import { api } from '../api.js';
import { escapeHtml, showAlert, hideAlert } from '../utils.js';

const DAY_OPTIONS = [
    { value: 1, label: 'Понедельник', shortLabel: 'Пн' },
    { value: 2, label: 'Вторник', shortLabel: 'Вт' },
    { value: 3, label: 'Среда', shortLabel: 'Ср' },
    { value: 4, label: 'Четверг', shortLabel: 'Чт' },
    { value: 5, label: 'Пятница', shortLabel: 'Пт' },
    { value: 6, label: 'Суббота', shortLabel: 'Сб' },
    { value: 7, label: 'Воскресенье', shortLabel: 'Вс' }
];

const SEMESTER_LABELS = {
    autumn: 'осенний',
    spring: 'весенний'
};

export async function initAcademicCalendar() {
    const academicYearForm = document.getElementById('academic-year-form');
    const academicYearFormTitle = document.getElementById('academic-year-form-title');
    const academicYearIdInput = document.getElementById('academic-year-id');
    const academicYearTitleInput = document.getElementById('academic-year-title');
    const academicYearStartInput = document.getElementById('academic-year-start');
    const academicYearEndInput = document.getElementById('academic-year-end');
    const academicYearResetButton = document.getElementById('academic-year-reset');
    const academicYearsTbody = document.getElementById('academic-years-tbody');
    const academicYearsRefreshButton = document.getElementById('academic-years-refresh');

    const semesterForm = document.getElementById('semester-form');
    const semesterFormTitle = document.getElementById('semester-form-title');
    const semesterIdInput = document.getElementById('semester-id');
    const semesterYearSelect = document.getElementById('semester-year');
    const semesterTypeSelect = document.getElementById('semester-type');
    const semesterStartInput = document.getElementById('semester-start');
    const semesterEndInput = document.getElementById('semester-end');
    const semesterResetButton = document.getElementById('semester-reset');

    const calendarForm = document.getElementById('academic-calendar-form');
    const calendarFormTitle = document.getElementById('academic-calendar-form-title');
    const calendarIdInput = document.getElementById('academic-calendar-id');
    const calendarTitleInput = document.getElementById('academic-calendar-title');
    const calendarYearSelect = document.getElementById('academic-calendar-year');
    const calendarSpecialtySelect = document.getElementById('academic-calendar-specialty');
    const calendarProfileSelect = document.getElementById('academic-calendar-profile');
    const calendarStudyFormSelect = document.getElementById('academic-calendar-study-form');
    const calendarCourseCountInput = document.getElementById('academic-calendar-course-count');
    const calendarResetButton = document.getElementById('academic-calendar-reset');
    const calendarsRefreshButton = document.getElementById('academic-calendars-refresh');
    const calendarsTbody = document.getElementById('academic-calendars-tbody');

    const editorCalendarSelect = document.getElementById('calendar-editor-calendar');
    const editorLoadButton = document.getElementById('calendar-editor-load');
    const editorSaveButton = document.getElementById('calendar-editor-save');
    const fillCourseSelect = document.getElementById('calendar-fill-course');
    const fillStartInput = document.getElementById('calendar-fill-start');
    const fillEndInput = document.getElementById('calendar-fill-end');
    const fillActivitySelect = document.getElementById('calendar-fill-activity');
    const fillApplyButton = document.getElementById('calendar-fill-apply');
    const calendarGrid = document.getElementById('calendar-grid');
    const calendarTotals = document.getElementById('calendar-totals');
    const calendarDayDialog = document.getElementById('calendar-day-dialog');
    const calendarDayDialogClose = document.getElementById('calendar-day-dialog-close');
    const calendarDayDialogDate = document.getElementById('calendar-day-dialog-date');
    const calendarDayDialogCourse = document.getElementById('calendar-day-dialog-course');
    const calendarDayDialogWeek = document.getElementById('calendar-day-dialog-week');
    const calendarDayDialogDay = document.getElementById('calendar-day-dialog-day');
    const calendarDayDialogActivitySummary = document.getElementById('calendar-day-dialog-activity-summary');
    const calendarDayDialogActivitySelect = document.getElementById('calendar-day-dialog-activity');
    const calendarDayDialogTimeScopeSelect = document.getElementById('calendar-day-dialog-time-scope');
    const calendarDayDialogTimeSaveButton = document.getElementById('calendar-day-dialog-time-save');
    const calendarDayDialogTimeClearButton = document.getElementById('calendar-day-dialog-time-clear');

    let academicYears = [];
    let semesters = [];
    let specialties = [];
    let profilesBySpecialty = new Map();
    let studyForms = [];
    let activityTypes = [];
    let calendars = [];
    let timeSlotScopes = [];
    let timeSlotDateAssignments = [];
    let activeCalendarDay = null;
    let selectedCalendarDayKey = null;

    bindEvents();

    try {
        await Promise.all([
            loadBaseLists(),
            loadYears(),
            loadStudyForms(),
            loadActivityTypes(),
            loadTimeSlotScopes(),
            loadTimeSlotDateAssignments()
        ]);
        await loadCalendars();
    } catch (error) {
        showAlert('academic-calendar-alert', error.message || 'Ошибка загрузки календарных графиков', 'error');
    }

