if (typeof window.fetch === 'function' && !window.__fetchPatched) {
    window.__fetchPatched = true;
    const _origFetch = window.fetch.bind(window);
    window.fetch = function(input, init) {
        init = init || {};
        init.credentials = 'include';
        init.cache = 'no-store';
        const method = (init.method || 'GET').toUpperCase();
        if (['POST', 'PUT', 'PATCH', 'DELETE'].includes(method)) {
            const token = window.__CSRF_TOKEN;
            if (token) {
                if (!init.headers) init.headers = {};
                if (typeof init.headers === 'object' && !(init.headers instanceof Headers)) {
                    init.headers['X-CSRF-Token'] = token;
                } else if (init.headers instanceof Headers) {
                    init.headers.set('X-CSRF-Token', token);
                }
            }
        }
        return _origFetch(input, init);
    };
}

const dropZone = document.getElementById('dropZone');
const fileInput = document.getElementById('fileInput');
const uploadBtn = document.getElementById('uploadBtn');
const uploadStatus = document.getElementById('uploadStatus');
const statusEl = document.getElementById('status');

let selectedFile = null;

dropZone.addEventListener('dragover', (e) => { e.preventDefault(); dropZone.classList.add('drag-over'); });
dropZone.addEventListener('dragleave', () => dropZone.classList.remove('drag-over'));
dropZone.addEventListener('drop', (e) => {
  e.preventDefault();
  dropZone.classList.remove('drag-over');
  if (e.dataTransfer.files.length) {
    selectedFile = e.dataTransfer.files[0];
    uploadBtn.disabled = false;
    dropZone.querySelector('.drop-text').textContent = 'Выбран: ' + selectedFile.name;
  }
});

fileInput.addEventListener('change', () => {
  if (fileInput.files.length) {
    selectedFile = fileInput.files[0];
    uploadBtn.disabled = false;
    dropZone.querySelector('.drop-text').textContent = 'Выбран: ' + selectedFile.name;
  }
});

document.getElementById('uploadForm').addEventListener('submit', async (e) => {
  e.preventDefault();
  if (!selectedFile) return;

  uploadBtn.disabled = true;
  uploadStatus.textContent = 'Загрузка...';
  uploadStatus.className = '';

  const progressEl = document.getElementById('uploadProgress');
  const progressFill = progressEl.querySelector('.progress-fill');
  const progressText = progressEl.querySelector('.progress-text');
  progressEl.classList.remove('hidden');
  const startTime = Date.now();
  let timer = setInterval(() => {
    const elapsed = Math.floor((Date.now() - startTime) / 1000);
    progressText.textContent = `Обработка... ${elapsed}с`;
  }, 1000);

  const formData = new FormData();
  formData.append('pdf', selectedFile);

  try {
    const res = await fetch('/api/upload', { method: 'POST', body: formData });
    const data = await res.json();
    if (data.error) {
      uploadStatus.textContent = 'Ошибка: ' + data.error;
      uploadStatus.className = 'error';
      clearInterval(timer);
      progressEl.classList.add('hidden');
      resetUpload();
      return;
    }

    if (data.taskId) {
      clearInterval(timer);
      progressFill.classList.add('determinate');
      await pollTask(data.taskId, progressFill, progressText, startTime);
      progressFill.classList.remove('determinate');
    } else {
      uploadStatus.textContent = data.message;
      uploadStatus.className = 'success';
      statusEl.textContent = 'Данные загружены';
      statusEl.classList.add('loaded');
      loadFilters();
      loadAll();
    }
  } catch (err) {
    uploadStatus.textContent = 'Ошибка: ' + err.message;
    uploadStatus.className = 'error';
  }

  clearInterval(timer);
  progressEl.classList.add('hidden');
  resetUpload();
});

let _pollTimer = null;

async function pollTask(taskId, progressFill, progressText, startTime) {
  const updateProgress = (task) => {
    const pct = task.total ? Math.round(task.done / task.total * 100) : 0;
    progressFill.style.width = pct + '%';
    let txt = task.done + '/' + task.total + ' файлов · ' + task.elapsed + 'с';
    if (task.lastFile) {
      txt = '[Загружен] ' + task.lastFile + ' → ' + (task.lastResult || '') + ' · ' + task.elapsed + 'с';
    }
    progressText.textContent = txt;
  };

