// files.js — file preview + attachment handling extracted from helpers.js.
// Sheet preview (PDF embed, XLSX viewer, Luckysheet modal) + file upload/attachment
// staging (handleImageUpload, handleFileUpload, stageAttachment, renderStagedAttachments,
// pdfPageToText, ...). stagedAttachments stays global (sendChat reads it).
function togglePdfEmbed(url, containerId, btn) {
  var container = document.getElementById(containerId);
  if (!container) return;
  var iframe = container.querySelector('iframe');
  if (container.style.display === 'none') {
    container.style.display = 'block';
    if (iframe) iframe.src = url; // src=""이면 현재페이지로 해석 → 항상 명시 설정
    btn.innerHTML = '▲ 닫기';
  } else {
    container.style.display = 'none';
    btn.innerHTML = '◀ 미리보기';
  }
}

var _luckyCurrentSaveUrl = null;

function openXlsxNewWindow(url, title) {
  var q = '/html/xlsx-viewer.html?file=' + encodeURIComponent(url)
        + '&save=' + encodeURIComponent(url)
        + '&title=' + encodeURIComponent(title || '스프레드시트');
  window.open(q, '_blank', 'width=1200,height=800,menubar=no,toolbar=no,location=no,status=no,scrollbars=no,resizable=yes');
}

function toggleXlsxEmbedBtn(btn) {
  var url = encodeURI(btn.getAttribute('data-xlsx-url'));
  var card = btn.closest('.xlsx-card');
  var nameEl = card ? card.querySelector('span[style*="font-weight"]') : null;
  var title = nameEl ? nameEl.textContent : url.split('/').pop();
  var saveUrl = card ? card.querySelector('[data-xlsx-save-url]')?.getAttribute('data-xlsx-save-url') : null;
  openLuckyModal(url, title, saveUrl);
}

function openLuckyModal(url, title, saveUrl) {
  var modal = document.getElementById('lucky-modal');
  var titleEl = document.getElementById('lucky-modal-title');
  var container = document.getElementById('lucky-container');
  if (!modal || !container) return;

  // Reset box to centered state on each open
  var box = document.getElementById('lucky-modal-box');
  if (box) {
    box.style.position = 'relative';
    box.style.left = ''; box.style.top = '';
    box.style.width = '96vw'; box.style.height = '92vh';
    box._isAbsolute = false; box.dataset.minimized = '0';
  }
  modal.style.display = 'flex';
  modal.style.alignItems = 'center';
  modal.style.justifyContent = 'center';
  titleEl.textContent = title || '스프레드시트';
  _luckyCurrentSaveUrl = saveUrl || null;
  container.innerHTML = '<div style="display:flex;align-items:center;justify-content:center;height:100%;color:#666;font-size:13px">Luckysheet 로딩 중… (최초 1회 ~3MB)</div>';
  initLuckyModalInteraction();

  fetch(url, { headers: authHeaders() })
    .then(function(r) { if (!r.ok) throw new Error('HTTP ' + r.status); return r.arrayBuffer(); })
    .then(function(buf) {
      loadLuckysheet(function() {
        if (typeof LuckyExcel === 'undefined' || typeof luckysheet === 'undefined') {
          container.innerHTML = '<div style="padding:20px;color:red">Luckysheet 로드 실패 — 네트워크 연결을 확인하세요.</div>'; return;
        }
        var file = new File([buf], 'sheet.xlsx', { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
        LuckyExcel.transformExcelToLucky(file, function(exportInfo) {
          container.innerHTML = '';
          try { luckysheet.destroy(); } catch(e) {}
          luckysheet.create({
            container: 'lucky-container',
            data: exportInfo.sheets,
            title: '',
            lang: 'en',
            showinfobar: false,
            showstatisticBar: false,
            sheetBottomConfig: true,
            allowUpdate: true,
            enableAddRow: true,
            enableAddCol: true,
            showToolbar: true,
            plugins: [],
            defaultFontSize: 11,
            defaultFontName: 'Nanum Gothic',
          });
        }, function(err) {
          container.innerHTML = '<div style="padding:20px;color:red">Excel 변환 오류: ' + escHtml(String(err?.message || err)) + '</div>';
        });
      });
    })
    .catch(function(e) {
      container.innerHTML = '<div style="padding:20px;color:red">불러오기 실패: ' + escHtml(e.message) + '</div>';
    });
}

