// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using Microsoft.AspNetCore.Http;
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>
    public class AcceptedResult : ObjectResult
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="AcceptedResult"/> class with the values
        /// provided.
        /// </summary>      
        public AcceptedResult()
            : base(value: null)
        {
            StatusCode = StatusCodes.Status202Accepted;
        }

        /// <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, object value)
            : base(value)
        {
            Location = location;
            StatusCode = StatusCodes.Status202Accepted;
        }

        /// <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
        /// It is an optional paramater and may be null</param>
        /// <param name="value">The value to format in the entity body.</param>
        public AcceptedResult(Uri locationUri, 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 = StatusCodes.Status202Accepted;
        }

        /// <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[HeaderNames.Location] = Location;
            }
        }
    }
}