#!/usr/bin/perl -w

use strict;
use warnings;
use JSON;
use File::Which;
use Getopt::Long;

my $json;
@{$json->{data}} = ();
my $zpool  = which('zpool');
my $zfs    = which('zfs');
my $sanoid = which('sanoid');

if (not $zpool or not $zfs){
  print 'ZBX_NOTSUPPOTED';
  exit(0);
}

my $pools      = 1;
my $fs         = 0;
my $zvol       = 0;
my $snap       = 0;
my $sanoidmon  = 0;
my $pretty     = 0;

GetOptions(
  "pools"           => \$pools,
  "fs|filesystems"  => \$fs,
  "zvols|volumes"   => \$zvol,
  "snapshots"       => \$snap,
  "sanoid"          => \$sanoidmon,
  "pretty"          => \$pretty
);

if ($fs or $zvol or $snap or $sanoidsnap){
  $pools = 0;
}
if ($pools + $fs + $zvol + $snap + $sanoidmon != 1){
  die "One and only one type of discovery should be provided\n";
}
if ($sanoidmon and not $sanoid){
  print to_json($json);
  exit 0;
}

if ($pools){
  foreach (qx($zpool list -H -o name)){
    chomp;
    push @{$json->{data}}, { '{#ZPOOL}' => $_ };
  }
} elsif ($fs){
  foreach (qx($zfs list -H -o name -t filesystem)){
    chomp;
    push @{$json->{data}}, { '{#ZFS_FS}' => $_ };
  }
} elsif ($zvol){
  foreach (qx($zfs list -H -o name -t volume)){
    chomp;
    push @{$json->{data}}, { '{#ZFS_ZVOL}' => $_ };
  }
} elsif ($snap){
  foreach (qx($zfs list -H -o name -t snap)){
    chomp;
    # Remove @ as they are not allowed in item key names
    # They will be converted back to @ by check_zfs script
    $_ =~ s/\@/%40/g;
    push @{$json->{data}}, { '{#ZFS_SNAP}' => $_ };
  }
} elsif ($sanoidmon){
  push @{$json->{data}}, { '{#ZFS_SANOID}' => $_ } foreach (qw(snapshot capacity health));
}
print to_json($json, { pretty => $pretty });