#!/usr/bin/env perl

use 5.010;
use strict;
use warnings;

my @test_subjects = (
    '--[RV: vRealize Operations Manager] new alert Type:Virtualization/Hypervisor, Sub-Type:Availability, State:critical, Object Type:VMwareAdapter Instance, Name:HOSTVCENTER01 from 192.168.1.121---',
    '--[RV: vRealize Operations Manager] new State:critical, Object Type:VMwareAdapter Instance, alert Type:Virtualization/Hypervisor, Sub-Type:Availability, Name:HOSTVCENTER01 from 192.168.1.121---',
    '--[RV: vRealize Operations Manager] new alert Type:Virtualization/Hypervisor, State:critical, Name:HOSTVCENTER01 from 192.168.1.121---',
);

my $subject_re = qr{(?x:
    (?>
            Manager ] \s+   (?<event>   \S+     )
        |   alert \s Type:  (?<type>    [^,]+   )
        |   Sub-Type:       (?<subtype> [^,]+   )
        |   State:          (?<state>   [^,]+   )
        |   Object \s Type: (?<object>  [^,]+   )
        |   Name:           (?<host>    \S+     )
        |   from \s+        (?<from>    [0-9.]+ )
    )
)};

my @fields = qw{event type subtype state object host from};
my $format = '%-'
           . (length((sort { length $b <=> length $a } @fields)[0]) + 1)
           . "s %s\n";
my $pre_subject  = '=== Subject ' . '=' x 30;
my $post_subject = '=' x 42;
my %empty; @empty{@fields} = ('Not supplied!') x @fields;

for my $subject (@test_subjects) {
    my %captured;

    while ($subject =~ /$subject_re/g) {
        $captured{$_} = $+{$_} for keys %+;
    }

    my %found = (%empty, %captured);

    say for $pre_subject, $subject, $post_subject;
    printf $format, "$_:", $found{$_} for @fields;
}

##</code><code>##

=== Subject ==============================
--[RV: vRealize Operations Manager] new alert Type:Virtualization/Hypervisor, Sub-Type:Availability, State:critical, Object Type:VMwareAdapter Instance, Name:HOSTVCENTER01 from 192.168.1.121---
==========================================
event:   new
type:    Virtualization/Hypervisor
subtype: Availability
state:   critical
object:  VMwareAdapter Instance
host:    HOSTVCENTER01
from:    192.168.1.121
=== Subject ==============================
--[RV: vRealize Operations Manager] new State:critical, Object Type:VMwareAdapter Instance, alert Type:Virtualization/Hypervisor, Sub-Type:Availability, Name:HOSTVCENTER01 from 192.168.1.121---
==========================================
event:   new
type:    Virtualization/Hypervisor
subtype: Availability
state:   critical
object:  VMwareAdapter Instance
host:    HOSTVCENTER01
from:    192.168.1.121
=== Subject ==============================
--[RV: vRealize Operations Manager] new alert Type:Virtualization/Hypervisor, State:critical, Name:HOSTVCENTER01 from 192.168.1.121---
==========================================
event:   new
type:    Virtualization/Hypervisor
subtype: Not supplied!
state:   critical
object:  Not supplied!
host:    HOSTVCENTER01
from:    192.168.1.121