#!/usr/bin/perl -wT

use strict;
use warnings;

$ENV{PATH} = '/bin:/usr/bin'; # untaint

BEGIN {

    unless (eval { require Beekeeper }) {
        # Modules not installed yet
        unshift @INC, ($ENV{'PERL5LIB'} =~ m/([^:]+)/g);
    }
}

use Beekeeper::Service::Supervisor;
use Term::ReadKey;
use Getopt::Long;

ReadMode "cbreak";
END { ReadMode "restore" }

my ($opt_host, $opt_pool, $opt_class, $opt_list, $opt_help);

GetOptions(
    "host=s"    => \$opt_host,    # --host
    "pool=s"    => \$opt_pool,    # --pool
    "class=s"   => \$opt_class,   # --class
    "list"      => \$opt_list,    # --list
    "help"      => \$opt_help,    # --help    
) or exit;

my $Help = "
Usage: bkpr-top [OPTIONS]
Display real-time performance metrics of running workers.

  -h, --host  str  display status only of specified host
  -p, --pool  str  display status only of specified pool
  -c, --class str  display status only of specified worker class
  -l, --list       show detailed status of all individual workers
  -h, --help       display this help and exit

Filters --host, --pool and --class can be combined.

Change sorting field with (M)emory, (C)pu, (L)oad, (N)otifications and (J)obs.

";

if ($opt_help) {
    print $Help;
    exit;
}

if ($opt_list) {

    # Clear the screen
    print "\033[2J";

    my $printed_lines = 0;
    my $sort_field = 'pid';
    my $order_desc = 1;
    my $scr_size = '';

    my %sort_fields = (
        'S' => 'class',
        'P' => 'pool',
        'H' => 'host',
        'I' => 'pid',
        'M' => 'msize',
        'N' => 'nps',
        'J' => 'jps',
        'C' => 'cpu',
        'L' => 'load',
    );

    while (1) {

        my $workers = Beekeeper::Service::Supervisor->get_workers_status(
            host  => $opt_host,
            pool  => $opt_pool,
            class => $opt_class,
        );

        my ($columns) = `tput cols`  =~ m/(\d+)/;
        my ($lines)   = `tput lines` =~ m/(\d+)/;

        # Clear the screen when dimensions change
        print "\033[2J" if ($scr_size ne "$columns-$lines");
        $scr_size = "$columns-$lines";

        my $w = $columns - 60;
        $w = 0 if $w < 0;

        # Echo title
        print "\033[0;0H";  # jump to 0,0
        print "\033[7m";    # reverse
        printf("%-${w}.${w}s %-8s %-8s %-8s %5s %5s %5s %5s %7s \n",
               'class','pool','host','pid','mem','nps','jps','cpu','load');
        print "\033[0m";    # normal

        # Sort
        my @workers = ($sort_field =~ m/class|pool|host|queue/) ? 
            sort { ($b->{$sort_field} || '') cmp ($a->{$sort_field} || '') || $a->{pid} <=> $b->{pid} } @$workers :
            sort { ($a->{$sort_field} || 0 ) <=> ($b->{$sort_field} || 0 ) || $a->{pid} <=> $b->{pid} } @$workers ;

        @workers = reverse @workers if ($order_desc);

        # Limit displayed lines in order to fit screen
        splice( @workers, $lines - 2 );

        foreach my $worker (@workers) {
            printf("%-${w}.${w}s %-8s %-8s %-8s %5s %5s %5s %5s %5s %% \n",
                $worker->{class},
                $worker->{pool},
                $worker->{host},
                $worker->{pid},
                $worker->{mem} || '-',
                sprintf("%.0f", $worker->{nps}  + .5) || '0',
                sprintf("%.0f", $worker->{jps}  + .5) || '0',
                sprintf("%.0f", $worker->{cpu}  + .5) || '0',
                sprintf("%.0f", $worker->{load} + .5) || '0',
            );
        }

        # Clear old lines at bottom screen
        print " " x $columns . "\n" for (@workers..$printed_lines-1);
        $printed_lines = scalar @workers;

        sleep 1;

        my $key = uc( ReadKey(-1) || '');
        last if ($key eq 'Q');
        if ($sort_fields{$key}) {
            $order_desc = ($sort_field eq $sort_fields{$key}) ? !$order_desc : 1;
            $sort_field = $sort_fields{$key};
        }
    }
}
else {

