#!/usr/bin/env perl
#
#  Copyright (C) 2009-2010 D. R. Commander.  All Rights Reserved.
#  Copyright (C) 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
#  Copyright (C) 2002-2003 Constantin Kaplinsky.  All Rights Reserved.
#  Copyright (C) 2002-2005 RealVNC Ltd.
#  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
#
#  This is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This software is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License along
#  with this program; if not, write to the Free Software Foundation, Inc.,
#  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

#
# vncserver - wrapper script to start an X VNC server.
#

use v5.10;
use warnings;

sub DEVENV() { $ENV{KASMVNC_DEVELOPMENT} };
use if DEVENV, Devel::StackTrace;

use Time::HiRes qw (sleep);
use Switch;
use File::Basename;
use List::Util qw(first);
use List::MoreUtils qw(any uniq);
use Data::Dumper;
use Try::Tiny;

use KasmVNC::CliOption;
use KasmVNC::ConfigKey;
use KasmVNC::PatternValidator;
use KasmVNC::EnumValidator;
use KasmVNC::Config;
use KasmVNC::Users;
use KasmVNC::TextOption;
use KasmVNC::TextUI;
use KasmVNC::Utils;
use KasmVNC::Logger;

use constant {
  NO_ARG_VALUE => 0,
  REQUIRED_ARG_VALUE => 1,
  OPTIONAL_ARG_VALUE => 2
};

InitLogger();

CheckWeCanRunInThisEnvironment();

DefineFilePathsAndStuff();

ParseAndProcessCliOptions();

PrepareLoggingAndXvncKillingFramework();
CreateUserConfigIfNeeded();
DefineConfigToCLIConversion();
LoadConfigs();
ActivateConfigToCLIConversion();
SetAppSettingsFromConfigAndCli();
DisableLegacyVncAuth();
AllowXProgramsToConnectToXvnc();
EnsureAtLeastOneKasmUserExists();
ConfigureDeToRun();

StartXvncOrExit();

PrintLogFilenameAndConfiguredUsersAndStuff();

if (! $skipxstartup) {
  CreateXstartupIfNeeded();
  RunXstartup();
}

PrintBrowserUrl();

exit;

###############################################################################
# Functions
###############################################################################

#
# CheckGeometryAndDepthAreSensible simply makes sure that the geometry and depth
# values are sensible.
#

sub CheckGeometryAndDepthAreSensible
{
  if ($geometry =~ /^(\d+)x(\d+)$/) {
    $width = $1; $height = $2;

    if (($width<1) || ($height<1)) {
      die "$prog: geometry $geometry is invalid\n";
    }

    $geometry = "${width}x$height";
  } else {
    die "$prog: geometry $geometry is invalid\n";
  }

  if ($depth && (($depth < 8) || ($depth > 32))) {
    die "Depth must be between 8 and 32\n";
  }
}


#
# GetLowestAvailableDisplayNumber gets the lowest available display number.  A
# display number n is taken if something is listening on the VNC server port
# (5900+n) or the X server port (6000+n).
#

sub GetLowestAvailableDisplayNumber
{
  foreach $n (1..99) {
    if (CheckVncIsntRunningOnDisplay($n)) {
      return $n+0; # Bruce Mah's workaround for bug in perl 5.005_02
    }
  }

  die "$prog: no free display number on $host.\n";
}


#
# CheckVncIsntRunningOnDisplay checks if the given display number is available.  A
# display number n is taken if something is listening on the VNC server port
# (5900+n) or the X server port (6000+n).
#

sub CheckVncIsntRunningOnDisplay
{
  local ($n) = @_;

  socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";
  eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';
  if (!bind(S, pack('S n x12', $AF_INET, 6000 + $n))) {
    close(S);
    return 0;
  }
  close(S);

  socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";
  eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';
  if (!bind(S, pack('S n x12', $AF_INET, 5900 + $n))) {
    close(S);
    return 0;
  }
  close(S);

  if (-e "/tmp/.X$n-lock") {
    $logger->warn("\nWarning: $host:$n is taken because of /tmp/.X$n-lock");
    $logger->warn("Remove this file if there is no X server $host:$n");
    return 0;
  }

