using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Timers;

namespace PeriodicMessage
{
    class Program
    {
        static Timer _timer1 = new Timer(TimeSpan.FromMilliseconds(600).TotalMilliseconds) { Enabled = true };

        // This value should have been 1500ms
        static Timer _timer2 = new Timer(TimeSpan.FromMilliseconds(700).TotalMilliseconds) { Enabled = true };

        static Timer _timerCounter = new Timer(TimeSpan.FromMilliseconds(CounterTimeIncrementMs).TotalMilliseconds){Enabled = true};

        private static int _counter = 0;
        private static int _elapsedMs = 0;

        static Device _device = new Device();
        static Message _message = new Message();

        const int CounterTimeIncrementMs = 80;

        static void Main(string[] args)
        {
            _timer1.Elapsed += Timer1_Elapsed;
            _timer2.Elapsed += Timer2_Elapsed;
            _timerCounter.Elapsed += TimerCounter_Elapsed;

            Console.WriteLine("Press enter to terminate");
            Console.ReadLine();
        }

        private static void Timer1_Elapsed(object sender, ElapsedEventArgs e) => _device.SendMessage(" I", _message.GetNextMessage(),_counter);
        private static void Timer2_Elapsed(object sender, ElapsedEventArgs e) => _device.SendMessage("II", _message.GetNextMessage(),_counter);
        private static void TimerCounter_Elapsed(object sender, ElapsedEventArgs e)
        {
            _elapsedMs += CounterTimeIncrementMs;

            if (_elapsedMs > 150 && _elapsedMs< 850) // Even though the chart shows that the bits seem to shift every 80ms, the first 80ms there is no change.
            {
                if (_counter == 0) // Give it a bit for the second hit
                    _counter = 1;
                else if (_elapsedMs != 480) // From the chart we should be bit shifting by one every 80ms, apart from 480
                    _counter <<= 1;
            }
            else if (_elapsedMs >= 1000) // Roll Over
                _counter = _elapsedMs = 0;

        }
    }

    class Device
    {
        public void SendMessage(string prefix, IEnumerable<byte> message, int counter)
        {
            //First, Second, <Counter>, Second to last, Last
            var first = message.First();
            var second = message.Skip(1).First();
            var thrid = message.Skip(message.Count() - 2).First();
            var fourth = message.Last();
            Console.WriteLine($"Sending {prefix} message: {first:x2}-{second:x2}-{counter:x2}-{thrid:x2}-{fourth:x2}");
        }
    }

    class Message
    {
        byte[] _randomMessage = new byte[4];
        Random _random = new Random();

        public IEnumerable<byte> GetNextMessage()
        {
            _random.NextBytes(_randomMessage);
            var result = new List<byte>();

            for (int i = 0; i < _randomMessage.Length; i++)
                result.Add(_randomMessage[i]);

            return result;
        }
    }
}