#======================================================================

#                    L A D C P P R O C . L O A D C T D 

#                    doc: Thu Dec  9 18:39:01 2010

#                    (c) 2010 A.M. Thurnherr

#======================================================================

# HISTORY:

#	Dec  9, 2010: - exported from LADCPproc

#				  - added support for ASCII files

#	Dec 16, 2010: - BUG cnv read did not work any more

#	Jan 10, 2011: - added code to skip ANTS header

#	Jan 22, 2011: - adapted to new -g

#	Jul 15, 2011: - added $CTD{first_elapsed}

#	Feb  5, 2012: - BUG: ASCII file did not deal with leading spaces correctly

#	Apr 11, 2012: - BUG: ASCII file did not handle nan latlons correctly

#	Apr 17, 2012: - fiddled

#	Oct 19, 2012: - BUG: support for $CTD{first_elapsed} had not been implemented

#						 for binary files

#				  - BUG: CTD_badval had not been considered when setting $CTD{first_elapsed}

#				  - BUG: CNV format error was not detected correctly any more

sub readCTD_ASCII($$)

{

	my($fn,$dtaR) = @_;

	croak("$fn: unknown pressure field\n")    unless defined($CTD_ASCII_press_field);

	croak("$fn: unknown temperature field\n") unless defined($CTD_ASCII_temp_field);

	croak("$fn: unknown salinity field\n")    unless defined($CTD_ASCII_salin_field);

	unless (numberp($dtaR->{lat})) {

		croak("$fn: unknown latitude field\n")    unless defined($CTD_ASCII_lat_field);

		croak("$fn: unknown longitude field\n")   unless defined($CTD_ASCII_lon_field);

	}

	$CTD_ASCII_badval = 9e99 unless defined($CTD_ASCII_badval);

	open(F,$fn) || croak("$fn: $!\n");

	my($sumLat,$sumLon); my($nPos) = 0;

	my($ds);

	while (chomp($ds = <F>)) {

		my(@rec) = split('\s+',$ds);

		push(@{$dtaR->{press}},($rec[$CTD_ASCII_press_field-1] == $CTD_ASCII_badval) ? nan : $rec[$CTD_ASCII_press_field-1]);

		push(@{$dtaR->{temp}}, ($rec[$CTD_ASCII_temp_field-1]  == $CTD_ASCII_badval) ? nan : $rec[$CTD_ASCII_temp_field-1]);

		push(@{$dtaR->{salin}},($rec[$CTD_ASCII_salin_field-1] == $CTD_ASCII_badval) ? nan : $rec[$CTD_ASCII_salin_field-1]);

		if (defined($CTD_ASCII_lat_field) &&

		    numberp($rec[$CTD_ASCII_lat_field-1]) &&

			$rec[$CTD_ASCII_lat_field-1] != $CTD_ASCII_badval) {

				$nPos++;

				$sumLat += $rec[$CTD_ASCII_lat_field-1];

				$sumLon += $rec[$CTD_ASCII_lon_field-1];

		}

	}

	close(F);

	if ($nPos > 0) {

		$dtaR->{lat} = $sumLat / $nPos;

		$dtaR->{lon} = $sumLon / $nPos;

	}

	$dtaR->{sampint} = 1 / $CTD_ASCII_sampfreq;

}

sub readCTD_CNV($$)

{

	my($fn,$dtaR) = @_;

	my($CTD_nrecs,$CTD_nfields,$pressF,$tempF,$salinF,$elapsedF);

	my($CTD_badval,$CTD_file_type);

	open(F,$fn) || croak("$fn: $!\n");

	while (1) { 														# parse header

		my($hdr);

		chomp($hdr = <F>);

		croak(" unexpected EOF (format error)!\n") unless defined($hdr);

		$hdr =~ s/\r*$//;

		last if ($hdr eq '*END*');

		$CTD_nfields = $',next if ($hdr =~ /nquan = /); 				# Layout

		$CTD_nrecs = $',next if ($hdr =~ /nvalues = /);

		$elapsedF = $1,next if ($hdr =~ /name (\d+) = timeS:/);

		$pressF = $1,next if ($hdr =~ /name (\d+) = prDM:/);

		if ($opt_2) {

			$tempF	= $1,next if ($hdr =~ /name (\d+) = t190C:/);

			$salinF = $1,next if ($hdr =~ /name (\d+) = sal11:/);

		} else {

			$tempF	= $1,next if ($hdr =~ /name (\d+) = t090C:/);

			$salinF = $1,next if ($hdr =~ /name (\d+) = sal00:/);

		}

		&antsAddParams('start_time',$1),next							# selected metadata

			if ($hdr =~ /start_time = (.*)/);

		&antsAddParams('station',$1),next

			if ($hdr =~ /Station\s*:\s*(.*)/);

		&antsAddParams('ship',$1),next

			if ($hdr =~ /Ship\s*:\s*(.*)\s*$/);

