///
/// Copyright (c) 2013-2015 Sensus Metering Systems
///
using System;
using System.Diagnostics;
using System.IO;
using System.Text;
using log4net;
using TBF.UiBridge;

namespace TBF.BenchControl.Cameras.IdcCamera
{
	///
	/// File I/O implementation
	///
	public class SerialFileIO
	{
		static readonly ILog log = LogManager.GetLogger(typeof(SerialFileIO));

		static TBF.Tools.ByteFormatter byteFormatter = new TBF.Tools.ByteFormatter();

		const int BUFSIZE = 1024;
		const int MAXFNAMESIZE = 62;

		int cameraIdx;
		string imagesPath;

		StringBuilder fioFilenameBuilder;
		string fioFullPathname;
		int packetSize;
		byte[] fioBuffer;
		BinaryWriter fioWriter;

        enum FioState
        {
            Command,	/// 'o', 'c' or	'w'
            Open,		/// 'p'
            Open2,		/// 'e'
            Open3,		/// 'n'
            Open4,		///  1
            Filename,
            Close,		///		 'l'
            Close2,		///		 'o'
            Close3,		///		 's'
            Close4,		///		 'e'
            Close5,		///		  1
            Write,		///				'r'
            Write2,		///				'i'
            Write3,		///				't'
            Write4,		///				'e'
            Write5,		///				 1
            PktSize1,
            PktSize2,
            PktSize3,
            Data,
        }

        FioState state;

		public string TransferredFile
		{
			get { return fioFullPathname; }
		}

		public SerialFileIO(int cameraIdx, string imagesPath)
		{
			this.cameraIdx = cameraIdx;
			this.imagesPath = imagesPath;
			state = FioState.Command;
            fioFullPathname = string.Empty;
            fioFilenameBuilder = new StringBuilder(16);
			fioBuffer = new byte[BUFSIZE];
		}

		public void ProcessByte(byte b)
		{
			///
			/// Reaching break in any case of the following switch is an error
			///
			if (state == FioState.Data)
			{
				if (packetSize > 0)
				{
					if (fioWriter != null)
					{
						fioWriter.Write(b);
					}
					if (--packetSize == 0)
					{
						state = FioState.Command;
					}
					return;
				}

				log.ErrorFormat("{0}: FIO error 17", cameraIdx);
			}
			else
			{
				switch (state)
				{
					case FioState.Command:
						if ((char)b == 'o') { state = FioState.Open; return; }
						if ((char)b == 'c') { state = FioState.Close; return; }
						if ((char)b == 'w') { state = FioState.Write; return; }
						log.ErrorFormat("{0}: FIO error 1, fullPathName={1}", cameraIdx, fioFullPathname);
						break;
					case FioState.Open:
						if ((char)b == 'p') { state = FioState.Open2; return; }
						log.ErrorFormat("{0}: FIO error 2", cameraIdx);
						break;
					case FioState.Open2:
						if ((char)b == 'e') { state = FioState.Open3; return; }
						log.ErrorFormat("{0}: FIO error 3", cameraIdx);
						break;
					case FioState.Open3:
						if ((char)b == 'n') { state = FioState.Open4; return; }
						log.ErrorFormat("{0}: FIO error 4", cameraIdx);
						break;
					case FioState.Open4:
						if (b == 1)
						{
							fioFilenameBuilder.Clear();
							state = FioState.Filename;
							return;
						}
						log.ErrorFormat("{0}: FIO error 5", cameraIdx);
						break;
					case FioState.Filename:
						if (b == 0)
						{
							if (fioWriter != null)
							{
								fioWriter.Close();
								fioWriter.Dispose();
							}

							try
							{
								fioFullPathname = imagesPath + fioFilenameBuilder.ToString();
								fioWriter = new BinaryWriter(File.Open(fioFullPathname, FileMode.Create));
								log.DebugFormat("{0}: Open(\"{1}\")", cameraIdx, fioFullPathname);
							}
							catch
							{
								fioWriter = null;
								log.WarnFormat("{0}: Failed to open(\"{1}\")", cameraIdx, fioFullPathname);
							}
							state = FioState.Command;
							return;
						}
						else if (fioFilenameBuilder.Length < MAXFNAMESIZE)
						{
							fioFilenameBuilder.Append((char)b);
							return;
						}
						log.ErrorFormat("{0}: FIO error 6", cameraIdx);
						break;
					case FioState.Close:
						if ((char)b == 'l') { state = FioState.Close2; return; }
						log.ErrorFormat("{0}: FIO error 7", cameraIdx);
						break;
					case FioState.Close2:
						if ((char)b == 'o') { state = FioState.Close3; return; }
						log.ErrorFormat("{0}: FIO error 8", cameraIdx);
						break;
					case FioState.Close3:
						if ((char)b == 's') { state = FioState.Close4; return; }
						log.ErrorFormat("{0}: FIO error 9", cameraIdx);
						break;
					case FioState.Close4:
						if ((char)b == 'e') { state = FioState.Close5; return; }
						log.ErrorFormat("{0}: FIO error 10", cameraIdx);
						break;
					case FioState.Close5:
						if ((char)b == '1' && fioWriter != null)
						{
							log.DebugFormat("{0}: Close()", cameraIdx);
							fioWriter.Close();
							fioWriter.Dispose();
							fioWriter = null;
							Bridge.OnImageUpdated(this, new ImageUpdatedEventArgs(cameraIdx, fioFullPathname));
							fioFullPathname = String.Empty;
							state = FioState.Command;
							return;
						}
						log.ErrorFormat("{0}: FIO error 11", cameraIdx);
						break;
					case FioState.Write:
						if ((char)b == 'r') { state = FioState.Write2; return; }
						log.ErrorFormat("{0}: FIO error 12", cameraIdx);
						break;
					case FioState.Write2:
						if ((char)b == 'i') { state = FioState.Write3; return; }
						log.ErrorFormat("{0}: FIO error 13", cameraIdx);
						break;
					case FioState.Write3:
						if ((char)b == 't') { state = FioState.Write4; return; }
						log.ErrorFormat("{0}: FIO error 14", cameraIdx);
						break;
					case FioState.Write4:
						if ((char)b == 'e') { state = FioState.Write5; return; }
						log.ErrorFormat("{0}: FIO error 15", cameraIdx);
						break;
					case FioState.Write5:
						if ((char)b == '1') { state = FioState.PktSize1; return; }
						log.ErrorFormat("{0}: FIO error 16", cameraIdx);
						break;
					case FioState.PktSize1:
						packetSize = (int)b;
						state = FioState.PktSize2;
						return;
					case FioState.PktSize2:
						packetSize = (256 * packetSize) + (int)b;
						state = FioState.PktSize3;
						return;
					case FioState.PktSize3:
						packetSize = (256 * packetSize) + (int)b;
						log.DebugFormat("{0}: write(len={1})", cameraIdx, packetSize);
						state = FioState.Data;
						return;
					default:
						log.ErrorFormat("{0}: FIO error 18", cameraIdx);
						break;
				}
			}

			state = FioState.Command;
		}
	}
}