#!/usr/bin/perl

use lib "/usr/share/BackupPC/lib";
use BackupPC::Lib;
use BackupPC::CGI::Lib;
use POSIX;
use JSON;
use Getopt::Long;
use Data::Dumper;

my $host   = undef;
my $entity = undef;
my $pretty = 0;

GetOptions(
  "host=s"   => \$host,
  "entity=s" => \$entity,
  "pretty"   => \$pretty
);

# We need to switch to backuppc UID/GID
my $uid = getuid();
my $gid = getgid();
my (undef,undef,$bkpuid,$bkpgid) = getpwnam('backuppc');
setuid($bkpuid) if ($uid ne $bkpuid);
setgid($bkpgid) if ($gid ne $bkpgid);

my $bpc = BackupPC::Lib->new();
my $mainConf = $bpc->ConfigDataRead();
my $json = {};

if ( $host ) {
  my $hostConf = $bpc->ConfigDataRead($host);
  my $conf = { %$mainConf, %$hostConf };
  my $age = -1;

  # Backup frequency
  my $freq = ($conf->{FullPeriod} > $conf->{IncrPeriod}) ? $conf->{IncrPeriod} : $conf->{FullPeriod};

  my $lastXferErrors = 0;
  my $maxErrors = 0;
  my $new_size_of_last_full = 0;

  foreach my $backup ( $bpc->BackupInfoRead($host) ) {
    # Skip partial or active backups
    next if ( $backup->{type} !~ m/^full|incr$/ );
    if ( $backup->{type} eq "full" ) {
      $json->{full_size} = $backup->{size};
      $new_size_of_last_full = $backup->{sizeNew};
    }
    $json->{last_errors} = $backup->{xferErrs};
    $json->{new_size}    = $backup->{sizeNew};
    $json->{total_size} += $backup->{sizeNew};
    $json->{duration}    = $backup->{endTime} - $backup->{startTime};
    $json->{type}        = $backup->{type};
    $json->{ratio}       = ( $backup->{sizeNew} > 0 ) ? sprintf( "%.2f", 100 - ( $backup->{sizeNewComp} * 100 / $backup->{sizeNew} ) ) : 0;
    $age                 = $backup->{startTime};
  }
  $json->{enabled}     = ( $conf->{BackupsDisable} > 0 ) ? 0 : 1;
  $json->{total_size} += $json->{full_size} - 2 * $new_size_of_last_full;
  $json->{age} = time - $age;

  $json->{max_errors} = $conf->{MaxXferError} if (defined $conf->{MaxXferError});
} elsif ( $entity ) {

  $json = {
    perf  => 0,
    size  => 0,
    hosts => 0,
    bkp   => 0,
    ratio => 0
  };

  my $total_new  = 0;
  my $total_comp = 0;

  foreach my $host ( keys %{ $bpc->HostInfoRead } ) {
    next unless $host =~ m/^(vm_)?\Q$entity\E_.*/;
    my $full_size;

    $json->{hosts}++;

    my $hostConf = $bpc->ConfigDataRead($host);
    my $conf     = { %$mainConf, %$hostConf };
    my $freq     = ($conf->{FullPeriod} > $conf->{IncrPeriod}) ? $conf->{IncrPeriod} : $conf->{FullPeriod};
    my $duration = 0;
    my $bkp_num  = 0;

    foreach my $backup ( $bpc->BackupInfoRead( $host ) ) {
      next if ( $backup->{type} !~ m/^full|incr$/ );
      # For the last full backup of this host, we do not count
      # the new file size, but the total size
      # We substract 2 times the new file size because we want the total size
      if ( $backup->{type} eq 'full' ) {
        $full_size  = $backup->{size} - 2 * $backup->{sizeNew};
      }
      $size       += $backup->{sizeNew};
      $total_new  += $backup->{sizeNew};
      $total_comp += $backup->{sizeNewComp};
      $duration   += $backup->{endTime} - $backup->{startTime};
      $bkp_num++;
      $json->{bkp}++;
    }
    # Compute the average cost as the number of hours per day spent
    # to backup this host
    $json->{perf} += ( $bkp_num > 0 ) ? $duration / ( 3600 * $bkp_num * $freq ) : 0;
    $json->{size} += $size + $full_size;
  }
  $json->{ratio} = ( $total_new > 0 ) ? 100 - ( $total_comp * 100 / $total_new ) : 0;

  # Round some values
  foreach my $key ( qw(ratio perf) ) {
    $json->{$key} = sprintf( "%.2f", $json->{$key} );
  }
} else {
  print<<"EOF";

Usage: $0 --host=<host> or --entity=<entity>

EOF
}

print to_json( $json, { pretty => $pretty } );
exit(0);