const API = 'api.php';
let customers = [];
let sortField = 'yritys';
let sortAsc = true;
let currentDetailId = null;

// Elements
const loginScreen = document.getElementById('login-screen');
const dashboard = document.getElementById('dashboard');
const loginForm = document.getElementById('login-form');
const loginError = document.getElementById('login-error');
const searchInput = document.getElementById('search-input');
const tbody = document.getElementById('customer-tbody');
const noCustomers = document.getElementById('no-customers');
const customerCount = document.getElementById('customer-count');
const totalBilling = document.getElementById('total-billing');
const customerModal = document.getElementById('customer-modal');
const detailModal = document.getElementById('detail-modal');
const customerForm = document.getElementById('customer-form');

// API helpers
async function apiCall(action, method = 'GET', body = null) {
    const opts = { method, credentials: 'include' };
    if (body) {
        opts.headers = { 'Content-Type': 'application/json' };
        opts.body = JSON.stringify(body);
    }
    const res = await fetch(`${API}?action=${action}`, opts);
    const data = await res.json();
    if (!res.ok) throw new Error(data.error || 'Virhe');
    return data;
}

// Auth
async function checkAuth() {
    try {
        const data = await apiCall('check_auth');
        if (data.authenticated) {
            showDashboard();
        }
    } catch (e) { /* not logged in */ }
}

loginForm.addEventListener('submit', async (e) => {
    e.preventDefault();
    const password = document.getElementById('login-password').value;
    try {
        await apiCall('login', 'POST', { password });
        loginError.style.display = 'none';
        showDashboard();
    } catch (err) {
        loginError.textContent = err.message;
        loginError.style.display = 'block';
    }
});

document.getElementById('btn-logout').addEventListener('click', async () => {
    await apiCall('logout');
    dashboard.style.display = 'none';
    loginScreen.style.display = 'flex';
    document.getElementById('login-password').value = '';
});

async function showDashboard() {
    loginScreen.style.display = 'none';
    dashboard.style.display = 'block';
    await loadCustomers();
}

// Customers
async function loadCustomers() {
    customers = await apiCall('customers');
    renderTable();
}

function renderTable() {
    const query = searchInput.value.toLowerCase().trim();
    let filtered = customers;
    if (query) {
        filtered = customers.filter(c =>
            c.yritys.toLowerCase().includes(query) ||
            c.asennusosoite.toLowerCase().includes(query) ||
            (c.yhteyshenkilö && c.yhteyshenkilö.toLowerCase().includes(query))
        );
    }

    // Sort
    filtered.sort((a, b) => {
        let va = a[sortField] ?? '';
        let vb = b[sortField] ?? '';
        if (sortField === 'hinta') {
            va = parseFloat(va) || 0;
            vb = parseFloat(vb) || 0;
        } else {
            va = String(va).toLowerCase();
            vb = String(vb).toLowerCase();
        }
        if (va < vb) return sortAsc ? -1 : 1;
        if (va > vb) return sortAsc ? 1 : -1;
        return 0;
    });

    if (filtered.length === 0) {
        tbody.innerHTML = '';
        noCustomers.style.display = 'block';
        document.getElementById('customer-table').style.display = 'none';
    } else {
        noCustomers.style.display = 'none';
        document.getElementById('customer-table').style.display = 'table';
        tbody.innerHTML = filtered.map(c => `
            <tr data-id="${c.id}">
                <td>${esc(c.yritys)}</td>
                <td>${esc(c.asennusosoite)}</td>
                <td>${esc(c.liittymanopeus)}</td>
                <td class="price-cell">${formatPrice(c.hinta)}</td>
                <td class="actions-cell">
                    <button onclick="event.stopPropagation(); editCustomer('${c.id}')" title="Muokkaa">✏️</button>
                    <button onclick="event.stopPropagation(); deleteCustomer('${c.id}', '${esc(c.yritys)}')" title="Poista">🗑️</button>
                </td>
            </tr>
        `).join('');
    }

    updateSummary(filtered);
}

function updateSummary(filtered) {
    const count = customers.length;
    const total = customers.reduce((sum, c) => sum + (parseFloat(c.hinta) || 0), 0);
    customerCount.textContent = `${count} asiakasta`;
    totalBilling.textContent = `Laskutus yhteensä: ${formatPrice(total)}/kk`;
}

function formatPrice(val) {
    return parseFloat(val || 0).toFixed(2).replace('.', ',') + ' €';
}

function esc(str) {
    if (!str) return '';
    const div = document.createElement('div');
    div.textContent = str;
    return div.innerHTML;
}

