'use strict';
/* admin → assignments section (классные/индивидуальные задания) */
(function () {
  'use strict';
  let inited = false;

  let allAssignments = [];
  let editingAId    = null;
  const SUBJ_NAMES  = { bio:'Биология', chem:'Химия', math:'Математика', phys:'Физика' };
  const SUBJ_COLORS_A = { bio:'#9B5DE5', chem:'#06D6A0', math:'#06B6D4', phys:'#F59E0B' };
  const SUBJ_ICONS_A  = { bio:'dna', chem:'flask-conical', math:'calculator', phys:'zap' };
  let _aFilter = 'all';

  // create-modal state
  let _afSrc = 'random';
  let _afLoadedTests = [];
  let _acSrc = 'random';
  let _acTarget = 'class';
  let _acFileId = null, _acAllFiles = null;
  let _acStudentId = null, _acAllStudents = null;

  async function load() {
    document.getElementById('a-body').innerHTML = '<div class="spinner"></div>';
    try {
      allAssignments = await LS.teacherAssignments();
      renderAssignments();
    } catch (e) {
      document.getElementById('a-body').innerHTML = `<div class="error">Ошибка: ${esc(e.message)}</div>`;
    }
  }

  function setAFilter(f) {
    _aFilter = f;
    document.querySelectorAll('.a-f-chip').forEach(c =>
      c.classList.toggle('active', c.textContent.trim() === {all:'Все',active:'Активные',overdue:'Просрочены',done:'Завершены'}[f])
    );
    renderAssignments();
  }

  function aClassify(a) {
    const pct = a.total_members ? Math.round(a.completed_count / a.total_members * 100) : null;
    if (pct === 100) return 'done';
    if (a.deadline && new Date(a.deadline) < new Date()) return 'overdue';
    return 'active';
  }

  function renderAssignments() {
    const { MODES, pctClass } = AdminCtx;
    const subjF   = document.getElementById('a-subject').value;
    const searchF = document.getElementById('a-search').value.toLowerCase();
    const sortF   = document.getElementById('a-sort')?.value || 'date';

    let list = allAssignments.filter(a => {
      if (subjF   && a.subject_slug !== subjF) return false;
      if (searchF && !a.title.toLowerCase().includes(searchF)) return false;
      if (_aFilter === 'active'  && aClassify(a) !== 'active')  return false;
      if (_aFilter === 'overdue' && aClassify(a) !== 'overdue') return false;
      if (_aFilter === 'done'    && aClassify(a) !== 'done')    return false;
      return true;
    });

    list = [...list].sort((a, b) => {
      if (sortF === 'deadline') {
        const da = a.deadline ? new Date(a.deadline) : new Date(9e15);
        const db = b.deadline ? new Date(b.deadline) : new Date(9e15);
        return da - db;
      }
      if (sortF === 'progress_asc') {
        const pa = a.total_members ? a.completed_count / a.total_members : 0;
        const pb = b.total_members ? b.completed_count / b.total_members : 0;
        return pa - pb;
      }
      if (sortF === 'progress_desc') {
        const pa = a.total_members ? a.completed_count / a.total_members : 0;
        const pb = b.total_members ? b.completed_count / b.total_members : 0;
        return pb - pa;
      }
      return 0;
    });

    const all     = allAssignments;
    const nActive  = all.filter(a => aClassify(a) === 'active').length;
    const nOverdue = all.filter(a => aClassify(a) === 'overdue').length;
    const nDone    = all.filter(a => aClassify(a) === 'done').length;
    document.getElementById('a-summary').innerHTML = [
      `<span class="a-sum-chip s-all">Всего: ${all.length}</span>`,
      nActive  ? `<span class="a-sum-chip s-active">Активных: ${nActive}</span>`    : '',
      nOverdue ? `<span class="a-sum-chip s-overdue">Просрочено: ${nOverdue}</span>` : '',
      nDone    ? `<span class="a-sum-chip s-done">Завершено: ${nDone}</span>`        : '',
    ].join('');

    document.getElementById('a-count').textContent = `${list.length} заданий`;
    const container = document.getElementById('a-body');

    if (!list.length) {
      container.innerHTML = '<div class="empty">Заданий нет</div>';
      return;
    }

    const now = new Date();
    container.innerHTML = list.map(a => {
      const pct      = a.total_members ? Math.round(a.completed_count / a.total_members * 100) : null;
      const cls      = aClassify(a);
      const rowCls   = cls === 'overdue' ? 'a-overdue' : cls === 'done' ? 'a-done' : '';
      const sColor   = SUBJ_COLORS_A[a.subject_slug] || '#9B5DE5';
      const dlMs     = a.deadline ? new Date(a.deadline) - now : Infinity;
      const isUrgent = cls === 'active' && dlMs > 0 && dlMs < 24 * 3600 * 1000;