function minimizeLuckyModal() {
  var box = document.getElementById('lucky-modal-box');
  var modal = document.getElementById('lucky-modal');
  var btn = event.target;
  if (!box || !modal) return;
  var minimized = box.dataset.minimized === '1';
  if (minimized) {
    box.style.height = box._savedHeight || '92vh';
    box.dataset.minimized = '0';
    btn.textContent = '–';
    btn.title = '최소화';
    if (!box._isAbsolute) { modal.style.alignItems = 'center'; modal.style.justifyContent = 'center'; }
  } else {
    box._savedHeight = box.style.height || '92vh';
    box.dataset.minimized = '1';
    btn.innerHTML = '&#9723;';
    btn.title = '복원';
    if (box._isAbsolute) {
      box.style.top = (window.innerHeight - 52) + 'px';
      box.style.height = 'auto';
    } else {
      box.style.height = 'auto';
      modal.style.alignItems = 'flex-end';
      modal.style.justifyContent = 'center';
      modal.style.paddingBottom = '0';
    }
  }
}

function closeLuckyModal() {
  var modal = document.getElementById('lucky-modal');
  var box = document.getElementById('lucky-modal-box');
  if (modal) { modal.style.display = 'none'; modal.style.alignItems = 'center'; modal.style.justifyContent = 'center'; }
  if (box) {
    box.style.position = 'relative';
    box.style.left = ''; box.style.top = '';
    box.style.width = '96vw'; box.style.height = '92vh';
    box._isAbsolute = false; box._savedHeight = null;
    box.dataset.minimized = '0';
  }
  try { luckysheet.destroy(); } catch(e) {}
  _luckyCurrentSaveUrl = null;
}

// Close on backdrop click
document.getElementById('lucky-modal')?.addEventListener('click', function(e) {
  if (e.target === this) closeLuckyModal();
});

function initLuckyModalInteraction() {
  var box = document.getElementById('lucky-modal-box');
  var modal = document.getElementById('lucky-modal');
  if (!box || box._interactInit) return;
  box._interactInit = true;

  // Inject 8 resize handles
  [
    { dir:'n',  css:'top:0;left:10px;right:10px;height:6px;cursor:n-resize' },
    { dir:'s',  css:'bottom:0;left:10px;right:10px;height:6px;cursor:s-resize' },
    { dir:'e',  css:'right:0;top:10px;bottom:10px;width:6px;cursor:e-resize' },
    { dir:'w',  css:'left:0;top:10px;bottom:10px;width:6px;cursor:w-resize' },
    { dir:'ne', css:'top:0;right:0;width:12px;height:12px;cursor:ne-resize' },
    { dir:'nw', css:'top:0;left:0;width:12px;height:12px;cursor:nw-resize' },
    { dir:'se', css:'bottom:0;right:0;width:12px;height:12px;cursor:se-resize' },
    { dir:'sw', css:'bottom:0;left:0;width:12px;height:12px;cursor:sw-resize' },
  ].forEach(function(d) {
    var h = document.createElement('div');
    h.className = 'lucky-rh';
    h.dataset.dir = d.dir;
    h.style.cssText = 'position:absolute;z-index:200;' + d.css;
    box.appendChild(h);
  });

  function toAbsolute() {
    if (box._isAbsolute) return;
    var rect = box.getBoundingClientRect();
    modal.style.display = 'block';
    box.style.position = 'absolute';
    box.style.left = rect.left + 'px';
    box.style.top = rect.top + 'px';
    box.style.width = rect.width + 'px';
    box.style.height = rect.height + 'px';
    box._isAbsolute = true;
  }

  // Title bar drag
  var header = box.firstElementChild;
  if (header) {
    header.style.cursor = 'grab';
    header.addEventListener('mousedown', function(e) {
      if (e.target.tagName === 'BUTTON') return;
      toAbsolute();
      var rect = box.getBoundingClientRect();
      var ox = e.clientX - rect.left, oy = e.clientY - rect.top;
      header.style.cursor = 'grabbing';
      function onMove(e) {
        box.style.left = (e.clientX - ox) + 'px';
        box.style.top = Math.max(0, e.clientY - oy) + 'px';
      }
      function onUp() {
        header.style.cursor = 'grab';
        document.removeEventListener('mousemove', onMove);
        document.removeEventListener('mouseup', onUp);
      }
      document.addEventListener('mousemove', onMove);
      document.addEventListener('mouseup', onUp);
      e.preventDefault();
    });
  }

