using System;
using System.Web;
using VAR.Json;

namespace VAR.WebForms.Common.Code
{
    public static class ExtensionMethods
    {
        #region HttpContext

        public static string GetRequestParm(this HttpContext context, string parm)
        {
            foreach (string key in context.Request.Params.AllKeys)
            {
                if (string.IsNullOrEmpty(key) == false && key.EndsWith(parm))
                {
                    return context.Request.Params[key];
                }
            }
            return string.Empty;
        }

        public static void ResponseObject(this HttpContext context, object obj)
        {
            var jsonWritter = new JsonWriter();
            context.Response.ContentType = "text/json";
            string strObject = jsonWritter.Write(obj);
            context.Response.Write(strObject);
        }

        public static void PrepareCacheableResponse(this HttpResponse response)
        {
            const int secondsInDay = 86400;
            response.ExpiresAbsolute = DateTime.Now.AddSeconds(secondsInDay);
            response.Expires = secondsInDay;
            response.Cache.SetCacheability(HttpCacheability.Public);
            response.Cache.SetMaxAge(new TimeSpan(0, 0, secondsInDay));
        }

        public static void PrepareUncacheableResponse(this HttpResponse response)
        {
            response.ExpiresAbsolute = DateTime.Now.AddDays(-2d);
            response.Expires = -1500;
            response.AddHeader("Cache-Control", "max-age=0, no-cache, no-store");
            response.BufferOutput = true;
        }

        #endregion HttpContext
    }
}