  while (true) {
    await new Promise(r => setTimeout(r, 3000));
    try {
      const controller = new AbortController();
      const timeoutId = setTimeout(() => controller.abort(), 30000);
      const res = await fetch('/api/task/' + taskId, { signal: controller.signal });
      clearTimeout(timeoutId);

      if (!res.ok) {
        const text = await res.text();
        if (text.startsWith('<')) throw new Error('Сервер временно недоступен');
        throw new Error('HTTP ' + res.status);
      }

      const task = await res.json();

      updateProgress(task);

      if (task.status === 'done' || task.status === 'partial') {
        progressFill.style.width = '100%';
        uploadStatus.textContent = task.result.message;
        uploadStatus.className = 'success';
        statusEl.textContent = 'Данные загружены';
        statusEl.classList.add('loaded');
        loadFilters();
        loadAll();
        return;
      }
      if (task.status === 'error') {
        uploadStatus.textContent = 'Ошибка: ' + (task.error || '');
        uploadStatus.className = 'error';
        return;
      }
    } catch (err) {
      if (err.name === 'AbortError') {
        progressText.textContent = 'Таймаут запроса, повтор...';
      } else {
        progressText.textContent = 'Ожидание сервера... ' + err.message;
      }
    }
  }
}

function resetUpload() {
  selectedFile = null;
  fileInput.value = '';
  uploadBtn.disabled = true;
  dropZone.querySelector('.drop-text').textContent = 'Перетащите PDF или ZIP сюда или кликните для выбора';
}

document.querySelectorAll('.tab').forEach(tab => {
  tab.addEventListener('click', () => {
    document.querySelectorAll('.tab').forEach(t => t.classList.remove('active'));
    document.querySelectorAll('.tab-content').forEach(c => c.classList.remove('active'));
    tab.classList.add('active');
    document.getElementById(tab.dataset.tab).classList.add('active');
  });
});

function getFilterParams() {
  const params = {};
  const student = document.getElementById('gfStudent').value.trim();
  const subject = document.getElementById('gfSubject').value.trim();
  const teacher = document.getElementById('gfTeacher').value.trim();
  const classVal = document.getElementById('gfClass').value.trim();
  const parallel = document.getElementById('gfParallel').value.trim();
  const from = document.getElementById('gfDateFrom').value;
  const to = document.getElementById('gfDateTo').value;
  if (student) params.student = student;
  if (subject) params.subject = subject;
  if (teacher) params.teacher = teacher;
  if (classVal) params.class = classVal;
  if (parallel) params.parallel = parallel;
  if (from) params.date_from = from.slice(5);
  if (to) params.date_to = to.slice(5);
  return params;
}

function buildQuery(params) {
  const q = new URLSearchParams();
  for (const [k, v] of Object.entries(params)) q.set(k, v);
  return q.toString();
}

async function loadAll() {
  const params = getFilterParams();
  const qs = buildQuery(params);

  const [statsRes, dailyRes] = await Promise.all([
    fetch('/api/stats?' + qs),
    fetch('/api/daily?' + qs + '&limit=150&offset=0')
  ]);

  const stats = await statsRes.json();
  const daily = await dailyRes.json();

  renderSummary(stats.summary);
  renderAlerts(stats);
  renderSubjectsTable(stats);
  renderTeachersTable(stats);
  renderClassesTable(stats);
  renderDailyTable(daily);
  loadPivot();
  loadControl();
}

async function loadFilters() {
  try {
    const res = await fetch('/api/filters');
    const data = await res.json();
    if (data.error) return;

    const fill = (id, items) => {
      const dl = document.getElementById(id);
      if (dl) dl.innerHTML = (items || []).map(v => `<option value="${v}">`).join('');
    };
    fill('dlStudents', data.students);
    fill('dlSubjects', data.subjects);
    fill('dlTeachers', data.teachers);
    fill('dlClasses', data.classes);
    fill('dlParallels', data.parallels);
  } catch (e) {
    console.error(e);
  }
}

