let data = {};

function fetchData() {
    fetch('/api/data').then(r => r.json()).then(d => {
        data = d;
        renderTable();
    });
}

function saveData() {
    fetch('/api/data', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(data)
    });
}

function renderTable() {
    const container = document.getElementById('attendance-table');
    container.innerHTML = '';
    const table = document.createElement('table');
    // Header row
    const thead = document.createElement('thead');
    const headRow = document.createElement('tr');
    headRow.appendChild(document.createElement('th')).innerText = 'Date';
    data.players.forEach((name, i) => {
        const th = document.createElement('th');
        th.innerText = name;
        th.classList.add('name-col');
        headRow.appendChild(th);
    });
    // Guest column
    const guestTh = document.createElement('th');
    guestTh.innerText = data.guest || 'Guest';
    guestTh.classList.add('name-col');
    headRow.appendChild(guestTh);
    // Guest Name column (per date)
    const guestNameTh = document.createElement('th');
    guestNameTh.innerText = 'Guest Name';
    guestNameTh.classList.add('name-col');
    headRow.appendChild(guestNameTh);
    thead.appendChild(headRow);
    table.appendChild(thead);
    // Body rows
    const tbody = document.createElement('tbody');
    if (!data.guestNames) data.guestNames = {};
    // Custom order: last played date (<= today) on top, next date (> today) second, others after
    const today = new Date();
    // Parse dates as DD/MM/YY
    function parseDate(str) {
        const [d, m, y] = str.split('/').map(Number);
        // Assume 20xx for years < 100
        return new Date(2000 + y, m - 1, d);
    }
    const pastDates = data.dates.filter(date => parseDate(date) <= today);
    const futureDates = data.dates.filter(date => parseDate(date) > today);
    // Find most recent past date (last match)
    const lastMatch = pastDates.length > 0 ? pastDates.reduce((a, b) => parseDate(a) > parseDate(b) ? a : b) : null;
    // Find next match (soonest future date)
    const nextMatch = futureDates.length > 0 ? futureDates.reduce((a, b) => parseDate(a) < parseDate(b) ? a : b) : null;
    // Remaining dates
    const otherDates = data.dates.filter(date => date !== lastMatch && date !== nextMatch);
    // Sort remaining dates descending (most recent first)
    otherDates.sort((a, b) => parseDate(b) - parseDate(a));
    // Compose ordered list
    const orderedDates = [];
    if (lastMatch) orderedDates.push(lastMatch);
    if (nextMatch) orderedDates.push(nextMatch);
    orderedDates.push(...otherDates);
    orderedDates.forEach((date, rowIdx) => {
        const tr = document.createElement('tr');
        // Date cell
        const dateTd = document.createElement('td');
        dateTd.innerText = date;
        tr.appendChild(dateTd);
        // Player attendance
        [...data.players, data.guest].forEach((player, colIdx) => {
            const td = document.createElement('td');
            td.className = 'clickable name-col';
            const key = `${date}|${colIdx}`;
            if (data.attendance[key]) {
                td.innerText = 'Yes';
                td.classList.add('yes');
            } else {
                td.innerText = '';
            }
            td.onclick = () => {
                if (data.attendance[key]) {
                    delete data.attendance[key];
                } else {
                    data.attendance[key] = true;
                }
                saveData();
                renderTable();
            };
            tr.appendChild(td);
        });
        // Guest Name column (input per date)
        const guestNameTd = document.createElement('td');
        guestNameTd.classList.add('name-col');
        const guestNameInput = document.createElement('input');
        guestNameInput.type = 'text';
        guestNameInput.value = data.guestNames[date] || '';
        guestNameInput.placeholder = 'Enter guest name';
        guestNameInput.maxLength = 50;
        guestNameInput.onchange = e => {
            let value = e.target.value;
            // Allow clearing the guest name (empty string is valid)
            if (value === "") {
                delete data.guestNames[date];
                saveData();
                return;
            }
            // Only allow plain text, disallow HTML/script tags, max 50 chars
            if (/</.test(value) || />/.test(value) || /["'`\\]/.test(value)) {
                alert("Guest name cannot contain code or special characters like <, >, \", \\, or backticks.");
                guestNameInput.value = data.guestNames[date] || '';
                return;
            }
            // Only allow a-z, A-Z, 0-9, spaces, hyphens, periods
            if (!/^([a-zA-Z0-9 .-]+)$/.test(value)) {
                alert('Guest name can only contain letters, numbers, spaces, hyphens, and periods.');
                guestNameInput.value = data.guestNames[date] || '';
                return;
            }
            if (value.length > 50) {
                alert('Guest name cannot be longer than 50 characters.');
                guestNameInput.value = value.slice(0, 50);
                value = value.slice(0, 50);
            }
            data.guestNames[date] = value;
            saveData();
        };
        guestNameTd.appendChild(guestNameInput);
        tr.appendChild(guestNameTd);
        tbody.appendChild(tr);
    });
    table.appendChild(tbody);
    container.appendChild(table);
}

document.getElementById('add-date').onclick = function() {
    const date = prompt('Enter date (DD/MM/YY):');
    // Check format: DD/MM/YY
    const dateRegex = /^\d{2}\/\d{2}\/\d{2}$/;
    if (!dateRegex.test(date)) {
        alert('Date must be in DD/MM/YY format.');
        return;
    }
    if (date && !data.dates.includes(date)) {
        data.dates.push(date);
        saveData();
        renderTable();
    }
};

window.onload = fetchData;