using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
using Avalonia;
using Avalonia.Controls;
using Avalonia.Layout;
using Avalonia.Markup.Xaml;
using Avalonia.Media;
using Avalonia.Threading;
using StreamPlayer.Desktop.Models;
using StreamPlayer.Desktop.ViewModels;

namespace StreamPlayer.Desktop.Views;

public partial class MainWindow : Window
{
    private readonly CancellationTokenSource _lifetimeCts = new();
    private MainWindowViewModel? _viewModel;

    public MainWindow()
    {
        InitializeComponent();
        DataContextChanged += OnDataContextChanged;
        Opened += OnOpened;
        Closed += OnClosed;
        AttachViewModel(DataContext as MainWindowViewModel);
    }

    private void OnDataContextChanged(object? sender, EventArgs e)
    {
        AttachViewModel(DataContext as MainWindowViewModel);
    }

    private void AttachViewModel(MainWindowViewModel? newViewModel)
    {
        if (_viewModel != null)
        {
            _viewModel.ChannelRequested -= OnChannelRequested;
            _viewModel.UpdateAvailable -= OnUpdateAvailable;
            _viewModel.DeviceStatusEvaluated -= OnDeviceStatusEvaluated;
            _viewModel.ErrorRaised -= OnErrorRaised;
        }

        _viewModel = newViewModel;
        if (_viewModel != null)
        {
            _viewModel.ChannelRequested += OnChannelRequested;
            _viewModel.UpdateAvailable += OnUpdateAvailable;
            _viewModel.DeviceStatusEvaluated += OnDeviceStatusEvaluated;
            _viewModel.ErrorRaised += OnErrorRaised;
        }
    }

    private async void OnOpened(object? sender, EventArgs e)
    {
        if (_viewModel == null)
        {
            return;
        }
        try
        {
            await _viewModel.InitializeAsync(_lifetimeCts.Token);
            await _viewModel.CheckForUpdatesAsync(_lifetimeCts.Token);
            await _viewModel.VerifyDeviceAsync(_lifetimeCts.Token);
        }
        catch (OperationCanceledException)
        {
            // ignored
        }
    }

    private void OnClosed(object? sender, EventArgs e)
    {
        _lifetimeCts.Cancel();
        _lifetimeCts.Dispose();
        AttachViewModel(null);
    }

    private void OnChannelRequested(object? sender, StreamChannel channel)
    {
        if (channel == null)
        {
            return;
        }
        Dispatcher.UIThread.Post(() =>
        {
            var player = new PlayerWindow(channel);
            player.Show(this);
        });
    }

    private async void OnUpdateAvailable(object? sender, UpdateInfo info)
    {
        var mandatory = info.IsMandatory(AppVersion.VersionCode);
        var dialog = new UpdateDialog(info, mandatory);
        var result = await dialog.ShowDialog<UpdateDialogAction>(this);
        switch (result)
        {
            case UpdateDialogAction.Download:
                LaunchUrl(info.DownloadUrl);
                if (mandatory)
                {
                    Close();
                }
                break;
            case UpdateDialogAction.ViewRelease:
                LaunchUrl(string.IsNullOrWhiteSpace(info.ReleasePageUrl)
                    ? info.DownloadUrl
                    : info.ReleasePageUrl);
                if (mandatory)
                {
                    Close();
                }
                break;
            case UpdateDialogAction.Exit:
                Close();
                break;
            case UpdateDialogAction.Skip:
            default:
                break;
        }
    }

    private async void OnDeviceStatusEvaluated(object? sender, DeviceStatus status)
    {
        if (!status.IsBlocked)
        {
            return;
        }
        var dialog = new BlockedDialog(status.Reason, status.TokenPart);
        await dialog.ShowDialog(this);
        Close();
    }

    private async void OnErrorRaised(object? sender, string message)
    {
        if (string.IsNullOrWhiteSpace(message))
        {
            return;
        }
        await ShowInfoAsync("Aviso", message);
    }

    private static void LaunchUrl(string? url)
    {
        if (string.IsNullOrWhiteSpace(url))
        {
            return;
        }
        try
        {
            Process.Start(new ProcessStartInfo
            {
                FileName = url,
                UseShellExecute = true
            });
        }
        catch
        {
            // ignore
        }
    }

    private Task ShowInfoAsync(string title, string message)
    {
        var okButton = new Button
        {
            Content = "Aceptar",
            HorizontalAlignment = HorizontalAlignment.Right,
            Width = 120
        };

        var stack = new StackPanel
        {
            Spacing = 12
        };
        stack.Children.Add(new TextBlock
        {
            Text = message,
            TextWrapping = TextWrapping.Wrap
        });
        stack.Children.Add(okButton);

        var dialog = new Window
        {
            Title = title,
            Width = 420,
            SizeToContent = SizeToContent.Height,
            WindowStartupLocation = WindowStartupLocation.CenterOwner,
            CanResize = false,
            Content = new Border
            {
                Padding = new Thickness(20),
                Child = stack
            }
        };

        okButton.Click += (_, _) => dialog.Close();

        return dialog.ShowDialog(this);
    }

    private void InitializeComponent()
    {
        AvaloniaXamlLoader.Load(this);
    }
}