function renderSummary(summary) {
  const cards = document.getElementById('summaryCards');
  if (!summary || !summary.totalStudents) {
    cards.innerHTML = '<div class="empty-state">Нет данных. Загрузите PDF журнала.</div>';
    return;
  }
  cards.innerHTML = `
    <div class="card"><div class="value">${summary.totalClasses}</div><div class="label">Классов</div></div>
    <div class="card"><div class="value">${summary.totalStudents}</div><div class="label">Учеников</div></div>
    <div class="card"><div class="value">${summary.totalTeachers}</div><div class="label">Учителей</div></div>
    <div class="card"><div class="value">${summary.totalSubjects}</div><div class="label">Предметов</div></div>
    <div class="card"><div class="value">${summary.totalDaily}</div><div class="label">Подневных оценок</div></div>
  `;
}

function renderAlerts(stats) {
  const alerts = document.getElementById('alerts');
  let html = '';

  if (stats.subjectsWithFewGrades && stats.subjectsWithFewGrades.length > 0) {
    for (const s of stats.subjectsWithFewGrades) {
      html += `<div class="alert warning">⚠️ ${s.warning}</div>`;
    }
  }

  if (stats.teachersWithNoGrades && stats.teachersWithNoGrades.length > 0) {
    for (const t of stats.teachersWithNoGrades) {
      html += `<div class="alert danger">❌ Учитель «${t.name}» (${t.subject_name}) — нет отметок</div>`;
    }
  }

  if (!html) {
    const total = stats.summary ? stats.summary.totalDaily : 0;
    if (total > 0) html = '<div class="alert info">Все предметы имеют достаточное количество оценок. Проблем не обнаружено.</div>';
    else html = '<div class="alert info">Загрузите PDF журнала для отображения предупреждений.</div>';
  }

  alerts.innerHTML = html;
}

function renderSubjectsTable(stats) {
  const tbody = document.querySelector('#subjectsTable tbody');
  const arr = stats.gradeCountBySubject || [];
  if (!arr.length) {
    tbody.innerHTML = '<tr><td colspan="11" class="empty-state">Нет данных</td></tr>';
    return;
  }

  const threshold = 10;

  tbody.innerHTML = arr.map(s => {
    const cls = s.student_count < threshold ? 'low-grades' : '';
    return `<tr>
      <td class="${cls}">${s.subject}</td>
      <td class="num ${cls}">${s.total}</td>
      <td class="num">${s.fives}</td>
      <td class="num">${s.fours}</td>
      <td class="num">${s.threes}</td>
      <td class="num">${s.twos}</td>
      <td class="num">${s.n_count || 0}</td>
      <td class="num">${s.b_count || 0}</td>
      <td class="num">${s.u_count || 0}</td>
      <td class="num">${s.avg_grade !== null ? s.avg_grade : '—'}</td>
      <td class="num">${s.student_count}</td>
    </tr>`;
  }).join('');
}

function renderTeachersTable(stats) {
  const tbody = document.querySelector('#teachersTable tbody');
  const arr = stats.gradeCountByTeacher || [];
  const noGrades = new Set((stats.teachersWithNoGrades || []).map(t => t.name));

  let html = '';
  for (const t of arr) {
    const cls = noGrades.has(t.teacher) ? 'no-grades' : '';
    html += `<tr>
      <td class="${cls}">${t.teacher}</td>
      <td>${t.subject_name}</td>
      <td class="num ${cls}">${t.total}</td>
      <td class="num">${t.fives}</td>
      <td class="num">${t.fours}</td>
      <td class="num">${t.threes}</td>
      <td class="num">${t.twos}</td>
      <td class="num">${t.n_count || 0}</td>
      <td class="num">${t.b_count || 0}</td>
      <td class="num">${t.u_count || 0}</td>
      <td class="num">${t.student_count || '—'}</td>
    </tr>`;
  }

