using Avalonia;
using Avalonia.Controls;
using Avalonia.Layout;
using Avalonia.Media;
using Avalonia.Threading;
using Nonemm.App.Configuration;
using Nonemm.Core;
using Nonemm.Session;

namespace Nonemm.App.Windows;

/// Every recording a phone message names, whether it is there, and a button to
/// play it or record it again. The list is read out of the phone function key
/// file and the QTC window's four, so it says what this station would actually
/// play rather than what some other station's file names.
///
/// The operator box picks whose folder is looked in. It starts at whoever is
/// at the microphone, so an operator taking over records his own voice into
/// his own folder without changing anything.
public sealed partial class VoiceKeyerWindow : RefreshableWindow
{
    private readonly AppSession session;

    public VoiceKeyerWindow(AppSession session)
    {
        this.session = session;
        InitializeComponent();
        PlayBox.Text = session.Settings.VoicePlayCommand;
        RecordBox.Text = session.Settings.VoiceRecordCommand;
        PttBox.IsChecked = session.Settings.VoiceKeysPtt;
        PlayBox.LostFocus += (_, _) => SaveCommands();
        RecordBox.LostFocus += (_, _) => SaveCommands();
        PttBox.IsCheckedChanged += (_, _) => SaveCommands();
        OperatorBox.SelectionChanged += (_, _) => Refresh();
        FillOperators();
        Refresh();
    }

    public override void Refresh()
    {
        Lines.Children.Clear();
        Lines.RowDefinitions.Clear();
        string who = OperatorBox.SelectedItem as string ?? "";
        FolderText.Text = session.Recordings.PathOf(who);
        IReadOnlyList<VoiceLine> lines = VoiceLines.For(
            Messages.For(ModeCategory.Phone, "", session.Settings.PhoneMessageFile),
            who);
        int at = 0;
        Header(at++);
        foreach (VoiceLine line in lines)
        {
            Row(line, at++);
        }
        int missing = lines.Count(line => !session.Recordings.Has(line.Name));
        Status(lines.Count == 0
            ? "no phone message names a recording — Config ▸ Change SSB Function Key Definitions"
            : $"{lines.Count - missing} of {lines.Count} recorded");
    }

    /// The operators the settings know about, the station callsign last: a
    /// single-operator station keeps its recordings in the folder named after
    /// the station, which is what the empty operator means.
    private void FillOperators()
    {
        List<string> names = [.. session.Settings.Operators
            .Select(o => o.Callsign.Trim().ToUpperInvariant())
            .Where(name => name.Length > 0)];
        string station = session.Settings.Station.Callsign.Trim().ToUpperInvariant();
        if (station.Length > 0 && !names.Contains(station))
        {
            names.Add(station);
        }
        names.Add("");
        OperatorBox.ItemsSource = names;
        string current = session.Settings.CurrentOperator.Trim().ToUpperInvariant();
        OperatorBox.SelectedItem = names.Contains(current) ? current : names[0];
    }

    private void Header(int row)
    {
        Lines.RowDefinitions.Add(new RowDefinition(GridLength.Auto));
        Put(Label("Where", header: true), row, 0);
        Put(Label("Says", header: true), row, 1);
        Put(Label("File", header: true), row, 2);
        Put(Label("Recorded", header: true), row, 3);
    }

    private void Row(VoiceLine line, int row)
    {
        Lines.RowDefinitions.Add(new RowDefinition(GridLength.Auto));
        bool has = session.Recordings.Has(line.Name);
        Put(Label(line.Where), row, 0);
        Put(Label(line.Says), row, 1);
        Put(Label(FileName(line)), row, 2);
        Put(
            new TextBlock
            {
                Text = has ? "yes" : "no",
                Foreground = new SolidColorBrush(has ? Color.Parse("#27AE60") : Color.Parse("#C0392B")),
                VerticalAlignment = VerticalAlignment.Center,
                Margin = new Thickness(0, 2, 8, 2),
            },
            row,
            3);
        Put(Buttons(line, has), row, 4);
    }

    private Control Buttons(VoiceLine line, bool has)
    {
        Button play = new() { Content = "Play", IsEnabled = has, Margin = new Thickness(0, 1, 4, 1) };
        play.Click += (_, _) => _ = PlayAsync(line);
        bool isRecording = session.Recording == line.Name;
        Button record = new()
        {
            Content = isRecording ? "Stop" : has ? "Record again" : "Record",
            // one microphone, so the other rows wait for this one to finish.
            // The entry window's Ctrl+Shift+F keys record into the same one,
            // which is why the state is the session's rather than this
            // window's
            IsEnabled = session.Recording is null || isRecording,
            Margin = new Thickness(0, 1, 0, 1),
        };
        record.Click += (_, _) => _ = RecordAsync(line);
        return new StackPanel
        {
            Orientation = Orientation.Horizontal,
            Children = { play, record },
        };
    }

    private async Task PlayAsync(VoiceLine line)
    {
        Status($"playing {line.Name}");
        try
        {
            await session.Sound.PlayAsync(session.Recordings.PathOf(line.Name));
            Status($"played {line.Name}");
        }
        catch (Exception failure) when (failure is InvalidOperationException or IOException)
        {
            Status(failure.Message);
        }
    }

    /// Starts recording, or stops the recording that is running. What was
    /// recorded goes over the old file only when the recorder has finished
    /// with it, so a stop that fails leaves the old recording playable.
    private async Task RecordAsync(VoiceLine line)
    {
        if (session.Recording is not null)
        {
            session.StopRecording();
            return;
        }
        if (!session.Sound.CanRecord)
        {
            Status("there is no recorder — name one in the box below");
            return;
        }
        Status($"recording {line.Name} — press Stop when you have finished speaking");
        string outcome = await session.RecordAsync(line.Name);
        // the redraw comes first: it writes the tally over the status line, and
        // what happened to this recording is worth more than the tally
        Refresh();
        Status(outcome);
    }

    private void SaveCommands()
    {
        Settings settings = session.Settings with
        {
            VoicePlayCommand = (PlayBox.Text ?? "").Trim(),
            VoiceRecordCommand = (RecordBox.Text ?? "").Trim(),
            VoiceKeysPtt = PttBox.IsChecked == true,
        };
        if (settings == session.Settings)
        {
            return;
        }
        session.Save(settings);
        // the keyer holds the commands, so it is built again with the new ones
        session.ApplyKeyerSettings();
    }

    /// The file without the folder in front of it: the folder is the operator
    /// picked at the top and is the same for every row that has one.
    private static string FileName(VoiceLine line) =>
        line.Name[(line.Name.LastIndexOfAny(['\\', '/']) + 1)..];

    private void Status(string text) => StatusText.Text = text;

    private static TextBlock Label(string text, bool header = false) =>
        new()
        {
            Text = text,
            FontSize = header ? 11 : 12,
            Opacity = header ? 0.7 : 1,
            VerticalAlignment = VerticalAlignment.Center,
            Margin = new Thickness(0, 2, 8, 2),
        };

    private void Put(Control control, int row, int column)
    {
        Grid.SetRow(control, row);
        Grid.SetColumn(control, column);
        Lines.Children.Add(control);
    }
}