LearnBridgeNET-Archive/PseudoHotReload/PhrPollFile.cs

using Bridge.Html5;
using Logging;
using System;
using FetchTypeDefine;
using static Bridge.Html5.Window;

namespace PseudoHotReload
{
    public class PhrPollFile
    {
        private readonly string _stampFile;
        private readonly int _interval;

        private string _lastStamp;
        private int _timeOutId;

        public PhrPollFile(string stampFile = "phr-stamp.txt", int interval = 1000, bool start = true)
        {
            _stampFile = stampFile;
            _interval = interval;
            if (start) Start();
        }

        private void CheckStamp()
        {
            var url = _stampFile + "?" + DateTime.Now.Ticks;
            Logger.Debug($"PHR:Fetching:{url}");

            new Fetch(url, new FetchParams { Method = "GET" })
                .Then(r =>
                {
                    if (false == r.Ok) throw new Exception("Response was not ok.");
                    return r.Text();
                })
                .Then(r =>
                {
                    Logger.Debug($"PHR:Fetched:{r ?? "(null)"}");
                    if (_lastStamp == null)
                    {
                        _lastStamp = r;
                        _timeOutId = SetTimeout(CheckStamp, _interval);
                        Logger.Debug($"PHR:Stamp stored,started another timer:{_timeOutId}");
                    }
                    else if (_lastStamp != r)
                    {
                        Logger.Info("PHR:Stamp change detected, reloading...");
                        Window.Location.Reload(true);
                    }
                    else
                    {
                        _timeOutId = SetTimeout(CheckStamp, _interval);
                        Logger.Debug($"PHR:Stamp nochg,started another timer:{_timeOutId}");
                    }
                }).Catch(e =>
                {
                    _timeOutId = SetTimeout(CheckStamp, _interval);
                    Logger.Debug($"PHR:Server seem down,waiting until alive again,started another timer:{_timeOutId}");
                });
        }

        public void Start()
        {
            Stop();
            _lastStamp = null;
            _timeOutId = SetTimeout(CheckStamp, _interval);
            Logger.Debug($"PHR:Started on timer:{_timeOutId}");
        }

        public void Stop()
        {
            ClearTimeout(_timeOutId);
        }
    }
}