﻿namespace System.Web.Mvc {
    using System;
    using System.Diagnostics.CodeAnalysis;
    using System.Web.Mvc.Resources;

    [SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes",
        Justification = "Unsealed because type contains virtual extensibility points.")]
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
    public class RequireHttpsAttribute : FilterAttribute, IAuthorizationFilter {

        public virtual void OnAuthorization(AuthorizationContext filterContext) {
            if (filterContext == null) {
                throw new ArgumentNullException("filterContext");
            }

            if (!filterContext.HttpContext.Request.IsSecureConnection) {
                HandleNonHttpsRequest(filterContext);
            }
        }

        protected virtual void HandleNonHttpsRequest(AuthorizationContext filterContext) {
            // only redirect for GET requests, otherwise the browser might not propagate the verb and request
            // body correctly.

            if (!String.Equals(filterContext.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase)) {
                throw new InvalidOperationException(MvcResources.RequireHttpsAttribute_MustUseSsl);
            }

            // redirect to HTTPS version of page
            string url = "https://" + filterContext.HttpContext.Request.Url.Host + filterContext.HttpContext.Request.RawUrl;
            filterContext.Result = new RedirectResult(url);
        }

    }
}
