using SharpPcap.LibPcap;

namespace gatuna_client;

public partial class MainForm : Form
{
    readonly SessionManager _sessions = new();
    readonly ComboBox _deviceBox = new();
    readonly Button _discoverBtn = new();
    readonly Button _testBtn = new();
    readonly Label _serverLabel = new();
    readonly Label _pingStatsLabel = new();
    readonly ListView _listView = new();
    readonly Label _statusLabel = new();
    TunnelLink? _link;
    PingTest? _pingTest;

    public MainForm()
    {
        Text = "gatuna";
        Width = 520;
        Height = 420;
        FormBorderStyle = FormBorderStyle.FixedSingle;
        MaximizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;
        Icon = SystemIcons.GetStockIcon(StockIconId.NetworkConnect, 32);
        InitializeComponents();

        _sessions.Log += msg => this.Invoke(() => _statusLabel.Text = msg);
        _sessions.ManifestReceived += (hostname, mac, entries) =>
            this.Invoke(() => PopulateList(hostname, mac, entries));

        foreach (var d in TunnelLink.ListDevices())
        {
            var friendly = d.Interface?.FriendlyName ?? "";
            var desc = d.Interface?.Description ?? "";
            var mac = d.MacAddress?.GetAddressBytes();
            var macStr = mac != null
                ? string.Join(":", mac.Select(b => b.ToString("X2")))
                : "??-??-??-??-??-??";
            _deviceBox.Items.Add($"{friendly} — {desc} — {macStr}");
        }
        if (_deviceBox.Items.Count > 0)
            _deviceBox.SelectedIndex = 0;
    }

    void InitializeComponents()
    {
        const int pad = 12;

        _deviceBox.Left = pad; _deviceBox.Top = 12;
        _deviceBox.Width = ClientSize.Width - pad * 2;
        _deviceBox.DropDownStyle = ComboBoxStyle.DropDownList;
        Controls.Add(_deviceBox);

        _discoverBtn.Text = "Discover";
        _discoverBtn.Left = pad; _discoverBtn.Top = _deviceBox.Bottom + 8;
        _discoverBtn.Width = 80;
        _discoverBtn.Click += OnDiscover;
        Controls.Add(_discoverBtn);

        _testBtn.Text = "Test";
        _testBtn.Left = _discoverBtn.Right + 8; _testBtn.Top = _discoverBtn.Top;
        _testBtn.Width = 60;
        _testBtn.Click += OnTest;
        Controls.Add(_testBtn);

        _serverLabel.Left = pad; _serverLabel.Top = _discoverBtn.Bottom + 8;
        _serverLabel.Width = ClientSize.Width - pad * 2;
        _serverLabel.AutoEllipsis = true;
        _serverLabel.Text = "Server: not connected";
        Controls.Add(_serverLabel);

        _pingStatsLabel.Left = pad; _pingStatsLabel.Top = _serverLabel.Bottom + 4;
        _pingStatsLabel.Width = ClientSize.Width - pad * 2;
        _pingStatsLabel.AutoEllipsis = true;
        _pingStatsLabel.Text = "";
        Controls.Add(_pingStatsLabel);

        _listView.Left = pad; _listView.Top = _pingStatsLabel.Bottom + 8;
        _listView.Width = ClientSize.Width - pad * 2;
        _listView.Height = 180;
        _listView.View = View.Details;
        _listView.FullRowSelect = true;
        _listView.CheckBoxes = true;
        _listView.Columns.Add("ID", 36);
        _listView.Columns.Add("Proto", 50);
        _listView.Columns.Add("Port", 56);
        _listView.Columns.Add("Label", 160);
        _listView.Columns.Add("Mirror", 70);
        _listView.ItemChecked += OnItemChecked;
        Controls.Add(_listView);

        _statusLabel.Left = pad; _statusLabel.Top = _listView.Bottom + 8;
        _statusLabel.Width = ClientSize.Width - pad * 2;
        _statusLabel.AutoEllipsis = true;
        Controls.Add(_statusLabel);
    }

    void OnDiscover(object? s, EventArgs e)
    {
        if (_deviceBox.SelectedIndex < 0)
        {
            MessageBox.Show("Select a network adapter first.");
            return;
        }

        if (_link != null)
        {
            _sessions.StopAll();
            _sessions.DetachLink();
            _link.Dispose();
        }

        var devices = TunnelLink.ListDevices();
        var device = devices[_deviceBox.SelectedIndex];
        _link = new TunnelLink(device);
        _link.Log += msg => this.Invoke(() => _statusLabel.Text = msg);
        _sessions.AttachLink(_link);
        _link.Open();
        _sessions.Discover();
        _serverLabel.Text = "Server: discovering...";
        _statusLabel.Text = "discovering...";
    }

    void OnTest(object? s, EventArgs e)
    {
        if (_pingTest != null && _pingTest.Running)
        {
            _sessions.StopPing();
            _pingTest = null;
            _testBtn.Text = "Test";
            return;
        }

        _pingTest = _sessions.StartPing();
        if (_pingTest == null)
        {
            MessageBox.Show("Discover a server first.");
            return;
        }
        _pingTest.StatsUpdated += stats => this.Invoke(() =>
        {
            _pingStatsLabel.Text =
                $"sent: {stats.Sent}  recv: {stats.Received}  " +
                $"loss: {stats.LossPct:F1}%  " +
                $"avg: {stats.AvgLatencyMs:F1}ms  " +
                $"jitter: {stats.JitterMs:F1}ms";
        });
        _testBtn.Text = "Stop";
        _pingStatsLabel.Text = "pinging...";
    }

    void PopulateList(string hostname, byte[] mac, UpstreamEntry[] entries)
    {
        var macStr = string.Join(":", mac.Select(b => b.ToString("X2")));
        _serverLabel.Text = $"Server: {hostname} — {macStr}";

        _listView.BeginUpdate();
        _listView.Items.Clear();
        foreach (var up in entries)
        {
            var item = new ListViewItem(up.Id.ToString());
            item.SubItems.Add(up.ProtoName);
            item.SubItems.Add(up.Port.ToString());
            item.SubItems.Add(up.Label ?? "");
            item.SubItems.Add("");
            item.Tag = up;
            _listView.Items.Add(item);
        }
        _listView.EndUpdate();
    }

    void OnItemChecked(object? s, ItemCheckedEventArgs e)
    {
        if (e.Item.Tag is not UpstreamEntry up) return;
        if (e.Item.Checked)
        {
            var port = _sessions.StartListener(up);
            e.Item.SubItems[4].Text = port.ToString();
        }
        else
        {
            if (int.TryParse(e.Item.SubItems[4].Text, out var port) && port > 0)
            {
                _sessions.StopListener(port);
                e.Item.SubItems[4].Text = "";
            }
        }
    }

    protected override void OnResize(EventArgs e)
    {
        base.OnResize(e);
        if (WindowState == FormWindowState.Minimized)
        {
            Hide();
            WindowState = FormWindowState.Normal;
        }
    }

    protected override void OnFormClosing(FormClosingEventArgs e)
    {
        Shutdown();
        base.OnFormClosing(e);
    }

    public void Shutdown()
    {
        _sessions.Dispose();
        _link?.Dispose();
    }
}