  // Resize handle drag
  box.addEventListener('mousedown', function(e) {
    var handle = e.target.closest ? e.target.closest('.lucky-rh') : null;
    if (!handle) return;
    toAbsolute();
    var dir = handle.dataset.dir;
    var rect = box.getBoundingClientRect();
    var sx = e.clientX, sy = e.clientY;
    var sl = rect.left, st = rect.top, sw = rect.width, sh = rect.height;
    document.body.style.userSelect = 'none';
    document.body.style.cursor = handle.style.cursor;
    function onMove(e) {
      var dx = e.clientX - sx, dy = e.clientY - sy;
      var nl = sl, nt = st, nw = sw, nh = sh;
      if (dir.includes('e')) nw = Math.max(380, sw + dx);
      if (dir.includes('s')) nh = Math.max(180, sh + dy);
      if (dir.includes('w')) { nw = Math.max(380, sw - dx); nl = sl + sw - nw; }
      if (dir.includes('n')) { nh = Math.max(180, sh - dy); nt = st + sh - nh; }
      box.style.left = nl + 'px'; box.style.top = nt + 'px';
      box.style.width = nw + 'px'; box.style.height = nh + 'px';
    }
    function onUp() {
      document.body.style.userSelect = '';
      document.body.style.cursor = '';
      document.removeEventListener('mousemove', onMove);
      document.removeEventListener('mouseup', onUp);
    }
    document.addEventListener('mousemove', onMove);
    document.addEventListener('mouseup', onUp);
    e.preventDefault();
    e.stopPropagation();
  });
}

function saveLuckyModal() {
  var url = _luckyCurrentSaveUrl;
  if (!url) { alert('저장할 파일 경로가 없습니다.'); return; }
  var btn = document.getElementById('lucky-modal-save');
  var relPath = url.replace(/^\/api\/files\//, '');
  loadSheetJS(function() {
    try {
      // Luckysheet → SheetJS aoa conversion
      var sheets = luckysheet.getAllSheets();
      var wb = XLSX.utils.book_new();
      sheets.forEach(function(sheet) {
        var celldata = sheet.celldata || [];
        if (!celldata.length) { XLSX.utils.book_append_sheet(wb, XLSX.utils.aoa_to_sheet([[]]), sheet.name || 'Sheet'); return; }
        var maxR = 0, maxC = 0;
        celldata.forEach(function(c) { maxR = Math.max(maxR, c.r); maxC = Math.max(maxC, c.c); });
        var aoa = [];
        for (var r = 0; r <= maxR; r++) aoa.push(new Array(maxC + 1).fill(''));
        celldata.forEach(function(c) {
          if (c.v == null) return;
          var val = (typeof c.v === 'object') ? (c.v.m !== undefined ? c.v.m : (c.v.v !== undefined ? c.v.v : '')) : c.v;
          aoa[c.r][c.c] = val;
        });
        XLSX.utils.book_append_sheet(wb, XLSX.utils.aoa_to_sheet(aoa), sheet.name || 'Sheet');
      });
      var xlsxBuf = XLSX.write(wb, { bookType: 'xlsx', type: 'array' });
      btn.disabled = true; btn.textContent = '저장 중…';
      fetch('/api/files/' + relPath, {
        method: 'PUT', headers: authHeaders(),
        body: new Blob([xlsxBuf], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' }),
      })
      .then(function(r) { return r.json(); })
      .then(function(res) {
        btn.disabled = false; btn.innerHTML = '&#128190; 저장';
        if (res.success) { btn.textContent = '✓ 저장됨'; setTimeout(function() { btn.innerHTML = '&#128190; 저장'; }, 2000); }
        else alert('저장 실패: ' + (res.error || '알 수 없는 오류'));
      })
      .catch(function(e) { btn.disabled = false; btn.innerHTML = '&#128190; 저장'; alert('저장 오류: ' + e.message); });
    } catch(e) { alert('Excel 변환 오류: ' + e.message); }
  });
}

function toggleStagedExcelPreview(id) {
  var el = document.getElementById('excel-staged-' + id);
  if (!el) return;
  el.style.display = el.style.display === 'none' ? 'block' : 'none';
}

function toggleTxtEmbedBtn(btn) {
  var card = btn.closest('.txt-card');
  if (!card) return;
  var container = card.querySelector('.txt-preview-body');
  if (!container) return;
  var url = encodeURI(btn.getAttribute('data-txt-url'));
  if (container.style.display === 'none') {
    container.style.display = 'block';
    btn.innerHTML = '&#9650; 접기';
    if (!container.dataset.loaded) {
      container.textContent = '불러오는 중…';
      fetch(url, { headers: authHeaders() })
        .then(function(r) {
          if (!r.ok) throw new Error('HTTP ' + r.status);
          return r.text();
        })
        .then(function(t) {
          container.textContent = t;
          container.dataset.loaded = '1';
        })
        .catch(function(e) {
          container.textContent = '텍스트를 불러올 수 없습니다. (' + e.message + ')';
        });
    }
  } else {
    container.style.display = 'none';
    btn.innerHTML = '&#9664; 미리보기';
  }
}
function togglePptxPreview(fileUrl, containerId, btn) {
  var container = document.getElementById(containerId);
  if (!container) return;
  var isVisible = container.style.display !== 'none';
  if (isVisible) {
    container.style.display = 'none';
    btn.innerHTML = '&#9664; Preview';
    return;
  }
  // Show loading state
  container.style.display = 'flex';
  container.innerHTML = '<span style="color:var(--muted);font-size:13px;padding:12px">Generating preview...</span>';
  btn.innerHTML = '&#9650; Preview';
  btn.classList.add('loading');

