Speaking Garmin

using System;
using System.Windows.Forms;
using System.IO;

namespace Speaking_Garmin
{
	/// <summary>
	/// Class that implements the Garmin Protocol.
	/// </summary>
	public class Garmin
	{
		#region Variables
		Serial.Port serialPort;
		private bool received=false;
		private bool logging=false;
		private bool done=false;

		private int q=0;
		private int bytesEstimated;

		private System.Collections.ArrayList bytesReceived=new System.Collections.ArrayList(100);
		#endregion


		#region Properties
		/// <summary>
		/// Estimate percentage already transfered
		/// </summary>
		public double Progress
		{
			get
			{
				return Math.Min((double)(bytesReceived.Count*100)/(double)bytesEstimated,100.0);
			}
		}
		/// <summary>
		/// Get bytes received from GPS to save them or whatever
		/// </summary>
		public System.Collections.ArrayList Bytes
		{
			get{return bytesReceived;}
		}
		#endregion


		#region Constructors
		public Garmin()
		{
		}
		#endregion


		#region Public Functions
		public System.Collections.ArrayList GetTracks()
		{
			bytesReceived.Clear();
			bytesEstimated=-1;
			logging=false;

			byte[] sendTracks = {0x10,0x0A,0x02,0x06,0x00,0xEE,0x10,0x03}; /* Ask for tracks */

			Serial.BasicPortSettings a=new Serial.BasicPortSettings();
			a.BaudRate = Serial.BaudRates.CBR_9600;
			serialPort=new Serial.Port("COM1:",a);

			serialPort.DataReceived += new Serial.Port.CommEvent(serialPort_DataReceived);
			serialPort.OnError += new Serial.Port.CommErrorEvent(OnError);

			if(!serialPort.IsOpen)
                serialPort.Open();

			logging=true;
			SendData(sendTracks); /* Ask for tracks */
			Application.DoEvents();
			System.Threading.Thread.Sleep(200); /* Wait for response */
			if(received)
				received=false;
			else
			{
				serialPort.Close();
				serialPort.Dispose();serialPort=null;
				return null;
			}
			q=Environment.TickCount; /* Keep track of elapsed time */
			while(!done)
			{
				if(Environment.TickCount-q>2000) /* Timeout */
				{
					serialPort.Close();
					serialPort.Dispose();serialPort=null;
					return null;
				}
				Application.DoEvents();
				System.Threading.Thread.Sleep(1000);
			}
			serialPort.Close();
			serialPort.Dispose();serialPort=null;

			System.Collections.ArrayList retval=new System.Collections.ArrayList(2);
			Track tempTrack=null;

			System.Collections.ArrayList al=SplitBytes(bytesReceived);
			
			System.Collections.ArrayList command;

			int nWaited=-1;
			int nReceived=0;
			for(int i=0;i<al.Count;i++)
			{
				command=(System.Collections.ArrayList)al[i];
                
				if(command.Count>=7 && (byte)command[0]==0x10)
				{
					if((byte)command[1]==0x1B)
					{ /* Number of commands to be sent */
						nWaited=0;
						for(int j=2+(byte)command[2];j>=3;j--)
						{
							nWaited <<= 8;
							nWaited+=(byte)command[j];
						}
					}
					else if((byte)command[1]==0x06)
					{ /* OK - Do nothing */
					}
					else if((byte)command[1]==0x22)
					{ /* New point */
						++nReceived;;
						if(tempTrack!=null)
						{
							/* Create new point based on received info. */
							tempTrack.AddPoint(command);
						}
					}
					else if((byte)command[1]==0x63)
					{ /* New track */
						++nReceived;