  if ((stats.teachersWithNoGrades || []).length > 0 && !arr.length) {
    for (const t of stats.teachersWithNoGrades) {
      html += `<tr>
        <td class="no-grades">${t.name}</td>
        <td>${t.subject_name}</td>
        <td class="num no-grades">0</td>
        <td class="num">0</td><td class="num">0</td><td class="num">0</td><td class="num">0</td><td class="num">0</td><td class="num">0</td><td class="num">0</td><td class="num">0</td>
      </tr>`;
    }
  }

  if (!html) html = '<tr><td colspan="11" class="empty-state">Нет данных</td></tr>';
  tbody.innerHTML = html;
}

function renderClassesTable(stats) {
  const tbody = document.querySelector('#classesTable tbody');
  const arr = stats.gradeCountByClass || [];
  if (!arr.length) {
    tbody.innerHTML = '<tr><td colspan="10" class="empty-state">Нет данных</td></tr>';
    return;
  }
  tbody.innerHTML = arr.map(c => `<tr>
    <td>${c.class}</td>
    <td class="num">${c.student_count}</td>
    <td class="num">${c.total}</td>
    <td class="num">${c.fives}</td>
    <td class="num">${c.fours}</td>
    <td class="num">${c.threes}</td>
    <td class="num">${c.twos}</td>
    <td class="num">${c.n_count || 0}</td>
    <td class="num">${c.b_count || 0}</td>
    <td class="num">${c.u_count || 0}</td>
  </tr>`).join('');
}

function renderDailyTable(data) {
  const tbody = document.querySelector('#dailyTable tbody');
  if (!data.rows || !data.rows.length) {
    tbody.innerHTML = '<tr><td colspan="6" class="empty-state">Нет данных</td></tr>';
    document.getElementById('dailyPagination').innerHTML = '';
    return;
  }

  tbody.innerHTML = data.rows.map(r => {
    const g = r.grade || r.symbol || '—';
    return `<tr>
      <td>${r.grade_date}</td>
      <td>${r.student}</td>
      <td>${r.class}</td>
      <td>${r.subject}</td>
      <td>${r.teacher}</td>
      <td class="num">${g}</td>
    </tr>`;
  }).join('');

  const totalPages = Math.ceil(data.total / 150);
  document.getElementById('dailyPagination').innerHTML = totalPages > 1 ? `
    <button ${true ? 'disabled' : ''} onclick="dailyNav(0)">←</button>
    <span>стр. 1 / ${totalPages}</span>
    <button ${totalPages > 1 ? '' : 'disabled'} onclick="dailyNav(1)">→</button>
  ` : '';
}

window.dailyPage = 0;
window.dailyNav = async function(page) {
  window.dailyPage = page;
  const params = getFilterParams();
  const qs = buildQuery(params) + '&limit=150&offset=' + (page * 150);
  const res = await fetch('/api/daily?' + qs);
  const data = await res.json();
  renderDailyTable(data);
  document.querySelectorAll('.tab').forEach(t => t.classList.remove('active'));
  document.querySelectorAll('.tab-content').forEach(c => c.classList.remove('active'));
  document.querySelector('[data-tab="daily"]').classList.add('active');
  document.getElementById('daily').classList.add('active');
};

document.getElementById('gfApply').addEventListener('click', () => loadAll());
document.getElementById('gfParallel').addEventListener('change', () => loadAll());
document.getElementById('gfParallel').addEventListener('keydown', (e) => { if (e.key === 'Enter') loadAll(); });
document.getElementById('gfReset').addEventListener('click', () => {
  document.getElementById('gfStudent').value = '';
  document.getElementById('gfSubject').value = '';
  document.getElementById('gfTeacher').value = '';
  document.getElementById('gfClass').value = '';
  document.getElementById('gfParallel').value = '';
  document.getElementById('gfDateFrom').value = '';
  document.getElementById('gfDateTo').value = '';
  loadAll();
});

const modal = document.getElementById('clearModal');
document.getElementById('clearBtn').addEventListener('click', () => {
  modal.classList.add('open');
  loadClassList();
});
document.getElementById('modalClose').addEventListener('click', () => modal.classList.remove('open'));
modal.addEventListener('click', (e) => { if (e.target === modal) modal.classList.remove('open'); });