  // Extract relative path from various URL formats:
  // /api/files/Folder/file.pptx  →  Folder/file.pptx
  // https://host/api/files/Folder/file.pptx  →  Folder/file.pptx
  // Folder/file.pptx  →  Folder/file.pptx
  var filePath = fileUrl;
  // Handle sandboxed environments where origin may be sandbox:/
  if (fileUrl.charAt(0) === '/') {
    filePath = fileUrl;  // Already an absolute path, use as-is
  } else {
    try { filePath = new URL(fileUrl, window.location.origin).pathname; } catch(e) {}
  }
  filePath = filePath.replace(/^\/api\/files\/?/, '');
  // If the link itself is a preview URL, extract the path query parameter
  var previewMatch = filePath.match(/^\/api\/pptx\/preview\?path=(.+)$/);
  if (previewMatch) {
    filePath = previewMatch[1];
  }
  // Safely decode - handle already-decoded or invalid encodings
  try { filePath = decodeURIComponent(filePath); } catch(e) {}
  fetch('/api/pptx/preview?path=' + encodeURIComponent(filePath), {
    headers: authHeaders()
  })
    .then(function(r) { return r.json(); })
    .then(function(data) {
      btn.classList.remove('loading');
      if (!data.success || !data.images || !data.images.length) {
        container.innerHTML = '<span style="color:#ef4444;font-size:13px;padding:12px">Preview failed: ' + escHtml(data.error || 'No slides found') + '</span>';
        return;
      }
      // img 태그는 Bearer 헤더를 보낼 수 없어서 auth 없이 요청 → user context 미설정 → 파일 못 찾음.
      // fetch()로 auth 포함해 가져온 뒤 Blob URL로 교체.
      Promise.all(data.images.map(function(imgUrl) {
        return fetch(imgUrl, { headers: authHeaders() })
          .then(function(r) { return r.ok ? r.blob() : Promise.reject(new Error('HTTP ' + r.status)); })
          .then(function(blob) { return URL.createObjectURL(blob); })
          .catch(function() { return imgUrl; });
      })).then(function(srcs) {
        container.innerHTML = srcs.map(function(src, i) {
          return '<img src="' + src + '" alt="Slide ' + (i + 1) + '" onclick="openImageZoom(this.src)" loading="lazy" />';
        }).join('');
      });
    })
    .catch(function(err) {
      btn.classList.remove('loading');
      container.innerHTML = '<span style="color:#ef4444;font-size:13px;padding:12px">Preview error: ' + escHtml(err.message) + '</span>';
    });
}

function handleImageUpload(input) {
  var file = input.files && input.files[0];
  if (!file) return;
  input.value = '';
  var formData = new FormData();
  formData.append('image', file);
  fetch('/api/upload/image', {
    method: 'POST',
    headers: authHeaders(),
    body: formData
  })
    .then(function(r) { return r.json(); })
    .then(function(data) {
      if (data.success && data.path) {
        var chatInput = document.getElementById('chat-input');
        var imgRef = '![image](/api/files/' + data.path + ')';
        chatInput.value = chatInput.value ? chatInput.value + '\n' + imgRef : imgRef;
        chatInput.focus();
      } else {
        alert(data.error || 'Upload failed');
      }
    })
    .catch(function(e) { alert('Upload error: ' + e.message); });
}

// ── 파일 첨부 (이미지·PDF·Excel·txt·csv 등) ─────────────────────────────────
function handleFileUpload(input) {
  var file = input.files && input.files[0];
  if (!file) return;
  input.value = '';
  var name = file.name.toLowerCase();

  // MIDI → 악보 변환
  if (/\.(mid|midi)$/.test(name) || file.type === 'audio/midi' || file.type === 'audio/x-midi') {
    uploadMidiAndRender(file);
    return;
  }

  // 이미지
  if (file.type.startsWith('image/')) {
    var imgForm = new FormData();
    imgForm.append('image', file);
    fetch('/api/upload/image', { method: 'POST', headers: authHeaders(), body: imgForm })
      .then(function(r) { return r.json(); })
      .then(function(data) {
        if (data.success && data.path) {
          insertIntoChatInput('![' + file.name + '](/api/files/' + data.path + ')');
        } else { alert(data.error || '이미지 업로드 실패'); }
      })
      .catch(function(e) { alert('업로드 오류: ' + e.message); });

  // txt / md
  } else if (/\.(txt|md)$/.test(name)) {
    var r1 = new FileReader();
    r1.onload = function(e) {
      var ext = name.split('.').pop();
      stageAttachment(file.name, null, '**[파일: ' + file.name + ']**\n```' + ext + '\n' + e.target.result + '\n```', 'text');
    };
    r1.readAsText(file, 'UTF-8');