		&antsAddParams('cruise',$1),next

			if ($hdr =~ /Cruise\s*:\s*(.*)\s*$/);

		&antsAddParams('time',$1),next

			if ($hdr =~ /Time\s*:\s*(.*)/);

		&antsAddParams('date',$1),next

			if ($hdr =~ /Date\s*:\s*(.*)/);

		if ($hdr =~ /Latitude\s*[=:]\s*/) {

			($deg,$min,$NS) = split(/ /,$');

			$dtaR->{lat} = $deg + $min/60;

			$dtaR->{lat} *= -1 if ($NS eq 'S');

			next;

		}

		if ($hdr =~ /Longitude\s*[=:]\s*/) {

			($deg,$min,$EW) = split(/ /,$');

			$dtaR->{lon} = $deg + $min/60;

			$dtaR->{lon} *= -1 if ($EW eq 'W');

			next;

		}

		if ($hdr =~ /interval = seconds: /) {

			$dtaR->{sampint} = 1*$';

			next;

		}

		$CTD_badval = $',next

			if ($hdr =~ /bad_flag = /); 

		$CTD_file_type = $',next

			if ($hdr =~ /file_type = /);    

	}

	croak("$CTD_file: cannot determine CTD file layout\n")

		unless ($CTD_nfields && $CTD_nrecs);

	croak("$CTD_file: cannot determine missing value\n")

		unless defined($CTD_badval);

	croak("$CTD_file: not a CTD time series file\n")

		unless ($dtaR->{sampint});

	croak("$CTD_file: no pressure field\n")

		unless defined($pressF);

	croak("$CTD_file: no suitable temperature field\n")

		unless defined($tempF);

	croak("$CTD_file: no suitable salinity field\n")

		unless defined($salinF);

	if ($CTD_file_type eq 'ascii') {

		while (1) {

			last unless (my(@rec) = &antsFileIn(F));

			$dtaR->{first_elapsed} = $rec[$elapsedF]

				if !defined($dtaR->{first_elapsed}) && defined($elapsedF) &&  $rec[$elapsedF]!=$CTD_badval;

			push(@{$dtaR->{press}},($rec[$pressF] == $CTD_badval) ? nan : $rec[$pressF]);

			push(@{$dtaR->{temp}}, ($rec[$tempF]  == $CTD_badval) ? nan : $rec[$tempF]);

			push(@{$dtaR->{salin}},($rec[$salinF] == $CTD_badval) ? nan : $rec[$salinF]);

		}

	} elsif ($CTD_file_type eq 'binary') {

		my($fbits) = 8 * length(pack('f',0));

		croak(sprintf("$0: incompatible native CPU float representation (%d instead of 32bits)\n",fbits))

			unless ($fbits == 32);  

		croak("$fn: can't read binary data\n")

			unless (read(F,my($dta),4*$CTD_nfields*$CTD_nrecs) == 4*$CTD_nfields*$CTD_nrecs);

		print(STDERR "$fn: WARNING: extraneous data at EOF\n") unless eof(F);

		$dta = pack('V*',unpack('N*',$dta)) 			# big-endian CPU

			if (unpack('h*', pack('s', 1)) =~ /01/);	# c.f. perlport(1)

		my(@dta) = unpack("f*",$dta);

		for (my($r)=0; $r<$CTD_nrecs; $r++) {

			$dtaR->{first_elapsed} = $dta[$r*$CTD_nfields+$elapsedF]

                if !defined($dtaR->{first_elapsed}) && defined($elapsedF) && $dta[$r*$CTD_nfields+$elapsedF]!=$CTD_badval;

			push(@{$dtaR->{press}},($dta[$r*$CTD_nfields+$pressF] == $CTD_badval) ? nan : $dta[$r*$CTD_nfields+$pressF]);

			push(@{$dtaR->{temp}}, ($dta[$r*$CTD_nfields+$tempF]  == $CTD_badval) ? nan : $dta[$r*$CTD_nfields+$tempF]);

			push(@{$dtaR->{salin}},($dta[$r*$CTD_nfields+$salinF] == $CTD_badval) ? nan : $dta[$r*$CTD_nfields+$salinF]);

		}

	} else {

		croak("$fn: unknown CTD file type $CTD_file_type\n");

	}

	close(F);

}

sub readCTD($$)

{

	my($fn,$dtaR) = @_;

	if (defined($CTD_ASCII_sampfreq)) {

		readCTD_ASCII($fn,$dtaR);

	} else {

		readCTD_CNV($fn,$dtaR);

	}

	croak("$0: unknown latitude\n") unless defined($dtaR->{lat});

	&antsAddParams('lat',$dtaR->{lat});

	croak("$0: unknown longitude\n") unless defined($dtaR->{lon});

	&antsAddParams('lon',$dtaR->{lon});

	&antsAddParams('CTD_sampfreq',1/$dtaR->{sampint});

	&antsAddParams('ITS',$P{ITS} = 90);

}

1;