using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Platform.Storage;
using Nonemm.App.Configuration;

namespace Nonemm.App.Dialogs;

/// What the operator dialog closed with: the operator to change to, or the one
/// to drop from the list.
public sealed record OperatorChoice(StoredOperator Operator, bool IsRemoval);

/// N1MM's Ctrl+O: who is at the radio now. It closes with the operator to
/// change to, or with null when nothing is to change. An operator whose
/// callsign is not in the list yet is made by typing it.
public sealed partial class OperatorDialog : Window
{
    private readonly IReadOnlyList<StoredOperator> known;

    public OperatorDialog(Settings settings)
    {
        known = settings.Operators;
        InitializeComponent();
        KnownBox.ItemsSource = known.Select(o => o.Callsign).ToList();
        CallBox.Text = settings.CurrentOperator;
        WavBox.Text = Find(settings.CurrentOperator)?.WavPath ?? "";
        ShowWhatIsKept();
        // the callsign is all most operators type here, so the cursor starts in
        // it and Enter closes the dialog
        Opened += (_, _) =>
        {
            CallBox.Focus();
            // the operator taking over types his own callsign over the one
            // leaving rather than clearing the box first
            CallBox.SelectAll();
        };
    }

    /// The operator as the dialog leaves him: the callsign typed, keeping
    /// whatever was stored for him before.
    private StoredOperator Picked
    {
        get
        {
            string callsign = (CallBox.Text ?? "").Trim().ToUpperInvariant();
            StoredOperator stored = Find(callsign) ?? new StoredOperator();
            return stored with { Callsign = callsign, WavPath = (WavBox.Text ?? "").Trim() };
        }
    }

    private StoredOperator? Find(string callsign) =>
        known.FirstOrDefault(o => string.Equals(o.Callsign, callsign.Trim(), StringComparison.OrdinalIgnoreCase));

    private void OnPickedKnown(object? sender, SelectionChangedEventArgs e)
    {
        if (KnownBox.SelectedItem is not string callsign)
        {
            return;
        }
        CallBox.Text = callsign;
        WavBox.Text = Find(callsign)?.WavPath ?? "";
        ShowWhatIsKept();
    }

    private void ShowWhatIsKept()
    {
        StoredOperator? stored = Find(CallBox.Text ?? "");
        AboutText.Text = stored is null
            ? "A new operator: the windows and colours on the screen now become his."
            : $"{stored.Windows.Count} window positions kept"
              + (stored.Theme.Length > 0 ? $", {stored.Theme} colours" : ", the colours as they are");
    }

    private async void OnBrowseWav(object? sender, RoutedEventArgs e)
    {
        IReadOnlyList<IStorageFolder> picked = await StorageProvider.OpenFolderPickerAsync(
            new FolderPickerOpenOptions { Title = "The operator's recordings", AllowMultiple = false });
        if (picked.Count > 0)
        {
            WavBox.Text = picked[0].Path.LocalPath;
        }
    }

    private void OnOk(object? sender, RoutedEventArgs e)
    {
        if (Picked.Callsign.Length > 0)
        {
            Close(new OperatorChoice(Picked, IsRemoval: false));
        }
    }

    /// Drops the operator from the list. The contacts he logged keep his
    /// callsign: they are in the log, not in the settings.
    private void OnRemove(object? sender, RoutedEventArgs e)
    {
        if (Find(CallBox.Text ?? "") is { } stored)
        {
            Close(new OperatorChoice(stored, IsRemoval: true));
        }
    }

    private void OnCancel(object? sender, RoutedEventArgs e) => Close(null);
}