#!/usr/bin/perl -w
use strict;
use Getopt::Long;
use Time::HiRes;
use List::Util qw( sum );
use Data::Dumper;
#use IO::Select; # does not work the way I want on Windows

GetOptions(
    'debug|d'    => \my $debug,
    're:s'       => \my @buckets,
    'totals|t'   => \my $totals,
    'window|w:s' => \my @windows, # in seconds
    'update|u:i' => \my $update,
);

if (! @windows) {
    @windows = qw(1 5 60);
};

@windows = sort { $a <=> $b } @windows;

$update ||= 1;

@buckets = map { s/:(\w+)$// ? [ $1 => qr/$_/ ] : [$_ => qr/$_/ ] } @buckets;
if ($totals) {
    unshift @buckets, ['totals' => qr/(?!)/ ];
};

my @names = map { $_->[0] } @buckets;

my @slots;

my $last = 0;
my $last_update = 0;
while (<>) {
    my $now = time;
    $last ||= $now - $windows[-1];
    my $elapsed = $now - $last;
    #print "Elapsed: $elapsed ($slots[0]->{totals})\n";
    chomp;

    # Check how many buckets have passed without data
    for (0..int($now - $last)-1) {
        unshift @slots, +{ map {; $_ => 0 } @names };
    };
    # Limit slots to maximum reporting size
    splice @slots, $windows[-1]+1;

    if ($totals) {
        $slots[0]->{totals}++;
    };
    BUCKET: for my $b (@buckets) {
        my ($n,$r) = @$b;
        if (/$r/) {
            $slots[0]->{ $n }++;
            last BUCKET;
        };
    };

    $last = $now;
    if ($now - $last_update >= $update) {
        local $" = "\t";
        print "\t@windows\n";
        for my $n (@names) {
            print "$n\t";
            for my $w (@windows) {
                print sprintf "%0.2f\t", sum( map { $_->{ $n } } @slots[ 1.. $w ] ) / $w;
            };
            print "\n";
        };
        $last_update = $now;
    };
};