using GpsClient2.Model;
using GpsClient2.NmeaMessages;
using GpsClient2.Exceptions;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO.Ports;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace GpsClient2 {
    public class ComPortGpsClient : BaseGpsClient {
        #region Private Properties

        private readonly NmeaParser _parser = new NmeaParser();
        private SerialPort _serialPort;

        private DateTime? _previousReadTime;

        #endregion

        #region Constructors

        public ComPortGpsClient(ComPortInfo connectionData) : base(GpsType.ComPort, connectionData) {
        }

        public ComPortGpsClient(BaseGpsInfo connectionData) : base(GpsType.ComPort, connectionData) {
        }

        #endregion

        #region Connect and Disconnect

        public override bool Connect() {
            var data = (ComPortInfo)GpsInfo;

            IsRunning = true;
            OnGpsStatusChanged(GpsStatus.Connecting);
            _serialPort = new SerialPort(data.ComPort, 9600, Parity.None, 8, StopBits.One);

            // Attach a method to be called when there
            // is data waiting in the port's buffer
            _serialPort.DataReceived += port_DataReceived;
            try {
                // Begin communications
                _serialPort.Open();

                OnGpsStatusChanged(GpsStatus.Connected);
                // Enter an application loop to keep this thread alive
                while (_serialPort.IsOpen) {
                    Thread.Sleep(data.ReadFrequenty);
                }
            } catch {
                Disconnect();
                throw;
            }

            return true;
        }

        public override bool Disconnect() {
            _serialPort.Close();
            IsRunning = false;
            OnGpsStatusChanged(GpsStatus.Disabled);
            return true;
        }

        #endregion

        #region Location Callbacks

        private void port_DataReceived(object sender, SerialDataReceivedEventArgs e) {
            try {
                var readString = _serialPort.ReadExisting();
                OnRawGpsDataReceived(readString);
                var result = _parser.Parse(readString);
                if (typeof(GprmcMessage) != result.GetType()) return;
                if (_previousReadTime != null && GpsInfo.ReadFrequenty != 0 && ((GprmcMessage)result).UpdateDate.Subtract(new TimeSpan(0, 0, 0, 0, GpsInfo.ReadFrequenty)) <= _previousReadTime) return;
                OnGpsDataReceived(new GpsDataEventArgs((GprmcMessage)result));
            } catch (UnknownTypeException ex) {
                Console.WriteLine(ex.Message);
            }
        }

        #endregion
    }
}