  if (-e "/tmp/.X11-unix/X$n") {
    $logger->warn("\nWarning: $host:$n is taken because of /tmp/.X11-unix/X$n");
    $logger->warn("Remove this file if there is no X server $host:$n");
    return 0;
  }

  return 1;
}


#
# GetXDisplayDefaults uses xdpyinfo to find out the geometry, depth and pixel
# format of the current X display being used.  If successful, it sets the
# options as appropriate so that the X VNC server will use the same settings
# (minus an allowance for window manager decorations on the geometry).  Using
# the same depth and pixel format means that the VNC server won't have to
# translate pixels when the desktop is being viewed on this X display (for
# TrueColor displays anyway).
#

sub GetXDisplayDefaults
{
  local (@lines, @matchlines, $width, $height, $defaultVisualId, $i,
    $red, $green, $blue);

  $wmDecorationWidth = 4;     # a guess at typical size for window manager
  $wmDecorationHeight = 24;   # decoration size

  return if (!defined($ENV{DISPLAY}));

  @lines = `xdpyinfo 2>/dev/null`;

  return if ($? != 0);

  @matchlines = grep(/dimensions/, @lines);
  if (@matchlines) {
    ($width, $height) = ($matchlines[0] =~ /(\d+)x(\d+) pixels/);

    $width -= $wmDecorationWidth;
    $height -= $wmDecorationHeight;

    $geometry = "${width}x$height";
  }

  @matchlines = grep(/default visual id/, @lines);
  if (@matchlines) {
    ($defaultVisualId) = ($matchlines[0] =~ /id:\s+(\S+)/);

    for ($i = 0; $i < @lines; $i++) {
      if ($lines[$i] =~ /^\s*visual id:\s+$defaultVisualId$/) {
        if (($lines[$i+1] !~ /TrueColor/) ||
          ($lines[$i+2] !~ /depth/) ||
          ($lines[$i+4] !~ /red, green, blue masks/))
        {
          return;
        }
        last;
      }
    }

    return if ($i >= @lines);

    ($depth) = ($lines[$i+2] =~ /depth:\s+(\d+)/);
    ($red,$green,$blue)
    = ($lines[$i+4]
      =~ /masks:\s+0x([0-9a-f]+), 0x([0-9a-f]+), 0x([0-9a-f]+)/);

    $red = hex($red);
    $green = hex($green);
    $blue = hex($blue);

    if ($red > $blue) {
      $red = int(log($red) / log(2)) - int(log($green) / log(2));
      $green = int(log($green) / log(2)) - int(log($blue) / log(2));
      $blue = int(log($blue) / log(2)) + 1;
      $pixelformat = "rgb$red$green$blue";
    } else {
      $blue = int(log($blue) / log(2)) - int(log($green) / log(2));
      $green = int(log($green) / log(2)) - int(log($red) / log(2));
      $red = int(log($red) / log(2)) + 1;
      $pixelformat = "bgr$blue$green$red";
    }
  }
}


#
# quotedString returns a string which yields the original string when parsed
# by a shell.
#

sub quotedString
{
  local ($in) = @_;

  $in =~ s/\'/\'\"\'\"\'/g;

  return "'$in'";
}


#
# removeSlashes turns slashes into underscores for use as a file name.
#

sub removeSlashes
{
  local ($in) = @_;

  $in =~ s|/|_|g;

  return "$in";
}


#
# Usage
#

sub Usage
{
  die("\nusage: $prog [:<number>] [-desktop <desktop-name>] [-depth <depth>]\n".
    "                 [-geometry <width>x<height>]\n".
    "                 [-pixelformat rgbNNN|bgrNNN]\n".
    "                 [-fp <font-path>]\n".
    "                 [-fg]\n".
    "                 [-autokill]\n".
    "                 [-noxstartup]\n".
    "                 [-xstartup <file>]\n".
    "                 <Xvnc-options>...\n\n".
    "       $prog -kill <X-display>\n\n".
    "       $prog -list\n\n");
}


#
# List
#

sub List
{
  opendir(dirHandle, $vncUserDir);
  my @filelist = readdir(dirHandle);
  closedir(dirHandle);
  print "\nKasmVNC server sessions:\n\n";
  print "X DISPLAY #\tPROCESS ID\n";
  foreach my $file (@filelist) {
    if ($file =~ /$host:(\d+).pid/) {
      chop($tmp_pid = `cat $vncUserDir/$file`);
      if (IsProcessRunning($tmp_pid)) {
        print ":".$1."\t\t".`cat $vncUserDir/$file`;
      } else {
        unlink ($vncUserDir . "/" . $file);
      }
    }
  }
  exit 1;
}