    function bindEvents() {
        academicYearsRefreshButton?.addEventListener('click', loadYears);
        calendarsRefreshButton?.addEventListener('click', loadCalendars);
        academicYearResetButton?.addEventListener('click', resetAcademicYearForm);
        semesterResetButton?.addEventListener('click', resetSemesterForm);
        calendarResetButton?.addEventListener('click', resetCalendarForm);
        calendarSpecialtySelect?.addEventListener('change', () => populateProfileSelect(calendarProfileSelect, calendarSpecialtySelect.value));
        editorLoadButton?.addEventListener('click', loadCalendarGrid);
        editorSaveButton?.addEventListener('click', saveCalendarGrid);
        fillApplyButton?.addEventListener('click', applyCalendarFill);

        calendarGrid?.addEventListener('change', (event) => {
            if (event.target.matches('.calendar-day-activity')) {
                updateCalendarDayVisual(event.target.closest('.calendar-day'));
                renderCalendarTotals();
            }
        });
        calendarGrid?.addEventListener('click', (event) => {
            const day = event.target.closest('.calendar-day');
            if (day) openCalendarDayDialog(day);
        });
        calendarGrid?.addEventListener('keydown', (event) => {
            if (event.key !== 'Enter' && event.key !== ' ') return;
            const day = event.target.closest('.calendar-day');
            if (!day) return;
            event.preventDefault();
            openCalendarDayDialog(day);
        });
        calendarDayDialogClose?.addEventListener('click', closeCalendarDayDialog);
        calendarDayDialog?.addEventListener('click', (event) => {
            if (event.target === calendarDayDialog) closeCalendarDayDialog();
        });
        calendarDayDialogActivitySelect?.addEventListener('change', () => {
            if (!activeCalendarDay) return;
            const select = activeCalendarDay.querySelector('.calendar-day-activity');
            select.value = calendarDayDialogActivitySelect.value;
            updateCalendarDayVisual(activeCalendarDay);
            updateCalendarDayDialogSummary(activeCalendarDay);
            renderCalendarTotals();
        });
        calendarDayDialogTimeSaveButton?.addEventListener('click', saveTimeSlotDateAssignment);
        calendarDayDialogTimeClearButton?.addEventListener('click', clearTimeSlotDateAssignment);

        academicYearForm?.addEventListener('submit', saveAcademicYear);
        semesterForm?.addEventListener('submit', saveSemester);
        calendarForm?.addEventListener('submit', saveCalendar);

        academicYearsTbody?.addEventListener('click', handleAcademicYearTableClick);
        calendarsTbody?.addEventListener('click', handleCalendarTableClick);
    }

    async function loadBaseLists() {
        specialties = await api.get('/api/specialties');
        await loadProfiles();
        populateSpecialtySelects();
    }

    async function loadProfiles() {
        const pairs = await Promise.all(specialties.map(async (speciality) => {
            const profiles = await api.get(`/api/specialties/${speciality.id}/profiles`);
            return [String(speciality.id), profiles];
        }));
        profilesBySpecialty = new Map(pairs);
    }

    async function loadYears() {
        academicYearsTbody.innerHTML = '<tr><td colspan="4" class="loading-row">Загрузка...</td></tr>';
        try {
            academicYears = await api.get('/api/admin/calendar/years');
            semesters = academicYears.flatMap(year => year.semesters || []);
            renderAcademicYears();
            populateYearSelects();
        } catch (error) {
            academicYearsTbody.innerHTML = `<tr><td colspan="4" class="loading-row">Ошибка загрузки: ${escapeHtml(error.message)}</td></tr>`;
            throw error;
        }
    }

    function renderAcademicYears() {
        if (!academicYears.length) {
            academicYearsTbody.innerHTML = '<tr><td colspan="4" class="loading-row">Учебные годы не созданы</td></tr>';
            return;
        }
        academicYearsTbody.innerHTML = academicYears.map(year => `
            <tr>
                <td>${escapeHtml(year.title)}</td>
                <td>${escapeHtml(year.startDate)} - ${escapeHtml(year.endDate)}</td>
                <td>${renderSemesterList(year.semesters || [])}</td>
                <td>
                    <button class="btn-edit-classroom btn-edit-year" data-id="${year.id}">Изменить</button>
                    <button class="btn-delete btn-delete-year" data-id="${year.id}">Удалить</button>
                </td>
            </tr>
        `).join('');
    }

    function renderSemesterList(items) {
        if (!items.length) return '<span class="muted">Нет семестров</span>';
        return items.map(semester => `
            <div class="schedule-semester-line">
                ${escapeHtml(semesterLabel(semester))}
                <button class="btn-edit-classroom btn-edit-semester" data-id="${semester.id}">Изменить</button>
            </div>
        `).join('');
    }

    async function saveAcademicYear(event) {
        event.preventDefault();
        hideAlert('academic-year-alert');
        const payload = {
            title: academicYearTitleInput.value.trim(),
            startDate: academicYearStartInput.value,
            endDate: academicYearEndInput.value
        };
        try {
            if (!payload.title || !payload.startDate || !payload.endDate) throw new Error('Заполните название и даты учебного года');
            const id = academicYearIdInput.value;
            await (id
                ? api.put('/api/admin/calendar/years/' + id, payload)
                : api.post('/api/admin/calendar/years', payload));
            showAlert('academic-year-alert', 'Учебный год сохранён', 'success');
            resetAcademicYearForm();
            await loadYears();
            await loadCalendars();
        } catch (error) {
            showAlert('academic-year-alert', error.message || 'Ошибка сохранения учебного года', 'error');
        }
    }

    async function handleAcademicYearTableClick(event) {
        const editYearButton = event.target.closest('.btn-edit-year');
        const deleteYearButton = event.target.closest('.btn-delete-year');
        const editSemesterButton = event.target.closest('.btn-edit-semester');

