownloadGate();
    try {
      const r = await fetch(`api/supplier/${state.jobId}`, {
        method: "POST", headers: { "Content-Type": "application/json" },
        body: JSON.stringify(ico ? { ico } : {}),
      });
      const d = await r.json();
      if (d.found) {
        card.innerHTML = supplierReportHtml(d);
        state.supplierDone = true;
      } else {
        card.innerHTML = supplierManualHtml(d);
        bindSupplierManual();
        state.supplierStatus = "manual";
      }
    } catch (err) {
      card.innerHTML = supplierManualHtml({ reason: "Ověření selhalo: " + err.message });
      bindSupplierManual();
      state.supplierStatus = "manual";
    }
    updateDownloadGate();
  }

  function supplierReportHtml(d) {
    const a = d.report.ares, v = d.report.vat;
    const flags = (d.report.flags || []).map(([lvl, txt]) =>
      `<span class="rep-flag rep-${lvl}">${escapeHtml(txt)}</span>`).join("");
    const row = (k, val) => val ? `<div class="rep-row"><span>${k}</span><span>${escapeHtml(String(val))}</span></div>` : "";
    const srcMap = { contract: "z textu smlouvy", ares_name: "podle názvu (ARES)", manual: "zadáno ručně" };
    return `
      <div class="supplier-head">
        <span class="supplier-title">Protistrana — ověření v rejstřících</span>
        <button class="btn-link" id="supplier-edit" type="button">Změnit IČO</button>
      </div>
      <div class="rep-flags">${flags}</div>
      ${row("Název", a.name)}
      ${row("IČO / DIČ", [a.ico, a.dic].filter(Boolean).join(" / "))}
      ${row("Adresa", a.address)}
      ${row("Vznik", a.founded)}
      ${a.dissolved ? row("Zánik", a.dissolved) : ""}
      <div class="rep-row"><span>Aktivní v rejstříku</span><span>${a.active ? "ano" : "ne"}</span></div>
      <div class="rep-row"><span>Plátce DPH</span><span>${a.vat_registered ? "ano" : "ne"}</span></div>
      <div class="rep-row"><span>Insolvence</span><span>${a.in_insolvency ? "ANO — pozor" : "ne"}</span></div>
      <div class="rep-row"><span>Nespolehlivý plátce DPH</span><span>${v.unreliable === true ? "ANO — pozor" : v.unreliable === false ? "ne" : "neověřeno"}</span></div>
      ${v.accounts && v.accounts.length ? `<div class="rep-row"><span>Zveřejněné účty</span><span>${v.accounts.slice(0,4).map(escapeHtml).join(", ")}${v.accounts.length>4?" …":""}</span></div>` : ""}
      <div class="rep-source">Zdroj: ${srcMap[d.source] || d.source} · ARES + MFČR</div>`;
  }

  function supplierManualHtml(d) {
    const cands = (d.candidates || []).map((c) =>
      `<button class="btn btn-secondary btn-sm sup-cand" data-ico="${escapeHtmlAttr(c.ico)}" type="button">${escapeHtml(c.name || c.ico)} (${escapeHtml(c.ico || "?")})</button>`).join(" ");
    return `
      <div class="supplier-head"><span class="supplier-title">Protistrana — ověření v rejstřících</span></div>
      <p class="supplier-reason">${escapeHtml(d.reason || "IČO se nepodařilo zjistit.")}</p>
      ${d.name_guess ? `<p class="supplier-reason">Odhad názvu: <strong>${escapeHtml(d.name_guess)}</strong></p>` : ""}
      ${cands ? `<div class="sup-cands">${cands}</div>` : ""}
      <div class="sup-manual-row">
        <input type="text" id="sup-ico" class="add-item-input" placeholder="Zadejte IČO (8 číslic)">
        <button class="btn btn-primary btn-sm" id="sup-check" type="button">Ověřit</button>
      </div>`;
  }

