//                           UNCLASSIFIED
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RAYTHEON PROPRIETARY: THIS DOCUMENT CONTAINS DATA OR INFORMATION
PROPRIETARY TO RAYTHEON COMPANY AND IS RESTRICTED TO USE ONLY BY PERSONS
AUTHORIZED BY RAYTHEON COMPANY IN WRITING TO USE IT. DISCLOSURE TO
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OUTSIDE RAYTHEON COMPANY WITHOUT THE EXPRESS WRITTEN APPROVAL OF RAYTHEON
COMPANY.

THIS PROPRIETARY NOTICE IS NOT APPLICABLE IF DELIVERED TO THE U.S.
GOVERNMENT.

UNPUBLISHED WORK - COPYRIGHT RAYTHEON COMPANY.
-------------------------------------------------------------------------*/

using System;
using System.IO.Ports;
using System.Threading;
using NLog;
using Raytheon.Common;

namespace Raytheon.Instruments
{
	/// <summary>
	/// A class the provides an interface for read/write to registers on an FPGA that implement PC Node communication
	/// </summary>
	public class CommFpgaPcNode2x : IFpgaComm, IDisposable
	{
		#region PrivateClassMembers
		private SerialPort _serialPort;
		private readonly uint _pcNodeAddress;
		private byte[] _readBuf;
		private static object _syncObj = new Object();
		private uint _delayBeforeReadMs;
		private SelfTestResult _selfTestResult;
		private State _state;
		private string _name;

		/// <summary>
		/// NLog logger
		/// </summary>
		private readonly ILogger _logger;
		/// <summary>
		/// Raytheon configuration
		/// </summary>
		private readonly IConfigurationManager _configurationManager;
		private readonly IConfiguration _configuration;

		#endregion

		#region PrivateFuctions

		/// <summary>
		/// The Finalizer
		/// </summary>
		~CommFpgaPcNode2x()
		{
			Dispose(false);
		}

		/// <summary>
		/// Builds a command in the PC node format
		/// </summary>
		/// <param name="address">The address to write to</param>
		/// <param name="data">The data to write</param>
		/// <param name="isForRead">True is the command is to perform a read, false to perform a write</param>
		/// <returns>The formatted command</returns>
		private byte[] BuildCommand(uint address, uint data, bool isForRead)
		{
			byte[] command = new byte[9];

			byte type = 0;

			// 2 bit shift per the spec, regardless of its a read or write
			address = address >> 2;

			if (isForRead == true)
			{
				type = 0xf1;

				// 2 bit shift per the spec for the read (this would be the PC node address)
				data = data >> 2;
			}
			else
			{
				type = 0xf0;
			}

			command[0] = type;
			byte[] addressBytes = BitConverter.GetBytes(address);
			Array.Copy(addressBytes, 0, command, 1, addressBytes.Length);

			byte[] dataBytes = BitConverter.GetBytes(data);
			Array.Copy(dataBytes, 0, command, 5, dataBytes.Length);

			return command;
		}

		/// <summary>
		/// Reads the serial port until it is empty
		/// </summary>
		private void ClearBuffer()
		{
			lock (_syncObj)
			{
				bool isClearComplete = false;

				while (isClearComplete == false)
				{
					try
					{
						int numBytesRead = _serialPort.Read(_readBuf, 0, _readBuf.Length);

						if (numBytesRead < _readBuf.Length)
						{
							isClearComplete = true;
						}
					}
					catch (Exception)
					{
						//expected if buffer is already cleared
						isClearComplete = true;
					}
				}
			}
		}

		/// <summary>
		/// Dispose of this object
		/// </summary>
		/// <param name="disposing"></param>
		protected virtual void Dispose(bool disposing)
		{
			try
			{
				if (disposing)
				{
					if (_state == State.Ready)
					{
						_serialPort.Dispose();

						_state = State.Uninitialized;
					}
				}
			}
			catch (Exception)
			{
				try
				{
					//ErrorLogger.Instance().Write(err.Message + "\r\n" + err.StackTrace);
				}
				catch (Exception)
				{
					//Do not rethrow. Exception from error logger that has already been garbage collected
				}
			}
		}

		#endregion

		#region PublicFuctions

		/// <summary>
		/// CommFpgaPcNode2x factory constructor
		/// </summary>
		/// <param name="deviceName"></param>
		/// <param name="configurationManager"></param>
		public CommFpgaPcNode2x(string deviceName, IConfigurationManager configurationManager, ILogger logger)
		{
			Name = deviceName;

