#!/usr/bin/perl -w
use strict;
# This script removes the headers of each XBT file.
# Done with UNIX Power Tools in a Perl shell

# The last line of the header starts with "^Depth (m)" (^ is in a
# Regex meaning), so the idea is to 
#   grep -n "^Depth (m)" -- to find the the end of the header, then
#   wc                   -- to find the total file length, then
#   head                 -- to pull off the header part, and
#   tail                 -- to pull off the nonheader part

# new addition -- make info file of known format that can be loaded into matlab
# lines are: year, month, day, hour, minute, second, longitude, latitude

my $data_directory = $ARGV[0];

my $tempval;

my $file;
my @files;

opendir(DIR, $data_directory);
@files = grep(/\.EDF$/,readdir(DIR));
closedir(DIR);

my $grepline;
my @parts;
my $header_length;
my $file_length;
my $data_length;

my ($year, $month, $day, $hour, $minute, $second);
my ($lon, $lat);

foreach $file (@files) {

    # get total number of lines ($file_length)
    $tempval = `wc -l $data_directory$file`;
    @parts = split(/ /, $tempval);
    $file_length = $parts[0];

    # get header length ($header_length)
    $tempval = 'grep -n "^Depth (m)" ' . $data_directory . $file;
    $grepline = `$tempval`;
    @parts = split(/:/, $grepline);
    $header_length = $parts[0];

    # get data length
    $data_length = $file_length - $header_length;

    system("head -$header_length $data_directory$file > " .
	   $data_directory . $file . "_hdr");
    system("tail -$data_length $data_directory$file > " .
	   $data_directory . $file . "_dat");

    # parse out latitude
    $tempval = `grep -n Latitude $data_directory$file`;

    @parts = split(/:/,$tempval);
    $tempval = $parts[2];
    @parts = split(/  /,$tempval);
    $tempval = $parts[1];
    @parts = split(/ /, $tempval);
    $lat = $parts[0];
    $tempval = $parts[1];
    @parts = split(/[NS]/,$tempval);
    $lat = $lat + $parts[0]/60;
    # flip sign if in southern hemisphere
    if ($tempval !~ /S/) {
	$lat = - $lat;
    }

    #parse out longitude, very similar to latitude
    $tempval = `grep -n Longitude $data_directory$file`;

    @parts = split(/:/,$tempval);
    $tempval = $parts[2];
    @parts = split(/  /,$tempval);
    $tempval = $parts[1];
    @parts = split(/ /, $tempval);
    $lon = $parts[0];
    $tempval = $parts[1];
    @parts = split(/[WE]/,$tempval);
    $lon = $lon + $parts[0]/60;
    # flip sign if in southern hemisphere
    if ($tempval !~ /E/) {
	$lon = - $lon;
    }
    
    # parse out date
    $tempval = `grep -n Date $data_directory$file`;
    @parts = split(/:/,$tempval);
    $tempval = $parts[2];
    @parts = split(/\//, $tempval);
    $month = $parts[0];
    $month =~ s/\s+//g;
    $day = $parts[1];
    $year = $parts[2];
    $year =~ s/\s+//;

    # parse out time
    $tempval = `grep -n Time $data_directory$file`;
    @parts = split(/: /,$tempval);
    $tempval = $parts[1];
    @parts = split(/:/, $tempval);
    $hour = $parts[0];
    $hour =~ s/\s+//g;
    $minute = $parts[1];
    $second = $parts[2];
    $second =~ s/\s+//;

    open(FOUT, "> $data_directory$file"."_info");
    print FOUT "$year\n$month\n$day\n$hour\n$minute\n$second\n";
    print FOUT "$lon\n$lat\n";
    close(FOUT);
}