/**
 * My Presence Page
 * Personal calendar for marking daily presence
 */

let currentUser = null;
let currentDate = new Date();
let presenceData = {};
let parkingData = {};
let currentAssignmentId = null;

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

    await Promise.all([loadPresences(), loadParkingAssignments()]);
    renderCalendar();
    setupEventListeners();
});

async function loadPresences() {
    const year = currentDate.getFullYear();
    const month = currentDate.getMonth();
    const firstDay = new Date(year, month, 1);
    const lastDay = new Date(year, month + 1, 0);

    const startDate = utils.formatDate(firstDay);
    const endDate = utils.formatDate(lastDay);

    const response = await api.get(`/api/presence/my-presences?start_date=${startDate}&end_date=${endDate}`);
    if (response && response.ok) {
        const presences = await response.json();
        presenceData = {};
        presences.forEach(p => {
            presenceData[p.date] = p;
        });
    }
}

async function loadParkingAssignments() {
    const year = currentDate.getFullYear();
    const month = currentDate.getMonth();
    const firstDay = new Date(year, month, 1);
    const lastDay = new Date(year, month + 1, 0);

    const startDate = utils.formatDate(firstDay);
    const endDate = utils.formatDate(lastDay);

    const response = await api.get(`/api/parking/my-assignments?start_date=${startDate}&end_date=${endDate}`);
    if (response && response.ok) {
        const assignments = await response.json();
        parkingData = {};
        assignments.forEach(a => {
            parkingData[a.date] = a;
        });
    }
}

function renderCalendar() {
    const year = currentDate.getFullYear();
    const month = currentDate.getMonth();
    const weekStartDay = currentUser.week_start_day || 0; // 0=Sunday, 1=Monday

    // Update month header
    document.getElementById('currentMonth').textContent = `${utils.getMonthName(month)} ${year}`;

    // Get calendar info
    const daysInMonth = utils.getDaysInMonth(year, month);
    const firstDayOfMonth = new Date(year, month, 1).getDay(); // 0=Sunday
    const today = new Date();

    // Calculate offset based on week start preference
    let firstDayOffset = firstDayOfMonth - weekStartDay;
    if (firstDayOffset < 0) firstDayOffset += 7;

    // Build calendar grid
    const grid = document.getElementById('calendarGrid');
    grid.innerHTML = '';

    // Day headers - reorder based on week start day
    const allDayNames = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];
    const dayNames = [];
    for (let i = 0; i < 7; i++) {
        dayNames.push(allDayNames[(weekStartDay + i) % 7]);
    }
    dayNames.forEach(name => {
        const header = document.createElement('div');
        header.className = 'calendar-day';
        header.style.cursor = 'default';
        header.style.fontWeight = '600';
        header.style.fontSize = '0.75rem';
        header.textContent = name;
        grid.appendChild(header);
    });

    // Empty cells before first day
    for (let i = 0; i < firstDayOffset; i++) {
        const empty = document.createElement('div');
        empty.className = 'calendar-day';
        empty.style.visibility = 'hidden';
        grid.appendChild(empty);
    }

    // Day cells
    for (let day = 1; day <= daysInMonth; day++) {
        const date = new Date(year, month, day);
        const dateStr = utils.formatDate(date);
        const dayOfWeek = date.getDay();
        const isWeekend = dayOfWeek === 0 || dayOfWeek === 6;
        const isHoliday = utils.isItalianHoliday(date);
        const isToday = date.toDateString() === today.toDateString();
        const presence = presenceData[dateStr];
        const parking = parkingData[dateStr];

        const cell = document.createElement('div');
        cell.className = 'calendar-day';
        cell.dataset.date = dateStr;

        if (isWeekend) cell.classList.add('weekend');
        if (isHoliday) cell.classList.add('holiday');
        if (isToday) cell.classList.add('today');

        if (presence) {
            cell.classList.add(`status-${presence.status}`);
        }

        // Show parking badge if assigned
        const parkingBadge = parking
            ? `<span class="parking-badge">${parking.spot_display_name || parking.spot_id}</span>`
            : '';

        cell.innerHTML = `
            <div class="day-number">${day}</div>
            ${parkingBadge}
        `;

        cell.addEventListener('click', () => openDayModal(dateStr, presence, parking));
        grid.appendChild(cell);
    }
}

function openDayModal(dateStr, presence, parking) {
    const modal = document.getElementById('dayModal');
    const title = document.getElementById('dayModalTitle');

    title.textContent = utils.formatDateDisplay(dateStr);

    // Highlight current status
    document.querySelectorAll('.status-btn').forEach(btn => {
        const status = btn.dataset.status;
        if (presence && presence.status === status) {
            btn.classList.add('active');
        } else {
            btn.classList.remove('active');
        }
    });

    // Update parking section
    const parkingSection = document.getElementById('parkingSection');
    const parkingInfo = document.getElementById('parkingInfo');
    const releaseBtn = document.getElementById('releaseParkingBtn');

    if (parking) {
        parkingSection.style.display = 'block';
        const spotName = parking.spot_display_name || parking.spot_id;
        parkingInfo.innerHTML = `<strong>Parking:</strong> Spot ${spotName}`;
        releaseBtn.dataset.assignmentId = parking.id;
        document.getElementById('reassignParkingBtn').dataset.assignmentId = parking.id;
        currentAssignmentId = parking.id;
    } else {
        parkingSection.style.display = 'none';
    }

    modal.dataset.date = dateStr;
    modal.style.display = 'flex';
}

async function markPresence(status) {
    const modal = document.getElementById('dayModal');
    const date = modal.dataset.date;

