/**
 * Team Calendar Page
 * Shows presence and parking for all team members
 * Filtered by office (office-centric model)
 */

let currentUser = null;
let currentStartDate = null;
let viewMode = 'week'; // 'week' or 'month'
let offices = [];
let teamData = [];
let parkingDataLookup = {};
let parkingAssignmentLookup = {};
let selectedUserId = null;
let selectedDate = null;
let currentAssignmentId = null;
let officeClosingRules = {}; // { officeId: { weekly: [], specific: [] } }

document.addEventListener('DOMContentLoaded', async () => {
    currentUser = await api.requireAuth();
    if (!currentUser) return;

    // Initialize start date based on week start preference
    const weekStartDay = currentUser.week_start_day || 1;
    currentStartDate = utils.getWeekStart(new Date(), weekStartDay);

    await loadOffices();
    await loadTeamData();
    await loadTeamData();

    // Initialize Modal Logic
    ModalLogic.init({
        onMarkPresence: handleMarkPresence,
        onClearPresence: handleClearPresence,
        onReleaseParking: handleReleaseParking,
        onReassignParking: handleReassignParking
    });

    renderCalendar();
    setupEventListeners();
});

function updateOfficeDisplay() {
    const display = document.getElementById('currentOfficeNameDisplay');
    if (!display) return;

    const select = document.getElementById('officeFilter');

    // If user is employee, show their office name directly
    if (currentUser.role === 'employee') {
        display.textContent = currentUser.office_name || "Mio Ufficio";
        return;
    }

    // For admin/manager, show selected
    if (select && select.value) {
        // Find name in options
        const option = select.options[select.selectedIndex];
        if (option) {
            // Remove the count (xx utenti) part if desired, or keep it. 
            // User requested "nome del'ufficio", let's keep it simple.
            // Option text is "Name (Count users)"
            // let text = option.textContent.split('(')[0].trim();
            display.textContent = option.textContent;
        } else {
            display.textContent = "Tutti gli Uffici";
        }
    } else {
        display.textContent = "Tutti gli Uffici";
    }
}

async function loadOffices() {
    const select = document.getElementById('officeFilter');

    // Only Admins and Managers can list offices
    // Employees will just see their own office logic handled in loadTeamData
    // Only Admins can see the office selector
    if (currentUser.role !== 'admin') {
        select.style.display = 'none';
        // Employees stop here, Managers continue to allow auto-selection logic below
        if (currentUser.role === 'employee') return;
    }

    const response = await api.get('/api/offices');
    if (response && response.ok) {
        offices = await response.json();

        let filteredOffices = offices;
        if (currentUser.role === 'manager') {
            // Manager only sees their own office in the filter?
            // Actually managers might want to filter if they (hypothetically) managed multiple, 
            // but currently User has 1 office.
            if (currentUser.office_id) {
                filteredOffices = offices.filter(o => o.id === currentUser.office_id);
            } else {
                filteredOffices = [];
            }
        }

        filteredOffices.forEach(office => {
            const option = document.createElement('option');
            option.value = office.id;
            option.textContent = `${office.name} (${office.user_count || 0} utenti)`;
            select.appendChild(option);
        });

        // Auto-select for managers
        if (currentUser.role === 'manager' && filteredOffices.length === 1) {
            select.value = filteredOffices[0].id;
        }
    }

    // Initial update of office display
    updateOfficeDisplay();

    // Show export card for Admin/Manager
    if (['admin', 'manager'].includes(currentUser.role)) {
        const exportCard = document.getElementById('exportCard');
        if (exportCard) {
            exportCard.style.display = 'block';