        if (editYearButton) {
            const year = academicYears.find(item => item.id == editYearButton.dataset.id);
            if (!year) return;
            academicYearFormTitle.textContent = 'Редактирование учебного года';
            academicYearIdInput.value = year.id;
            academicYearTitleInput.value = year.title || '';
            academicYearStartInput.value = year.startDate || '';
            academicYearEndInput.value = year.endDate || '';
            hideAlert('academic-year-alert');
            academicYearForm.scrollIntoView({ behavior: 'smooth', block: 'start' });
            return;
        }

        if (editSemesterButton) {
            const semester = semesters.find(item => item.id == editSemesterButton.dataset.id);
            if (!semester) return;
            semesterFormTitle.textContent = 'Редактирование семестра';
            semesterIdInput.value = semester.id;
            semesterYearSelect.value = semester.academicYearId || '';
            semesterTypeSelect.value = normalizeSemesterType(semester.semesterType);
            semesterStartInput.value = semester.startDate || '';
            semesterEndInput.value = semester.endDate || '';
            syncSelects(semesterYearSelect, semesterTypeSelect);
            hideAlert('semester-alert');
            semesterForm.scrollIntoView({ behavior: 'smooth', block: 'start' });
            return;
        }

        if (deleteYearButton) {
            if (!confirm('Удалить учебный год вместе с семестрами и календарными графиками?')) return;
            try {
                await api.delete('/api/admin/calendar/years/' + deleteYearButton.dataset.id);
                showAlert('academic-year-alert', 'Учебный год удалён', 'success');
                await loadYears();
                await loadCalendars();
            } catch (error) {
                showAlert('academic-year-alert', error.message || 'Ошибка удаления учебного года', 'error');
            }
        }
    }

    function resetAcademicYearForm() {
        academicYearForm.reset();
        academicYearFormTitle.textContent = 'Учебный год';
        academicYearIdInput.value = '';
        hideAlert('academic-year-alert');
    }

    async function saveSemester(event) {
        event.preventDefault();
        hideAlert('semester-alert');
        const yearId = semesterYearSelect.value;
        const payload = {
            semesterType: semesterTypeSelect.value,
            startDate: semesterStartInput.value,
            endDate: semesterEndInput.value
        };
        try {
            if (!yearId || !payload.semesterType || !payload.startDate || !payload.endDate) {
                throw new Error('Заполните учебный год, тип и даты семестра');
            }
            const id = semesterIdInput.value;
            await (id
                ? api.put('/api/admin/calendar/semesters/' + id, payload)
                : api.post(`/api/admin/calendar/years/${yearId}/semesters`, payload));
            showAlert('semester-alert', 'Семестр сохранён', 'success');
            resetSemesterForm();
            await loadYears();
        } catch (error) {
            showAlert('semester-alert', error.message || 'Ошибка сохранения семестра', 'error');
        }
    }

    function resetSemesterForm() {
        semesterForm.reset();
        semesterFormTitle.textContent = 'Семестр';
        semesterIdInput.value = '';
        syncSelects(semesterYearSelect, semesterTypeSelect);
        hideAlert('semester-alert');
    }

    async function loadStudyForms() {
        studyForms = await api.get('/api/education-forms');
        populateStudyFormSelect();
    }

    async function loadActivityTypes() {
        activityTypes = await api.get('/api/admin/calendar/activity-types');
        populateActivitySelects();
    }

    async function loadTimeSlotScopes() {
        timeSlotScopes = await api.get('/api/admin/time-slots/scopes');
    }

    async function loadTimeSlotDateAssignments() {
        timeSlotDateAssignments = await api.get('/api/admin/time-slots/date-assignments');
    }

    async function loadCalendars() {
        calendarsTbody.innerHTML = '<tr><td colspan="7" class="loading-row">Загрузка...</td></tr>';
        try {
            calendars = await api.get('/api/admin/academic-calendars');
            renderCalendars();
            populateEditorCalendarSelect();
        } catch (error) {
            calendarsTbody.innerHTML = `<tr><td colspan="7" class="loading-row">Ошибка загрузки: ${escapeHtml(error.message)}</td></tr>`;
            throw error;
        }
    }

    function renderCalendars() {
        if (!calendars.length) {
            calendarsTbody.innerHTML = '<tr><td colspan="7" class="loading-row">Календарные графики не созданы</td></tr>';
            return;
        }
        calendarsTbody.innerHTML = calendars.map(calendar => `
            <tr>
                <td>${escapeHtml(calendar.title)}</td>
                <td>${escapeHtml(calendar.academicYearTitle || '-')}</td>
                <td>${escapeHtml(`${calendar.specialtyCode || ''} ${calendar.specialtyName || ''}`.trim() || '-')}</td>
                <td>${escapeHtml(calendar.specialtyProfileName || '-')}</td>
                <td>${escapeHtml(calendar.studyFormName || '-')}</td>
                <td>${escapeHtml(String(calendar.courseCount || '-'))}</td>
                <td>
                    <button class="btn-edit-classroom btn-edit-calendar" data-id="${calendar.id}">Изменить</button>
                    <button class="btn-edit-classroom btn-open-calendar-grid" data-id="${calendar.id}">Сетка</button>
                    <button class="btn-delete btn-delete-calendar" data-id="${calendar.id}">Удалить</button>
                </td>
            </tr>
        `).join('');
    }

