// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Threading.Tasks;

namespace Microsoft.AspNetCore.Mvc.Filters
{
    /// <summary>
    /// A filter that asynchronously surrounds execution of a page handler method. This filter is executed only when
    /// decorated on a handler's type and not on individual handler methods.
    /// </summary>
    public interface IAsyncPageFilter : IFilterMetadata
    {
        /// <summary>
        /// Called asynchronously after the handler method has been selected, but before model binding occurs.
        /// </summary>
        /// <param name="context">The <see cref="PageHandlerSelectedContext"/>.</param>
        /// <returns>A <see cref="Task"/> that on completion indicates the filter has executed.</returns>
        Task OnPageHandlerSelectionAsync(PageHandlerSelectedContext context);

        /// <summary>
        /// Called asynchronously before the handler method is invoked, after model binding is complete.
        /// </summary>
        /// <param name="context">The <see cref="PageHandlerExecutingContext"/>.</param>
        /// <param name="next">
        /// The <see cref="PageHandlerExecutionDelegate"/>. Invoked to execute the next page filter or the handler method itself.
        /// </param>
        /// <returns>A <see cref="Task"/> that on completion indicates the filter has executed.</returns>
        Task OnPageHandlerExecutionAsync(PageHandlerExecutingContext context, PageHandlerExecutionDelegate next);
    }
}