      const dl = a.deadline
        ? new Date(a.deadline).toLocaleDateString('ru', {day:'numeric', month:'short'})
        : null;

      const targetStr = a.target_user_id
        ? esc(a.target_user_name || 'Ученик')
        : esc(a.class_name || '—');

      const metaParts = [
        targetStr,
        SUBJ_NAMES[a.subject_slug] || a.subject_slug,
        `<span class="mode-badge mode-${a.mode}">${MODES[a.mode]||a.mode}</span>`,
        a.count + ' вопр.',
        dl ? `до ${dl}` : null,
        isUrgent  ? `<span class="a-tag-urgent"><i data-lucide="zap" style="width:10px;height:10px;vertical-align:-1px"></i> срочно</span>` : null,
        cls === 'overdue' ? `<span class="a-tag-over">просрочено</span>` : null,
      ].filter(Boolean);

      const barColor = pct >= 75 ? '#06D6A0' : pct >= 40 ? '#F59E0B' : '#F15BB5';
      const pctLabel = pct !== null ? `${pct}%` : '—';

      return `<div class="a-row ${rowCls}${isUrgent ? ' a-urgent' : ''}" style="--ac:${sColor}">
        <div class="a-icon" style="background:${sColor}18;color:${sColor}"><i data-lucide="${SUBJ_ICONS_A[a.subject_slug]||'file-text'}" style="width:18px;height:18px"></i></div>
        <div class="a-main">
          <div class="a-title">${esc(a.title)}</div>
          <div class="a-meta">${metaParts.join(' · ')}</div>
        </div>
        <div class="a-prog">
          <div class="a-prog-nums">
            <span>${a.completed_count} / ${a.total_members} сдали</span>
            <span class="a-prog-pct ${pctClass(pct)}">${pctLabel}</span>
          </div>
          <div class="a-prog-bar">
            <div class="a-prog-fill" style="width:${pct||0}%;background:${barColor}"></div>
          </div>
        </div>
        <div class="a-actions">
          <button class="btn-edit-q" onclick="openAModal(${a.id})">Изменить</button>
          <button class="btn-del-q"  onclick="deleteAsgn(${a.id})"><i data-lucide="x" style="width:14px;height:14px"></i></button>
        </div>
      </div>`;
    }).join('');
    if (window.lucide) lucide.createIcons();
  }

  function setAfSrc(src) {
    _afSrc = src;
    document.querySelectorAll('[data-afsrc]').forEach(b => b.classList.toggle('active', b.dataset.afsrc === src));
    document.getElementById('af-random-fields').style.display = src === 'random' ? '' : 'none';
    document.getElementById('af-test-fields').style.display   = src === 'test'   ? '' : 'none';
  }

  async function openAModal(id) {
    const a = allAssignments.find(x => x.id === id);
    if (!a) return;
    editingAId = id;
    document.getElementById('a-modal-title').textContent = `Редактировать: ${a.title}`;
    document.getElementById('af-title').value    = a.title;
    document.getElementById('af-deadline').value = a.deadline ? a.deadline.split('T')[0] : '';
    document.getElementById('af-error').textContent = '';

    const testSel = document.getElementById('af-test');
    testSel.innerHTML = '<option value="">Загрузка…</option>';
    try {
      _afLoadedTests = await LS.getTests();
      testSel.innerHTML = _afLoadedTests.length
        ? '<option value="">— выберите тест —</option>' + _afLoadedTests.map(t => `<option value="${t.id}">${esc(t.title)} (${t.question_count} вопр.)</option>`).join('')
        : '<option value="">Нет тестов</option>';
    } catch {
      testSel.innerHTML = '<option value="">Ошибка загрузки</option>';
      _afLoadedTests = [];
    }

    if (a.test_id) {
      setAfSrc('test');
      testSel.value = a.test_id;
      document.getElementById('af-mode-test').value = a.mode;
    } else {
      setAfSrc('random');
      document.getElementById('af-subject').value = a.subject_slug;
      document.getElementById('af-mode').value    = a.mode;
      document.getElementById('af-count').value   = a.count;
    }

    document.getElementById('a-modal').classList.add('open');
    setTimeout(() => document.getElementById('af-title').focus(), 80);
  }

  function closeAModal() {
    document.getElementById('a-modal').classList.remove('open');
    editingAId = null;
  }