    async function saveCalendar(event) {
        event.preventDefault();
        hideAlert('academic-calendar-alert');
        const payload = {
            id: calendarIdInput.value ? Number(calendarIdInput.value) : null,
            title: calendarTitleInput.value.trim(),
            academicYearId: Number(calendarYearSelect.value),
            specialtyId: Number(calendarSpecialtySelect.value),
            specialtyProfileId: Number(calendarProfileSelect.value),
            studyFormId: Number(calendarStudyFormSelect.value),
            courseCount: Number(calendarCourseCountInput.value)
        };
        try {
            if (!payload.title || !payload.academicYearId || !payload.specialtyId
                || !payload.specialtyProfileId || !payload.studyFormId || !payload.courseCount) {
                throw new Error('Заполните все поля календарного графика');
            }
            const id = calendarIdInput.value;
            const saved = id
                ? await api.put('/api/admin/academic-calendars/' + id, payload)
                : await api.post('/api/admin/academic-calendars', payload);
            showAlert('academic-calendar-alert', `График "${escapeHtml(saved.title)}" сохранён`, 'success');
            resetCalendarForm();
            await loadCalendars();
        } catch (error) {
            showAlert('academic-calendar-alert', error.message || 'Ошибка сохранения календарного графика', 'error');
        }
    }

    async function handleCalendarTableClick(event) {
        const editButton = event.target.closest('.btn-edit-calendar');
        const gridButton = event.target.closest('.btn-open-calendar-grid');
        const deleteButton = event.target.closest('.btn-delete-calendar');

        if (editButton) {
            const calendar = calendars.find(item => item.id == editButton.dataset.id);
            if (!calendar) return;
            calendarFormTitle.textContent = 'Редактирование календарного графика';
            calendarIdInput.value = calendar.id;
            calendarTitleInput.value = calendar.title || '';
            calendarYearSelect.value = calendar.academicYearId || '';
            calendarSpecialtySelect.value = calendar.specialtyId || '';
            populateProfileSelect(calendarProfileSelect, calendarSpecialtySelect.value, calendar.specialtyProfileId);
            calendarStudyFormSelect.value = calendar.studyFormId || '';
            calendarCourseCountInput.value = calendar.courseCount || 4;
            syncSelects(calendarYearSelect, calendarSpecialtySelect, calendarProfileSelect, calendarStudyFormSelect);
            hideAlert('academic-calendar-alert');
            calendarForm.scrollIntoView({ behavior: 'smooth', block: 'start' });
            return;
        }

        if (gridButton) {
            editorCalendarSelect.value = gridButton.dataset.id;
            syncSelects(editorCalendarSelect);
            await loadCalendarGrid();
            calendarGrid.scrollIntoView({ behavior: 'smooth', block: 'start' });
            return;
        }

        if (deleteButton) {
            if (!confirm('Удалить календарный график?')) return;
            try {
                await api.delete('/api/admin/academic-calendars/' + deleteButton.dataset.id);
                showAlert('academic-calendar-alert', 'Календарный график удалён', 'success');
                await loadCalendars();
            } catch (error) {
                showAlert('academic-calendar-alert', error.message || 'Ошибка удаления календарного графика', 'error');
            }
        }
    }

    function resetCalendarForm() {
        calendarForm.reset();
        calendarFormTitle.textContent = 'Календарный учебный график';
        calendarIdInput.value = '';
        calendarCourseCountInput.value = 4;
        populateProfileSelect(calendarProfileSelect, calendarSpecialtySelect.value);
        syncSelects(calendarYearSelect, calendarSpecialtySelect, calendarProfileSelect, calendarStudyFormSelect);
        hideAlert('academic-calendar-alert');
    }

    async function loadCalendarGrid() {
        hideAlert('calendar-editor-alert');
        const calendar = selectedEditorCalendar();
        if (!calendar) {
            showAlert('calendar-editor-alert', 'Выберите календарный график', 'error');
            return;
        }
        try {
            await loadTimeSlotDateAssignments();
            const rows = await api.get(`/api/admin/academic-calendars/${calendar.id}/grid`);
            const gridRows = rows.length ? rows : buildDefaultGrid(calendar);
            renderCalendarGrid(gridRows);
            showAlert('calendar-editor-alert', rows.length ? 'Сетка загружена' : 'Подготовлена новая сетка по датам учебного года', 'success');
        } catch (error) {
            showAlert('calendar-editor-alert', error.message || 'Ошибка загрузки сетки', 'error');
        }
    }

    async function saveCalendarGrid() {
        hideAlert('calendar-editor-alert');
        const calendar = selectedEditorCalendar();
        if (!calendar) {
            showAlert('calendar-editor-alert', 'Выберите календарный график', 'error');
            return;
        }
        const rows = Array.from(calendarGrid.querySelectorAll('.calendar-day')).map(day => ({
            calendarId: calendar.id,
            courseNumber: Number(day.dataset.course),
            date: day.dataset.date,
            weekNumber: Number(day.dataset.week),
            dayOfWeek: Number(day.dataset.day),
            activityTypeId: Number(day.querySelector('.calendar-day-activity').value)
        }));
        if (!rows.length) {
            showAlert('calendar-editor-alert', 'Сначала загрузите сетку графика', 'error');
            return;
        }
        try {
            await api.put(`/api/admin/academic-calendars/${calendar.id}/grid`, rows);
            showAlert('calendar-editor-alert', 'Календарный учебный график сохранён', 'success');
            await loadCalendarGrid();
        } catch (error) {
            showAlert('calendar-editor-alert', error.message || 'Ошибка сохранения сетки', 'error');
        }
    }