  function bindSupplierManual() {
    const chk = $("sup-check");
    if (chk) chk.addEventListener("click", () => {
      const ico = ($("sup-ico").value || "").replace(/\D/g, "");
      if (ico.length === 8) renderSupplier(ico);
      else alert("IČO musí mít 8 číslic.");
    });
    document.querySelectorAll(".sup-cand").forEach((b) =>
      b.addEventListener("click", () => renderSupplier(b.dataset.ico)));
    const card = $("supplier-card");
    card.querySelector("#supplier-edit") &&
      card.querySelector("#supplier-edit").addEventListener("click", () =>
        { card.innerHTML = supplierManualHtml({ reason: "Zadejte IČO protistrany ručně." }); bindSupplierManual(); });
  }
  // delegate "Změnit IČO" (present in the report view)
  $("supplier-card").addEventListener("click", (e) => {
    if (e.target.id === "supplier-edit") {
      $("supplier-card").innerHTML = supplierManualHtml({ reason: "Zadejte IČO protistrany ručně." });
      bindSupplierManual();
    }
  });

  // ── Chat with the contract ──
  let chatMessages = [];
  function resetChat() {
    chatMessages = [];
    $("chat-log").innerHTML = "";
  }
  // Minimal markdown → HTML for assistant replies (bold, headings, bullets).
  function mdToHtml(md) {
    let s = escapeHtml(md);
    s = s.replace(/^#{3,}\s+(.*)$/gm, "<h4>$1</h4>")
         .replace(/^##\s+(.*)$/gm, "<h3>$1</h3>")
         .replace(/\*\*(.+?)\*\*/g, "<strong>$1</strong>");
    s = s.replace(/^\s*[-•]\s+(.*)$/gm, "<li>$1</li>");
    s = s.replace(/(<li>[\s\S]*?<\/li>)/g, (m) => "<ul>" + m + "</ul>");
    return s.split(/\n{2,}/).map((b) =>
      /^<(ul|h3|h4)/.test(b.trim()) ? b : "<p>" + b.replace(/\n/g, "<br>") + "</p>"
    ).join("");
  }
  function appendChat(role, text) {
    const wrap = document.createElement("div");
    wrap.className = `msg msg-${role}`;
    const author = role === "user" ? "Vy" : "Asistent";
    const ava = role === "user"
      ? '<span class="msg-avatar you">Vy</span>'
      : '<span class="msg-avatar">AI</span>';
    const body = role === "user" ? escapeHtml(text) : mdToHtml(text);
    wrap.innerHTML = `<div class="msg-author">${ava}${author}</div><div class="msg-body">${body}</div>`;
    $("chat-log").appendChild(wrap);
    $("chat-log").scrollTop = $("chat-log").scrollHeight;
    return wrap.querySelector(".msg-body");
  }
  // Assistant placeholder with animated typing dots (same as Firemní asistent).
  function appendTyping() {
    const wrap = document.createElement("div");
    wrap.className = "msg msg-assistant msg-typing";
    wrap.innerHTML =
      '<div class="msg-author"><span class="msg-avatar">AI</span>Asistent</div>' +
      '<div class="msg-body"><span class="dot"></span><span class="dot"></span><span class="dot"></span></div>';
    $("chat-log").appendChild(wrap);
    $("chat-log").scrollTop = $("chat-log").scrollHeight;
    return wrap;
  }
  $("chat-form").addEventListener("submit", async (e) => {
    e.preventDefault();
    const inp = $("chat-input");
    const q = inp.value.trim();
    if (!q || !state.jobId) return;
    inp.value = "";
    inp.style.height = "auto";
    appendChat("user", q);
    chatMessages.push({ role: "user", content: q });
    const msgEl = appendTyping();
    const body = msgEl.querySelector(".msg-body");
    $("chat-send").disabled = true;
    let acc = "", first = false;
    try {
      const r = await fetch(`api/chat/${state.jobId}`, {
        method: "POST", headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ messages: chatMessages }),
      });
      if (!r.ok || !r.body) throw new Error("HTTP " + r.status);
      const reader = r.body.getReader();
      const dec = new TextDecoder();
      let buf = "";
      while (true) {
        const { done, value } = await reader.read();
        if (done) break;
        buf += dec.decode(value, { stream: true });
        let idx;
        while ((idx = buf.indexOf("\n\n")) !== -1) {
          const raw = buf.slice(0, idx); buf = buf.slice(idx + 2);
          if (!raw.startsWith("data:")) continue;
          let evt; try { evt = JSON.parse(raw.slice(5).trim()); } catch { continue; }
          if (evt.type === "textResponseChunk") {
            if (!first) { msgEl.classList.remove("msg-typing"); body.innerHTML = ""; first = true; }
            acc += evt.textResponse || "";
            body.innerHTML = mdToHtml(acc);
            $("chat-log").scrollTop = $("chat-log").scrollHeight;
          } else if (evt.type === "finalizeResponseStream") {
            msgEl.classList.remove("msg-typing");
            acc = evt.textResponse || acc;
            body.innerHTML = mdToHtml(acc);
          } else if (evt.type === "error") {
            msgEl.classList.remove("msg-typing");
            body.innerHTML = `<span class="chat-err">Chyba: ${escapeHtml(evt.error || "")}</span>`;
          }
        }
      }
      if (acc) chatMessages.push({ role: "assistant", content: acc });
      else { msgEl.classList.remove("msg-typing"); body.textContent = "Bez odpovědi."; }
    } catch (err) {
      msgEl.classList.remove("msg-typing");
      body.innerHTML = `<span class="chat-err">Spojení selhalo: ${escapeHtml(String(err))}</span>`;
    } finally {
      $("chat-send").disabled = false;
    }
  });

