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

using System;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Infrastructure;
using Microsoft.Net.Http.Headers;

namespace Microsoft.AspNetCore.Mvc
{
    /// <summary>
    /// An <see cref="ActionResult"/> that returns an Accepted (202) response with a Location header.
    /// </summary>
    [DefaultStatusCode(DefaultStatusCode)]
    public class AcceptedResult : ObjectResult
    {
        private const int DefaultStatusCode = StatusCodes.Status202Accepted;

        /// <summary>
        /// Initializes a new instance of the <see cref="AcceptedResult"/> class with the values
        /// provided.
        /// </summary>
        public AcceptedResult()
            : base(value: null)
        {
            StatusCode = DefaultStatusCode;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="AcceptedResult"/> class with the values
        /// provided.
        /// </summary>
        /// <param name="location">The location at which the status of requested content can be monitored.</param>
        /// <param name="value">The value to format in the entity body.</param>
        public AcceptedResult(string? location, [ActionResultObjectValue] object? value)
            : base(value)
        {
            Location = location;
            StatusCode = DefaultStatusCode;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="AcceptedResult"/> class with the values
        /// provided.
        /// </summary>
        /// <param name="locationUri">The location at which the status of requested content can be monitored.</param>
        /// <param name="value">The value to format in the entity body.</param>
        public AcceptedResult(Uri locationUri, [ActionResultObjectValue] object? value)
            : base(value)
        {
            if (locationUri == null)
            {
                throw new ArgumentNullException(nameof(locationUri));
            }

            if (locationUri.IsAbsoluteUri)
            {
                Location = locationUri.AbsoluteUri;
            }
            else
            {
                Location = locationUri.GetComponents(UriComponents.SerializationInfoString, UriFormat.UriEscaped);
            }

            StatusCode = DefaultStatusCode;
        }

        /// <summary>
        /// Gets or sets the location at which the status of the requested content can be monitored.
        /// </summary>
        public string? Location { get; set; }

        /// <inheritdoc />
        public override void OnFormatting(ActionContext context)
        {
            if (context == null)
            {
                throw new ArgumentNullException(nameof(context));
            }

            base.OnFormatting(context);

            if (!string.IsNullOrEmpty(Location))
            {
                context.HttpContext.Response.Headers.Location = Location;
            }
        }
    }
}