    function applyCalendarFill() {
        hideAlert('calendar-editor-alert');
        const activityId = fillActivitySelect.value;
        const start = fillStartInput.value;
        const end = fillEndInput.value;
        if (!activityId || !start || !end) {
            showAlert('calendar-editor-alert', 'Выберите даты и код активности для заполнения', 'error');
            return;
        }
        if (end < start) {
            showAlert('calendar-editor-alert', 'Дата окончания не может быть раньше даты начала', 'error');
            return;
        }
        const course = fillCourseSelect.value;
        let changed = 0;
        calendarGrid.querySelectorAll('.calendar-day').forEach(day => {
            const sameCourse = !course || day.dataset.course === course;
            const inRange = day.dataset.date >= start && day.dataset.date <= end;
            if (sameCourse && inRange) {
                day.querySelector('.calendar-day-activity').value = activityId;
                updateCalendarDayVisual(day);
                changed += 1;
            }
        });
        renderCalendarTotals();
        showAlert('calendar-editor-alert', `Обновлено ячеек: ${changed}`, 'success');
    }

    function renderCalendarGrid(rows) {
        activeCalendarDay = null;
        selectedCalendarDayKey = null;
        const grouped = groupBy(rows, row => row.courseNumber);
        calendarGrid.innerHTML = Array.from(grouped.entries()).map(([course, courseRows], index) => `
            <details class="calendar-course-block" ${index === 0 ? 'open' : ''}>
                <summary class="calendar-course-header">
                    <span class="calendar-course-title">
                        <span class="calendar-course-chevron" aria-hidden="true"></span>
                        <span>${course} курс</span>
                    </span>
                    <span class="calendar-course-meta">${courseRows.length} дней</span>
                </summary>
                <div class="calendar-semesters-grid">
                    ${renderCourseSemesters(Number(course), courseRows)}
                </div>
            </details>
        `).join('');
        populateFillCourseSelect();
        renderCalendarTotals();
    }

    function renderCourseSemesters(course, courseRows) {
        const calendar = selectedEditorCalendar();
        const semestersForCourse = semesterBlocksForCourse(calendar, course, courseRows);
        return semestersForCourse.map(block => `
            <section class="calendar-semester-block">
                <div class="calendar-semester-header">
                    <h4>${block.semesterNumber} семестр</h4>
                    <span>${escapeHtml(block.caption)}</span>
                </div>
                ${renderSemesterTable(block.rows)}
            </section>
        `).join('');
    }

    function renderSemesterTable(rows) {
        if (!rows.length) {
            return '<div class="calendar-empty-semester">Нет дат в этом семестре</div>';
        }

        const rowsByWeek = groupBy(rows, row => row.weekNumber);
        const weeks = Array.from(rowsByWeek.keys()).sort((a, b) => Number(a) - Number(b));
        const cellByWeekAndDay = new Map(rows.map(row => [`${row.weekNumber}:${row.dayOfWeek}`, row]));
        return `
            <div class="calendar-semester-table-wrap">
                <table class="calendar-semester-table">
                    <thead>
                        <tr>
                            <th class="calendar-day-head">День</th>
                            ${weeks.map(week => `<th title="Неделя ${week} учебного года">${week}</th>`).join('')}
                        </tr>
                    </thead>
                    <tbody>
                        ${DAY_OPTIONS.map(day => `
                            <tr>
                                <th class="calendar-day-head">${escapeHtml(day.shortLabel)}</th>
                                ${weeks.map(week => {
                                    const row = cellByWeekAndDay.get(`${week}:${day.value}`);
                                    return row ? renderCalendarDay(row) : '<td class="calendar-empty-day"></td>';
                                }).join('')}
                            </tr>
                        `).join('')}
                    </tbody>
                </table>
            </div>
        `;
    }

    function renderCalendarDay(row) {
        const selected = row.activityTypeId || activityIdByCode(row.activityCode) || theoryActivityId();
        const dayName = shortDayLabel(row.dayOfWeek);
        const activity = activityById(selected) || activityTypes[0] || {};
        const code = activity.code || row.activityCode || 'Т';
        const color = activity.colorCode || '#64748b';
        return `
            <td class="calendar-day"
                 data-course="${row.courseNumber}"
                 data-date="${row.date}"
                 data-week="${row.weekNumber}"
                 data-day="${row.dayOfWeek}"
                 data-time-assignment-id="${timeAssignmentForDate(row.date)?.id || ''}"
                 data-time-scope-id="${timeAssignmentForDate(row.date)?.scopeId || ''}"
                 role="button"
                 tabindex="0"
                 aria-label="${escapeHtml(`${formatShortDate(row.date)} ${dayName}, ${row.weekNumber} неделя, код ${code}`)}"
                 title="${escapeHtml(`${formatLongDate(row.date)}, ${dayName}, ${row.weekNumber} неделя, ${code} - ${activity.name || ''}`)}"
                 style="--activity-color:${escapeHtml(color)}">
                <strong class="calendar-day-code">${escapeHtml(code)}</strong>
                ${timeAssignmentForDate(row.date) ? '<span class="calendar-day-time-marker">вр.</span>' : ''}
                <select class="calendar-day-activity custom-select-initialized" aria-hidden="true" tabindex="-1">${options(activityTypes.map(toActivityOption), selected)}</select>
            </td>
        `;
    }