async function loadClassList() {
  try {
    const res = await fetch('/api/stats');
    const stats = await res.json();
    const dl = document.getElementById('dlClasses');
    if (dl && stats.classes) {
      dl.innerHTML = stats.classes.map(c => `<option value="${c.name}">`).join('');
    }
  } catch (e) {}
}

document.getElementById('clearClassBtn').addEventListener('click', async () => {
  const name = document.getElementById('clearClass').value.trim();
  if (!name) return;
  const msg = document.getElementById('clearClassMsg');
  if (!confirm(`Удалить класс ${name} и все его данные?`)) return;
  msg.className = '';
  msg.textContent = '...';
  try {
    const res = await fetch('/api/classes/' + encodeURIComponent(name), { method: 'DELETE' });
    const data = await res.json();
    msg.className = data.error ? 'error' : 'success';
    msg.textContent = data.message || data.error;
    if (data.ok) { loadFilters(); loadAll(); }
  } catch (e) {
    msg.className = 'error';
    msg.textContent = e.message;
  }
});

document.getElementById('clearParallelBtn').addEventListener('click', async () => {
  const grade = document.getElementById('clearParallel').value.trim();
  if (!grade) return;
  const msg = document.getElementById('clearParallelMsg');
  if (!confirm(`Удалить ВСЕ классы параллели ${grade}?`)) return;
  msg.className = '';
  msg.textContent = '...';
  try {
    const res = await fetch('/api/parallel/' + encodeURIComponent(grade), { method: 'DELETE' });
    const data = await res.json();
    msg.className = data.error ? 'error' : 'success';
    msg.textContent = data.message || data.error;
    if (data.ok) { loadFilters(); loadAll(); }
  } catch (e) {
    msg.className = 'error';
    msg.textContent = e.message;
  }
});

document.getElementById('clearAllBtn').addEventListener('click', async () => {
  const msg = document.getElementById('clearAllMsg');
  if (!confirm('Удалить ВСЕ данные без возможности восстановления?')) return;
  if (!confirm('Точно?')) return;
  msg.className = '';
  msg.textContent = '...';
  try {
    const res = await fetch('/api/data', { method: 'DELETE' });
    const data = await res.json();
    msg.className = data.error ? 'error' : 'success';
    msg.textContent = data.message || data.error || 'Всё удалено';
    if (data.ok) { loadFilters(); loadAll(); }
  } catch (e) {
    msg.className = 'error';
    msg.textContent = e.message;
  }
});

let pivotMode = 'month';

document.querySelectorAll('.per-btn').forEach(btn => {
  btn.addEventListener('click', () => {
    document.querySelectorAll('.per-btn').forEach(b => b.classList.remove('active'));
    btn.classList.add('active');
    pivotMode = btn.dataset.per;
    loadPivot();
  });
});

async function loadPivot() {
  const params = getFilterParams();
  params.period = pivotMode;
  const qs = buildQuery(params);

  const infoEl = document.getElementById('pivotInfo');
  const start = Date.now();
  const timer = setInterval(() => { infoEl.textContent = 'Загрузка... ' + Math.floor((Date.now() - start) / 1000) + 'с'; }, 500);

  try {
    const res = await fetch('/api/pivot?' + qs);
    clearInterval(timer);
    const data = await res.json();
    if (data.error) {
      document.querySelector('#pivotTable tbody').innerHTML = '<tr><td class="empty-state">' + data.error + '</td></tr>';
      document.getElementById('pivotInfo').textContent = '';
      return;
    }

    renderPivot(data);
  } catch (e) {
    console.error(e);
  }
}

function renderPivot(data) {
  const thead = document.querySelector('#pivotTable thead');
  const tbody = document.querySelector('#pivotTable tbody');

  document.getElementById('pivotInfo').textContent = data.rows.length + ' строк, ' + data.periods.length + ' периодов';

  let headHtml = '<tr><th>Предмет / Учитель / Ученик</th>';
  for (const lbl of data.periodLabels) {
    headHtml += '<th>' + lbl + '</th>';
  }
  headHtml += '</tr>';
  thead.innerHTML = headHtml;

  if (!data.rows.length) {
    tbody.innerHTML = '<tr><td colspan="' + (data.periods.length + 1) + '" class="empty-state">Нет данных</td></tr>';
    return;
  }

