using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

namespace ZeroLevel.Services.Async
{
	public interface IAsyncBatchCollection<T> : IReadOnlyCollection<IReadOnlyList<T>>
	{
		int BatchSize { get; }

		void Add(T item);
		void Flush();
		ValueTask<IReadOnlyList<T>> TakeAsync(CancellationToken cancellationToken);
	}

	public static class AsyncBatchCollectionExtensions
	{
		public static ValueTask<IReadOnlyList<T>> TakeAsync<T>(this IAsyncBatchCollection<T> collection) => collection.TakeAsync(CancellationToken.None);
		public static TimerAsyncBatchQueue<T> WithFlushEvery<T>(this IAsyncBatchCollection<T> collection, TimeSpan flushPeriod) => new TimerAsyncBatchQueue<T>(collection, flushPeriod);
	}
}