#!/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_lvm
# Linux LVM2: storage.lvm keys (PVs resolved to disks, md or partitions), and the
# old diskinfo LVM keys (replaces all_lvm2). Runs only when lvs is installed.
#
# Revision History:
# 2026-10-18 Claude v1.0.0 new sensor, split from unix_storage (bug 210)

package linux_lvm;

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 = 'storage';
my $OLD_CATEGORY = 'diskinfo';
#######################################################
#
# parseLvm( $pvsText, $vgsText, $lvsText )
#
# Parses pvs, vgs and lvs output (--units b --nosuffix --noheadings
# --separator '|', default columns).
#
# Parameters:
#   $pvsText - pvs output (pv|vg|fmt|attr|psize|pfree)
#   $vgsText - vgs output (vg|#pv|#lv|#sn|attr|vsize|vfree)
#   $lvsText - lvs output (lv|vg|attr|lsize|...)
#
# Returns:
#   hash reference with array references pvs, vgs, lvs of hashes
#
# Side Effects:
#   none
#
#######################################################
sub parseLvm {
   my ($pvsText, $vgsText, $lvsText) = @_;
   my %lvm = ('pvs' => [], 'vgs' => [], 'lvs' => []);
   my $rows = sub {
      my $text = shift;
      return map { [map { trim($_) } split(/\|/, $_, -1)] } grep { /\S/ } split(/\n/, defined($text) ? $text : '');
   };
   foreach my $f ($rows->($pvsText)) {
      push @{$lvm{'pvs'}}, {'pv' => $f->[0], 'vg' => $f->[1], 'size' => $f->[4], 'free' => $f->[5]} if defined($f->[5]);
   }
   foreach my $f ($rows->($vgsText)) {
      push @{$lvm{'vgs'}}, {'vg' => $f->[0], 'size' => $f->[5], 'free' => $f->[6]} if defined($f->[6]);
   }
   foreach my $f ($rows->($lvsText)) {
      push @{$lvm{'lvs'}}, {'lv' => $f->[0], 'vg' => $f->[1], 'attr' => $f->[2], 'size' => $f->[3]} if defined($f->[3]);
   }
   return \%lvm;
}

#######################################################
#
# oldLvmLines( $lvm )
#
# Old diskinfo LVM keys, as v3.7.1 all_lvm2: sizes in whole KiB (v3.7.1
# used --units k and int), LVs keyed by name alone, VG used = size -
# free, VG components = its PVs.
#
# Parameters:
#   $lvm - hash reference from parseLvm
#
# Returns:
#   array reference of lines
#
# Side Effects:
#   none
#
#######################################################
sub oldLvmLines {
   my $lvm = shift;
   my @out;
   my $k = sub { return int($_[0] / 1024); };
   foreach my $lv (@{$lvm->{'lvs'}}) {
      push @out, "$OLD_CATEGORY\t$lv->{'lv'}\tsize\t" . $k->($lv->{'size'});
      push @out, "$OLD_CATEGORY\t$lv->{'lv'}\tfstype\tlvm2 lv";
      push @out, "$OLD_CATEGORY\t$lv->{'lv'}\tvg\t$lv->{'vg'}";
   }
   foreach my $vg (@{$lvm->{'vgs'}}) {
      push @out, "$OLD_CATEGORY\t$vg->{'vg'}\tsize\t" . $k->($vg->{'size'});
      push @out, "$OLD_CATEGORY\t$vg->{'vg'}\tused\t" . ($k->($vg->{'size'}) - $k->($vg->{'free'}));
      push @out, "$OLD_CATEGORY\t$vg->{'vg'}\tfstype\tlvm2 vg";
      push @out, "$OLD_CATEGORY\t$vg->{'vg'}\tcomponents\t" . join(' ', map { $_->{'pv'} } grep { $_->{'vg'} eq $vg->{'vg'} } @{$lvm->{'pvs'}});
   }
   foreach my $pv (@{$lvm->{'pvs'}}) {
      push @out, "$OLD_CATEGORY\t$pv->{'pv'}\tsize\t" . $k->($pv->{'size'});
      push @out, "$OLD_CATEGORY\t$pv->{'pv'}\tfstype\tlvm2 pv";
   }
   return \@out;
}

