gistfile1.pl

use warnings;
use strict;

use Text::CSV;

use constant {
    ID => 0,
    TYPE => 1,
    SOURCE => 2,
    AMOUNT => 3,
    FEE => 4,
    NET => 5,
    CURRENCY => 6,
    DATE_CREATED => 7,
    DATE_AVAILABLE => 8,
    DESCRIPTION => 9
};

my $csvFile = shift or die "usage: $0 <balance_history.csv>";
my $csv = Text::CSV->new;

open my $file, '<', $csvFile or die "unable to open $csvFile: $!";

my ($amount, $fee, $net, $fee_refund, $fee_adj, $refund, $adjustment, $transfer);
while (my $row = $csv->getline($file)) {
    next if $row->[ID] eq "id";
    my $created = $row->[DATE_CREATED];
    my ($date, $time) = split ' ', $created;
    my $month = (split '-', $date)[1];
    $month =~ s/^0//;
    if ($row->[TYPE] eq "charge") {
        $amount->{$month} += $row->[AMOUNT];
        $fee->{$month} += $row->[FEE];
        $net->{$month} += $row->[NET];
    }
    elsif ($row->[TYPE] eq "refund") {
        $refund->{$month} += $row->[AMOUNT];
        $fee_refund->{$month} += $row->[FEE];
        $net->{$month} += $row->[NET];
    }
    elsif ($row->[TYPE] eq "adjustment") {
        $adjustment->{$month} += $row->[AMOUNT];
        $fee_adj->{$month} += $row->[FEE];
        $net->{$month} += $row->[NET];
    }
    elsif ($row->[TYPE] eq "transfer") {
        $transfer->{$month} += $row->[AMOUNT];
    }
}

my $total;
    printf "MONTH AMOUNT   FEE      REFUND   REFUND_FEE ADJUSTMENT ADJUSTMENT_FEE NET      TRANSFER\n";
for (1..12) {
    printf "%-5d %-8.02f %-8.02f %-8.02f %-10.02f %-10.02f %-14.02f %-8.02f %-8.02f\n", $_, $amount->{$_}, $fee->{$_}, $refund->{$_} || 0, $fee_refund->{$_} || 0, $adjustment->{$_} || 0, $fee_adj->{$_} || 0, $net->{$_}, $transfer->{$_};
    $total += $amount->{$_};
}

printf "      %-8.02f\n", $total;