  // Enter sends, Shift+Enter = newline; textarea auto-grows.
  const chatInput = $("chat-input");
  chatInput.addEventListener("keydown", (e) => {
    if (e.key === "Enter" && !e.shiftKey) {
      e.preventDefault();
      $("chat-form").requestSubmit();
    }
  });
  chatInput.addEventListener("input", () => {
    chatInput.style.height = "auto";
    chatInput.style.height = Math.min(chatInput.scrollHeight, 160) + "px";
  });

  // Download is gated on the reliability check; opens the include-modal.
  $("download-pdf-btn").addEventListener("click", () => {
    if (!state.jobId) return;
    if (!state.supplierDone) {
      alert("Nejprve dokončete ověření protistrany — bude součástí PDF.");
      return;
    }
    $("inc-chat").checked = chatMessages.length > 0;
    $("export-modal").classList.remove("hidden");
  });
  $("export-cancel").addEventListener("click", () =>
    $("export-modal").classList.add("hidden"));
  $("export-go").addEventListener("click", async () => {
    const btn = $("export-go"); const old = btn.textContent;
    btn.disabled = true; btn.textContent = "Generuji…";
    try {
      const r = await fetch(`api/annotated/${state.jobId}`, {
        method: "POST", headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          include_supplier: true,
          include_advice: $("inc-advice").checked,
          include_chat: $("inc-chat").checked,
          chat: chatMessages,
        }),
      });
      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] : "kontrola.pdf";
      document.body.appendChild(a); a.click(); a.remove();
      setTimeout(() => URL.revokeObjectURL(a.href), 60000);
      $("export-modal").classList.add("hidden");
    } catch (err) {
      alert("Chyba: " + err.message);
    } finally {
      btn.disabled = false; btn.textContent = old;
    }
  });

  $("restart-btn").addEventListener("click", () => {
    state = {
      jobId: null,
      checklist: state.checklist,
      analysis: null,
      pendingFile: null,
    };
    fileInput.value = "";
    $("file-info").classList.add("hidden");
    dropZone.classList.remove("compact");
    show("setup");
    updateRunButton();
  });

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

  loadChecklist();
})();