/* FluentGerman.ai — Auth page logic */

document.addEventListener('DOMContentLoaded', () => {
    // If already logged in, redirect
    const token = getToken();
    const user = getUser();
    if (token && user) {
        window.location.href = user.is_admin ? '/admin.html' : '/chat.html';
        return;
    }

    const form = document.getElementById('login-form');
    const errorEl = document.getElementById('login-error');

    form.addEventListener('submit', async (e) => {
        e.preventDefault();
        errorEl.classList.add('hidden');

        const username = document.getElementById('username').value.trim();
        const password = document.getElementById('password').value;

        if (!username || !password) {
            errorEl.textContent = 'Please fill in all fields.';
            errorEl.classList.remove('hidden');
            return;
        }

        try {
            const response = await fetch('/api/auth/login', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ username, password }),
            });

            if (!response.ok) {
                const err = await response.json().catch(() => ({}));
                throw new Error(err.detail || 'Login failed');
            }

            const data = await response.json();
            setToken(data.access_token);

            // Fetch user info
            const meResp = await fetch('/api/auth/me', {
                headers: { 'Authorization': `Bearer ${data.access_token}` },
            });
            const userData = await meResp.json();
            setUser(userData);

            window.location.href = userData.is_admin ? '/admin.html' : '/chat.html';
        } catch (err) {
            errorEl.textContent = err.message;
            errorEl.classList.remove('hidden');
        }
    });
});