using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Tango.Core;
using Tango.Core.Threading;
using Tango.FSE.Common;
using Tango.FSE.Common.Connection;
using Tango.FSE.Common.Diagnostics;
using Tango.PMR.Diagnostics;
using Tango.Settings;

namespace Tango.FSE.UI.Diagnostics
{
    /// <summary>
    /// Represents the <see cref="IDiagnosticsProvider"/> default implementation.
    /// </summary>
    /// <seealso cref="Tango.Core.ExtendedObject" />
    /// <seealso cref="Tango.FSE.Common.Diagnostics.IDiagnosticsProvider" />
    public class DefaultDiagnosticsProvider : ExtendedObject, IDiagnosticsProvider
    {
        private IntervalMessageDispatcher<StartDiagnosticsResponse> _frameDispatcher;
        private IMachineProvider _machineProvider;

        #region Events

        /// <summary>
        /// Occurs when a diagnostics frame is available.
        /// </summary>
        public event EventHandler<DiagnosticsFrameReceivedEventArgs> FrameReceived;

        #endregion

        #region Properties

        /// <summary>
        /// Gets the current diagnostics frame.
        /// </summary>
        public DiagnosticsFrame CurrentFrame { get; private set; }

        private int _frameRate;
        /// <summary>
        /// Gets the current frame rate.
        /// </summary>
        public int FrameRate
        {
            get { return _frameRate; }
            set { _frameRate = value; RaisePropertyChangedAuto(); }
        }

        /// <summary>
        /// Gets or sets the diagnostics frames throttling mode.
        /// </summary>
        public DiagnosticsThrottlingMode ThrottlingMode { get; set; }

        #endregion

        #region Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="DefaultDiagnosticsProvider"/> class.
        /// </summary>
        /// <param name="machineProvider">The machine provider.</param>
        public DefaultDiagnosticsProvider(IMachineProvider machineProvider)
        {
            _machineProvider = machineProvider;
            ThrottlingMode = DiagnosticsThrottlingMode.Direct; //SettingsManager.Default.GetOrCreate<FSESettings>().DiagnosticsThrottlingMode;
            machineProvider.MachineOperator.DiagnosticsDataAvailable += MachineOperator_DiagnosticsDataAvailable;

            _frameDispatcher = new IntervalMessageDispatcher<StartDiagnosticsResponse>(PostDiagnostics);
            _frameDispatcher.DriftCompensationInterval = (int)TimeSpan.FromSeconds(30).TotalMilliseconds;
            _frameDispatcher.Start();
        }

        #endregion

        #region Private Methods

        private void MachineOperator_DiagnosticsDataAvailable(object sender, StartDiagnosticsResponse diagnostics)
        {
            if (ThrottlingMode == DiagnosticsThrottlingMode.Direct)
            {
                PostDiagnostics(diagnostics);
            }
            else
            {
                _frameDispatcher.Interval = (int)diagnostics.ElapsedMilli;
                _frameDispatcher.Push(diagnostics);
            }
        }

        private void PostDiagnostics(StartDiagnosticsResponse data)
        {
            if (data.Monitors == null || _machineProvider.MachineOperator.DeviceInformation == null) return;

            FrameRate = (int)data.ElapsedMilli;

            uint interval = _machineProvider.MachineOperator.DeviceInformation.DiagnosticsInterval;
            DateTime diagnosticsTime = DateTime.ParseExact(data.DateTime, "MM/dd/yyyy HH:mm:ss.fff", null);
            TimeSpan delta = TimeSpan.FromMilliseconds(data.ElapsedMilli);

            var frame = new DiagnosticsFrame()
            {
                Data = data,
                DiagnosticsTime = diagnosticsTime,
                Delta = delta,
                Interval = interval
            };

            FrameReceived?.Invoke(this, new DiagnosticsFrameReceivedEventArgs()
            {
                Frame = frame,
            });

            CurrentFrame = frame;
        }

        #endregion
    }
}