            // Set defaults (current month)
            const today = new Date();
            const firstDay = new Date(today.getFullYear(), today.getMonth(), 1);
            const lastDay = new Date(today.getFullYear(), today.getMonth() + 1, 0);

            document.getElementById('exportStartDate').valueAsDate = firstDay;
            document.getElementById('exportEndDate').valueAsDate = lastDay;

            document.getElementById('exportBtn').addEventListener('click', handleExport);
        }
    }
}

async function handleExport() {
    const startStr = document.getElementById('exportStartDate').value;
    const endStr = document.getElementById('exportEndDate').value;
    const officeId = document.getElementById('officeFilter').value;

    if (!startStr || !endStr) {
        alert('Seleziona le date di inizio e fine');
        return;
    }

    // Construct URL
    let url = `/api/reports/team-export?start_date=${startStr}&end_date=${endStr}`;
    if (officeId) {
        url += `&office_id=${officeId}`;
    }

    try {
        const btn = document.getElementById('exportBtn');
        const originalText = btn.innerHTML;
        btn.disabled = true;
        btn.textContent = 'Generazione...';

        // Use fetch directly to handle blob
        const token = api.getToken();
        const headers = token ? { 'Authorization': `Bearer ${token}` } : {};

        const response = await fetch(url, { headers });

        if (response.ok) {
            const blob = await response.blob();
            const downloadUrl = window.URL.createObjectURL(blob);
            const a = document.createElement('a');
            a.href = downloadUrl;
            a.download = `report_presenze_${startStr}_${endStr}.xlsx`;
            document.body.appendChild(a);
            a.click();
            window.URL.revokeObjectURL(downloadUrl);
            a.remove();
        } else {
            const err = await response.json();
            alert('Errore export: ' + (err.detail || 'Sconosciuto'));
        }

        btn.disabled = false;
        btn.innerHTML = originalText;
    } catch (e) {
        console.error(e);
        alert('Errore durante l\'export');
        document.getElementById('exportBtn').disabled = false;
        document.getElementById('exportBtn').textContent = 'Esporta Excel';
    }
}

function getDateRange() {
    let startDate = new Date(currentStartDate);
    let endDate = new Date(currentStartDate);

    if (viewMode === 'week') {
        endDate.setDate(endDate.getDate() + 6);
    } else {
        // Month view - start from first day of month
        startDate = new Date(currentStartDate.getFullYear(), currentStartDate.getMonth(), 1);
        endDate = new Date(currentStartDate.getFullYear(), currentStartDate.getMonth() + 1, 0);
    }

    return { startDate, endDate };
}

async function loadTeamData() {
    await loadClosingData();
    const { startDate, endDate } = getDateRange();
    const startStr = utils.formatDate(startDate);
    const endStr = utils.formatDate(endDate);

    let url = `/api/presence/team?start_date=${startStr}&end_date=${endStr}`;

    const officeFilter = document.getElementById('officeFilter').value;
    if (officeFilter) {
        url += `&office_id=${officeFilter}`;
    }

    const response = await api.get(url);
    if (response && response.ok) {
        teamData = await response.json();
        // Build parking lookup with spot names and assignment IDs
        parkingDataLookup = {};
        parkingAssignmentLookup = {};
        teamData.forEach(member => {
            if (member.parking_info) {
                member.parking_info.forEach(p => {
                    const key = `${member.id}_${p.date}`;
                    parkingDataLookup[key] = p.spot_display_name || p.spot_id;
                    parkingAssignmentLookup[key] = p.id;
                });
            }
        });
    }
}


async function loadClosingData() {
    officeClosingRules = {};
    let officeIdsToLoad = [];

    const selectedOfficeId = document.getElementById('officeFilter').value;

    if (selectedOfficeId) {
        officeIdsToLoad = [selectedOfficeId];
    } else if (currentUser.role === 'employee' || (currentUser.role === 'manager' && currentUser.office_id)) {
        officeIdsToLoad = [currentUser.office_id];
    } else if (offices.length > 0) {
        // Admin viewing all or Manager with access to list
        officeIdsToLoad = offices.map(o => o.id);
    }

    if (officeIdsToLoad.length === 0) return;