  // CSV
  } else if (/\.csv$/.test(name)) {
    var r2 = new FileReader();
    r2.onload = function(e) {
      stageAttachment(file.name, null, '**[파일: ' + file.name + ']**\n```csv\n' + e.target.result + '\n```', 'csv');
    };
    r2.readAsText(file, 'UTF-8');

  // Excel
  } else if (/\.(xlsx|xls)$/.test(name)) {
    var xlsxFile = file;
    var xlsxForm = new FormData();
    xlsxForm.append('file', xlsxFile);
    var xlsxUploadPromise = fetch('/api/upload/file', { method: 'POST', headers: authHeaders(), body: xlsxForm })
      .then(function(r) { return r.json(); }).catch(function() { return {}; });
    loadSheetJS(function() {
      var r3 = new FileReader();
      r3.onload = function(e) {
        try {
          var wb = XLSX.read(e.target.result, { type: 'array' });
          var markdownContent = '**[파일: ' + xlsxFile.name + ']**\n\n';
          var previewHtml = '';
          wb.SheetNames.forEach(function(sn) {
            var rows = XLSX.utils.sheet_to_json(wb.Sheets[sn], { header: 1 });
            markdownContent += '### ' + sn + '\n';
            rows.forEach(function(row) { markdownContent += '| ' + row.map(function(c) { return String(c ?? ''); }).join(' | ') + ' |\n'; });
            markdownContent += '\n';
            previewHtml += '<div style="margin-bottom:6px;font-weight:700;font-size:11px">' + escHtml(sn) + '</div>';
            previewHtml += '<div style="overflow-x:auto"><table style="border-collapse:collapse;font-size:11px">';
            rows.slice(0, 30).forEach(function(row, ri) {
              previewHtml += '<tr>';
              row.forEach(function(cell) {
                var tag = ri === 0 ? 'th' : 'td';
                previewHtml += '<' + tag + ' style="border:1px solid var(--line);padding:3px 7px;text-align:left;white-space:nowrap">' + escHtml(String(cell ?? '')) + '</' + tag + '>';
              });
              previewHtml += '</tr>';
            });
            if (rows.length > 30) previewHtml += '<tr><td colspan="99" style="text-align:center;color:var(--muted);font-size:10px;padding:4px">… ' + (rows.length - 30) + '행 더</td></tr>';
            previewHtml += '</table></div>';
          });
          xlsxUploadPromise.then(function(d) {
            var fileUrl = (d.success && d.path) ? '/api/files/' + d.path : null;
            stageAttachment(xlsxFile.name, fileUrl, markdownContent, 'excel', { excelPreviewHtml: previewHtml });
          });
        } catch(err) { alert('Excel 파싱 오류: ' + err.message); }
      };
      r3.readAsArrayBuffer(xlsxFile);
    });

  // PDF — 업로드 + PDF.js 텍스트 추출 + txt 자동 저장
  } else if (/\.pdf$/.test(name)) {
    var pdfFile = file;
    var pdfForm = new FormData();
    pdfForm.append('file', pdfFile);
    var uploadPromise = fetch('/api/upload/file', { method: 'POST', headers: authHeaders(), body: pdfForm })
      .then(function(r) { return r.json(); });

    var extractPromise = new Promise(function(resolve) {
      loadPdfJs(function() {
        var fr = new FileReader();
        fr.onload = function(e) {
          pdfjsLib.getDocument({ data: new Uint8Array(e.target.result) }).promise
            .then(function(pdf) {
              var pages = [];
              for (var i = 1; i <= pdf.numPages; i++) pages.push(pdf.getPage(i));
              Promise.all(pages).then(function(ps) {
                return Promise.all(ps.map(function(p, pi) {
                  return p.getTextContent().then(function(tc) {
                    return pdfPageToText(tc.items, pi + 1, pdf.numPages);
                  });
                }));
              }).then(function(texts) {
                resolve({ text: texts.join('\n\n'), pages: pdf.numPages });
              }).catch(function() { resolve({ text: '', pages: 0 }); });
            }).catch(function() { resolve({ text: '', pages: 0 }); });
        };
        fr.readAsArrayBuffer(pdfFile);
      });
    });

