using System;
using System.IO;
using System.Net;
using System.Text;
using System.Threading;

namespace ConsoleApp4
{
    class Program
    {
        static event EventHandler<string> SearchResponse;

        static void Main(string[] args)
        {
            SearchResponse += Program_SearchResponse;
            SearchAsync("spongebob squarepants");


            Console.Read();
        }

        private static void Program_SearchResponse(object sender, string e)
        {
            Console.WriteLine("Got a search response of " + e.Length + " characters.");
        }

        static void SearchAsync(string value)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://www.google.com/?q=" + Uri.EscapeDataString(value));
            request.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36";
            request.Proxy = default(WebProxy);
            request.Headers.Set("DNT", "1");
            request.Referer = "https://www.google.com/";
            request.BeginGetResponse(new AsyncCallback(ResponseCallback), request);
        }

        static void ResponseCallback(IAsyncResult ar)
        {
            if (!ar.IsCompleted)
                ar.AsyncWaitHandle.WaitOne(1000);

            HttpWebRequest request = (HttpWebRequest)ar.AsyncState;
            HttpWebResponse response;
            try
            {
                response = (HttpWebResponse)request.EndGetResponse(ar);
            }
            catch (WebException e)
            {
                response = (HttpWebResponse)e.Response;
            }

            if (response == null)
                return;

            if (response.StatusCode != HttpStatusCode.OK)
                return;

            ThreadPool.QueueUserWorkItem((object o) => HandleResponse(response), null);
        }

        static void HandleResponse(HttpWebResponse response)
        {
            using (Stream stream = response.GetResponseStream())
            using (StreamReader reader = new StreamReader(stream, Encoding.UTF8, true))
            {
                string html = reader.ReadToEnd();
                SearchResponse(null, html);
            }
        }
    }
}