using Connected;
using Connected.Notifications.Events;

namespace Common.Documents;
public abstract class DocumentListener<TArgs, TDocument, TPrimaryKey> : EventListener<TArgs>
	where TArgs : IDto
	where TDocument : IDocument<TPrimaryKey>
	where TPrimaryKey : notnull
{
	public DocumentListener(IDocumentLocker<TDocument, TPrimaryKey> locker)
	{
		Locker = locker;
	}

	private IDocumentLocker<TDocument, TPrimaryKey> Locker { get; }
	protected abstract TDocument Document { get; }
	protected override async Task OnInvoke()
	{
		await OnPreparing();

		if (Document is null)
			return;

		Locker.Expired += async (s, e) => { await OnException(new TimeoutException()); };

		try
		{
			await Locker.Lock(Document);
			await OnInvoking();
			await Locker.Unlock();
		}
		catch (Exception ex)
		{
			await Locker.Unlock();
			await OnException(ex);
		}
	}

	protected virtual async Task<bool> OnPreparing()
	{
		await Task.CompletedTask;

		return false;
	}

	protected virtual async Task OnInvoking()
	{
		await Task.CompletedTask;
	}

	protected virtual async Task OnException(Exception ex)
	{
		await Task.CompletedTask;
	}

	protected override void OnDisposing()
	{
		Locker.Dispose();
	}
}