  const subjectGroups = {};
  for (const row of data.rows) {
    if (!subjectGroups[row.subject]) subjectGroups[row.subject] = [];
    subjectGroups[row.subject].push(row);
  }

  let html = '';
  for (const [subject, rows] of Object.entries(subjectGroups).sort()) {
    const subjId = 's_' + subject.replace(/[^a-zа-яё0-9]/gi, '_');
    html += '<tr class="pivot-subject-row" data-group="' + subjId + '">';
    html += '<td class="pivot-subject" onclick="toggleGroup(\'' + subjId + '\')"><span class="toggle" id="tog_' + subjId + '">▶</span> ' + subject + '</td>';
    for (let i = 0; i < data.periods.length; i++) html += '<td></td>';
    html += '</tr>';

    const teacherGroups = {};
    for (const row of rows) {
      if (!teacherGroups[row.teacher]) teacherGroups[row.teacher] = [];
      teacherGroups[row.teacher].push(row);
    }

    for (const [teacher, trows] of Object.entries(teacherGroups)) {
      const tchId = subjId + '_t_' + teacher.replace(/[^a-zа-яё0-9]/gi, '_');
      html += '<tr class="pivot-hidden ' + subjId + ' pivot-teacher-row" data-group="' + tchId + '">';
      html += '<td class="pivot-teacher" onclick="toggleGroup(\'' + tchId + '\')"><span class="toggle" id="tog_' + tchId + '">▶</span> ' + teacher + '</td>';
      for (let i = 0; i < data.periods.length; i++) html += '<td></td>';
      html += '</tr>';

      for (const row of trows) {
        html += '<tr class="pivot-hidden ' + subjId + ' ' + tchId + '">';
        html += '<td class="pivot-student">' + row.student + '</td>';
        for (let i = 0; i < data.periods.length; i++) {
          const val = row.cells[i] || '';
          html += '<td class="pivot-cell">' + val + '</td>';
        }
        html += '</tr>';
      }
    }
  }

  tbody.innerHTML = html;
}

window.toggleGroup = function(groupId) {
  const rows = document.querySelectorAll('.' + groupId);
  const tog = document.getElementById('tog_' + groupId);
  if (!rows.length) return;
  const firstRow = rows[0];
  if (firstRow.classList.contains('pivot-hidden')) {
    rows.forEach(r => r.classList.remove('pivot-hidden'));
    if (tog) tog.classList.add('open');
  } else {
    rows.forEach(r => r.classList.add('pivot-hidden'));
    if (tog) tog.classList.remove('open');
  }
};

let controlMode = 'homework';

document.querySelectorAll('.ctrl-tab').forEach(btn => {
  btn.addEventListener('click', () => {
    document.querySelectorAll('.ctrl-tab').forEach(b => b.classList.remove('active'));
    btn.classList.add('active');
    controlMode = btn.dataset.ctrl;
    document.getElementById('ctrlFiltersHW').style.display = controlMode === 'homework' ? '' : 'none';
    document.getElementById('ctrlFiltersGrades').style.display = controlMode === 'grades' ? '' : 'none';
    document.getElementById('ctrlFiltersDvoiki').style.display = controlMode === 'dvoiki' ? '' : 'none';
    document.getElementById('ctrlTableWrap').style.display = controlMode === 'dvoiki' ? 'none' : '';
    document.getElementById('dvoikiCards').style.display = controlMode === 'dvoiki' ? '' : 'none';
    loadControl();
  });
});

document.getElementById('ctrlNoTopic').addEventListener('change', loadControl);
document.getElementById('ctrlNoHomework').addEventListener('change', loadControl);
document.getElementById('ctrlMinGrades').addEventListener('change', loadControl);

async function loadControl() {
  const params = getFilterParams();

  if (controlMode === 'dvoiki') {
    const qs = buildQuery(params);
    const container = document.getElementById('dvoikiCards');
    container.innerHTML = '<div class="empty-state"><span class="spinner"></span> <span id="ctrlLoadText">Загрузка...</span></div>';
    const loadText = document.getElementById('ctrlLoadText');
    const start = Date.now();
    const timer = setInterval(() => { if (loadText) loadText.textContent = 'Загрузка... ' + Math.floor((Date.now() - start) / 1000) + 'с'; }, 500);

