using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.Text;
using System.Threading;
using Cef3;

namespace Sashulin.common
{

    internal sealed class RequestResourceHandler : CefResourceHandler
    {
        private static int _requestNo;

        private byte[] responseData;
        private int pos;
        

        protected override bool ProcessRequest(CefRequest request, CefCallback callback)
        {
            var requestNo = Interlocked.Increment(ref _requestNo);
            
            var response = new StringBuilder();

            response.AppendFormat("<pre>\n");
            response.AppendFormat("Requests processed by DemoAppResourceHandler: {0}\n", requestNo);

            response.AppendFormat("Method: {0}\n", request.Method);
            response.AppendFormat("URL: {0}\n", request.Url);

            response.AppendLine();
            response.AppendLine("Headers:");
            var headers = request.GetHeaderMap();
            foreach (string key in headers)
            {
                foreach (var value in headers.GetValues(key))
                {
                    response.AppendFormat("{0}: {1}\n", key, value);
                }
            }
            response.AppendLine();

            response.AppendFormat("</pre>\n");

            responseData = Encoding.UTF8.GetBytes(response.ToString());

            callback.Continue();
            return true;
        }

        protected override void GetResponseHeaders(CefResponse response, out long responseLength, out string redirectUrl)
        {
            response.MimeType = "text/html";
            response.Status = 200;
            response.StatusText = "OK, hello from handler!";

            var headers = new NameValueCollection(StringComparer.InvariantCultureIgnoreCase);
            headers.Add("Cache-Control", "private");
            response.SetHeaderMap(headers);

            responseLength = responseData.LongLength;
            redirectUrl = null;
        }

        protected override bool ReadResponse(Stream response, int bytesToRead, out int bytesRead, CefCallback callback)
        {
            if (bytesToRead == 0 || pos >= responseData.Length)
            {
                bytesRead = 0;
                return false;
            }
            else
            {
                response.Write(responseData, pos, bytesToRead);
                pos += bytesToRead;
                bytesRead = bytesToRead;
                return true;
            }
        }

        protected override bool CanGetCookie(CefCookie cookie)
        {
            return false;
        }

        protected override bool CanSetCookie(CefCookie cookie)
        {
            return false;
        }

        protected override void Cancel()
        {
        }
    }
}