#include <fcntl.h> 
#include <termios.h>
#include <stdio.h> 
#include <fstream> 
#include <stdlib.h> 
#include <time.h>
#include <iostream>
#include <string>
#include <vector>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

using namespace std;

int main(int argc, char *argv[]) 
{
struct termios SerialOptions;

string Port = argv[1];
int FileDescriptor = open(Port.c_str(), O_RDWR | O_NOCTTY);

if(FileDescriptor == -1) 
	{
	cout<<"Error: Cannot open port "<<Port<<"!"<<endl;
	return 1;
	} 
else 
	{	
	tcgetattr(FileDescriptor, &SerialOptions);

	tcflush(FileDescriptor, TCIFLUSH);
	tcflush(FileDescriptor, TCOFLUSH);

	SerialOptions.c_cflag = CS8 | CREAD | CLOCAL | CRTSCTS;
	SerialOptions.c_oflag = 0;
	SerialOptions.c_iflag = 0;
	SerialOptions.c_lflag = 0;
	SerialOptions.c_line =  0;
	
	cfsetispeed(&SerialOptions, B9600);	
	cfsetospeed(&SerialOptions, B9600);
	tcsetattr(FileDescriptor, TCSANOW, &SerialOptions);
	}
fcntl(FileDescriptor, F_SETFL, FNDELAY); 

bool decode = false;
if(argc == 3) if(atoi(argv[2]) == 1) decode = true;

while(1)
	{		
	char Datastream[1000];		
	read(FileDescriptor, Datastream, 1000);
	if(!decode) cout<<Datastream<<endl;
	string Data = Datastream;

	int FoundGPGGA = Data.find("$GPGGA,");
	int FoundStar = Data.find("*", FoundGPGGA);
	
	if(FoundStar != -1 && FoundGPGGA != -1 && decode)
		{
		int ChecksumStream = strtol(Data.substr(FoundStar+1,Data.size()).c_str(),NULL,16);

		int Checksum = 0;
		if(FoundStar-FoundGPGGA <= Data.size())
			{
			for(unsigned int i = FoundGPGGA+1; i < FoundStar; i++) 
				{
				Checksum ^= Data.at(i);
				//cout<<hex<<Checksum<<" "<<Data.at(i)<<dec<<endl;
				}
			
			if(FoundGPGGA != -1 && FoundStar != -1 && Checksum == ChecksumStream) 
				{
				cout<<Data.substr(FoundGPGGA,FoundStar-FoundGPGGA)<<endl;

				vector<int> CommaPos;
				for(unsigned int k = FoundGPGGA+1; k < FoundStar; k++) if(Data.substr(k,1) == ",") CommaPos.push_back(k);

				if(CommaPos.size() == 14) 
					{
					float GpsClockH = 0;
					float GpsClockM = 0;
					float GpsClockS = 0;
					if(CommaPos.at(1)-CommaPos.at(0) > 6)
						{
						string Temp = Data.substr(CommaPos.at(0)+1,CommaPos.at(1)-CommaPos.at(0)-1);
						
						GpsClockH = atoi(Temp.substr(0,2).c_str());
						GpsClockM = atof(Temp.substr(2,2).c_str());
						GpsClockS = atof(Temp.substr(4,CommaPos.at(1)-1).c_str());
					
						cout<<"gps clock: "<<GpsClockH<<":";
						if(GpsClockM<10) cout<<0;
						cout<<GpsClockM<<":";
						if(GpsClockS<10) cout<<0;
						cout<<GpsClockS<<" UTC"<<endl;
						}
						
					float Latitude = 0;			
					if(CommaPos.at(2)-CommaPos.at(1) > 4)
						{
						string Temp = Data.substr(CommaPos.at(1)+1,CommaPos.at(2)-CommaPos.at(1)-1);
						
						Latitude += atoi(Temp.substr(0,2).c_str());
						Latitude += atof(Temp.substr(2,CommaPos.at(2)-1).c_str())/60;
						
						cout<<"latitude: "<<Latitude<<endl;
						}					
					
					float Longitude = 0;			
					if(CommaPos.at(4)-CommaPos.at(3) > 5)
						{
						string Temp = Data.substr(CommaPos.at(3)+1,CommaPos.at(4)-CommaPos.at(1)-1);
						
						Longitude += atoi(Temp.substr(0,3).c_str());
						Longitude += atof(Temp.substr(3,CommaPos.at(4)-1).c_str())/60;
							
						cout<<"longitude: "<<Longitude<<endl;
						}					
					
					unsigned char QualityIndicator = 0x0F;
					if(CommaPos.at(6)-CommaPos.at(5) > 1) 
						{
						QualityIndicator = (atoi(Data.substr(CommaPos.at(5)+1,CommaPos.at(6)-1).c_str())) & 0x0F;
					
						cout<<"quality: "<<int(QualityIndicator)<<endl;
						}
					
					unsigned char Satellites = 0xFF;
					if(CommaPos.at(7)-CommaPos.at(6) > 1) 
						{
						Satellites = atoi(Data.substr(CommaPos.at(6)+1,CommaPos.at(7)-1).c_str());
					
						cout<<"satellites: "<<int(Satellites)<<endl;
						}
					
					float Hdop = 0;
					if(CommaPos.at(8)-CommaPos.at(7) > 1) 
						{
						Hdop = atof(Data.substr(CommaPos.at(7)+1,CommaPos.at(8)-1).c_str());
					
						cout<<"hdop: "<<Hdop<<endl;
						}
					
					float Altitude = 0;
					if(CommaPos.at(9)-CommaPos.at(8) > 1) 
						{
						Altitude = atof(Data.substr(CommaPos.at(8)+1,CommaPos.at(9)-1).c_str());
					
						cout<<"altitude: "<<Altitude<<endl;
						}
					
					float Separation = 0;
					if(CommaPos.at(11)-CommaPos.at(10) > 1) 
						{
						Separation = atof(Data.substr(CommaPos.at(10)+1,CommaPos.at(11)-1).c_str());
					
						cout<<"separation: "<<Separation<<endl;
						}
					
					float Delay = 0;
					if(CommaPos.at(13)-CommaPos.at(12) > 1) 
						{
						Delay = atof(Data.substr(CommaPos.at(12)+1,CommaPos.at(13)-1).c_str());
					
						cout<<"delay: "<<Delay<<endl;
						}
					
					unsigned short StationId = 0xFFFF;
					if(FoundStar-CommaPos.at(13) > 1) 
						{
						StationId = atof(Data.substr(CommaPos.at(13)+1,FoundStar-1).c_str());
					
						cout<<"station id: "<<StationId<<endl;
						}
					}
				
			
				}
			}
		}		
	sleep(1);
	}
	
return 0;
}