% Satlantic.m
% Jeff Scrutton
% annotated by Erich Riencker 10-29-97
%
% Reads in argos data file and parses into good data (messages.txt)  Reject data(regects.txt)
% a log file of all of the processed data (log.txt) and a location file (location.txt)
	fclose('all');
	clear all ;

	[filename,pathname] = uigetfile('*.txt','ARGOS file...');

	if filename == 0
		disp('Program cancelled.');
		break;
	end

	fname = [ pathname filename ];

	f = fopen(fname,'r'); %read the input file

	log = fopen('log.txt','w');		%open log file	
	rej = fopen('rejects.txt','w');	%open rejects file
	keep = fopen('messages.txt','w');%open message file
	locn = fopen('location.txt','w');%open location file

	separator = '-----';
	message = '';
	messages = 0;
	rejects = 0;
	valid = 0;
	false = 0;
	true = 1;

	while ~feof(f)

		%
		% Find start of block...
		%
		line = fgetl(f);
      
      % I dont think this is running because feof prevents line from getting to -1
      if (line == -1) %report at end
			disp('End of input file.');
			fprintf(1,'%d messages processed (%d valid / %d rejects)\r\n',messages,valid,rejects);
			fclose('all');
			return;
		end
      
      %what the heck is this doing anyway
      if ( length(findstr(line(1),'0123456789')) == 0 ) %first char must be 0 to 9
			disp('Warning: strange input file!');
		end
      
      while line(1) == ' ' 	%while line begins with a space
			line = fgetl(f);		%Just get another line
			if (line == -1)
				disp('End of input file.');
				fclose('all');
				return;
			end
		end   %while line(1)== ' '
      
      
		fprintf(locn,'%s\r\n',line); %print the line to location
		fprintf(log,'%s\r\n',line);	%print the line to log
		%disp(line); %debug tool
      
      % The first line of each block starts at the far left side of the page
      % the third value on the line tells how many lines in the block
		n = sscanf(line,'%d',4);%scan the line for doubles no bigger than 4 chars long
		nlines = n(3);				%Third value in is the Number of lines in this block

		for i = 1:nlines-1; % Read so many lines of data for this block
			line = fgetl(f);
         
         if (line == -1)
				fclose('all');
				error('Premature end of input file.');
			end

			if ( line(6) == '-' ); %then it is a ' 1997-10-11 ....' type of line
				if ( length(message) > 0 ); 
					text = message(2:22); %year-month-day time [int]
					words = sscanf(message(23:length(message)),'%X'); %the rest of the line is hex data
               %the next line creates the output
               text = [ text  sprintf(' %04X',words) ]; %then we put it back together WITH leading zeros
					reject = false;
               
               if ( length(words) ~= 16 )	% Not a good data message
						reject = true;
					else
						bytes = [ fix(words/256) fix(rem(words,256)) ];
						sum = 0;
						for j = 1 : 31
							sum = sum + bytes(j);
						end
						if ( rem(sum,256) ~= bytes(32) )
							reject = true;
						end
					end
               
               
					if ( reject )
						rejects = rejects + 1;
						fprintf(rej,'%s\r\n',text); %write to the rejects file
						text = [ 'X ' text];
					else
						valid = valid + 1;
						fprintf(keep,'%s\r\n',text); %write the output to the keep file
						text = ['  ' text];
					end
					fprintf(log,'%s\r\n',text); %Good or bad, write to file
					%disp(text);
               
            end
				message = '';
				messages = messages + 1;
			end
			message = [ message line ];
		end

		fprintf(log,'%s',separator);
		%disp(separator);
	end