    Promise.all([uploadPromise, extractPromise]).then(function(res) {
      var upData = res[0], extracted = res[1];
      var fileUrl = (upData.success && upData.path) ? '/api/files/' + upData.path : null;
      var fullText = (extracted.text || '').trim();

      if (fullText) {
        var txtName = pdfFile.name.replace(/\.pdf$/i, '.txt');
        var txtBlob = new Blob([extracted.text], { type: 'text/plain; charset=utf-8' });
        var txtForm = new FormData();
        txtForm.append('file', new File([txtBlob], txtName, { type: 'text/plain' }));
        fetch('/api/upload/file', { method: 'POST', headers: authHeaders(), body: txtForm })
          .then(function(r) { return r.json(); })
          .then(function(d) {
            var txtUrl = (d.success && d.path) ? '/api/files/' + d.path : null;
            if (txtUrl) addProcessEntry('info', '📝 텍스트 저장: ' + txtName);
            var content = '[' + pdfFile.name + '](' + (fileUrl || '') + ')';
            if (txtUrl) content += '\n[' + txtName + '](' + txtUrl + ')';
            content += '\n\n이 파일로 무엇을 도와드릴까요? 사용자가 원하는 작업을 직접 알려주기 전까지 어떤 변환이나 생성 작업도 시작하지 마세요.';
            stageAttachment(pdfFile.name, fileUrl, content, 'pdf', {
              txtPreview: fullText.slice(0, 500),
              txtUrl: txtUrl,
              txtName: txtName,
              pages: extracted.pages
            });
          }).catch(function() {
            var content = '[' + pdfFile.name + '](' + (fileUrl || '') + ')\n\n이 파일로 무엇을 도와드릴까요?';
            stageAttachment(pdfFile.name, fileUrl, content, 'pdf', {
              txtPreview: fullText.slice(0, 500),
              pages: extracted.pages
            });
          });
      } else {
        var content = '[' + pdfFile.name + '](' + (fileUrl || '') + ')\n*(텍스트 추출 불가 — 스캔 이미지이거나 보안 잠금 PDF)*';
        stageAttachment(pdfFile.name, fileUrl, content, 'pdf');
      }
    }).catch(function(e) { alert('PDF 처리 오류: ' + e.message); });

  // 기타 (docx/pptx 등)
  } else {
    var otherForm = new FormData();
    otherForm.append('file', file);
    fetch('/api/upload/file', { method: 'POST', headers: authHeaders(), body: otherForm })
      .then(function(r) { return r.json(); })
      .then(function(data) {
        if (data.success && data.path) {
          insertIntoChatInput('[' + file.name + '](/api/files/' + data.path + ')');
        } else { alert(data.error || '파일 업로드 실패'); }
      })
      .catch(function(e) { alert('업로드 오류: ' + e.message); });
  }
}

function insertIntoChatInput(text) {
  var el = document.getElementById('chat-input');
  el.value = el.value ? el.value + '\n' + text : text;
  el.focus();
  el.dispatchEvent(new Event('input'));
}

// ── 첨부 파일 스테이징 ──────────────────────────────────────────────────────
var stagedAttachments = [];

function stageAttachment(name, url, content, type, extra) {
  var id = 'att-' + Date.now() + '-' + Math.random().toString(36).substr(2, 5);
  var att = { id: id, name: name, url: url, content: content, type: type };
  if (extra) Object.assign(att, extra);
  stagedAttachments.push(att);
  renderStagedAttachments();
}

function removeStagedAttachment(id) {
  stagedAttachments = stagedAttachments.filter(function(a) { return a.id !== id; });
  renderStagedAttachments();
}

function clearStagedAttachments() {
  stagedAttachments = [];
  renderStagedAttachments();
}

function renderStagedAttachments() {
  var container = document.getElementById('staged-attachments');
  if (!container) return;
  if (!stagedAttachments.length) { container.style.display = 'none'; container.innerHTML = ''; return; }
  container.style.display = 'flex';
  container.innerHTML = stagedAttachments.map(function(a) {
    var icon = a.type === 'pdf' ? '📄' : a.type === 'excel' ? '📊' : a.type === 'csv' ? '📋' : '📝';
    var btnStyle = 'background:none;border:1px solid var(--brand);cursor:pointer;font-size:11px;color:var(--brand);padding:2px 6px;border-radius:4px';

