using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Security.Claims;
using System.Security.Principal;
using System.Threading;
using System.Threading.Tasks;
using System.Web;

namespace Api.ApiExtend.Handlers
{
    /// <summary>
    ///token授权提供器
    /// 解析请求头中basic授权信息
    /// </summary>
    public class YwartTokenAuthProvider : DelegatingHandler
    {
        /// <summary>
        /// 以异步操作发送 HTTP 请求到内部管理器以发送到服务器。
        /// <param name="request">要发送到服务器的 HTTP 请求消息。</param>
        /// <param name="cancellationToken">取消操作的取消标记。</param>
        /// <returns> 返回 System.Threading.Tasks.Task`1。 表示异步操作的任务对象。</returns>
        /// </summary>
        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            Authorized(request);
            return base.SendAsync(request, cancellationToken);
        }
        private void Authorized(HttpRequestMessage request)
        {

            if (request == null || request.Headers == null || request.Headers.Authorization == null || request.Headers.Authorization.Scheme != "Token")
            {
                return;
            }

            Guid token;
            if (!Guid.TryParse(request.Headers.Authorization.Parameter, out token))
            {
                return;
            }

            var tokenModel = DbFactory.AccessToken
                .Single(m =>
                    m.Token == token.ToString()
                    && m.IsDel == false
                    && m.Timeout > DateTime.Now);
            if (tokenModel == null)
            {
                return;
            }
            var user = DbFactory.User.Single(m => m.Id == tokenModel.UserId);
            if (user == null)
            {
                return;
            }
            var userEntity = new UserEntity
            {
            };

            var identity = new GenericIdentity(userEntity.Id.ToString(), "Token");
            identity.AddClaim(new Claim(ClaimTypes.UserData, userEntity.ToJson()));
            identity.AddClaim(new Claim("UserInfo.Id", user.Id.ToString()));
            //将用户实体序列化放到声明中
            IPrincipal principal = new GenericPrincipal(identity, new string[] { });
            Thread.CurrentPrincipal = principal;
            if (HttpContext.Current != null)
            {
                HttpContext.Current.User = principal;
            }
        }
    }
}