// Login page logic: detects first-run setup mode and swaps the form into
// admin-creation mode. Talks to /api/auth/setup or /api/auth/login.

(async function init() {
    const errorBox = document.getElementById('errorBox');
    const errorText = document.getElementById('errorText');
    const setupNote = document.getElementById('setupNote');
    const setupTopBar = document.getElementById('setupTopBar');
    const brandIcon = document.getElementById('brandIcon');
    const title = document.getElementById('title');
    const subtitle = document.getElementById('subtitle');
    const submitBtn = document.getElementById('submitBtn');
    const submitLabel = document.getElementById('submitLabel');
    const submitIcon = document.getElementById('submitIcon');
    const form = document.getElementById('loginForm');
    const passwordInput = document.getElementById('password');

    let setupMode = false;

    function showError(msg) {
        errorText.textContent = msg;
        errorBox.style.display = 'flex';
    }
    function clearError() {
        errorText.textContent = '';
        errorBox.style.display = 'none';
    }

    try {
        const r = await fetch('/api/auth/setup-required');
        if (r.ok) {
            const data = await r.json();
            setupMode = !!data.setupRequired;
        }
    } catch (_) {
        // network error -> stay in login mode
    }

    if (setupMode) {
        title.textContent = 'Ersteinrichtung';
        subtitle.textContent = 'Willkommen beim Provisions-Tracker.';
        setupNote.style.display = 'flex';
        setupTopBar.style.display = 'block';
        submitLabel.textContent = 'Administrator anlegen';
        submitIcon.textContent = 'person_add';
        // Brand icon switches to admin look in setup mode
        brandIcon.classList.remove('bg-primary', 'text-on-primary');
        brandIcon.classList.add('bg-surface-variant', 'text-on-surface');
        brandIcon.querySelector('span').textContent = 'admin_panel_settings';
        passwordInput.setAttribute('autocomplete', 'new-password');
        passwordInput.setAttribute('minlength', '8');
    }

    form.addEventListener('submit', async (e) => {
        e.preventDefault();
        clearError();
        submitBtn.disabled = true;
        const username = document.getElementById('username').value.trim();
        const password = passwordInput.value;

        try {
            const url = setupMode ? '/api/auth/setup' : '/api/auth/login';
            const r = await fetch(url, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                credentials: 'same-origin',
                body: JSON.stringify({ username, password }),
            });
            const data = await r.json().catch(() => ({}));
            if (!r.ok) {
                showError(data.error || 'Anmeldung fehlgeschlagen');
                submitBtn.disabled = false;
                return;
            }
            window.location.href = '/';
        } catch (err) {
            showError('Netzwerkfehler: ' + err.message);
            submitBtn.disabled = false;
        }
    });
})();