#!/usr/bin/env php
<?php

chdir(dirname($argv[0]));

if (count($argv)<2) {
  help();
}

function help() {
  print "backup.php -ch -d <backupdirectory> [ -n <numberofbackups> ]\n";
  print "-h Help.\n";
  print "-c Instead of copying the rrd files, make a symlink in the tmp directory to the actual location.\n";
  print "-d <backupdirectory> Directory to write the backup tarballs, with optional rotation.\n";
  print "-n If no number of backups is given, there will be no rotation.\n";
  exit(1);
}

$options = getopt("chd:n:");
if (isset($options['d'])) {
  $backupdirectory=$options['d'];
} else {
  print "Need option -d <backupdirectory>\n";
  exit(1);
}
if (isset($options['n'])) {
  $maxnumberofbackups=$options['n'];
} else {
  $maxnumberofbackups=0;
}

$backupfilename='observium-backup.tar.gz';
$configphp='/opt/observium/config.php';
$cronfile='/etc/cron.d/observium';
include($configphp);

if (substr($backupdirectory,-1)!='/') {
  # we need a / at the end of the directory name
  $backupdirectory.='/';
}
if (!file_exists($backupdirectory)) {
  print "Backup directory does not exist or is not a directory.\n";
  exit(1);
}
$backupfilepath=$backupdirectory.$backupfilename;

print "Rotating the old backups.\n";
$maxbackupnumber=$maxnumberofbackups-1; # of backups includes the numberless one that will be written in this run
for ($backupnumber=$maxbackupnumber; $backupnumber>0; $backupnumber--) {

  if ($backupnumber<$maxbackupnumber) {
    $olderbackupnumber=$backupnumber+1;
    if (file_exists($backupfilepath.'.'.$backupnumber)) {
      system('mv ' . $backupfilepath.'.'.$backupnumber . ' ' . $backupfilepath.'.'.$olderbackupnumber);
    }
  }

  if ($backupnumber==1) {
    if (file_exists($backupfilepath)) {
      system('mv ' . $backupfilepath . ' ' . $backupfilepath.'.'.$backupnumber);
    }
  } else {
    $newerbackupnumber=$backupnumber-1;
    if (file_exists($backupfilepath.'.'.$newerbackupnumber)) {
      system('mv ' . $backupfilepath.'.'.$newerbackupnumber . ' ' . $backupfilepath.'.'.$backupnumber);
    }
  }
}

print "Creating tmp directory ";
$tmpdir=system('mktemp -d --tmpdir='.$backupdirectory.' tmp-XXXXXXXX');
if (!file_exists($tmpdir)) {
  print "Failed to create tmp directory.\n";
  exit(1);
}

print "Copying config.php...";
system('cp -a ' . $configphp . ' ' . $tmpdir, $cpconfigphpexitstatus);
if ($cpconfigphpexitstatus==0) {
  print "cp config.php succeeded.\n";
} else {
  print "cp config.php failed.\n";
  exit(1);
}

print "Copying $cronfile...";
system('cp -a ' . $cronfile . ' ' . $tmpdir, $cpcronfileexitstatus);
if ($cpcronfileexitstatus==0) {
  print "cp $cronfile succeeded.\n";
} else {
  print "cp $cronfile failed.\n";
  exit(1);
}

$mysqlcmd = 'mysqldump --add-drop-table';
$mysqlcmd .= ' --result-file=' . $tmpdir . '/backup.sql';
$mysqlcmd .= ' --host=' . $config['db_host'];
$mysqlcmd .= ' --user=' . $config['db_user'];
$mysqlcmd .= ' --password=' . $config['db_pass'];
$mysqlcmd .= ' ' . $config['db_name'];

print "Starting to dump observium db...";
system($mysqlcmd, $mysqldumpexitstatus);
if ($mysqldumpexitstatus==0) {
  print "dump succeeded.\n";
} else {
  print "dump failed.\n";
  exit(1);
}

if (isset($options['c'])) {
  print "Symlinking " . $config['rrd_dir'] . " in the tmp directory.\n";
  system('ln -s ' . $config['rrd_dir'] . ' ' . $tmpdir.'/rrd');
} else {
  print "Copying rrd/ directory...";
  system('cp -a ' . $config['rrd_dir'] . ' ' . $tmpdir.'/rrd', $cprrdexitstatus);
  if ($cprrdexitstatus==0) {
    print "cp rrd/ succeeded.\n";
  } else {
    print "cp rrd/ failed.\n";
    exit(1);
  }
}

$tarcmd = 'tar --dereference -cz';
$tarcmd .= ' -f ' . $backupfilepath;
$tarcmd .= ' -C ' . $tmpdir . ' .';
print "Creating tar archive from tmp directory...";
system ($tarcmd, $tarexitstatus);
if ($tarexitstatus==0) {
  print "tar succeeded.\n";
  print "Deleting tmp directory...";
  system ('rm -r ' . $tmpdir, $rmtmpdirexitstatus);
  if ($rmtmpdirexitstatus==0) {
    print "rm succeeded.\n";
  } else {
    print "rm failed.\n";
    exit(1);
  }
} else {
  print "tar failed.\n";
  exit(1);
}

?>