using DotBased.Logging;
using Manager.App.Extensions;
using Manager.App.Services;
using Microsoft.AspNetCore.Components;

namespace Manager.App.Components.Pages;

public partial class Services : ComponentBase
{
    private const int VisibleEventCapacity = 500;
    private string _searchText = "";
    private List<ExtendedBackgroundService> _backgroundServices = [];
    
    private List<ServiceEvent> _serviceEvents = [];
    private CancellationTokenSource _cts = new();

    protected override void OnInitialized()
    {
        _backgroundServices = ServiceManager.GetServices();
        _ = Task.Run(() => ReadEventStreamsAsync(_cts.Token));
    }
    
    private Func<ExtendedBackgroundService, bool> QuickFilter
        => x => string.IsNullOrWhiteSpace(_searchText) || $"{x.Name} {x.Description} {x.State} {x.ExecuteInterval}".Contains(_searchText);

    private async Task ReadEventStreamsAsync(CancellationToken token)
    {
        if (_backgroundServices.Count == 0)
        {
            return;
        }
        
        var totalToGet = VisibleEventCapacity / _backgroundServices.Count;
        _serviceEvents.AddRange(_backgroundServices.SelectMany(x => x.ProgressEvents.Items.TakeLast(totalToGet)));

        var asyncEnumerators = _backgroundServices.Select(x => x.ProgressEvents.GetStreamAsync());
        await foreach (var serviceEvent in AsyncEnumerableExtensions.Merge(asyncEnumerators, token))
        {
            if (!_serviceEvents.Contains(serviceEvent))
            {
                _serviceEvents.Add(serviceEvent);
            }
            
            if (_serviceEvents.Count > VisibleEventCapacity)
            {
                _serviceEvents.RemoveAt(0);
            }

            await InvokeAsync(StateHasChanged);
        }
    }
    
    private string GetLogClass(ServiceEvent serviceEvent) =>
        serviceEvent.Severity switch
        {
            LogSeverity.Info => "log-info",
            LogSeverity.Warning => "log-warning",
            LogSeverity.Error => "log-error",
            _ => "log-info"
        };
    
    public void Dispose()
    {
        _cts.Cancel();
        _cts.Dispose();
    }
}