    # Clear the screen
    print "\033[2J";

    my $printed_lines = 0;
    my $sort_field = 'class';
    my $order_desc = 1;
    my $scr_size = '';

    my %sort_fields = (
        'S' => 'class',
        'W' => 'count',
        'N' => 'nps',
        'J' => 'jps',
        'C' => 'cpu',
        'L' => 'load',
    );

    while (1) {

        my $services = Beekeeper::Service::Supervisor->get_services_status(
            host  => $opt_host,
            pool  => $opt_pool,
            class => $opt_class,
        );

        foreach my $svc (keys %$services) {
            $services->{$svc}->{class} = $svc;
        }

        my @services = values %$services;

        my ($columns) = `tput cols`  =~ m/(\d+)/;
        my ($lines)   = `tput lines` =~ m/(\d+)/;

        # Clear the screen when dimensions change
        print "\033[2J" if ($scr_size ne "$columns-$lines");
        $scr_size = "$columns-$lines";

        my $w = $columns - 48;
        $w = 0 if $w < 0;

        # Echo title
        print "\033[0;0H";  # jump to 0,0
        print "\033[7m";    # reverse
        printf("%-${w}.${w}s %5s %8s %8s %8s %5s %7s \n",
               'class','count','MB','nps','jps','cpu','load');
        print "\033[0m";    # normal

        # Sort
        @services = ($sort_field =~ m/class/) ? 
            sort { ($b->{$sort_field} || '') cmp ($a->{$sort_field} || '') } @services :
            sort { ($a->{$sort_field} || 0 ) <=> ($b->{$sort_field} || 0 ) } @services ;

        @services = reverse @services if ($order_desc);

        # Limit displayed lines in order to fit screen
        splice( @services, $lines - 2 );

        foreach my $svc (@services) {
            printf("%-${w}.${w}s %5d %8.1f %8.1f %8.1f %5.0f %5.0f %% \n", 
                $svc->{class},
                $svc->{count},
                $svc->{mem} / 1000,
                $svc->{nps},
                $svc->{jps},
                $svc->{cpu},
                $svc->{load},
            );
        }

        # Clear old lines at bottom screen
        print " " x $columns, "\n" for (@services..$printed_lines-1);
        $printed_lines = scalar @services;

        sleep 1;

        my $key = uc( ReadKey(-1) || '');
        last if ($key eq 'Q');
        if ($sort_fields{$key}) {
            $order_desc = ($sort_field eq $sort_fields{$key}) ? !$order_desc : 1;
            $sort_field = $sort_fields{$key};
        }
    }
}


__END__

=head1 NAME

bkpr-top - Display real-time performance metrics of running workers

=head1 VERSION

Version 0.01

=head1 SYNOPSIS

  Usage: bkpr-top [OPTIONS]
  
  Display real-time performance metrics of running workers.
  
    -h, --host  str  display status only of specified host
    -p, --pool  str  display status only of specified pool
    -c, --class str  display status only of specified worker class
    -l, --list       show detailed status of all individual workers
    -h, --help       display this help and exit
  
  Filters --host, --pool and --class can be combined.
  
  Change sorting field with (M)emory, (C)pu, (L)oad, (N)otifications and (J)obs.

=head1 DESCRIPTION

Display in real-time performance metrics of all running workers connected
to a logic message bus in a 'top' fashion.

 "nps":  number of received notifications per second
 "jps":  number of processed jobs per second
 "mem":  resident memory size in KB
 "cpu":  percentage of cpu load
 "load": percentage of busy time

Sorting order can be changed pressing keys N, J, M, C and L.
Pressing Q quits the program.

=head1 SEE ALSO

L<Beekeeper::Service::Supervisor>.

=head1 AUTHOR

José Micó, C<jose.mico@gmail.com>

=head1 COPYRIGHT AND LICENSE

Copyright 2015 José Micó.

This is free software; you can redistribute it and/or modify it under the same 
terms as the Perl 5 programming language itself.

This software is distributed in the hope that it will be useful, but it is 
provided “as is” and without any express or implied warranties. For details, 
see the full text of the license in the file LICENSE.

=cut
