document.addEventListener('DOMContentLoaded', () => {
    // Tab switching
    document.querySelectorAll('.auth-tab').forEach(tab => {
        tab.addEventListener('click', () => {
            const target = tab.dataset.tab;
            document.querySelectorAll('.auth-tab').forEach(t => t.classList.remove('active'));
            tab.classList.add('active');
            document.querySelectorAll('.auth-form').forEach(f => f.classList.remove('active'));
            document.getElementById(`${target}-form`).classList.add('active');
        });
    });
    // Login button
    document.getElementById('login-submit').addEventListener('click', async () => {
        const username = document.getElementById('login-username').value.trim();
        const password = document.getElementById('login-password').value;
        if (!username || !password) {
            showToast('Please enter username and password', true);
            return;
        }
        try {
          const res = await fetch(`${API_BASE}/login`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ username, password }),
            credentials: 'include'
          });
          const data = await res.json();
          if (!res.ok) throw new Error(data.error || 'Login failed');
          showToast(`Welcome, ${data.username}`);
          window.location.href = 'map-page.html';
        } catch (err) {
          showToast(err.message, true);
        }
    });
    // Register button
            document.getElementById('register-submit').addEventListener('click', async () => {
                const username = document.getElementById('register-username').value.trim();
                const password = document.getElementById('register-password').value;
                if (!username || !password) {
                    showToast('Please enter username and password', true);
                    return;
                }
                if (password.length < 4) {
                    showToast('Password must be at least 4 characters', true);
                    return;
                }
                try {
                    const res = await fetch(`${API_BASE}/register`, {
                        method: 'POST',
                        headers: { 'Content-Type': 'application/json' },
                        body: JSON.stringify({ username, password }),
                        credentials: 'include'
                    });
                    const data = await res.json();
                    if (!res.ok) throw new Error(data.error || 'Registration failed');
                    showToast(`Registered as ${data.username}. Logging in...`);
                    window.location.href = 'map-page.html';
                } catch (err) {
                    showToast(err.message, true);
                }
            });
        });