using System.IO;
using System.Windows;
using System.Windows.Threading;
using Microsoft.Extensions.Logging;
using TeamsISO.App.ViewModels;
using TeamsISO.Engine.Controller;
using TeamsISO.Engine.Interop;
using TeamsISO.Engine.Logging;
using TeamsISO.Engine.NdiInterop;
using TeamsISO.Engine.Persistence;
using TeamsISO.Engine.Pipeline;

namespace TeamsISO.App;

public partial class App : Application
{
    private ILoggerFactory? _loggerFactory;
    private NdiInteropPInvoke? _interop;
    private IsoController? _controller;
    private MainViewModel? _viewModel;

    protected override async void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);

        try
        {
            _loggerFactory = EngineLogging.CreateConsole(LogLevel.Information);
            var logger = _loggerFactory.CreateLogger<App>();

            // ---- Preflight: NDI runtime ----
            try
            {
                _interop = new NdiInteropPInvoke(_loggerFactory.CreateLogger<NdiInteropPInvoke>());
            }
            catch (Exception ex)
            {
                MessageBox.Show(
                    "TeamsISO could not initialize the NDI runtime.\n\n" +
                    "Install the NDI Runtime from https://ndi.video/tools/ and try again.\n\n" +
                    "Details: " + ex.Message,
                    "TeamsISO — NDI runtime missing",
                    MessageBoxButton.OK,
                    MessageBoxImage.Error);
                Shutdown(2);
                return;
            }

            // ---- Engine wiring ----
            var configPath = Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
                "TeamsISO", "config.json");
            var configStore = new ConfigStore(configPath, _loggerFactory.CreateLogger<ConfigStore>());

            var probe = new NdiRuntimeProbe(_interop, NdiVersion.ExpectedRuntimeVersionPrefix);
            var scaler = new ManagedNearestNeighborFrameScaler();

            var loggerFactoryRef = _loggerFactory;
            var interopRef = _interop;
            IsoPipeline PipelineFactory(IsoPipelineConfig config)
            {
                var clock = new PeriodicTimerFrameClock(config.Settings.FramerateHz);
                return new IsoPipeline(
                    config, interopRef, scaler, clock,
                    ExponentialBackoff.Default,
                    (delay, ct) => Task.Delay(delay, ct),
                    loggerFactoryRef);
            }

            _controller = new IsoController(
                _interop, PipelineFactory, configStore, probe, _loggerFactory);

            _viewModel = new MainViewModel(_controller, Dispatcher);
            var window = new MainWindow(_viewModel);
            window.Show();
            MainWindow = window;

            await _viewModel.InitializeAsync(CancellationToken.None);
        }
        catch (Exception ex)
        {
            MessageBox.Show(
                "TeamsISO failed to start.\n\nDetails: " + ex,
                "TeamsISO — startup error",
                MessageBoxButton.OK,
                MessageBoxImage.Error);
            Shutdown(1);
        }
    }

    protected override async void OnExit(ExitEventArgs e)
    {
        try
        {
            _viewModel?.Dispose();
            if (_controller is not null)
                await _controller.DisposeAsync();
            _interop?.Dispose();
            _loggerFactory?.Dispose();
        }
        catch
        {
            // Best-effort shutdown
        }
        base.OnExit(e);
    }
}