    // Fetch in parallel
    const promises = officeIdsToLoad.map(async (oid) => {
        try {
            const [weeklyRes, specificRes] = await Promise.all([
                api.get(`/api/offices/${oid}/weekly-closing-days`),
                api.get(`/api/offices/${oid}/closing-days`)
            ]);

            officeClosingRules[oid] = { weekly: [], specific: [] };

            if (weeklyRes && weeklyRes.ok) {
                const days = await weeklyRes.json();
                officeClosingRules[oid].weekly = days.map(d => d.weekday);
            }

            if (specificRes && specificRes.ok) {
                officeClosingRules[oid].specific = await specificRes.json();

                // OPTIMIZATION: Pre-calculate all specific closed dates into a Set
                const closedSet = new Set();
                officeClosingRules[oid].specific.forEach(range => {
                    let start = new Date(range.date);
                    let end = range.end_date ? new Date(range.end_date) : new Date(range.date);

                    // Normalize to noon to avoid timezone issues when stepping
                    start.setHours(12, 0, 0, 0);
                    end.setHours(12, 0, 0, 0);

                    let current = new Date(start);
                    while (current <= end) {
                        closedSet.add(utils.formatDate(current));
                        current.setDate(current.getDate() + 1);
                    }
                });
                officeClosingRules[oid].closedDatesSet = closedSet;
            }
        } catch (e) {
            console.error(`Error loading closing days for office ${oid}:`, e);
        }
    });

    await Promise.all(promises);
}

function renderCalendar() {
    const header = document.getElementById('calendarHeader');
    const body = document.getElementById('calendarBody');
    const { startDate, endDate } = getDateRange();

    // Update header text
    if (viewMode === 'week') {
        document.getElementById('currentWeek').textContent =
            `${utils.formatDateShort(startDate)} - ${utils.formatDateShort(endDate)}`;
    } else {
        document.getElementById('currentWeek').textContent =
            `${utils.getMonthName(startDate.getMonth())} ${startDate.getFullYear()}`;
    }

    // Calculate number of days
    const dayCount = Math.round((endDate - startDate) / (1000 * 60 * 60 * 24)) + 1;

    // Build header row
    const dayNames = ['Dom', 'Lun', 'Mar', 'Mer', 'Gio', 'Ven', 'Sab'];
    let headerHtml = '<th>Nome</th><th>Ufficio</th>';

    for (let i = 0; i < dayCount; i++) {
        const date = new Date(startDate);
        date.setDate(date.getDate() + i);
        const dayOfWeek = date.getDay();
        const isWeekend = dayOfWeek === 0 || dayOfWeek === 6;
        const isHoliday = utils.isItalianHoliday(date);
        const isToday = utils.formatDate(date) === utils.formatDate(new Date());

        let classes = [];
        if (isWeekend) classes.push('weekend');
        if (isHoliday) classes.push('holiday');
        if (isToday) classes.push('today');

        if (isToday) classes.push('today');

        // Header doesn't show closed status in multi-office view
        // unless we want to check if ALL are closed? 
        // For now, simpler to leave header clean.

        headerHtml += `<th class="${classes.join(' ')}">
            <div>${dayNames[dayOfWeek].charAt(0)}</div>
            <div class="day-number">${date.getDate()}</div>
        </th>`;
    }
    header.innerHTML = headerHtml;

    // Build body rows
    if (teamData.length === 0) {
        body.innerHTML = `<tr><td colspan="${dayCount + 2}" class="text-center">Nessun membro del team trovato</td></tr>`;
        return;
    }

    let bodyHtml = '';
    teamData.forEach(member => {
        bodyHtml += `<tr>
            <td class="member-name">${member.name || 'Unknown'}</td>
            <td class="member-manager">${member.office_name || '-'}</td>`;

        for (let i = 0; i < dayCount; i++) {
            const date = new Date(startDate);
            date.setDate(date.getDate() + i);
            const dateStr = utils.formatDate(date);
            const dayOfWeek = date.getDay();
            const isWeekend = dayOfWeek === 0 || dayOfWeek === 6;
            const isHoliday = utils.isItalianHoliday(date);

