#!/usr/bin/env perl

# Copyright (c) 2025, R. W. Rodolico
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# linux_virtual
# Unified Xen/libvirt guest inventory sensor.
# Replaces all_xen and all_libvirt.
#
# Revision History:
# 2026-10-12 Copilot v1.0.0 r? initial v3.8.0 unix virtual sensor
# 2026-10-12 Claude  v1.0.0 only running libvirt guests (as v3.7.1); xl header checks (F2a)
# 2026-10-18 Claude renamed from unix_virtual (bug 210)

package linux_virtual;

use strict;
use warnings;
use version;
our $VERSION = version->declare('v1.0.0');

use FindBin;
use File::Spec;
use lib File::Spec->catdir($FindBin::Bin), File::Spec->catdir("$FindBin::Bin/..");
use library qw(:all);

my $CATEGORY = 'xen';

#######################################################
#
# parseXlList( $xlText )
#
# Parses xl list output and emits xen.virtual guest fields.
#
# Parameters:
#   $xlText - text from xl list
#
# Returns:
#   array reference of output lines
#
# Side Effects:
#   none
#
#######################################################
sub parseXlList {
   my $xlText = shift;
   my @out;
   my @lines = split(/\n/, defined($xlText) ? $xlText : '');
   # as v3.7.1 all_xen: header, then Domain-0, then guests
   return \@out unless @lines >= 2 && $lines[0] =~ /^Name/ && $lines[1] =~ /^Domain-0/;
   for (my $i = 2; $i < @lines; $i++) {
      my $line = trim($lines[$i]);
      next unless $line =~ /\S/;
      my @f = split(/\s+/, $line);
      next unless @f >= 4;
      my ($name, $id, $memory, $numcpu) = ($f[0], $f[1], $f[2], $f[3]);
      push @out, "$CATEGORY\tvirtual\t$name\tid\t$id";
      push @out, "$CATEGORY\tvirtual\t$name\tmemory\t$memory";
      push @out, "$CATEGORY\tvirtual\t$name\tnumcpu\t$numcpu";
   }
   return \@out;
}

#######################################################
#
# parseVirshList( $virshText )
#
# Parses virsh list output (running guests) and emits id fields. Older
# reports usually only have id because v3.7.1 discarded other
# fields from libvirt listing.
#
# Parameters:
#   $virshText - text from virsh list
#
# Returns:
#   array reference of output lines
#
# Side Effects:
#   none
#
#######################################################
sub parseVirshList {
   my $virshText = shift;
   my @out;
   foreach my $line (split(/\n/, defined($virshText) ? $virshText : '')) {
      next if $line =~ /^\s*Id\s+Name\s+State\s*$/i;
      next if $line =~ /^\s*-+\s*$/;
      next unless $line =~ /\S/;
      my $trim = trim($line);
      my @f = split(/\s+/, $trim, 3);
      next unless @f >= 2;
      my ($id, $name) = ($f[0], $f[1]);
      # v3.7.1 ran 'virsh list' (running guests only), and libvirt gives only an id, which
      # is why libvirt hosts show just 'id' per guest; skip defined-but-stopped guests ('-')
      next unless $id =~ /^\d+$/;
      push @out, "$CATEGORY\tvirtual\t$name\tid\t$id";
   }
   return \@out;
}

#######################################################
#
# main()
#
# Emits virtual guest inventory on Linux hosts only.
#
# Parameters:
#   none
#
# Returns:
#   integer exit status
#
# Side Effects:
#   runs virtualization commands and writes STDOUT/STDERR
#
#######################################################
sub main {
   if (!checkOS({ 'linux' => undef })) {
      print STDERR "unsupported os\n";
      return 1;
   }

   unless (validCommandOnSystem({ 'xl' => undef }) || validCommandOnSystem({ 'virsh' => undef })) {
      print STDERR "neither xl nor virsh found\n";
      return 2;
   }

   my @out;
   push @out, @{parseXlList(runCommand('xl', 'list'))};
   push @out, @{parseVirshList(runCommand('virsh', 'list'))};

   if (!@out) {
      print STDERR "no xl or virsh guests found\n";
      return 2;
   }

   print join("\n", @out), "\n";
   return 0;
}

exit main() unless caller;
1;