						/* Last received track is now done. Add it to the values to be returned */
						if(tempTrack!=null)
							retval.Add(tempTrack);
						/* Create new point based on received info. */
						tempTrack=new Track(command);
					}
					else if((byte)command[0]==0x10 &&
						(byte)command[1]==0x0C &&
						(byte)command[2]==0x02 &&
						(byte)command[3]==0x06 &&
						(byte)command[4]==0x00 &&
						(byte)command[5]==0xEC &&
						(byte)command[6]==0x10 &&
						(byte)command[7]==0x03)
					{ /* EOF */
						/* Last received track is now done. Add it to the values to be returned */
						if(tempTrack!=null)
							retval.Add(tempTrack);
						/* Check if the information received matches what was expected*/
						if(nReceived!=nWaited)
							MessageBox.Show("Transfer error...\nNumber of commands expected: " + nWaited.ToString() + "\nNumber of commands received: " + nReceived.ToString(),"Error",MessageBoxButtons.OK,MessageBoxIcon.Hand,MessageBoxDefaultButton.Button1);
					}
				}
				else /* command[0] != 0x10 */
				{
					/* Invalid! */
					retval=null;
				}
			}

			return retval;
		}

		public System.Collections.ArrayList GetTracksFromFile(string filename)
		{
			bytesReceived.Clear();

			FileInfo fi=new FileInfo(filename);       
			FileStream fs=fi.OpenRead();
			byte[] ByteArray=new byte[600000];
			int nBytesRead=fs.Read(ByteArray, 0, 600000);
			fs.Close();

			for(int i=0;i<nBytesRead;i++)
			{
				bytesReceived.Add(ByteArray[i]); /* Pretend we received data from a GPS device */
			}

			System.Collections.ArrayList retval=new System.Collections.ArrayList(2);
			Track tempTrack=null;

			System.Collections.ArrayList al=SplitBytes(bytesReceived);
			
			System.Collections.ArrayList command;

			int nWaited=-1;
			int nReceived=0;
			for(int i=0;i<al.Count;i++)
			{
				command=(System.Collections.ArrayList)al[i];
				if(command.Count>=7 && (byte)command[0]==0x10)
				{
					if((byte)command[1]==0x1B)
					{ /* Number of commands to be sent */
						nWaited=0;
						for(int j=2+(byte)command[2];j>=3;j--)
						{
							nWaited <<= 8;
							nWaited+=(byte)command[j];
						}
					}
					else if((byte)command[1]==0x06)
					{ /* OK - Do nothing */
					}
					else if((byte)command[1]==0x22)
					{ /* New point */
						++nReceived;;
						if(tempTrack!=null)
						{
							tempTrack.AddPoint(command);
						}
					}
					else if((byte)command[1]==0x63)
					{ /* New track */
						++nReceived;
						if(tempTrack!=null)
							retval.Add(tempTrack);
						tempTrack=new Track(command);
					}
					else if((byte)command[0]==0x10 &&
						(byte)command[1]==0x0C &&
						(byte)command[2]==0x02 &&
						(byte)command[3]==0x06 &&
						(byte)command[4]==0x00 &&
						(byte)command[5]==0xEC &&
						(byte)command[6]==0x10 &&
						(byte)command[7]==0x03)
					{ /* EOF */
						if(tempTrack!=null)
							retval.Add(tempTrack);
						if(nReceived!=nWaited)
							MessageBox.Show("File corrupt...\nNumber of commands expected: " + nWaited.ToString() + "\nNumber of commands received: " + nReceived.ToString(),"Error",MessageBoxButtons.OK,MessageBoxIcon.Hand,MessageBoxDefaultButton.Button1);
					}
				}
				else /* command[0] != 0x10 */
				{
					retval=null;
				}
			}

			return retval;
		}

		public void Exit()
		{
			if(serialPort!=null)
                serialPort.Close();
		}
		#endregion