            const presence = member.presences.find(p => p.date === dateStr);
            const parkingKey = `${member.id}_${dateStr}`;
            const parkingSpot = parkingDataLookup[parkingKey];
            const hasParking = member.parking_dates && member.parking_dates.includes(dateStr);
            const isToday = dateStr === utils.formatDate(new Date());

            let cellClasses = ['calendar-cell'];
            if (isWeekend) cellClasses.push('weekend');
            if (isHoliday) cellClasses.push('holiday');
            if (isToday) cellClasses.push('today');
            if (presence) cellClasses.push(`status-${presence.status}`);

            if (isToday) cellClasses.push('today');
            if (presence) cellClasses.push(`status-${presence.status}`);

            // Optimized closing day check
            // Pre-calculate loop-invariant sets outside if not already done, but here we do it per-cell because of date dependency?
            // BETTER: We should pre-calculate a "closedMap" for the viewed range for each office?
            // OR: Just optimize the inner check.

            // Optimization: Create a lookup string for the current date once
            // (Already have dateStr)

            const memberRules = officeClosingRules[member.office_id];
            let isClosed = false;

            if (memberRules) {
                // Check weekly
                if (memberRules.weekly.includes(dayOfWeek)) {
                    isClosed = true;
                } else if (memberRules.specific && memberRules.specific.length > 0) {
                    // Check specific
                    // Optimization: Use the string date lookup if we had a Set, but we have ranges.
                    // We can optimize by converting ranges to Sets ONCE when loading data, 
                    // OR just stick to this check if N is small.
                    // Given the "optimization" task, let's just make sure we don't do new Date() inside.
                    // The `specific` array contains objects with `date` and `end_date` strings.
                    // We can compare strings directly if format is YYYY-MM-DD and we are careful.

                    // Optimization: check if dateStr is in a Set of closed dates for this office?
                    // Let's implement the Set lookup logic in `loadClosingData` or `renderCalendar` start.
                    // For now, let's assume `memberRules.closedDatesSet` exists.

                    if (memberRules.closedDatesSet && memberRules.closedDatesSet.has(dateStr)) {
                        isClosed = true;
                    }
                }
            }

            if (isClosed) {
                cellClasses.push('closed');
            }

            // Show parking badge instead of just 'P'
            let parkingBadge = '';
            if (hasParking) {
                const spotName = parkingSpot || 'P';
                parkingBadge = `<span class="parking-badge-sm">${spotName}</span>`;
            }

            bodyHtml += `<td class="${cellClasses.join(' ')}" data-user-id="${member.id}" data-date="${dateStr}" data-user-name="${member.name || ''}" ${isClosed ? 'data-closed="true"' : ''}>${parkingBadge}</td>`;
        }

        bodyHtml += '</tr>';
    });
    body.innerHTML = bodyHtml;

    // Add click handlers to cells (only for admins and managers)
    if (currentUser.role === 'admin' || currentUser.role === 'manager') {
        body.querySelectorAll('.calendar-cell').forEach(cell => {
            cell.style.cursor = 'pointer';
            if (cell.dataset.closed !== 'true') {
                cell.addEventListener('click', () => {
                    const userId = cell.dataset.userId;
                    const date = cell.dataset.date;
                    const userName = cell.dataset.userName;
                    openDayModal(userId, date, userName);
                });
            }
        });
    }
}

function openDayModal(userId, dateStr, userName) {
    selectedUserId = userId;
    selectedDate = dateStr;

    // Find current status and parking
    const member = teamData.find(m => m.id === userId);
    const presence = member?.presences.find(p => p.date === dateStr);
    const parkingKey = `${userId}_${dateStr}`;
    const parkingSpot = parkingDataLookup[parkingKey];
    const assignmentId = parkingAssignmentLookup[parkingKey];
    currentAssignmentId = assignmentId; // Ensure this is set for modal logic

    const parkingObj = assignmentId ? {
        id: assignmentId,
        spot_display_name: parkingSpot,
        spot_id: parkingSpot
    } : null;

