#!/usr/bin/perl
use strict;
use warnings;
use Getopt::Long;
use Date::Calc qw(:all);

my $input_file = undef;

GetOptions (
    "input=s" => \$input_file,
);
open INPUT, $input_file
    or die "Can't open $input_file for input: $!";

my @files = undef;   #list of files to run script on
while(my $line = <INPUT>){
    chomp($line);
    push @files, $line;
}


for(my $i=1; $i < scalar @files; $i++) {
    if(-e $files[$i]){
        open IN, "gunzip -c $files[$i]|"
            or die "Can't open $files[$i] for input: $!";

        open OUT, "> $files[$i]_out.txt"
            or die "Can't open $files[$i]_out.txt for output: $!";

        my $firstline = 1;
        my @dt = undef; # date and time
        my @date1 = undef;
        my @date2 = undef;

        if($firstline==1){        #extract header line and get start and end date from line
            chomp(my $line = <IN>);
            my @header = split(/,/, $line);
            @dt= $header[0] =~ /(\d+)/g;
            @date1 = ($dt[0], $dt[1], $dt[2], $dt[3], $dt[4], $dt[5]);
            @date2 = ($dt[6], $dt[7], $dt[8], $dt[9], $dt[10], $dt[11]);
            $firstline = 0;
        } else {
            <IN> for 1..1
        }
        print OUT "Date\tTime\tDay\tmg\n";    #print title

        my $count = 0;

        while(my $line1 = <IN>){                     #whilst reading file get 12 lines and print time and print average of 12 lines
            chomp($line1);
            my @mg1 = split(/,/, $line1);
            my $line2 = <IN>;
            chomp($line2);
            my @mg2 = split(/,/, $line2);
            my $line3 = <IN>;
            chomp($line3);
            my @mg3 = split(/,/, $line3);
            my $line4 = <IN>;
            chomp($line4);
            my @mg4 = split(/,/, $line4);
            my $line5 = <IN>;
            chomp($line5);
            my @mg5 = split(/,/, $line5);
            my $line6 = <IN>;
            chomp($line6);
            my @mg6 = split(/,/, $line6);
            my $line7 = <IN>;
            chomp($line7);
            my @mg7 = split(/,/, $line7);
            my $line8 = <IN>;
            chomp($line8);
            my @mg8 = split(/,/, $line8);
            my $line9 = <IN>;
            chomp($line9);
            my @mg9 = split(/,/, $line9);
            my $line10 = <IN>;
            chomp($line10);
            my @mg10 = split(/,/, $line10);
            my $line11 = <IN>;
            chomp($line11);
            my @mg11 = split(/,/, $line11);
            my $line12 = <IN>;
            chomp($line12);
            my @mg12 = split(/,/, $line12);
            my ($y, $mo, $d, $h, $m, $s) = Add_Delta_DHMS(@date1, 0, 0, $count, 0);
            printf OUT qq(%d-%02d-%02d %02d:%02d:%02d), $y, $mo, $d, $h, $m, $s;
            print OUT "\t" . Day_of_Week($y, $mo, $d);
            print OUT "\t" . (($mg1[0]+$mg2[0]+$mg3[0]+$mg4[0]+$mg5[0]+$mg6[0]+$mg7[0]+$mg8[0]+$mg9[0]+$mg10[0]+$mg11[0]+$mg12[0])/12) . "\n";
            $count +=1
        }
        close IN;
        close OUT
    }
}