using System;
using System.Threading.Tasks;

namespace Sharp.EventBus;

internal sealed class EventSubscription : IDisposable
{
    public Type EventType { get; }
    public int Priority { get; }
    public Func<object, Task> Handler { get; }
    public Func<object, bool>? Filter { get; }
    private readonly Action<EventSubscription> _onDispose;
    private bool _disposed;

    public EventSubscription(Type eventType, Func<object, Task> handler, Func<object, bool>? filter, int priority,
        Action<EventSubscription> onDispose)
    {
        EventType = eventType;
        Handler = handler;
        Filter = filter;
        Priority = priority;
        _onDispose = onDispose;
    }

    public bool CanHandle(object evt)
    {
        if (evt.GetType() != EventType) return false;
        return Filter == null || Filter(evt);
    }

    public void Dispose()
    {
        if (_disposed) return;
        _disposed = true;
        _onDispose(this);
    }
}