const { invoke } = window.__TAURI__.core;

let isConnected = false;

// Initialize
document.addEventListener('DOMContentLoaded', async () => {
    await loadServers();
    await updateStatus();
    
    // Update stats every 2 seconds when connected
    setInterval(async () => {
        if (isConnected) {
            await updateStatus();
        }
    }, 2000);
});

async function loadServers() {
    try {
        const servers = await invoke('fetch_servers');
        const select = document.getElementById('serverSelect');
        select.innerHTML = '';
        
        servers.forEach(server => {
            const option = document.createElement('option');
            option.value = server;
            option.textContent = server;
            select.appendChild(option);
        });
    } catch (error) {
        console.error('Failed to load servers:', error);
        showError('Failed to load server list');
    }
}

async function toggleConnection() {
    const button = document.getElementById('connectButton');
    const buttonText = document.getElementById('buttonText');
    
    button.disabled = true;
    buttonText.textContent = 'Connecting...';
    
    try {
        if (!isConnected) {
            const response = await invoke('connect_vpn');
            console.log('Connect response:', response);
            isConnected = true;
            updateUI(true);
        } else {
            const response = await invoke('disconnect_vpn');
            console.log('Disconnect response:', response);
            isConnected = false;
            updateUI(false);
        }
    } catch (error) {
        console.error('Connection error:', error);
        showError(error);
    } finally {
        button.disabled = false;
    }
}

function updateUI(connected) {
    const button = document.getElementById('connectButton');
    const buttonText = document.getElementById('buttonText');
    const statusIndicator = document.getElementById('statusIndicator');
    const statsGrid = document.getElementById('statsGrid');
    
    if (connected) {
        button.classList.add('connected');
        buttonText.textContent = 'Disconnect';
        statusIndicator.textContent = 'Connected';
        statusIndicator.classList.add('connected');
        statsGrid.style.display = 'grid';
    } else {
        button.classList.remove('connected');
        buttonText.textContent = 'Connect';
        statusIndicator.textContent = 'Disconnected';
        statusIndicator.classList.remove('connected');
        statsGrid.style.display = 'none';
    }
}

async function updateStatus() {
    if (!isConnected) return;
    
    try {
        const status = await invoke('get_status');
        const data = JSON.parse(status);
        
        // Update stats
        document.getElementById('uploadSpeed').textContent = formatSpeed(data.upload_speed);
        document.getElementById('downloadSpeed').textContent = formatSpeed(data.download_speed);
        document.getElementById('ping').textContent = `${data.ping} ms`;
    } catch (error) {
        console.error('Failed to update status:', error);
    }
}

function formatSpeed(bytesPerSecond) {
    if (bytesPerSecond < 1024) {
        return `${bytesPerSecond} B/s`;
    } else if (bytesPerSecond < 1024 * 1024) {
        return `${(bytesPerSecond / 1024).toFixed(1)} KB/s`;
    } else {
        return `${(bytesPerSecond / (1024 * 1024)).toFixed(2)} MB/s`;
    }
}

function showSettings() {
    alert('Settings panel coming soon!');
}

function showError(message) {
    // TODO: Better error UI
    alert(`Error: ${message}`);
}