#
# Kill
#

sub Kill
{
  $opt{'-kill'} =~ s/(:\d+)\.\d+$/$1/; # e.g. turn :1.0 into :1

  if ($opt{'-kill'} =~ /^:\d+$/) {
    $pidFile = "$vncUserDir/$host$opt{'-kill'}.pid";
  } else {
    if ($opt{'-kill'} !~ /^$host:/) {
      die "\nCan't tell if $opt{'-kill'} is on $host\n".
      "Use -kill :<number> instead\n\n";
    }
    $pidFile = "$vncUserDir/$opt{'-kill'}.pid";
  }

  if (! -r $pidFile) {
    die "\nCan't find file $pidFile\n".
    "You'll have to kill the Xvnc process manually\n\n";
  }

  $SIG{'HUP'} = 'IGNORE';
  chop($pid = `cat $pidFile`);
  $logger->warn("Killing Xvnc process ID $pid");

  if (IsProcessRunning($pid)) {
    system("kill $pid");
    WaitForTimeLimitOrSubReturningTrue(1, sub {
        !IsProcessRunning($pid)
      });
    if (IsProcessRunning($pid)) {
      print "Xvnc seems to be deadlocked.  Kill the process manually and then re-run\n";
      print "    ".$0." -kill ".$opt{'-kill'}."\n";
      print "to clean up the socket files.\n";
      exit
    }

  } else {
    $logger->warn("Xvnc process ID $pid already killed");
    $opt{'-kill'} =~ s/://;

    if (-e "/tmp/.X11-unix/X$opt{'-kill'}") {
      print "Xvnc did not appear to shut down cleanly.";
      print " Removing /tmp/.X11-unix/X$opt{'-kill'}\n";
      unlink "/tmp/.X11-unix/X$opt{'-kill'}";
    }
    if (-e "/tmp/.X$opt{'-kill'}-lock") {
      print "Xvnc did not appear to shut down cleanly.";
      print " Removing /tmp/.X$opt{'-kill'}-lock\n";
      unlink "/tmp/.X$opt{'-kill'}-lock";
    }
  }

  unlink $pidFile;
  exit;
}


#
# ParseOptionsAndRemoveMatchesFromARGV takes a list of possible options. Each
# option has a matching argument, indicating whether the option has a value
# following (can be required or optional), and sets up an associative array %opt
# of the values of the options given on the command line.  It removes all the
# arguments it uses from @ARGV and returns them in @optArgs.
#

sub ParseOptionsAndRemoveMatchesFromARGV
{
  local (@optval) = @_;
  local ($opt, @opts, %valFollows, @newargs);

  while (@optval) {
    $opt = shift(@optval);
    push(@opts,$opt);
    $valFollows{$opt} = shift(@optval);
  }

  @optArgs = ();
  %opt = ();

  arg: while (defined($arg = shift(@ARGV))) {
    foreach $opt (@opts) {
      if ($arg eq $opt) {
        push(@optArgs, $arg);
        switch($valFollows{$opt}) {
          case NO_ARG_VALUE {
            $opt{$opt} = 1;
            next arg;
          }
          case REQUIRED_ARG_VALUE {
            if (@ARGV == 0) {
              Usage();
            }

            $opt{$opt} = shift(@ARGV);
            push(@optArgs, $opt{$opt});

            next arg;
          }
          case OPTIONAL_ARG_VALUE {
            if (scalar @ARGV == 0 || $ARGV[0] =~ /^-/) {
              $opt{$opt} = 1;
              next arg;
            }