    // PDF 카드
    if (a.type === 'pdf') {
      var txtPreview = a.txtPreview ? escHtml(a.txtPreview) + (a.txtPreview.length >= 500 ? '...' : '') : '';
      var pagesInfo = a.pages ? ' (' + a.pages + '페이지)' : '';
      return '<div id="card-' + a.id + '" style="display:flex;flex-direction:column;gap:4px;background:var(--panel-2);border:1px solid var(--line);border-radius:8px;padding:6px 10px;font-size:12px;max-width:320px">'
        + '<div style="display:flex;align-items:center;gap:6px">'
        + '<span>📄</span>'
        + '<span style="font-weight:600;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap" title="' + escHtml(a.name) + pagesInfo + '">' + escHtml(a.name) + '</span>'
        + (txtPreview ? '<button onclick="toggleStagedTxtPdfPreview(\'' + a.id + '\')" style="' + btnStyle + '">txt 미리보기</button>' : '')
        + (a.url ? '<button onclick="toggleStagedPdfPreview(\'' + a.id + '\')" style="' + btnStyle + '">PDF</button>' : '')
        + (a.txtUrl ? '<a href="' + escHtml(a.txtUrl) + '" download="' + escHtml(a.txtName || '') + '" style="' + btnStyle + ';text-decoration:none;display:inline-block" title="txt 다운로드">📝⬇</a>' : '')
        + '<button onclick="removeStagedAttachment(\'' + a.id + '\')" style="background:none;border:none;cursor:pointer;color:var(--muted);font-size:14px;line-height:1;padding:0 2px">✕</button>'
        + '</div>'
        + (pagesInfo ? '<div style="font-size:10px;color:var(--muted);padding-left:2px">텍스트 추출 완료' + pagesInfo + '</div>' : '')
        + (txtPreview ? '<div id="txt-pdf-preview-' + a.id + '" style="display:none;max-height:200px;overflow-y:auto;background:var(--panel-1);border:1px solid var(--line);border-radius:6px;padding:8px;font-size:11px;white-space:pre-wrap;word-break:break-all;color:var(--text)">' + txtPreview + '</div>' : '')
        + '<div id="pdf-preview-' + a.id + '" style="display:none"><iframe data-src="' + escHtml(a.url || '') + '" style="width:100%;height:400px;border:1px solid var(--line);border-radius:6px"></iframe></div>'
        + '</div>';
    }

    // TXT 자동저장 카드 (미리보기 + 다운로드)
    if (a.type === 'txt-auto') {
      var preview = escHtml((a.content || '').slice(0, 300)) + ((a.content || '').length > 300 ? '...' : '');
      return '<div id="card-' + a.id + '" style="display:flex;flex-direction:column;gap:4px;background:var(--panel-2);border:1px dashed var(--brand);border-radius:8px;padding:6px 10px;font-size:12px;max-width:320px">'
        + '<div style="display:flex;align-items:center;gap:6px">'
        + '<span>📝</span>'
        + '<span style="font-weight:600;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">' + escHtml(a.name) + '</span>'
        + '<button onclick="toggleStagedTxtPreview(\'' + a.id + '\')" style="' + btnStyle + '">미리보기</button>'
        + (a.url ? '<a href="' + escHtml(a.url) + '" download="' + escHtml(a.name) + '" style="' + btnStyle + ';text-decoration:none;display:inline-block" title="다운로드">⬇ 저장</a>' : '')
        + '<button onclick="removeStagedAttachment(\'' + a.id + '\')" style="background:none;border:none;cursor:pointer;color:var(--muted);font-size:14px;line-height:1;padding:0 2px">✕</button>'
        + '</div>'
        + '<div id="txt-preview-' + a.id + '" style="display:none;max-height:200px;overflow-y:auto;background:var(--panel-1);border:1px solid var(--line);border-radius:6px;padding:8px;font-size:11px;white-space:pre-wrap;word-break:break-all;color:var(--text)">' + preview + '</div>'
        + '</div>';
    }

    // excel 카드
    if (a.type === 'excel') {
      return '<div id="card-' + a.id + '" style="display:flex;flex-direction:column;gap:4px;background:var(--panel-2);border:1px solid var(--line);border-radius:8px;padding:6px 10px;font-size:12px;max-width:360px">'
        + '<div style="display:flex;align-items:center;gap:6px">'
        + '<span>📊</span>'
        + '<span style="font-weight:600;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">' + escHtml(a.name) + '</span>'
        + (a.excelPreviewHtml ? '<button onclick="toggleStagedExcelPreview(\'' + a.id + '\')" style="' + btnStyle + '">미리보기</button>' : '')
        + (a.url ? '<a href="' + escHtml(a.url) + '" download="' + escHtml(a.name) + '" style="' + btnStyle + ';text-decoration:none;display:inline-block">⬇ 저장</a>' : '')
        + '<button onclick="removeStagedAttachment(\'' + a.id + '\')" style="background:none;border:none;cursor:pointer;color:var(--muted);font-size:14px;line-height:1;padding:0 2px">✕</button>'
        + '</div>'
        + (a.excelPreviewHtml ? '<div id="excel-staged-' + a.id + '" style="display:none;max-height:260px;overflow:auto;background:var(--panel-1);border:1px solid var(--line);border-radius:6px;padding:8px">' + a.excelPreviewHtml + '</div>' : '')
        + '</div>';
    }