    function openCalendarDayDialog(day) {
        activeCalendarDay = day;
        selectCalendarDay(day);
        calendarDayDialogDate.textContent = `${formatLongDate(day.dataset.date)} (${shortDayLabel(day.dataset.day)})`;
        calendarDayDialogCourse.textContent = `${day.dataset.course} курс`;
        calendarDayDialogWeek.textContent = `${day.dataset.week} неделя`;
        calendarDayDialogDay.textContent = dayLabel(day.dataset.day);
        calendarDayDialogActivitySelect.innerHTML = options(
            activityTypes.map(toActivityOption),
            day.querySelector('.calendar-day-activity').value
        );
        populateTimeScopeDialogSelect(day.dataset.date);
        syncSelects(calendarDayDialogActivitySelect);
        syncSelects(calendarDayDialogTimeScopeSelect);
        updateCalendarDayDialogSummary(day);
        renderCalendarTotals();
        calendarDayDialog.classList.add('open');
    }

    function closeCalendarDayDialog() {
        activeCalendarDay = null;
        calendarDayDialog.classList.remove('open');
    }

    function updateCalendarDayDialogSummary(day) {
        const activity = activityById(day.querySelector('.calendar-day-activity').value);
        if (!activity) {
            calendarDayDialogActivitySummary.innerHTML = '';
            return;
        }
        calendarDayDialogActivitySummary.innerHTML = `
            <span class="calendar-day-dialog-code" style="--activity-color:${escapeHtml(activity.colorCode || '#64748b')}">${escapeHtml(activity.code)}</span>
            <div>
                <strong>${escapeHtml(activity.name)}</strong>
                <p>${escapeHtml(activity.description || (activity.allowSchedule ? 'Обычные пары разрешены' : 'Обычные пары не генерируются'))}</p>
            </div>
        `;
    }

    async function saveTimeSlotDateAssignment() {
        if (!activeCalendarDay) return;
        hideAlert('calendar-day-dialog-time-alert');
        const scopeId = calendarDayDialogTimeScopeSelect.value;
        if (!scopeId) {
            await clearTimeSlotDateAssignment();
            return;
        }
        try {
            await api.post('/api/admin/time-slots/date-assignments', {
                date: activeCalendarDay.dataset.date,
                scopeId: Number(scopeId)
            });
            await loadTimeSlotDateAssignments();
            updateTimeAssignmentVisuals(activeCalendarDay.dataset.date);
            populateTimeScopeDialogSelect(activeCalendarDay.dataset.date);
            syncSelects(calendarDayDialogTimeScopeSelect);
            showAlert('calendar-day-dialog-time-alert', 'Ручная сетка применена к дате', 'success');
        } catch (error) {
            showAlert('calendar-day-dialog-time-alert', error.message || 'Ошибка применения временной сетки', 'error');
        }
    }

    async function clearTimeSlotDateAssignment() {
        if (!activeCalendarDay) return;
        hideAlert('calendar-day-dialog-time-alert');
        const assignment = timeAssignmentForDate(activeCalendarDay.dataset.date);
        if (!assignment) {
            calendarDayDialogTimeScopeSelect.value = '';
            syncSelects(calendarDayDialogTimeScopeSelect);
            showAlert('calendar-day-dialog-time-alert', 'Для даты нет ручной сетки', 'success');
            return;
        }
        try {
            await api.delete('/api/admin/time-slots/date-assignments/' + assignment.id);
            await loadTimeSlotDateAssignments();
            updateTimeAssignmentVisuals(activeCalendarDay.dataset.date);
            populateTimeScopeDialogSelect(activeCalendarDay.dataset.date);
            syncSelects(calendarDayDialogTimeScopeSelect);
            showAlert('calendar-day-dialog-time-alert', 'Ручная сетка убрана', 'success');
        } catch (error) {
            showAlert('calendar-day-dialog-time-alert', error.message || 'Ошибка удаления ручной сетки', 'error');
        }
    }

    function populateTimeScopeDialogSelect(date) {
        const assignment = timeAssignmentForDate(date);
        const manualScopes = timeSlotScopes.filter(scope => scope.applyMode === 'MANUAL');
        const automaticLabel = automaticTimeScopeLabel(date);
        calendarDayDialogTimeScopeSelect.innerHTML = `<option value="">${escapeHtml(automaticLabel)}</option>` +
            manualScopes.map(scope => `<option value="${scope.id}">${escapeHtml(scope.name)}</option>`).join('');
        calendarDayDialogTimeScopeSelect.value = assignment?.scopeId || '';
        calendarDayDialogTimeSaveButton.disabled = manualScopes.length === 0 && !assignment;
        calendarDayDialogTimeClearButton.disabled = !assignment;
    }

    function updateTimeAssignmentVisuals(date) {
        const assignment = timeAssignmentForDate(date);
        calendarGrid.querySelectorAll(`.calendar-day[data-date="${date}"]`).forEach(day => {
            day.dataset.timeAssignmentId = assignment?.id || '';
            day.dataset.timeScopeId = assignment?.scopeId || '';
            const marker = day.querySelector('.calendar-day-time-marker');
            if (assignment && !marker) {
                day.insertAdjacentHTML('beforeend', '<span class="calendar-day-time-marker">вр.</span>');
            }
            if (!assignment && marker) {
                marker.remove();
            }
        });
    }

    function updateCalendarDayVisual(day) {
        if (!day) return;
        const select = day.querySelector('.calendar-day-activity');
        const activity = activityById(select.value);
        const code = activity?.code || '-';
        const color = activity?.colorCode || '#64748b';
        day.style.setProperty('--activity-color', color);
        day.querySelector('.calendar-day-code').textContent = code;
        day.setAttribute('aria-label', `${formatShortDate(day.dataset.date)} ${shortDayLabel(day.dataset.day)}, ${day.dataset.week} неделя, код ${code}`);
        day.setAttribute('title', `${formatLongDate(day.dataset.date)}, ${shortDayLabel(day.dataset.day)}, ${day.dataset.week} неделя, ${code} - ${activity?.name || ''}`);
    }

