using SharpPcap.LibPcap;

namespace gatuna_client;

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

    public MainForm()
    {
        Text = "gatuna";
        Width = 520;
        Height = 380;
        FormBorderStyle = FormBorderStyle.FixedSingle;
        MaximizeBox = false;
        MinimizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;
        InitializeComponents();

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

        foreach (var d in TunnelLink.ListDevices())
            _deviceBox.Items.Add($"{d.Name} — {d.Interface?.FriendlyName ?? d.Interface?.Description}");
        if (_deviceBox.Items.Count > 0)
            _deviceBox.SelectedIndex = 0;
    }

    void InitializeComponents()
    {
        Controls.Add(new Label { Text = "Adapter:", Left = 12, Top = 12, AutoSize = true });

        _deviceBox.Left = 70; _deviceBox.Top = 9;
        _deviceBox.Width = 330; _deviceBox.DropDownStyle = ComboBoxStyle.DropDownList;
        Controls.Add(_deviceBox);

        _discoverBtn.Text = "Discover";
        _discoverBtn.Left = 410; _discoverBtn.Top = 8; _discoverBtn.Width = 80;
        _discoverBtn.Click += OnDiscover;
        Controls.Add(_discoverBtn);

        _listView.Left = 12; _listView.Top = 40;
        _listView.Width = 478; _listView.Height = 250;
        _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 = 12; _statusLabel.Top = 304;
        _statusLabel.Width = 478; _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();
        _statusLabel.Text = "discovering...";
    }

    void PopulateList(UpstreamEntry[] entries)
    {
        _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 OnFormClosing(FormClosingEventArgs e)
    {
        if (e.CloseReason == CloseReason.UserClosing)
        {
            e.Cancel = true;
            Hide();
            return;
        }
        base.OnFormClosing(e);
    }

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