#######################################################
#
# lvmLines( $lvm, $res, $realPaths )
#
# storage.lvm keys; each PV is resolved to its md, disk or partition.
#
# Parameters:
#   $lvm       - hash reference from parseLvm
#   $res       - resolver
#   $realPaths - optional hash reference path => readlink -f result
#
# Returns:
#   array reference of lines
#
# Side Effects:
#   none
#
#######################################################
sub lvmLines {
   my ($lvm, $res, $realPaths) = @_;
   my @out;
   foreach my $pv (@{$lvm->{'pvs'}}) {
      my $prefix = "lvm\tpvs\t$pv->{'pv'}";
      push @out, "$CATEGORY\t$prefix\tvg\t$pv->{'vg'}" if $pv->{'vg'} ne '';
      push @out, "$CATEGORY\t$prefix\tsize_bytes\t$pv->{'size'}", "$CATEGORY\t$prefix\tfree_bytes\t$pv->{'free'}";
      push @out, memberLines($prefix, resolveMember($pv->{'pv'}, $res, $realPaths));
   }
   foreach my $vg (@{$lvm->{'vgs'}}) {
      push @out, "$CATEGORY\tlvm\tvgs\t$vg->{'vg'}\tsize_bytes\t$vg->{'size'}", "$CATEGORY\tlvm\tvgs\t$vg->{'vg'}\tfree_bytes\t$vg->{'free'}";
   }
   foreach my $lv (@{$lvm->{'lvs'}}) {
      my $prefix = "$CATEGORY\tlvm\tlvs\t$lv->{'vg'}/$lv->{'lv'}";
      push @out, "$prefix\tvg\t$lv->{'vg'}", "$prefix\tsize_bytes\t$lv->{'size'}", "$prefix\tattr\t$lv->{'attr'}";
   }
   return \@out;
}

#######################################################
#
# main()
#
# Emits storage.lvm and old diskinfo LVM keys.
#
# Parameters:
#   none
#
# Returns:
#   integer exit status (1 wrong OS, 2 not applicable)
#
# Side Effects:
#   runs pvs, vgs, lvs, readlink and lsblk, writes STDOUT/STDERR
#
#######################################################
sub main {
   if (!checkOS({ 'linux' => undef })) {
      print STDERR "unsupported os\n";
      return 1;
   }
   unless (haveCommand('lvs')) {
      print STDERR "lvs not found\n";
      return 2;
   }
   my $inv = localDiskInventory();
   if (defined($inv->{'missing'})) {
      print STDERR "$inv->{'missing'} not found\n";
      return 2;
   }
   my @args = ('--units', 'b', '--nosuffix', '--noheadings', '--separator', '|');
   my $lvm = parseLvm(runCommand('pvs', @args), runCommand('vgs', @args), runCommand('lvs', @args));
   unless (@{$lvm->{'pvs'}} || @{$lvm->{'vgs'}} || @{$lvm->{'lvs'}}) {
      print STDERR "no LVM volumes\n";
      return 2;
   }
   my %realPaths;
   foreach my $pv (@{$lvm->{'pvs'}}) {
      next unless $pv->{'pv'} =~ m{^/dev/disk/};
      my $real = runCommand('readlink', '-f', $pv->{'pv'});
      chomp $real;
      $realPaths{$pv->{'pv'}} = $real if $real ne '';
   }
   my @out;
   push @out, @{oldLvmLines($lvm)};
   push @out, @{lvmLines($lvm, $inv->{'resolver'}, \%realPaths)};
   print join("\n", @out), "\n";
   return 0;
}

exit main() unless caller;
1;