// Search
searchInput.addEventListener('input', () => renderTable());

// Sort
document.querySelectorAll('th[data-sort]').forEach(th => {
    th.addEventListener('click', () => {
        const field = th.dataset.sort;
        if (sortField === field) {
            sortAsc = !sortAsc;
        } else {
            sortField = field;
            sortAsc = true;
        }
        renderTable();
    });
});

// Row click -> detail
tbody.addEventListener('click', (e) => {
    const row = e.target.closest('tr');
    if (!row) return;
    const id = row.dataset.id;
    showDetail(id);
});

function showDetail(id) {
    const c = customers.find(x => x.id === id);
    if (!c) return;
    currentDetailId = id;

    document.getElementById('detail-title').textContent = c.yritys;
    document.getElementById('detail-body').innerHTML = `
        <div class="detail-section">
            <h3>Liittymätiedot</h3>
            <div class="detail-grid">
                <div class="detail-item">
                    <div class="detail-label">Yritys</div>
                    <div class="detail-value">${esc(c.yritys) || '<span class="empty">-</span>'}</div>
                </div>
                <div class="detail-item">
                    <div class="detail-label">Y-tunnus</div>
                    <div class="detail-value">${esc(c.ytunnus) || '<span class="empty">-</span>'}</div>
                </div>
                <div class="detail-item">
                    <div class="detail-label">Asennusosoite</div>
                    <div class="detail-value">${esc(c.asennusosoite) || '<span class="empty">-</span>'}</div>
                </div>
                <div class="detail-item">
                    <div class="detail-label">Nopeus</div>
                    <div class="detail-value">${esc(c.liittymanopeus) || '<span class="empty">-</span>'}</div>
                </div>
                <div class="detail-item">
                    <div class="detail-label">Hinta</div>
                    <div class="detail-value price-cell">${formatPrice(c.hinta)}</div>
                </div>
            </div>
        </div>
        <div class="detail-section">
            <h3>Yhteystiedot</h3>
            <div class="detail-grid">
                <div class="detail-item">
                    <div class="detail-label">Yhteyshenkilö</div>
                    <div class="detail-value">${esc(c.yhteyshenkilö) || '<span class="empty">-</span>'}</div>
                </div>
                <div class="detail-item">
                    <div class="detail-label">Puhelin</div>
                    <div class="detail-value">${c.puhelin ? `<a href="tel:${esc(c.puhelin)}">${esc(c.puhelin)}</a>` : '<span class="empty">-</span>'}</div>
                </div>
                <div class="detail-item">
                    <div class="detail-label">Sähköposti</div>
                    <div class="detail-value">${c.sahkoposti ? `<a href="mailto:${esc(c.sahkoposti)}">${esc(c.sahkoposti)}</a>` : '<span class="empty">-</span>'}</div>
                </div>
            </div>
        </div>
        <div class="detail-section">
            <h3>Laskutustiedot</h3>
            <div class="detail-grid">
                <div class="detail-item">
                    <div class="detail-label">Laskutusosoite</div>
                    <div class="detail-value">${esc(c.laskutusosoite) || '<span class="empty">-</span>'}</div>
                </div>
                <div class="detail-item">
                    <div class="detail-label">Laskutussähköposti</div>
                    <div class="detail-value">${c.laskutussahkoposti ? `<a href="mailto:${esc(c.laskutussahkoposti)}">${esc(c.laskutussahkoposti)}</a>` : '<span class="empty">-</span>'}</div>
                </div>
            </div>
        </div>
        ${c.lisatiedot ? `
        <div class="detail-section">
            <h3>Lisätiedot</h3>
            <p style="white-space:pre-wrap; color:#555;">${esc(c.lisatiedot)}</p>
        </div>` : ''}
    `;

    detailModal.style.display = 'flex';
}

// Detail modal actions
document.getElementById('detail-close').addEventListener('click', () => detailModal.style.display = 'none');
document.getElementById('detail-cancel').addEventListener('click', () => detailModal.style.display = 'none');
document.getElementById('detail-edit').addEventListener('click', () => {
    detailModal.style.display = 'none';
    editCustomer(currentDetailId);
});
document.getElementById('detail-delete').addEventListener('click', () => {
    const c = customers.find(x => x.id === currentDetailId);
    if (c) {
        detailModal.style.display = 'none';
        deleteCustomer(currentDetailId, c.yritys);
    }
});