		#region Private Functions
		/// <summary>
		/// Function called each time data comes in which stores the received bytes
		/// </summary>
		/// <param name="bytes">byte[] array whose bytes are to be added to the ArrayList receivedBytes</param>
		/// <returns></returns>
		private bool Append(byte[] bytes)
		{
			for(int i=0;i<bytes.Length;i++)
			{
				bytesReceived.Add(bytes[i]);
			}

			if(bytesEstimated==-1) /* Not initialized yet */
			{
				if(bytesReceived.Count>=16)
				{
					System.Collections.ArrayList Data=SplitBytes(bytesReceived);
					if( (byte)((System.Collections.ArrayList)Data[1])[0]==0x10 &&
						(byte)((System.Collections.ArrayList)Data[1])[1]==0x1B)
					{ /* Received number of commands to be sent */
						bytesEstimated=0;
						for(int j=2+(byte)((System.Collections.ArrayList)Data[1])[2];j>=3;j--)
						{
							bytesEstimated <<= 8;
							bytesEstimated+=(byte)((System.Collections.ArrayList)Data[1])[j];
						}
						bytesEstimated*=30; /*Estimate each message has 30 bytes average */
					}
				}
			}

			return true;
		}


		/// <summary>
		/// Main function in parsing the received bytes, it splits the received bytes into messages
		/// </summary>
		/// <param name="arrayListBytes">ArrayList filled with elements of type byte which are to be split</param>
		/// <returns></returns>
		private static System.Collections.ArrayList SplitBytes(System.Collections.ArrayList arrayListBytes)
		{
			System.Collections.ArrayList retval=new System.Collections.ArrayList(10);
			System.Collections.ArrayList tempBytes;
			int count=0;

			for(int i=0;i<arrayListBytes.Count;i++)
			{
				if((byte)arrayListBytes[i]==0x10)
				{ /* First byte in a message */
					tempBytes=new System.Collections.ArrayList(8);
					tempBytes.Add(arrayListBytes[i]);
					for(int x=i+1;;x++)
					{
						i=x;
						tempBytes.Add(arrayListBytes[x]);
						if((byte)arrayListBytes[x]==0x10)
							++count;
						else if((byte)arrayListBytes[x]==0x03)
						{
							if(count%2==1) /* If found an even number of 0x10 followed by 0x03 we have to split the message here */
								break;
						}
						else
							count=0;
					}
					retval.Add(tempBytes);
				}
			}

			return retval;
		}


		/// <summary>
		/// Function used to send data through the serial port
		/// </summary>
		/// <param name="buffer"></param>
		/// <returns></returns>
		private bool SendData(byte[] buffer)
		{
			if(serialPort.IsOpen)
                serialPort.Output=buffer;
			else
				return false;

			return true;
		}

		#endregion


		#region Events Actions
		/// <summary>
		/// Response to error event raised by the serial port
		/// </summary>
		/// <param name="Description">String that contains error specifics</param>
		private void OnError(string Description)
		{
			MessageBox.Show("An error occured during the transfer:\n" + Description,"Error",MessageBoxButtons.OK,MessageBoxIcon.Hand,MessageBoxDefaultButton.Button1);
		}

		/// <summary>
		/// Response to DataReceived event raised by serialPort called each time new data is received
		/// </summary>
		private void serialPort_DataReceived()
		{
			q=Environment.TickCount; /* Keep track of the time in order to check for timeouts */
			received=true; /* Received data */
			if(logging) /* Keep track of data received */
			{
				byte[] a=serialPort.Input; /* Get what was received */
				Append(a); /* Store received bytes */
				if(bytesReceived.Count>=8)
					if(
						(byte)bytesReceived[bytesReceived.Count-8]==0x10 &&
						(byte)bytesReceived[bytesReceived.Count-7]==0x0C &&
						(byte)bytesReceived[bytesReceived.Count-6]==0x02 &&
						(byte)bytesReceived[bytesReceived.Count-5]==0x06 &&
						(byte)bytesReceived[bytesReceived.Count-4]==0x00 &&
						(byte)bytesReceived[bytesReceived.Count-3]==0xEC &&
						(byte)bytesReceived[bytesReceived.Count-2]==0x10 &&
						(byte)bytesReceived[bytesReceived.Count-1]==0x03)
					{ /* EOF */
                        done=true; /* Transfer is complete */
						logging=false; /* Stop logging */
						return;
					}
				/* Ask for next record as soon as data is received */
				SendData(new byte[] {0x10,0x06,0x02,0x22,0x00,0xD6,0x10,0x03});
			}
		}
		#endregion
	}
}