  async function saveAssignment() {
    const title    = document.getElementById('af-title').value.trim();
    const deadline = document.getElementById('af-deadline').value || null;
    const errEl    = document.getElementById('af-error');
    errEl.textContent = '';
    if (!title) { errEl.textContent = 'Введите название'; return; }

    let payload = { title, deadline };

    if (_afSrc === 'test') {
      const test_id = document.getElementById('af-test').value;
      const mode    = document.getElementById('af-mode-test').value;
      if (!test_id) { errEl.textContent = 'Выберите тест'; return; }
      const testObj = _afLoadedTests.find(t => t.id === Number(test_id));
      if (testObj && testObj.question_count === 0) { errEl.textContent = 'В выбранном тесте нет вопросов'; return; }
      payload = { ...payload, test_id: Number(test_id), mode };
    } else {
      const subject_slug = document.getElementById('af-subject').value;
      const mode         = document.getElementById('af-mode').value;
      const count        = Number(document.getElementById('af-count').value);
      if (!subject_slug)       { errEl.textContent = 'Выберите предмет'; return; }
      if (!count || count < 1) { errEl.textContent = 'Введите количество вопросов'; return; }
      payload = { ...payload, subject_slug, mode, count, test_id: null };
    }

    const btn = document.getElementById('af-save');
    btn.disabled = true; btn.textContent = 'Сохранение…';
    try {
      await LS.updateAssignment(editingAId, payload);
      const idx = allAssignments.findIndex(x => x.id === editingAId);
      if (idx !== -1) Object.assign(allAssignments[idx], payload);
      closeAModal();
      renderAssignments();
    } catch (e) {
      errEl.textContent = 'Ошибка: ' + e.message;
    } finally {
      btn.disabled = false; btn.textContent = 'Сохранить';
    }
  }

  /* ─── Create assignment modal ─── */
  function setAcTarget(t) {
    _acTarget = t;
    document.querySelectorAll('[data-actgt]').forEach(b => b.classList.toggle('active', b.dataset.actgt === t));
    document.getElementById('acf-class-field').style.display = t === 'class' ? '' : 'none';
    document.getElementById('acf-user-field').style.display  = t === 'user'  ? '' : 'none';
    if (t === 'user' && !_acAllStudents) loadAcStudents();
  }

  async function loadAcStudents() {
    const drop = document.getElementById('acf-student-drop');
    drop.innerHTML = '<div style="padding:8px 12px;font-size:13px;color:#9ca3af">Загрузка…</div>';
    drop.style.display = '';
    try {
      _acAllStudents = await LS.getStudentsList();
      openAcStudentDrop();
    } catch(e) {
      _acAllStudents = [];
      drop.innerHTML = `<div style="padding:8px 12px;font-size:13px;color:#ef4444">Ошибка загрузки: ${e.message}</div>`;
    }
  }

  function filterAcStudents(q) {
    openAcStudentDrop(q);
  }

  function openAcStudentDrop(q) {
    const drop = document.getElementById('acf-student-drop');
    if (_acAllStudents === null) { loadAcStudents(); return; }
    const list = _acAllStudents;
    const term = (q !== undefined ? q : document.getElementById('acf-student-search').value).toLowerCase().trim();
    const filtered = term ? list.filter(s => s.name.toLowerCase().includes(term) || s.email.toLowerCase().includes(term)) : list;
    if (!filtered.length) {
      drop.innerHTML = '<div style="padding:8px 12px;font-size:13px;color:#9ca3af">Нет учеников</div>';
      drop.style.display = '';
      return;
    }
    drop.innerHTML = filtered.slice(0, 50).map(s =>
      `<div style="padding:8px 12px;cursor:pointer;border-bottom:1px solid #f3f4f6;font-size:13px" data-id="${s.id}" data-name="${esc(s.name)}" data-email="${esc(s.email)}" onmousedown="selectAcStudent(+this.dataset.id,this.dataset.name,this.dataset.email)" onmouseover="this.style.background='#f9fafb'" onmouseout="this.style.background=''">${esc(s.name)} <span style="color:#9ca3af">${esc(s.email)}</span></div>`
    ).join('');
    drop.style.display = '';
  }

  function closeAcStudentDrop() {
    document.getElementById('acf-student-drop').style.display = 'none';
  }

  function selectAcStudent(id, name, email) {
    _acStudentId = id;
    document.getElementById('acf-student-search').value = name;
    document.getElementById('acf-student-selected').textContent = `${name} (${email})`;
    document.getElementById('acf-student-selected').style.display = '';
    closeAcStudentDrop();
  }