    ModalLogic.openModal({
        dateStr,
        userName,
        presence,
        parking: parkingObj,
        userId
    });
}

async function handleMarkPresence(status, date, userId) {
    // userId passed from ModalLogic if provided, or use selectedUserId
    const targetUserId = userId || selectedUserId;
    if (!targetUserId) return;

    const response = await api.post('/api/presence/admin/mark', {
        user_id: targetUserId,
        date: date,
        status: status
    });

    if (response && response.ok) {
        ModalLogic.closeModal();
        await loadTeamData();
        renderCalendar();
    } else {
        const error = await response.json();
        alert(error.detail || 'Impossibile segnare la presenza');
    }
}

async function handleClearPresence(date, userId) {
    const targetUserId = userId || selectedUserId;
    if (!targetUserId) return;

    // confirm is not needed here if ModalLogic doesn't mandate it, but keeping logic
    // ModalLogic buttons usually trigger this directly.

    const response = await api.delete(`/api/presence/admin/${targetUserId}/${date}`);
    if (response && response.ok) {
        ModalLogic.closeModal();
        await loadTeamData();
        renderCalendar();
    }
}

async function handleReleaseParking(assignmentId) {
    if (!confirm('Rilasciare il parcheggio per questa data?')) return;

    // Note: Admin endpoint for releasing ANY spot vs "my spot"
    // Since we are admin/manager here, we might need a general release endpoint or use reassign with null?
    // The current 'release_my_spot' is only for self.
    // 'reassign_spot' with null user_id is the way for admins.

    const response = await api.post('/api/parking/reassign-spot', {
        assignment_id: assignmentId,
        new_user_id: null // Release
    });

    if (response && response.ok) {
        ModalLogic.closeModal();
        await loadTeamData();
        renderCalendar();
    } else {
        const error = await response.json();
        alert(error.detail || 'Impossibile rilasciare il parcheggio');
    }
}


async function handleReassignParking(assignmentId, newUserId) {
    if (!assignmentId || !newUserId) {
        alert('Seleziona un utente');
        return;
    }

    const response = await api.post('/api/parking/reassign-spot', {
        assignment_id: assignmentId,
        new_user_id: newUserId
    });

    if (response && response.ok) {
        await loadTeamData();
        renderCalendar();
        ModalLogic.closeModal();
    } else {
        const error = await response.json();
        alert(error.detail || 'Impossibile riassegnare il parcheggio');
    }
}

function setupEventListeners() {
    // Navigation (prev/next)
    document.getElementById('prevWeek').addEventListener('click', async () => {
        if (viewMode === 'week') {
            currentStartDate.setDate(currentStartDate.getDate() - 7);
        } else {
            currentStartDate.setMonth(currentStartDate.getMonth() - 1);
        }
        await loadTeamData();
        renderCalendar();
    });

    document.getElementById('nextWeek').addEventListener('click', async () => {
        if (viewMode === 'week') {
            currentStartDate.setDate(currentStartDate.getDate() + 7);
        } else {
            currentStartDate.setMonth(currentStartDate.getMonth() + 1);
        }
        await loadTeamData();
        renderCalendar();
    });

    // View toggle (week/month)
    document.getElementById('viewToggle').addEventListener('change', async (e) => {
        viewMode = e.target.value;
        if (viewMode === 'month') {
            // Set to first day of current month
            currentStartDate = new Date(currentStartDate.getFullYear(), currentStartDate.getMonth(), 1);
        } else {
            // Set to current week start
            const weekStartDay = currentUser.week_start_day || 1;
            currentStartDate = utils.getWeekStart(new Date(), weekStartDay);
        }
        await loadTeamData();
        renderCalendar();
    });


    // Office filter
    document.getElementById('officeFilter').addEventListener('change', async () => {
        updateOfficeDisplay(); // Update label on change
        await loadTeamData();
        renderCalendar();
    });

    utils.setupModalClose('dayModal');
}