    try {
      const res = await fetch('/api/dvoiki?' + qs);
      clearInterval(timer);
      const data = await res.json();
      if (data.error) return;

      const allRows = data.rows || [];
      const openCount = allRows.filter(r => !r.resolved).length;
      const closedCount = allRows.filter(r => r.resolved).length;
      const unfixedCount = allRows.filter(r => !r.resolved && !r.objective).length;
      const objectiveCount = allRows.filter(r => !r.resolved && r.objective).length;

      const teacherStats = {};
      for (const r of allRows) {
        if (!r.resolved) {
          const t = r.teacher || '—';
          if (!teacherStats[t]) teacherStats[t] = { open: 0, closed: 0, total: 0 };
          teacherStats[t].total++;
          teacherStats[t].open++;
        }
      }
      const teacherList = Object.entries(teacherStats)
        .map(([name, s]) => ({ name, open: s.open, closed: s.closed, total: s.total }))
        .sort((a, b) => b.open - a.open || a.name.localeCompare(b.name));

      renderDvoikiPills(allRows.length, openCount, unfixedCount, objectiveCount, closedCount, teacherList);

      let rows = allRows;
      if (window._dvoikiFilter === 'unfixed') rows = rows.filter(r => !r.resolved && !r.objective);
      else if (window._dvoikiFilter === 'objective') rows = rows.filter(r => !r.resolved && r.objective);
      else if (window._dvoikiFilter === 'closed') rows = rows.filter(r => r.resolved);
      if (window._dvoikiTeacher && window._dvoikiTeacher !== 'all') {
        rows = rows.filter(r => (r.teacher || '—') === window._dvoikiTeacher);
      }

      renderDvoikiCards(rows);
    } catch (e) {
      console.error(e);
    }
    return;
  }

  if (controlMode === 'homework') {
    if (document.getElementById('ctrlNoTopic').checked) params.no_topic = 'true';
    if (document.getElementById('ctrlNoHomework').checked) params.no_homework = 'true';
  } else {
    params.low_grades = 'true';
    params.min_grades = document.getElementById('ctrlMinGrades').value || '3';
  }

  const qs = buildQuery(params);

  const thead = document.querySelector('#controlTable thead');
  thead.innerHTML = '<tr><th>Дата</th><th>Предмет</th><th>Учитель</th><th>Тема</th><th>ДЗ</th><th>Всего</th><th>Числ.</th><th>Симв.</th><th>Оценки</th></tr>';
  document.querySelector('#controlTable tbody').innerHTML = '<tr><td colspan="9" class="empty-state"><span class="spinner"></span> <span id="ctrlLoadText">Загрузка...</span></td></tr>';
  const loadText = document.getElementById('ctrlLoadText');
  const start = Date.now();
  const timer = setInterval(() => { if (loadText) loadText.textContent = 'Загрузка... ' + Math.floor((Date.now() - start) / 1000) + 'с'; }, 500);

  try {
    const res = await fetch('/api/lessons?' + qs);
    clearInterval(timer);
    const data = await res.json();
    if (data.error) return;

    const tbody = document.querySelector('#controlTable tbody');
    if (!data.rows || !data.rows.length) {
      tbody.innerHTML = '<tr><td colspan="9" class="empty-state">Нет данных</td></tr>';
      return;
    }

    const minNumeric = data.min_grades || 3;

    tbody.innerHTML = data.rows.map(r => {
      let topicCls = '';
      let hwCls = '';
      let rowCls = '';
      if (controlMode === 'homework') {
        if (!r.topic) topicCls = 'missing';
        if (!r.homework) hwCls = 'missing';
      } else {
        if (r.grades_numeric < minNumeric) rowCls = 'red-row';
      }
      return `<tr class="${rowCls}">
        <td>${r.lesson_date}</td>
        <td>${r.subject}</td>
        <td>${r.teacher}</td>
        <td class="${topicCls}">${r.topic || '—'}</td>
        <td class="${hwCls}">${r.homework || '—'}</td>
        <td class="num">${r.grades_total}</td>
        <td class="num">${r.grades_numeric}</td>
        <td class="num">${r.grades_symbol}</td>
        <td class="grades-cell">${r.grades_list || ''}</td>
      </tr>`;
    }).join('');
  } catch (e) {
    console.error(e);
  }
}