			_logger = logger;

			_configurationManager = configurationManager;
			_configuration = _configurationManager.GetConfiguration(Name);

			_pcNodeAddress = _configuration.GetConfigurationValue<uint>("CommFpgaPcNode2x", "PCNodeAddress", 0);

			string comPortName = _configuration.GetConfigurationValue("CommFpgaPcNode2x", "ComPortName", "COM1");
			int baudRate = _configuration.GetConfigurationValue("CommFpgaPcNode2x", "BaudRate", 115200);
			Parity parity = _configuration.GetConfigurationValue("CommFpgaPcNode2x", "Parity", Parity.None);
			int dataBits = _configuration.GetConfigurationValue("CommFpgaPcNode2x", "DataBits", 8);
			StopBits stopBits = _configuration.GetConfigurationValue("CommFpgaPcNode2x", "StopBits", StopBits.None);

			_delayBeforeReadMs = _configuration.GetConfigurationValue<uint>("CommFpgaPcNode2x", "DelayBeforeReadMs", 0);
			_pcNodeAddress = _configuration.GetConfigurationValue<uint>("CommFpgaPcNode2x", "PcNodeAddress", 0);

			const int READ_BUF_SIZE = 100;

			try
			{
				_serialPort = new SerialPort(comPortName, baudRate, parity, dataBits, stopBits)
				{
					ReadTimeout = 100
				};
			}
			catch (Exception ex)
			{
				_logger.Error(ex);

				if (_serialPort.IsOpen == true)
				{
					_serialPort.Close();
				}
				throw;
			}

			_readBuf = new byte[READ_BUF_SIZE];

			_selfTestResult = SelfTestResult.Unknown;
			_state = State.Uninitialized;
		}



		/// <summary>
		/// The constructor which opens up a serial port
		/// </summary>
		/// <param name="commFpgaPcNodeAddress">The address of the PC node</param>
		/// <param name="comPortName">The port name. "Com1' for example</param>
		/// <param name="delayBeforeReadMs">The num of ms to wait before a read</param>
		/// <param name="baudRate">The baud rate</param>
		/// <param name="parity">The parity</param>
		/// <param name="dataBits">Number of data bits</param>
		/// <param name="stopBits">Number of Stop Bits</param>
		public CommFpgaPcNode2x(string name, uint pcNodeAddress, string comPortName, uint delayBeforeReadMs, int baudRate = 115200, Parity parity = Parity.None, int dataBits = 8, StopBits stopBits = StopBits.One)
		{
			const int READ_BUF_SIZE = 100;

			try
			{
				_name = name;
				
				_logger = LogManager.GetCurrentClassLogger();

				_serialPort = new SerialPort(comPortName, baudRate, parity, dataBits, stopBits);

				_serialPort.ReadTimeout = 100;

				_delayBeforeReadMs = delayBeforeReadMs;

				_pcNodeAddress = pcNodeAddress;

				_readBuf = new byte[READ_BUF_SIZE];

				_selfTestResult = SelfTestResult.Unknown;
				_state = State.Uninitialized;
			}
			catch (Exception)
			{
				if (_serialPort.IsOpen == true)
				{
					_serialPort.Close();
				}

				throw;
			}
		}

		/// <summary>
		/// 
		/// </summary>
		/// <returns></returns>
		public bool ClearErrors()
		{
			return false;
		}

		/// <summary>
		/// 
		/// </summary>
		public string DetailedStatus
		{
			get
			{
				return "This is a FPGA PC Node called " + _name;
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public bool DisplayEnabled
		{
			get
			{
				return false;
			}

			set
			{
				throw new NotImplementedException();
			}
		}

		/// <summary>
		/// Dispose of this object
		/// </summary>
		public void Dispose()
		{
			try
			{
				Dispose(true);

				GC.SuppressFinalize(this);
			}
			catch (Exception)
			{
				try
				{
					//ErrorLogger.Instance().Write(err.Message + "\r\n" + err.StackTrace);
				}
				catch (Exception)
				{
					//Do not rethrow. Exception from error logger that has already been garbage collected
				}
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public bool FrontPanelEnabled
		{
			get
			{
				return false;
			}

			set
			{
				throw new NotImplementedException();
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public InstrumentMetadata Info
		{
			get
			{
				throw new NotImplementedException();
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public void Initialize()
		{
			Initialize(string.Empty);
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="fpga"></param>
		public void Initialize(string fpga)
		{
			lock (_syncObj)
			{
				if (_state == State.Uninitialized)
				{
					if (_serialPort.IsOpen == false)
					{
						_serialPort.Open();
					}

