#!/usr/bin/env perl
use warnings;
use strict;  

use version ; our $VERSION = 'v1.0.0';

# Template for modules to be used in sysinfo
# Author: R. W. Rodolico
# Date:   2017-11-24
#
# # get some information on lvm2
#
# Revision History
#
#

# find our location and use it for searching for libraries. library.pm must be in the same directory as the calling script
# or, if run interactively, in the parent of the modules
BEGIN {
   use FindBin;
   use File::Spec;
   # prepend the bin directory and its parent
   use lib File::Spec->catdir($FindBin::Bin), File::Spec->catdir("$FindBin::Bin/..");
   eval( 'use library;' );
   die sprintf( "Could not find library.pm in %s, INC is %s\n", __FILE__, join( "\n", @INC ) ) if $@;
}

#####
##### Change these to match your needs
#####

# Make this a list of all the modules we are going to use. You can replace undef with the version you need, if you like
my $modulesList = {
        'Data::Dumper'     => undef,
   };

# hash of commands that are needed for the system. key is the name of the command and, in some cases, the value will become
# the full path (from which or where)
my $commandsList = {
        'lvs' => undef,
        'vgs' => undef,
        'pvs' => undef,
   };

# list of operating systems this module can be used on.
my $osList = {
#         'mswin32' => undef,
#         'freebsd' => undef,
         'linux'   => undef,
   };

# the category the return data should go into. See sysinfo for a list
my $CATEGORY = 'diskinfo';

#####
##### End of required
#####

# some variables needed for our system
my $errorPrepend = 'error: in ' . __FILE__; # this is prepended to any error messages
my @out; # temporary location for each line of output

# Try to load the modules we need. If we can not, then make a list of missing modules for error message.
for my $module ( keys %$modulesList ) {
   eval ( "use $module;" );
   push @out, "$errorPrepend Could not load $module" if $@;
}

if ( ! @out && ! checkOS ( $osList ) ) { # check if we are on an acceptible operating system
    push @out, "$errorPrepend Invalid Operating System";
}
if ( !@out && ! validCommandOnSystem ( $commandsList ) ) {
   push @out, "$errorPrepend Can not find some commands needed";
}
if ( !@out ) { # we made it, we have everything, so do the processing
   #####
   ##### Your code starts here. Remember to push all output onto @out
   #####
   
   my @temp;
   my @output;
   my $line;

   my %pv;
   my %vg;
   my %lv;
   my $name;

   @output = qx( pvs --units k --noheadings );
   # this outputs several lines like the following
   #  /dev/md0   vg-md0 lvm2 a--  5860147200.00k 6995968.00k
   chomp @output;
   foreach $line ( @output ) {
      @temp = split( /\s+/, $line );
      $name = $temp[1];
      $pv{$name}{'vg'} = $temp[2];
      $pv{$name}{'size'} = $temp[5];
      $pv{$name}{'size'} =~ s/k//;
      $pv{$name}{'size'} = int( $pv{$name}{'size'} );
      $pv{$name}{'free'} = $temp[5];
      $pv{$name}{'free'} =~ s/k//;
      $pv{$name}{'free'} = int( $pv{$name}{'free'} );
   }

   # following outputs something like this
   #  vg-md0   1   9   0 wz--n- 5860147200.00k 6995968.00k
   @output = qx( 'vgs' --units k --noheadings );
   chomp @output;
   foreach $line ( @output ) {
      @temp = split( /\s+/, $line );
      $name = $temp[1];
      $vg{$name}{'size'} = $temp[6];
      $vg{$name}{'size'} =~ s/k//;
      $vg{$name}{'size'} = int( $vg{$name}{'size'} );
      $vg{$name}{'free'} = $temp[7];
      $vg{$name}{'free'} =~ s/k//;
      $vg{$name}{'free'} = int( $vg{$name}{'free'} );
   }

   # outputs something like this
   #  centos                      vg-md0 -wi-ao--   10485760.00k                                           
   @output = qx( lvs --units k --noheadings );
   chomp @output;
   foreach $line ( @output ) {
      @temp = split( /\s+/, $line );
      $name = $temp[1];
      $lv{$name}{'vg'} = $temp[2];
      $lv{$name}{'size'} = $temp[4];
      $lv{$name}{'size'} =~ s/k//;
      $lv{$name}{'size'} = int( $lv{$name}{'size'} );
   }

   my @out;

   foreach $line ( keys %lv ) {
      push @out, "$CATEGORY\t$line\tsize\t" . $lv{$line}{'size'};
      push @out, "$CATEGORY\t$line\tfstype\tlvm2 lv";
      push @out, "$CATEGORY\t$line\tvg\t" . $lv{$line}{'vg'};
   }

   foreach $line ( keys %vg ) {
      push @out, "$CATEGORY\t$line\tsize\t" . $vg{$line}{'size'};
      push @out, "$CATEGORY\t$line\tused\t" . ( $vg{$line}{'size'} - $vg{$line}{'free'}) ;
      push @out, "$CATEGORY\t$line\tfstype\tlvm2 vg";
      my @components;
      foreach my $pv ( keys %pv ) {
         if ( $pv{$pv}{'vg'} eq $line ) {
            push @components, $pv;
         }
      }
      push @out, "$CATEGORY\t$line\tcomponents\t" . join( ' ', @components );
   }

   foreach $line ( keys %pv ) {
      push @out, "$CATEGORY\t$line\tsize\t" . $pv{$line}{'size'};
      push @out, "$CATEGORY\t$line\tfstype\tlvm2 pv";
   }
   
   #####
   ##### Your code ends here.
   #####
}

# If we are testing from the command line (caller is undef), print the results for debugging
print join( "\n", @out ) . "\n" unless caller;
# called by do, which has a value of the last assignment made, so make the assignment. The equivilent of a return
my $return = join( "\n", @out );