using Microsoft.AspNetCore.Components;

namespace MxGateway.Server.Dashboard.Components;

public abstract class DashboardPageBase : ComponentBase, IAsyncDisposable
{
    private readonly CancellationTokenSource _disposeCancellation = new();
    private Task? _watchTask;

    [Inject]
    protected IDashboardSnapshotService SnapshotService { get; set; } = null!;

    protected DashboardSnapshot? Snapshot { get; private set; }

    protected override void OnInitialized()
    {
        _watchTask = WatchSnapshotsAsync();
    }

    public async ValueTask DisposeAsync()
    {
        await _disposeCancellation.CancelAsync().ConfigureAwait(false);
        if (_watchTask is not null)
        {
            await _watchTask.ConfigureAwait(false);
        }

        _disposeCancellation.Dispose();
        GC.SuppressFinalize(this);
    }

    private async Task WatchSnapshotsAsync()
    {
        try
        {
            await foreach (DashboardSnapshot snapshot in SnapshotService
                .WatchSnapshotsAsync(_disposeCancellation.Token)
                .ConfigureAwait(false))
            {
                Snapshot = snapshot;
                await InvokeAsync(StateHasChanged).ConfigureAwait(false);
            }
        }
        catch (OperationCanceledException) when (_disposeCancellation.IsCancellationRequested)
        {
        }
    }
}