  function setAcSrc(src) {
    _acSrc = src;
    document.querySelectorAll('[data-src]').forEach(b => b.classList.toggle('active', b.dataset.src === src));
    document.getElementById('acf-random-fields').style.display = src === 'random' ? '' : 'none';
    document.getElementById('acf-test-fields').style.display   = src === 'test'   ? '' : 'none';
    document.getElementById('acf-file-fields').style.display   = src === 'file'   ? '' : 'none';
    if (src === 'file' && !_acAllFiles) loadAcFiles();
  }

  async function loadAcFiles() {
    try {
      _acAllFiles = await LS.getFiles();
      renderAcFiles('');
    } catch { _acAllFiles = []; }
  }

  function renderAcFiles(q) {
    const el = document.getElementById('acf-file-list');
    if (!_acAllFiles) { el.innerHTML = '<div style="padding:10px;color:var(--text-3);font-size:.82rem;text-align:center">Загрузка…</div>'; return; }
    const lq = q.toLowerCase();
    const items = q ? _acAllFiles.filter(f => (f.title||'').toLowerCase().includes(lq)) : _acAllFiles;
    const SUBJ = { bio:'Биология', chem:'Химия', math:'Математика', phys:'Физика' };
    if (!items.length) { el.innerHTML = '<div style="padding:10px;color:var(--text-3);font-size:.82rem;text-align:center">Нет файлов</div>'; return; }
    el.innerHTML = items.map(f => `
      <div onclick="selectAcFile(${f.id},'${esc(f.title||'Файл')}','${f.subject_slug||''}')"
           style="padding:9px 12px;cursor:pointer;border-bottom:1px solid rgba(15,23,42,0.07);display:flex;align-items:center;gap:8px;${_acFileId===f.id?'background:rgba(155,93,229,0.08);':''} transition:background .15s">
        <div style="flex:1">
          <div style="font-size:.84rem;font-weight:600">${esc(f.title||'Файл')}</div>
          <div style="font-size:.74rem;color:var(--text-3)">${SUBJ[f.subject_slug]||f.subject_slug||''}</div>
        </div>
        ${_acFileId===f.id ? '<span style="color:var(--violet)"><i data-lucide="check" style="width:15px;height:15px"></i></span>' : ''}
      </div>`).join('');
    if (window.lucide) lucide.createIcons();
  }

  function filterAcFiles(q) { renderAcFiles(q); }

  function selectAcFile(id, title, subject_slug) {
    _acFileId = id;
    renderAcFiles(document.getElementById('acf-file-search').value);
    const sel = document.getElementById('acf-file-selected');
    sel.textContent = 'Выбран: ' + title;
    sel.style.display = '';
  }

  async function openCreateAModal() {
    _acSrc = 'random'; _acTarget = 'class'; _acFileId = null; _acStudentId = null; _acAllStudents = null;
    setAcSrc('random');
    setAcTarget('class');
    loadAcStudents();
    document.getElementById('acf-title').value          = '';
    document.getElementById('acf-subject').value         = '';
    document.getElementById('acf-mode').value            = 'exam';
    document.getElementById('acf-mode-test').value       = 'exam';
    document.getElementById('acf-count').value           = '25';
    document.getElementById('acf-deadline').value        = '';
    document.getElementById('acf-student-search').value   = '';
    document.getElementById('acf-student-selected').style.display = 'none';
    _acStudentId = null;
    document.getElementById('acf-error').textContent     = '';
    document.getElementById('acf-file-search').value     = '';
    document.getElementById('acf-file-selected').style.display = 'none';

    const [clsSel, testSel] = [document.getElementById('acf-class'), document.getElementById('acf-test')];
    clsSel.innerHTML = '<option value="">Загрузка…</option>';
    testSel.innerHTML = '<option value="">Загрузка…</option>';

    const [classesP, testsP] = await Promise.allSettled([LS.getClasses(), LS.getTests()]);

    if (classesP.status === 'fulfilled') {
      const classes = classesP.value;
      clsSel.innerHTML = classes.length
        ? '<option value="">— выберите класс —</option>' + classes.map(c => `<option value="${c.id}">${esc(c.name)} (${c.member_count} уч.)</option>`).join('')
        : '<option value="">Нет классов — создайте класс</option>';
    } else {
      clsSel.innerHTML = `<option value="">Ошибка загрузки классов</option>`;
    }

    if (testsP.status === 'fulfilled') {
      const tests = testsP.value;
      testSel.innerHTML = tests.length
        ? '<option value="">— выберите тест —</option>' + tests.map(t => `<option value="${t.id}">${esc(t.title)} (${t.question_count} вопр.)</option>`).join('')
        : '<option value="">Нет тестов — создайте тест</option>';
    } else {
      testSel.innerHTML = `<option value="">Ошибка загрузки тестов</option>`;
    }