    // 기타 카드 (text, csv)
    return '<div id="card-' + a.id + '" style="display:flex;flex-direction:column;gap:4px;background:var(--panel-2);border:1px solid var(--line);border-radius:8px;padding:6px 10px;font-size:12px;max-width:320px">'
      + '<div style="display:flex;align-items:center;gap:6px">'
      + '<span>' + icon + '</span>'
      + '<span style="font-weight:600;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">' + escHtml(a.name) + '</span>'
      + '<button onclick="removeStagedAttachment(\'' + a.id + '\')" style="background:none;border:none;cursor:pointer;color:var(--muted);font-size:14px;line-height:1;padding:0 2px">✕</button>'
      + '</div>'
      + '</div>';
  }).join('');
}

function toggleStagedPdfPreview(id) {
  var el = document.getElementById('pdf-preview-' + id);
  if (!el) return;
  var att = stagedAttachments.find(function(a) { return a.id === id; });
  if (el.style.display === 'none') {
    el.style.display = 'block';
    var iframe = el.querySelector('iframe');
    if (iframe && att && att.url) iframe.src = att.url; // 항상 명시 설정
  } else {
    el.style.display = 'none';
  }
}

function toggleStagedTxtPreview(id) {
  var el = document.getElementById('txt-preview-' + id);
  if (!el) return;
  el.style.display = el.style.display === 'none' ? 'block' : 'none';
}

function toggleStagedTxtPdfPreview(id) {
  var el = document.getElementById('txt-pdf-preview-' + id);
  if (!el) return;
  el.style.display = el.style.display === 'none' ? 'block' : 'none';
}

// PDF 카드에 txt 저장 버튼 동적 삽입 (txt 업로드 완료 후 호출)
function addTxtButtonToPdfCard(pdfName, txtName, txtUrl) {
  // stagedAttachments에서 해당 PDF 찾기
  var att = stagedAttachments.find(function(a) { return a.name === pdfName && a.type === 'pdf'; });
  if (!att) return;
  // txt 정보를 attachment에 저장 (전송 시 displayMessage에 포함용)
  att.txtName = txtName;
  att.txtUrl = txtUrl;
  // 카드 DOM에 txt 버튼 삽입
  var card = document.getElementById('card-' + att.id);
  if (!card) return;
  var btnRow = card.querySelector('div');
  if (!btnRow) return;
  var btnStyle = 'background:none;border:1px solid var(--brand);cursor:pointer;font-size:11px;color:var(--brand);padding:2px 6px;border-radius:4px;text-decoration:none;display:inline-block';
  var txtBtn = document.createElement('a');
  txtBtn.href = txtUrl;
  txtBtn.download = txtName;
  txtBtn.title = txtName + ' 다운로드';
  txtBtn.style.cssText = btnStyle;
  txtBtn.innerHTML = '📝 txt ⬇';
  // ✕ 버튼 바로 앞에 삽입
  var closeBtn = btnRow.lastElementChild;
  btnRow.insertBefore(txtBtn, closeBtn);
}

// ── PDF 페이지 텍스트 구조화 ────────────────────────────────────────────────
function pdfPageToText(items, pageNum, totalPages) {
  // filter out empty items
  var valid = items.filter(function(it) { return it.str && it.str.trim() !== ''; });
  if (!valid.length) return '';

  // sort top→bottom (y desc), left→right (x asc)
  valid.sort(function(a, b) {
    var ay = a.transform[5], by = b.transform[5];
    if (Math.abs(ay - by) > 2) return by - ay;
    return a.transform[4] - b.transform[4];
  });

  // group items into lines by y-coordinate proximity
  var LINE_Y_THRESH = 3;
  var lines = [];
  var cur = null;
  valid.forEach(function(item) {
    var y = item.transform[5];
    var h = item.height || 10;
    if (!cur || Math.abs(y - cur.y) > LINE_Y_THRESH) {
      cur = { y: y, h: h, items: [item] };
      lines.push(cur);
    } else {
      cur.items.push(item);
      if (h > cur.h) cur.h = h;
    }
  });

  // build output: join items per line; insert blank line on large y-gaps (paragraph break)
  var out = [];
  if (totalPages > 1) out.push('── ' + pageNum + '페이지 ──');
  for (var i = 0; i < lines.length; i++) {
    var lineText = lines[i].items.map(function(it) { return it.str; }).join('').replace(/\s+/g, ' ').trim();
    if (!lineText) continue;

    // paragraph break: gap > 1.4× current line height
    if (i > 0) {
      var gap = lines[i - 1].y - lines[i].y;
      if (gap > lines[i - 1].h * 1.4) out.push('');
    }
    // fix hyphenation: merge "단어-\n다음줄" → "단어다음줄"
    if (out.length && out[out.length - 1].endsWith('-')) {
      out[out.length - 1] = out[out.length - 1].slice(0, -1) + lineText;
    } else {
      out.push(lineText);
    }
  }
  return out.join('\n');
}