// Add/Edit modal
document.getElementById('btn-add').addEventListener('click', () => openCustomerForm());
document.getElementById('modal-close').addEventListener('click', () => customerModal.style.display = 'none');
document.getElementById('form-cancel').addEventListener('click', () => customerModal.style.display = 'none');

function openCustomerForm(customer = null) {
    document.getElementById('modal-title').textContent = customer ? 'Muokkaa asiakasta' : 'Lisää asiakas';
    document.getElementById('form-submit').textContent = customer ? 'Päivitä' : 'Tallenna';
    document.getElementById('form-id').value = customer ? customer.id : '';
    document.getElementById('form-yritys').value = customer ? customer.yritys : '';
    document.getElementById('form-ytunnus').value = customer ? customer.ytunnus : '';
    document.getElementById('form-asennusosoite').value = customer ? customer.asennusosoite : '';
    document.getElementById('form-liittymanopeus').value = customer ? customer.liittymanopeus : '';
    document.getElementById('form-hinta').value = customer ? customer.hinta : '';
    document.getElementById('form-yhteyshenkilo').value = customer ? customer.yhteyshenkilö : '';
    document.getElementById('form-puhelin').value = customer ? customer.puhelin : '';
    document.getElementById('form-sahkoposti').value = customer ? customer.sahkoposti : '';
    document.getElementById('form-laskutusosoite').value = customer ? customer.laskutusosoite : '';
    document.getElementById('form-laskutussahkoposti').value = customer ? customer.laskutussahkoposti : '';
    document.getElementById('form-lisatiedot').value = customer ? customer.lisatiedot : '';
    customerModal.style.display = 'flex';
    document.getElementById('form-yritys').focus();
}

function editCustomer(id) {
    const c = customers.find(x => x.id === id);
    if (c) openCustomerForm(c);
}

async function deleteCustomer(id, name) {
    if (!confirm(`Poistetaanko asiakas "${name}"?`)) return;
    await apiCall('customer_delete', 'POST', { id });
    await loadCustomers();
}

customerForm.addEventListener('submit', async (e) => {
    e.preventDefault();
    const id = document.getElementById('form-id').value;
    const data = {
        yritys: document.getElementById('form-yritys').value,
        ytunnus: document.getElementById('form-ytunnus').value,
        asennusosoite: document.getElementById('form-asennusosoite').value,
        liittymanopeus: document.getElementById('form-liittymanopeus').value,
        hinta: document.getElementById('form-hinta').value,
        yhteyshenkilö: document.getElementById('form-yhteyshenkilo').value,
        puhelin: document.getElementById('form-puhelin').value,
        sahkoposti: document.getElementById('form-sahkoposti').value,
        laskutusosoite: document.getElementById('form-laskutusosoite').value,
        laskutussahkoposti: document.getElementById('form-laskutussahkoposti').value,
        lisatiedot: document.getElementById('form-lisatiedot').value,
    };

    if (id) {
        data.id = id;
        await apiCall('customer_update', 'POST', data);
    } else {
        await apiCall('customer', 'POST', data);
    }

    customerModal.style.display = 'none';
    await loadCustomers();
});

// Close modals on backdrop click
customerModal.addEventListener('click', (e) => {
    if (e.target === customerModal) customerModal.style.display = 'none';
});
detailModal.addEventListener('click', (e) => {
    if (e.target === detailModal) detailModal.style.display = 'none';
});

// ESC to close modals
document.addEventListener('keydown', (e) => {
    if (e.key === 'Escape') {
        customerModal.style.display = 'none';
        detailModal.style.display = 'none';
    }
});

// Init
checkAuth();