    function selectCalendarDay(day) {
        if (!day) return;
        selectedCalendarDayKey = calendarDayKey(day);
        calendarGrid.querySelectorAll('.calendar-day.is-selected').forEach(item => item.classList.remove('is-selected'));
        day.classList.add('is-selected');
    }

    function calendarDayKey(day) {
        return `${day.dataset.course}:${day.dataset.date}`;
    }

    function buildDefaultGrid(calendar) {
        const rows = [];
        const dates = enumerateDates(calendar.academicYearStartDate, calendar.academicYearEndDate);
        for (let course = 1; course <= calendar.courseCount; course += 1) {
            dates.forEach((date, index) => {
                rows.push({
                    id: null,
                    calendarId: calendar.id,
                    courseNumber: course,
                    date: date.iso,
                    weekNumber: Math.floor(index / 7) + 1,
                    dayOfWeek: date.dayOfWeek,
                    activityTypeId: theoryActivityId(),
                    activityCode: 'Т'
                });
            });
        }
        return rows;
    }

    function semesterBlocksForCourse(calendar, course, courseRows) {
        const sortedRows = [...courseRows].sort((a, b) => String(a.date).localeCompare(String(b.date)));
        const year = academicYears.find(item => String(item.id) === String(calendar?.academicYearId));
        const yearSemesters = [...(year?.semesters || [])]
            .sort((a, b) => String(a.startDate).localeCompare(String(b.startDate)));

        if (!yearSemesters.length) {
            return [{
                semesterNumber: `${course * 2 - 1}-${course * 2}`,
                caption: dateRangeCaption(sortedRows),
                rows: sortedRows
            }];
        }

        return yearSemesters.map((semester, index) => {
            const nextSemester = yearSemesters[index + 1];
            const startDate = index === 0
                ? minIso(calendar.academicYearStartDate, semester.startDate)
                : semester.startDate;
            const endDate = nextSemester
                ? previousIsoDate(nextSemester.startDate)
                : maxIso(calendar.academicYearEndDate, semester.endDate);
            const rows = sortedRows.filter(row => row.date >= startDate && row.date <= endDate);
            return {
                semesterNumber: course * 2 - 1 + index,
                caption: dateRangeCaption(rows) || `${formatLongDate(startDate)} - ${formatLongDate(endDate)}`,
                rows
            };
        });
    }

    function renderCalendarTotals() {
        const counts = new Map();
        calendarGrid.querySelectorAll('.calendar-day-activity').forEach(select => {
            const activity = activityById(select.value);
            const key = activity ? activity.code : '-';
            counts.set(key, (counts.get(key) || 0) + 1);
        });
        const selectedDay = selectedCalendarDayKey
            ? Array.from(calendarGrid.querySelectorAll('.calendar-day')).find(day => calendarDayKey(day) === selectedCalendarDayKey)
            : null;
        const selectedActivity = selectedDay ? activityById(selectedDay.querySelector('.calendar-day-activity').value) : null;
        const selectedCode = selectedActivity?.code || null;
        calendarTotals.innerHTML = Array.from(counts.entries())
            .sort(([a], [b]) => a.localeCompare(b, 'ru'))
            .map(([code, count]) => {
                const activity = activityTypes.find(item => item.code === code);
                const selectedClass = selectedCode === code ? ' is-selected' : '';
                const suffix = selectedCode === code ? '<span class="calendar-total-selected">выбрано</span>' : '';
                return `<span class="calendar-total-chip${selectedClass}" style="--chip-color:${escapeHtml(activity?.colorCode || '#64748b')}">${escapeHtml(code)}: ${count}${suffix}</span>`;
            }).join('');
    }

    function populateYearSelects() {
        const yearOptions = '<option value="">Выберите учебный год</option>' +
            academicYears.map(year => `<option value="${year.id}">${escapeHtml(year.title)}</option>`).join('');
        semesterYearSelect.innerHTML = yearOptions;
        calendarYearSelect.innerHTML = yearOptions;
        syncSelects(semesterYearSelect, calendarYearSelect);
    }

    function populateSpecialtySelects() {
        calendarSpecialtySelect.innerHTML = '<option value="">Выберите специальность</option>' +
            specialties.map(speciality => `<option value="${speciality.id}">${escapeHtml(specialityLabel(speciality))}</option>`).join('');
        populateProfileSelect(calendarProfileSelect, calendarSpecialtySelect.value);
        syncSelects(calendarSpecialtySelect);
    }

    function populateProfileSelect(select, specialtyId, selectedProfileId = null) {
        const profiles = profilesBySpecialty.get(String(specialtyId)) || [];
        select.innerHTML = profiles.length
            ? '<option value="">Выберите профиль</option>' + profiles.map(profile =>
                `<option value="${profile.id}">${escapeHtml(profile.name)}</option>`
            ).join('')
            : '<option value="">Нет профилей</option>';
        if (selectedProfileId && profiles.some(profile => String(profile.id) === String(selectedProfileId))) {
            select.value = selectedProfileId;
        }
        syncSelects(select);
    }

    function populateStudyFormSelect() {
        calendarStudyFormSelect.innerHTML = '<option value="">Выберите форму</option>' +
            studyForms.map(form => `<option value="${form.id}">${escapeHtml(form.name)}</option>`).join('');
        syncSelects(calendarStudyFormSelect);
    }

