// ── Export ────────────────────────────────────────────────────────
function buildExportData() {
  const source=selectedRows.size>0?[...selectedRows].map(idx=>allData[idx]).filter(Boolean):allData;
  return source.map(({task})=>{
    const id=String(task.id), n=notesCache[id];
    const markFields={};
    MARKS_CONFIG.forEach(m=>{
      markFields[m.key]=isMark(id,m.key);
      markFields[`${m.key}_by`]=getMarkBy(id,m.key)||'';
    });
    return {
      tasknumber:task.tasknumber||task.id, name:task.name||'',
      note:n?.text||'', note_by:n?.by||'', note_updated:n?.at?fmtDate(new Date(n.at)):'',
      ...markFields,
      comments_count:getCommentCount(id),
    };
  });
}

function getExportConfig() {
  const groups = (exportFieldGroups instanceof Set && exportFieldGroups.size)
    ? exportFieldGroups
    : new Set(['note','status','comments']);
  const mode = exportStatusMode === 'B' ? 'B' : 'A';
  return { groups, mode };
}

function pickStatus(r) {
  const m=MARKS_CONFIG.find(m=>r[m.key]);
  return m?{label:m.exportLabel,by:r[`${m.key}_by`]}:{label:'Без статуса',by:''};
}

function dl(content, filename, mime){
  const a=document.createElement('a');
  a.href=URL.createObjectURL(new Blob([content],{type:mime}));
  a.download=filename; a.click();
}

function exportCSV(){
  const d=buildExportData();
  const { groups, mode } = getExportConfig();

  const h=['Номер','Название'];
  if (groups.has('note')) {
    h.push('Заметка','Заметка — кто','Заметка — когда');
  }
  if (groups.has('status')) {
    if (mode==='A') {
      MARKS_CONFIG.forEach(m=>h.push(m.exportLabel,`${m.exportLabel} — кто`));
    } else {
      h.push('Статус','Статус — кто');
    }
  }
  if (groups.has('comments')) {
    h.push('Комментариев');
  }

  const rows=d.map(r=>{
    const row=[
      r.tasknumber,
      r.id,
      `"${r.name.replace(/"/g,'""')}"`
    ];
    if (groups.has('note')) {
      row.push(
        `"${r.note.replace(/"/g,'""')}"`,
        r.note_by,
        r.note_updated
      );
    }
    if (groups.has('status')) {
      if (mode==='A') {
        MARKS_CONFIG.forEach(m=>row.push(r[m.key]?'Да':'Нет', r[`${m.key}_by`]));
      } else {
        const s = pickStatus(r);
        row.push(s.label, s.by);
      }
    }
    if (groups.has('comments')) {
      row.push(String(r.comments_count));
    }
    return row.join(';');
  });
  dl('\uFEFF'+[h.join(';'),...rows].join('\n'),`intradesk_${datestamp()}.csv`,'text/csv;charset=utf-8');
}

function exportJSON(){
  dl(JSON.stringify(buildExportData(),null,2),`intradesk_${datestamp()}.json`,'application/json');
}

function exportTXT(){
  const { groups, mode } = getExportConfig();
  const lines=buildExportData().map(r=>{
    const parts=[`#${r.tasknumber} — ${r.name}`];

    if (groups.has('status')) {
      if (mode==='A') {
        const flags=MARKS_CONFIG
          .filter(m=>r[m.key])
          .map(m=>`${m.exportLabel.toUpperCase()} (${r[`${m.key}_by`]})`)
          .join(', ');
        if (flags) parts.push(`  Статус: ${flags}`);
      } else {
        const s = pickStatus(r);
        parts.push(`  Статус: ${s.label}${s.by?` (${s.by})`:''}`);
      }
    }

    if (groups.has('note') && r.note) {
      parts.push(`  Заметка (${r.note_by}): ${r.note}`);
    }
    if (groups.has('comments') && r.comments_count) {
      parts.push(`  Наших комментариев: ${r.comments_count}`);
    }
    return parts.join('\n');
  });
  dl(lines.join('\n\n'),`intradesk_${datestamp()}.txt`,'text/plain;charset=utf-8');
}