using System;

using System.Configuration;

using System.Web.Mvc;

using Infrastructure.Exceptions;

using log4net;

namespace Infrastructure.Web.ActionFilters

{

    /// <summary>

    /// 统一处理Mvc站点异常过滤器

    /// </summary>

    public class UnifyMvcSiteHandleErrorAttribute: HandleErrorAttribute

    {

        private static readonly ILog Log = LogManager.GetLogger(typeof(UnifyMvcSiteHandleErrorAttribute));

        public readonly string BootStrapError = "~/Views/Shared/BootStrapError.cshtml";

        public MVCResultType MVCResultType { set; get; }

        public override void OnException(ExceptionContext filterContext)

        {

            if (filterContext == null || filterContext.ExceptionHandled)

                return;

            Log.Error(filterContext.Exception.GetFriendlyMessage(),filterContext.Exception);

            if (filterContext.RequestContext.HttpContext.Request.IsAjaxRequest())

            {

                HandleAjaxRequestError(filterContext);

            }

            else if(filterContext.Exception.IsTipException())

            {

                HandleRequestWithTipException(filterContext);

            }

            base.OnException(filterContext);

        }

        /// <summary>

        /// 处理Ajax请求产生的错误

        /// </summary>

        /// <param name="filterContext"></param>

        private void HandleAjaxRequestError(ExceptionContext filterContext)

        {

            var message = GetMessage(filterContext.Exception);

            filterContext.Result = BuildActionResultWithErrorMessage(filterContext, message);

            filterContext.HttpContext.Response.StatusCode = ;

            filterContext.ExceptionHandled = true;

        }

        /// <summary>

        /// 构建包含错误信息的动作结果

        /// </summary>

        /// <param name="filterContext"></param>

        /// <param name="message"></param>

        /// <returns></returns>

        private ActionResult BuildActionResultWithErrorMessage(ExceptionContext filterContext, string message)

        {

            var actionName = (string) filterContext.RouteData.Values["action"];

            if (MVCResultType == MVCResultType.PartialHtml || actionName.EndsWith("Partial"))

            {

                return new ContentResult() {Content = message};

            }

            if (MVCResultType == MVCResultType.BootStrapModal)

            {

                return new PartialViewResult()

                {

                    ViewName = BootStrapError,

                    ViewData = new ViewDataDictionary<string>(message)

                };

            }

            return new JsonResult()

            {

                Data = new {success = false, message, flag = false, msg = message},

                JsonRequestBehavior = JsonRequestBehavior.AllowGet

            };

        }

        /// <summary>

        /// 获取提示信息

        /// </summary>

        /// <param name="exception"></param>

        /// <returns></returns>

        private string GetMessage(Exception exception)

        {

            if (exception.IsTipException())

            {

                return GetTipMessage(exception);

            }

            if (ConfigurationManager.AppSettings["HideErrorToUser"] == "true")

            {

                return "Web内部异常，请联系系统管理员。";

            }

            return exception.GetFriendlyMessage();

        }

        /// <summary>

        /// 处理出现提示类异常的请求

        /// </summary>

        /// <param name="filterContext"></param>

        private void HandleRequestWithTipException(ExceptionContext filterContext)

        {

            var tipMessage = GetTipMessage(filterContext.Exception);

            filterContext.Result = new ViewResult()

            {

                ViewName = "Tip",

                MasterName = string.Empty,

                ViewData = new ViewDataDictionary<string>(tipMessage)

            };

            filterContext.ExceptionHandled = true;

            filterContext.HttpContext.Response.Clear();

            filterContext.HttpContext.Response.StatusCode = ;

            filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;

        }

        private string GetTipMessage(Exception exception)

        {

            if (exception is System.Web.HttpRequestValidationException)

            {

                return "请您输入合法字符。";

            }

            if (exception is TipInfoException)

            {

                return exception.Message;

            }

            return null;

        }

    }

    /// <summary>

    /// MVC动作结果类型

    /// </summary>

    public enum MVCResultType

    {

        /// <summary>

        /// 没有指定

        /// </summary>

        NotSpecify = ,

        /// <summary>

        /// Html片段

        /// </summary>

        PartialHtml = ,

        /// <summary>

        /// 弹出框

        /// </summary>

        BootStrapModal =

    }

}