// 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 System.Threading.Tasks;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

namespace Microsoft.AspNetCore.Http.Result
{
    /// <summary>
    /// An <see cref="IResult"/> that returns a Found (302), Moved Permanently (301), Temporary Redirect (307),
    /// or Permanent Redirect (308) response with a Location header.
    /// Targets a registered route.
    /// </summary>
    internal sealed partial class RedirectToRouteResult : IResult
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="RedirectToRouteResult"/> with the values
        /// provided.
        /// </summary>
        /// <param name="routeValues">The parameters for the route.</param>
        public RedirectToRouteResult(object? routeValues)
            : this(routeName: null, routeValues: routeValues)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RedirectToRouteResult"/> with the values
        /// provided.
        /// </summary>
        /// <param name="routeName">The name of the route.</param>
        /// <param name="routeValues">The parameters for the route.</param>
        public RedirectToRouteResult(
            string? routeName,
            object? routeValues)
            : this(routeName, routeValues, permanent: false)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RedirectToRouteResult"/> with the values
        /// provided.
        /// </summary>
        /// <param name="routeName">The name of the route.</param>
        /// <param name="routeValues">The parameters for the route.</param>
        /// <param name="permanent">If set to true, makes the redirect permanent (301). Otherwise a temporary redirect is used (302).</param>
        public RedirectToRouteResult(
            string? routeName,
            object? routeValues,
            bool permanent)
            : this(routeName, routeValues, permanent, fragment: null)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RedirectToRouteResult"/> with the values
        /// provided.
        /// </summary>
        /// <param name="routeName">The name of the route.</param>
        /// <param name="routeValues">The parameters for the route.</param>
        /// <param name="permanent">If set to true, makes the redirect permanent (301). Otherwise a temporary redirect is used (302).</param>
        /// <param name="preserveMethod">If set to true, make the temporary redirect (307) or permanent redirect (308) preserve the initial request method.</param>
        public RedirectToRouteResult(
            string? routeName,
            object? routeValues,
            bool permanent,
            bool preserveMethod)
            : this(routeName, routeValues, permanent, preserveMethod, fragment: null)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RedirectToRouteResult"/> with the values
        /// provided.
        /// </summary>
        /// <param name="routeName">The name of the route.</param>
        /// <param name="routeValues">The parameters for the route.</param>
        /// <param name="fragment">The fragment to add to the URL.</param>
        public RedirectToRouteResult(
            string? routeName,
            object? routeValues,
            string? fragment)
            : this(routeName, routeValues, permanent: false, fragment: fragment)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RedirectToRouteResult"/> with the values
        /// provided.
        /// </summary>
        /// <param name="routeName">The name of the route.</param>
        /// <param name="routeValues">The parameters for the route.</param>
        /// <param name="permanent">If set to true, makes the redirect permanent (301). Otherwise a temporary redirect is used (302).</param>
        /// <param name="fragment">The fragment to add to the URL.</param>
        public RedirectToRouteResult(
            string? routeName,
            object? routeValues,
            bool permanent,
            string? fragment)
            : this(routeName, routeValues, permanent, preserveMethod: false, fragment: fragment)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="RedirectToRouteResult"/> with the values
        /// provided.
        /// </summary>
        /// <param name="routeName">The name of the route.</param>
        /// <param name="routeValues">The parameters for the route.</param>
        /// <param name="permanent">If set to true, makes the redirect permanent (301). Otherwise a temporary redirect is used (302).</param>
        /// <param name="preserveMethod">If set to true, make the temporary redirect (307) or permanent redirect (308) preserve the initial request method.</param>
        /// <param name="fragment">The fragment to add to the URL.</param>
        public RedirectToRouteResult(
            string? routeName,
            object? routeValues,
            bool permanent,
            bool preserveMethod,
            string? fragment)
        {
            RouteName = routeName;
            RouteValues = routeValues == null ? null : new RouteValueDictionary(routeValues);
            PreserveMethod = preserveMethod;
            Permanent = permanent;
            Fragment = fragment;
        }

        /// <summary>
        /// Gets or sets the name of the route to use for generating the URL.
        /// </summary>
        public string? RouteName { get; }

        /// <summary>
        /// Gets or sets the route data to use for generating the URL.
        /// </summary>
        public RouteValueDictionary? RouteValues { get; }

        /// <summary>
        /// Gets or sets an indication that the redirect is permanent.
        /// </summary>
        public bool Permanent { get; }

        /// <summary>
        /// Gets or sets an indication that the redirect preserves the initial request method.
        /// </summary>
        public bool PreserveMethod { get; }

        /// <summary>
        /// Gets or sets the fragment to add to the URL.
        /// </summary>
        public string? Fragment { get; }

        /// <inheritdoc />
        public Task ExecuteAsync(HttpContext httpContext)
        {
            var linkGenerator = httpContext.RequestServices.GetRequiredService<LinkGenerator>();

            var destinationUrl = linkGenerator.GetUriByRouteValues(
                httpContext,
                RouteName,
                RouteValues,
                fragment: Fragment == null ? FragmentString.Empty : new FragmentString("#" + Fragment));
            if (string.IsNullOrEmpty(destinationUrl))
            {
                throw new InvalidOperationException("No route matches the supplied values.");
            }

            var logger = httpContext.RequestServices.GetRequiredService<ILogger<RedirectToRouteResult>>();
            Log.RedirectToRouteResultExecuting(logger, destinationUrl, RouteName);

            if (PreserveMethod)
            {
                httpContext.Response.StatusCode = Permanent ?
                    StatusCodes.Status308PermanentRedirect : StatusCodes.Status307TemporaryRedirect;
                httpContext.Response.Headers.Location = destinationUrl;
            }
            else
            {
                httpContext.Response.Redirect(destinationUrl, Permanent);
            }

            return Task.CompletedTask;
        }

        private static partial class Log
        {
            [LoggerMessage(1, LogLevel.Information,
                "Executing RedirectToRouteResult, redirecting to {Destination} from route {RouteName}.",
                EventName = "RedirectToRouteResultExecuting")]
            public static partial void RedirectToRouteResultExecuting(ILogger logger, string destination, string? routeName);
        }
    }
}