    function populateActivitySelects() {
        const activityOptions = '<option value="">Выберите код</option>' +
            activityTypes.map(type => `<option value="${type.id}">${escapeHtml(type.code)} - ${escapeHtml(type.name)}</option>`).join('');
        fillActivitySelect.innerHTML = activityOptions;
        syncSelects(fillActivitySelect);
    }

    function populateEditorCalendarSelect() {
        const current = editorCalendarSelect.value;
        editorCalendarSelect.innerHTML = '<option value="">Выберите график</option>' +
            calendars.map(calendar => `<option value="${calendar.id}">${escapeHtml(calendar.title)}</option>`).join('');
        if (current && calendars.some(calendar => String(calendar.id) === String(current))) {
            editorCalendarSelect.value = current;
        }
        syncSelects(editorCalendarSelect);
    }

    function populateFillCourseSelect() {
        const courses = new Set(Array.from(calendarGrid.querySelectorAll('.calendar-day')).map(day => day.dataset.course));
        fillCourseSelect.innerHTML = '<option value="">Все курсы</option>' +
            Array.from(courses).sort((a, b) => Number(a) - Number(b))
                .map(course => `<option value="${course}">${course} курс</option>`).join('');
        syncSelects(fillCourseSelect);
    }

    function options(items, selectedValue) {
        const selected = selectedValue == null ? '' : String(selectedValue);
        return '<option value="">Выберите</option>' + items.map(item => {
            const value = String(item.value);
            return `<option value="${escapeHtml(value)}" ${value === selected ? 'selected' : ''}>${escapeHtml(item.label)}</option>`;
        }).join('');
    }

    function toActivityOption(type) {
        return { value: type.id, label: `${type.code} - ${type.name}` };
    }

    function selectedEditorCalendar() {
        return calendars.find(calendar => String(calendar.id) === String(editorCalendarSelect.value));
    }

    function theoryActivityId() {
        return activityTypes.find(type => type.code === 'Т')?.id || activityTypes[0]?.id || '';
    }

    function activityIdByCode(code) {
        return activityTypes.find(type => type.code === code)?.id || null;
    }

    function activityById(id) {
        return activityTypes.find(type => String(type.id) === String(id));
    }

    function timeAssignmentForDate(date) {
        return timeSlotDateAssignments.find(item => item.date === date);
    }

    function automaticTimeScopeLabel(date) {
        const jsDate = new Date(`${date}T00:00:00`);
        const jsDay = jsDate.getDay();
        const isoDay = jsDay === 0 ? 7 : jsDay;
        const weekdayScope = timeSlotScopes.find(scope => scope.applyMode === 'WEEKDAY' && Number(scope.dayOfWeek) === isoDay);
        const defaultScope = timeSlotScopes.find(scope => scope.applyMode === 'DEFAULT');
        const scopeName = weekdayScope?.name || defaultScope?.name || 'базовая сетка';
        return `По правилу даты (${scopeName})`;
    }

    function semesterLabel(semester) {
        const type = normalizeSemesterType(semester.semesterType);
        return `${semester.academicYearTitle || '-'}, ${SEMESTER_LABELS[type] || type} (${semester.startDate} - ${semester.endDate})`;
    }

    function normalizeSemesterType(type) {
        return String(type || '').toLowerCase();
    }

    function specialityLabel(speciality) {
        const code = speciality.specialityCode || speciality.specialtyCode || speciality.specialty_code || speciality.id;
        const name = speciality.specialityName || speciality.name || '';
        return name ? `${code} - ${name}` : String(code);
    }

    function dayLabel(value) {
        return DAY_OPTIONS.find(day => String(day.value) === String(value))?.label || '-';
    }

    function shortDayLabel(value) {
        return DAY_OPTIONS.find(day => String(day.value) === String(value))?.shortLabel || '-';
    }

    function formatShortDate(value) {
        const [year, month, day] = String(value).split('-');
        return `${day}.${month}`;
    }

    function formatLongDate(value) {
        const [year, month, day] = String(value).split('-');
        return `${day}.${month}.${year}`;
    }

    function dateRangeCaption(rows) {
        if (!rows.length) return '';
        const dates = rows.map(row => row.date).sort();
        return `${formatLongDate(dates[0])} - ${formatLongDate(dates[dates.length - 1])}`;
    }

    function minIso(a, b) {
        return String(a) <= String(b) ? a : b;
    }

    function maxIso(a, b) {
        return String(a) >= String(b) ? a : b;
    }

    function previousIsoDate(value) {
        const date = new Date(`${value}T00:00:00Z`);
        date.setUTCDate(date.getUTCDate() - 1);
        return date.toISOString().slice(0, 10);
    }

    function enumerateDates(startIso, endIso) {
        const result = [];
        const current = new Date(`${startIso}T00:00:00Z`);
        const end = new Date(`${endIso}T00:00:00Z`);
        while (current <= end) {
            const iso = current.toISOString().slice(0, 10);
            const jsDay = current.getUTCDay();
            result.push({ iso, dayOfWeek: jsDay === 0 ? 7 : jsDay });
            current.setUTCDate(current.getUTCDate() + 1);
        }
        return result;
    }

    function groupBy(items, keyFn) {
        const grouped = new Map();
        items.forEach(item => {
            const key = keyFn(item);
            if (!grouped.has(key)) grouped.set(key, []);
            grouped.get(key).push(item);
        });
        return grouped;
    }

    function syncSelects(...selects) {
        selects.filter(Boolean).forEach(select => {
            select.dispatchEvent(new Event('change', { bubbles: true }));
        });
    }
}