    const response = await api.post('/api/presence/mark', { date, status });
    if (response && response.ok) {
        await Promise.all([loadPresences(), loadParkingAssignments()]);
        renderCalendar();
        modal.style.display = 'none';
    } else {
        const error = await response.json();
        alert(error.detail || 'Failed to mark presence');
    }
}

async function clearPresence() {
    const modal = document.getElementById('dayModal');
    const date = modal.dataset.date;

    if (!confirm('Clear presence for this date?')) return;

    const response = await api.delete(`/api/presence/${date}`);
    if (response && response.ok) {
        await Promise.all([loadPresences(), loadParkingAssignments()]);
        renderCalendar();
        modal.style.display = 'none';
    }
}

async function releaseParking() {
    const modal = document.getElementById('dayModal');
    const releaseBtn = document.getElementById('releaseParkingBtn');
    const assignmentId = releaseBtn.dataset.assignmentId;

    if (!assignmentId) return;
    if (!confirm('Release your parking spot for this date?')) return;

    const response = await api.post(`/api/parking/release-my-spot/${assignmentId}`);

    if (response && response.ok) {
        await loadParkingAssignments();
        renderCalendar();
        modal.style.display = 'none';
    } else {
        const error = await response.json();
        alert(error.detail || 'Failed to release parking spot');
    }
}

async function openReassignModal() {
    const assignmentId = currentAssignmentId;
    if (!assignmentId) return;

    // Load eligible users
    const response = await api.get(`/api/parking/eligible-users/${assignmentId}`);
    if (!response || !response.ok) {
        const error = await response.json();
        alert(error.detail || 'Failed to load eligible users');
        return;
    }

    const users = await response.json();
    const select = document.getElementById('reassignUser');
    select.innerHTML = '<option value="">Select user...</option>';

    if (users.length === 0) {
        select.innerHTML = '<option value="">No eligible users available</option>';
    } else {
        users.forEach(user => {
            const option = document.createElement('option');
            option.value = user.id;
            option.textContent = user.name;
            select.appendChild(option);
        });
    }

    // Get spot info from parking data
    const parking = Object.values(parkingData).find(p => p.id === assignmentId);
    if (parking) {
        const spotName = parking.spot_display_name || parking.spot_id;
        document.getElementById('reassignSpotInfo').textContent = `Spot ${spotName}`;
    }

    document.getElementById('dayModal').style.display = 'none';
    document.getElementById('reassignModal').style.display = 'flex';
}

async function confirmReassign() {
    const assignmentId = currentAssignmentId;
    const newUserId = document.getElementById('reassignUser').value;

    if (!assignmentId || !newUserId) {
        alert('Please select a user');
        return;
    }

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

    if (response && response.ok) {
        await loadParkingAssignments();
        renderCalendar();
        document.getElementById('reassignModal').style.display = 'none';
    } else {
        const error = await response.json();
        alert(error.detail || 'Failed to reassign parking spot');
    }
}

function setupEventListeners() {
    // Month navigation
    document.getElementById('prevMonth').addEventListener('click', async () => {
        currentDate.setMonth(currentDate.getMonth() - 1);
        await Promise.all([loadPresences(), loadParkingAssignments()]);
        renderCalendar();
    });

    document.getElementById('nextMonth').addEventListener('click', async () => {
        currentDate.setMonth(currentDate.getMonth() + 1);
        await Promise.all([loadPresences(), loadParkingAssignments()]);
        renderCalendar();
    });

    // Day modal
    document.getElementById('closeDayModal').addEventListener('click', () => {
        document.getElementById('dayModal').style.display = 'none';
    });

    document.querySelectorAll('.status-btn').forEach(btn => {
        btn.addEventListener('click', () => markPresence(btn.dataset.status));
    });

    document.getElementById('clearDayBtn').addEventListener('click', clearPresence);
    document.getElementById('releaseParkingBtn').addEventListener('click', releaseParking);
    document.getElementById('reassignParkingBtn').addEventListener('click', openReassignModal);

    utils.setupModalClose('dayModal');

    // Reassign modal
    document.getElementById('closeReassignModal').addEventListener('click', () => {
        document.getElementById('reassignModal').style.display = 'none';
    });
    document.getElementById('cancelReassign').addEventListener('click', () => {
        document.getElementById('reassignModal').style.display = 'none';
    });
    document.getElementById('confirmReassign').addEventListener('click', confirmReassign);
    utils.setupModalClose('reassignModal');

    // Bulk mark
    document.getElementById('bulkMarkBtn').addEventListener('click', () => {
        document.getElementById('bulkMarkModal').style.display = 'flex';
    });

    document.getElementById('closeBulkModal').addEventListener('click', () => {
        document.getElementById('bulkMarkModal').style.display = 'none';
    });

    document.getElementById('cancelBulk').addEventListener('click', () => {
        document.getElementById('bulkMarkModal').style.display = 'none';
    });

    utils.setupModalClose('bulkMarkModal');

    document.getElementById('bulkMarkForm').addEventListener('submit', async (e) => {
        e.preventDefault();

        const startDate = document.getElementById('startDate').value;
        const endDate = document.getElementById('endDate').value;
        const status = document.getElementById('bulkStatus').value;
        const weekdaysOnly = document.getElementById('weekdaysOnly').checked;

        const data = { start_date: startDate, end_date: endDate, status };
        if (weekdaysOnly) {
            data.days = [1, 2, 3, 4, 5]; // Mon-Fri (JS weekday)
        }

        const response = await api.post('/api/presence/mark-bulk', data);
        if (response && response.ok) {
            const results = await response.json();
            alert(`Marked ${results.length} dates`);
            document.getElementById('bulkMarkModal').style.display = 'none';
            await Promise.all([loadPresences(), loadParkingAssignments()]);
            renderCalendar();
        } else {
            const error = await response.json();
            alert(error.detail || 'Failed to bulk mark');
        }
    });
}