using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace Site.Filters
{
    public enum AuthorizeScheme
    {
        Backend = 0,
        Frontend = 1
    }

    // 自定义用户认证过滤器
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
    public class CustomAuthorization : AuthorizeAttribute // Authorize [ˈɔ:θəraɪz] vt. 授权，批准，委托
    {
        public AuthorizeScheme Scheme { get; set; }

        public CustomAuthorization() : base()
        {
            Scheme = AuthorizeScheme.Frontend;
        }

        public override void OnAuthorization(AuthorizationContext filterContext)
        {
            //解决自定义AuthorizeAttribute实现授权管理，AllowAnonymous属性失效导致无法匿名访问控制器的问题
            bool flag = filterContext.ActionDescriptor.IsDefined(typeof(AllowAnonymousAttribute), true) ||
                filterContext.ActionDescriptor.ControllerDescriptor.IsDefined(typeof(AllowAnonymousAttribute), true);
            if (flag)
            {
                return;
            }

            if (!filterContext.HttpContext.User.Identity.IsAuthenticated)
            {
                string returnUrl = filterContext.RequestContext.HttpContext.Request.Url.ToString();

                string host = HttpContext.Current.Request.Url.Host;
                int port = HttpContext.Current.Request.Url.Port;
                if (Scheme == AuthorizeScheme.Frontend)
                {
                    filterContext.HttpContext.Response.Redirect($"http://{host}:{port}/Login?return_url={returnUrl}");
                }
                else if (Scheme == AuthorizeScheme.Backend)
                {
                    filterContext.HttpContext.Response.Redirect($"http://{host}:{port}/Admin/Home/Login?return_url={returnUrl}");
                }
            }
            base.OnAuthorization(filterContext);
        }
    }
}