let _dvoikiFilter = 'all';

function renderDvoikiPills(total, open, unfixed, objective, closed, teacherList) {
  window._dvoikiFilter = window._dvoikiFilter || 'unfixed';
  window._dvoikiTeacher = window._dvoikiTeacher || 'all';

  const pills = [
    { key: 'all', label: 'Все', count: total, active: window._dvoikiFilter === 'all' },
    { key: 'unfixed', label: '⚠️ Не исправили', count: unfixed, active: window._dvoikiFilter === 'unfixed' },
    { key: 'objective', label: '🚫 Не могли исправить', count: objective, active: window._dvoikiFilter === 'objective' },
    { key: 'closed', label: '✅ Закрыто', count: closed, active: window._dvoikiFilter === 'closed' }
  ];

  let html = '<div class="dvoiki-pills">' +
    pills.map(p =>
      `<button class="pill ${p.active ? 'active' : ''}" data-filter="${p.key}">${p.label} (${p.count})</button>`
    ).join('') +
    '</div>';

  html += '<div class="dvoiki-pills" style="margin-top:6px">' +
    `<button class="pill ${window._dvoikiTeacher === 'all' ? 'active' : ''}" data-teacher="all">Все учителя</button>` +
    teacherList.map(t =>
      `<button class="pill ${window._dvoikiTeacher === t.name ? 'active' : ''}" data-teacher="${t.name}">
        ${t.name} ${t.open > 0 ? '<span class="pill-badge">' + t.open + '</span>' : ''}
      </button>`
    ).join('') +
    '</div>';

  document.getElementById('dvoikiPills').innerHTML = html;

  document.querySelectorAll('#dvoikiPills .pill').forEach(btn => {
    btn.addEventListener('click', () => {
      if (btn.dataset.filter) {
        window._dvoikiFilter = btn.dataset.filter;
      }
      if (btn.dataset.teacher) {
        window._dvoikiTeacher = btn.dataset.teacher;
      }
      loadControl();
    });
  });
}

function renderDvoikiCards(rows) {
  const container = document.getElementById('dvoikiCards');

  if (!rows.length) {
    container.innerHTML = '<div class="empty-state">Нет цепочек</div>';
    return;
  }

  const gradeClass = (g) => {
    if (g === '2') return 's-2';
    if (g === '3') return 's-3';
    if (g === '4' || g === '5') return 's-45';
    if (g === 'X') return 's-stop';
    if (g === '—') return 's-empty';
    return 's-sym';
  };

  container.innerHTML = rows.map(r => {
    const cardCls = r.resolved ? 'd-card resolved' : 'd-card unresolved';
    const statusIcon = r.resolved ? '✅' : '⚠️';
    const statusText = r.resolved ? `Закрыт (${r.reason})` : `Не закрыт — ${r.reason}`;

    const stepsHtml = r.chain.map(c =>
      `<div class="step">
        <div class="step-date">${c.date}</div>
        <div class="step-grade ${gradeClass(c.grade)}">${c.grade}</div>
      </div>`
    ).join('');

    return `<div class="${cardCls}">
      <div class="d-card-top">
        <span class="d-card-status">${statusIcon} ${statusText}</span>
        <span class="d-card-steps">${r.chain.length} шаг${r.chain.length > 1 ? (r.chain.length < 5 ? 'а' : 'ов') : ''}</span>
      </div>
      <div class="d-card-student">${r.student}</div>
      <div class="d-card-subject">${r.subject}  ·  ${r.teacher}</div>
      <div class="step-grid">${stepsHtml}</div>
    </div>`;
  }).join('');
}

document.addEventListener('DOMContentLoaded', function() {
    document.getElementById('login-form').addEventListener('submit', login);
    checkAuth();
});