#!/usr/bin/perl

use strict;
use warnings;

use SiteSummary;
use Getopt::Std;

my %kernelvers;
my %opts;

sub usage {
    my $retval = shift;
    print <<EOF;
Usage: $0 [-l]
   -l   list hosts using the given kernel versions
EOF
    exit $retval;
}

getopt("l", \%opts) || usage(1);

for_all_hosts(\&handle_host);

print_summary();

sub handle_host {
    my $hostid = shift;
    #print "$hostid\n";
    for my $kver (get_linux_kernel_ver($hostid)) {
        $kver = "" unless defined $kver;
        if (exists $kernelvers{$kver}) {
            push @{$kernelvers{$kver}}, $hostid ;
        } else {
            $kernelvers{$kver} = [$hostid];
        }
    }
}

sub print_summary {
    printf("  %-20s %5s\n", "kernel", "count");
    for my $kver (sort keys %kernelvers) {
        printf("  %-20s %5d\n", $kver,  scalar @{$kernelvers{$kver}});
        if (exists $opts{l}) {
            for my $hostid (sort @{$kernelvers{$kver}}) {
                my $hostname = get_hostname($hostid);
                my $site = get_site($hostid) || "";
                my $sitegroup = get_sitegroup($hostid) || "";
                printf "    %s %s/%s %s\n", $hostname, $site, $sitegroup, $hostid;
            }
        }
    }
}