using System;
using System.Threading;
using System.Threading.Tasks;
using Vinno.IUS.Common.Log;
using Vinno.IUS.Common.Network.Leaf;

namespace Vinno.vCloud.Common.FIS
{
    internal class ConnectionChecker
    {
        private readonly ClientLeaf _leaf;

        private readonly ManualResetEvent _waitEvent = new ManualResetEvent(false);

        /// <summary>
        ///get or set connection check cycle
        /// </summary>
        private readonly int _connectionCheckCycle;

        public event EventHandler Offlined;

        public ConnectionChecker(ClientLeaf clientLeaf, int connectionCheckCycle)
        {
            _leaf = clientLeaf;
            _connectionCheckCycle = connectionCheckCycle;
        }

        /// <summary>
        /// Start the Heartrate to keep the session available.
        /// </summary>
        public void Start()
        {
            Task.Run(() =>
            {
                while (!_waitEvent.WaitOne(TimeSpan.FromSeconds(_connectionCheckCycle)))
                {
                    DoCheck();
                }
            });
        }

        /// <summary>
        /// Stop the Heartrate
        /// </summary>
        public void Stop()
        {
            _waitEvent.Set();
        }

        private void DoCheck()
        {
            try
            {
                var echoResult = _leaf.Echo();
                if (!echoResult)
                {
                    OnOfflined();
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLineError($"Connection Checker do check failed:{ex}");
            }
        }

        private void OnOfflined()
        {
            Offlined?.Invoke(this, EventArgs.Empty);
        }
    }
}