    document.getElementById('ac-modal').classList.add('open');
    setTimeout(() => document.getElementById('acf-title').focus(), 80);
  }

  function closeCreateAModal() {
    document.getElementById('ac-modal').classList.remove('open');
  }

  async function saveNewAssignment() {
    const title    = document.getElementById('acf-title').value.trim();
    const deadline = document.getElementById('acf-deadline').value || null;
    const errEl    = document.getElementById('acf-error');
    errEl.textContent = '';
    if (!title) { errEl.textContent = 'Введите название'; return; }

    let payload = { title, deadline };

    if (_acSrc === 'file') {
      if (!_acFileId) { errEl.textContent = 'Выберите файл из библиотеки'; return; }
      const f = _acAllFiles.find(x => x.id === _acFileId);
      payload = { ...payload, file_id: _acFileId, subject_slug: f?.subject_slug || 'bio', mode: 'exam', count: 1 };
    } else if (_acSrc === 'test') {
      const test_id = document.getElementById('acf-test').value;
      const mode    = document.getElementById('acf-mode-test').value;
      if (!test_id) { errEl.textContent = 'Выберите тест'; return; }
      const selOpt = document.querySelector(`#acf-test option[value="${test_id}"]`);
      if (selOpt && selOpt.textContent.includes('(0 вопр.)')) { errEl.textContent = 'В выбранном тесте нет вопросов. Добавьте вопросы во вкладке «Тесты».'; return; }
      payload = { ...payload, test_id: Number(test_id), mode };
    } else {
      const subject_slug = document.getElementById('acf-subject').value;
      const mode         = document.getElementById('acf-mode').value;
      const count        = Number(document.getElementById('acf-count').value);
      if (!subject_slug) { errEl.textContent = 'Выберите предмет'; return; }
      if (!count || count < 1) { errEl.textContent = 'Укажите количество вопросов'; return; }
      payload = { ...payload, subject_slug, mode, count };
    }

    const btn = document.getElementById('acf-save');
    btn.disabled = true; btn.textContent = 'Создание…';
    try {
      if (_acTarget === 'user') {
        if (!_acStudentId) { errEl.textContent = 'Выберите ученика из списка'; btn.disabled=false; btn.textContent='Создать'; return; }
        await LS.createDirectAssignment({ ...payload, student_id: _acStudentId });
      } else {
        const class_id = document.getElementById('acf-class').value;
        if (!class_id) { errEl.textContent = 'Выберите класс'; btn.disabled=false; btn.textContent='Создать'; return; }
        await LS.createAssignment(class_id, payload);
      }
      closeCreateAModal();
      await load();
    } catch (e) {
      errEl.textContent = 'Ошибка: ' + e.message;
    } finally {
      btn.disabled = false; btn.textContent = 'Создать';
    }
  }

  async function deleteAsgn(id) {
    const a = allAssignments.find(x => x.id === id);
    if (!await LS.confirm(`Удалить задание «${a?.title}»?\nВсе связанные сессии будут удалены.`, { title: 'Удалить задание', confirmText: 'Удалить' })) return;
    try {
      await LS.deleteAssignment(id);
      allAssignments = allAssignments.filter(x => x.id !== id);
      renderAssignments();
    } catch (e) { LS.toast('Ошибка: ' + e.message, 'error'); }
  }

  // Expose handlers used by HTML/inline onclicks
  window.loadAssignments = load;
  window.renderAssignments = renderAssignments;
  window.setAFilter = setAFilter;
  window.setAfSrc = setAfSrc;
  window.openAModal = openAModal;
  window.closeAModal = closeAModal;
  window.saveAssignment = saveAssignment;
  window.setAcTarget = setAcTarget;
  window.filterAcStudents = filterAcStudents;
  window.openAcStudentDrop = openAcStudentDrop;
  window.closeAcStudentDrop = closeAcStudentDrop;
  window.selectAcStudent = selectAcStudent;
  window.setAcSrc = setAcSrc;
  window.filterAcFiles = filterAcFiles;
  window.selectAcFile = selectAcFile;
  window.openCreateAModal = openCreateAModal;
  window.closeCreateAModal = closeCreateAModal;
  window.saveNewAssignment = saveNewAssignment;
  window.deleteAsgn = deleteAsgn;

  window.AdminSections = window.AdminSections || {};
  window.AdminSections.assignments = {
    init: async () => { if (inited) return; inited = true; await load(); },
    reload: load,
  };
})();