					ClearBuffer();
					_state = State.Ready;
				}
				else
				{
					throw new Exception("expected the state to be Uninitialized, state was: " + _state.ToString() + " on card " + _name);
				}
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public string Name
		{
			get
			{
				return _name;
			}
			set { _name = value; }
		}

		/// <summary>
		/// 
		/// </summary>
		/// <returns></returns>
		public SelfTestResult PerformSelfTest()
		{
			_selfTestResult = SelfTestResult.Unknown;
			return _selfTestResult;
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="fpga"></param>
		/// <param name="address"></param>
		/// <returns></returns>
		public uint Read(string fpga, uint address)
		{
			const int NUM_BYTES_EXPECTED_ON_READ = 9;

			int numBytesRead = 0;

			// lock up the FPGA resource
			lock (_syncObj)
			{
				byte[] command = BuildCommand(address, _pcNodeAddress, true);

				for (uint numTries = 0; numTries < 2; numTries++)
				{
					_serialPort.Write(command, 0, command.Length);

					Array.Clear(_readBuf, 0, _readBuf.Length);

					Thread.Sleep((int)_delayBeforeReadMs);

					numBytesRead = _serialPort.Read(_readBuf, 0, _readBuf.Length);

					int numBytesExpectedToRead = NUM_BYTES_EXPECTED_ON_READ;

					if (numBytesRead != numBytesExpectedToRead)
					{
						//put out diagnostic
						byte[] errorDiag = new byte[numBytesRead];

						Array.Copy(_readBuf, errorDiag, numBytesRead);

						string errMessage = Util.ByteArrayToHexString(errorDiag);

						//ErrorLogger.Instance().Write("Read got wrong size. expected to read: " + numBytesExpectedToRead.ToString() + ", read: " + numBytesRead.ToString() + " The data received is: " + errMessage);

						if (numTries != 0)
						{
							//second time - not a good read
							throw new Exception("expected to read: " + numBytesExpectedToRead.ToString() + ", read: " + numBytesRead.ToString());
						}
					}
					else
					{
						break;//continue processing
					}
				}

				// Grab the last 4 bytes
				uint data = BitConverter.ToUInt32(_readBuf, numBytesRead - 4);

				return data;
			}
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="fpgaName"></param>
		/// <param name="address"></param>
		/// <param name="numberOfWordsToRead"></param>
		/// <param name="shallWeIncrementAddress"></param>
		/// <param name="dataRead"></param>
		public void ReadBlock(string fpgaName, uint address, uint numberOfWordsToRead, bool shallWeIncrementAddress, ref uint[] dataRead)
		{
			// lock up the FPGA resource
			lock (_syncObj)
			{
				throw new Exception("Not Implemented");
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public void Reset()
		{
			// lock up the FPGA resource
			lock (_syncObj)
			{
				ClearBuffer();
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public SelfTestResult SelfTestResult
		{
			get
			{
				return _selfTestResult;
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public void Shutdown()
		{
			// lock up the FPGA resource
			lock (_syncObj)
			{
				if (_state == State.Ready)
				{
					_serialPort.Dispose();

					_state = State.Uninitialized;
				}
			}
		}

		/// <summary>
		/// 
		/// </summary>
		public State Status
		{
			get
			{
				return _state;
			}
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="fpga"></param>
		/// <param name="address"></param>
		/// <param name="data"></param>
		public void Write(string fpga, uint address, uint data)
		{
			byte[] command = BuildCommand(address, data, false);

			// lock up the FPGA resource
			lock (_syncObj)
			{
				_serialPort.Write(command, 0, command.Length);
			}
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="fpgaName"></param>
		/// <param name="address"></param>
		/// <param name="numberOfWordsToWrite"></param>
		/// <param name="data"></param>
		/// <param name="shallWeIncrementAddress"></param>
		public void WriteBlock(string fpgaName, uint address, uint numberOfWordsToWrite, uint[] data, bool shallWeIncrementAddress)
		{
			// lock up the FPGA resource
			lock (_syncObj)
			{
				throw new Exception("Not Implemented");
			}
		}

		/// <summary>
		/// Loads firmware
		/// </summary>
		/// <param name="fpgaName"></param>
		public void LoadFirmware(string fpgaName)
		{
			Initialize(fpgaName);
		}

		#endregion
	}
}