            $opt{$opt} = shift(@ARGV);
            push(@optArgs, $opt{$opt});

            next arg;
          }
        }
      }
    }
    push(@newargs,$arg);
  }

  @ARGV = @newargs;
}


# Routine to make sure we're operating in a sane environment.
sub CheckRequiredDependenciesArePresent
{
  local ($cmd);

  # Get the program name
  ($prog) = ($0 =~ m|([^/]+)$|);

  #
  # Check we have all the commands we'll need on the path.
  #

  cmd:
  foreach $cmd ("uname","xauth","hostname","whoami") {
    for (split(/:/,$ENV{PATH})) {
      if (-x "$_/$cmd") {
        next cmd;
      }
    }
    die "$prog: couldn't find \"$cmd\" on your PATH.\n";
  }

  if($exedir eq "") {
    cmd2:
    foreach $cmd ("Xvnc","vncpasswd") {
      for (split(/:/,$ENV{PATH})) {
        if (-x "$_/$cmd") {
          next cmd2;
        }
      }
      die "$prog: couldn't find \"$cmd\" on your PATH.\n";
    }
  }
  else {
    cmd3:
    foreach $cmd ($exedir."Xvnc",$exedir."vncpasswd") {
      for (split(/:/,$ENV{PATH})) {
        if (-x "$cmd") {
          next cmd3;
        }
      }
      die "$prog: couldn't find \"$cmd\".\n";
    }
  }

  if (!defined($ENV{HOME})) {
    die "$prog: The HOME environment variable is not set.\n";
  }

  #
  # Find socket constants. 'use Socket' is a perl5-ism, so we wrap it in an
  # eval, and if it fails we try 'require "sys/socket.ph"'.  If this fails,
  # we just guess at the values.  If you find perl moaning here, just
  # hard-code the values of AF_INET and SOCK_STREAM.  You can find these out
  # for your platform by looking in /usr/include/sys/socket.h and related
  # files.
  #

  chop($os = `uname`);
  chop($osrev = `uname -r`);

  eval 'use Socket';
  if ($@) {
    eval 'require "sys/socket.ph"';
    if ($@) {
      if (($os eq "SunOS") && ($osrev !~ /^4/)) {
        $AF_INET = 2;
        $SOCK_STREAM = 2;
      } else {
        $AF_INET = 2;
        $SOCK_STREAM = 1;
      }
    } else {
      $AF_INET = &AF_INET;
      $SOCK_STREAM = &SOCK_STREAM;
    }
  } else {
    $AF_INET = &AF_INET;
    $SOCK_STREAM = &SOCK_STREAM;
  }
}

sub CheckSslCertReadable {
  return if IsDryRun();

  RequireSslCertsToBeReadable();
}

sub IsDebian {
  return -f "/etc/debian_version";
}

sub RequireSslCertsToBeReadable {
  my $certFilename = DerivedValue("network.ssl.pem_certificate");
  my $certKeyFilename = DerivedValue("network.ssl.pem_key");

  @certs = ($certFilename, $certKeyFilename);
  @certs = grep defined, @certs;
  @certs = uniq @certs;

  my @unreadableCertFiles = map { -r $_ ? () : $_ } @certs;
  return if (scalar @unreadableCertFiles == 0);

  foreach my $unreadableCert (@unreadableCertFiles) {
    GuideUserToMakeCertFileReadable($unreadableCert);
  }
  exit 1;
}

sub FileGroupName {
  my $file = shift;
  my $grpId = (stat($file))[5];

  getgrgid($grpId);
}

sub AddUserToGroupCmd {
  my $certGroup = shift;

  if (IsRpmSystem()) {
    "usermod -a -G $certGroup \$USER"
  } else {
    "addgroup \$USER $certGroup"
  }
}

sub GuideUserToMakeCertFileReadable {
  my $certFile = shift;
  if (! -f $certFile) {
    $logger->warn("$certFile: certificate file doesn't exist or isn't a file");
    return;
  }

  my $certGroup = FileGroupName $certFile;
  my $addUserToGroupCmd = AddUserToGroupCmd $certGroup;

  $logger->warn(<<EOF);
$certFile: certificate isn't readable.
Make the certificate readable by adding your user to group "$certGroup":
  '$addUserToGroupCmd'
EOF
}

sub IsRpmSystem {
  system("command -v rpm >/dev/null 2>&1") == 0;
}

sub RequireUserToHaveKasmvncCertGroup {
  my $certGroup = 'kasmvnc-cert';
  if (system("groups | grep -qw $certGroup") != 0) {
    $logger->warn(<<EOF);
  Can't access TLS certificate.
  Please add your user to $certGroup via 'usermod -a -G $certGroup \$USER'
EOF
    exit(1);
  }
}

sub CreateXstartupIfNeeded
{
  if ((-e "$xstartupFile")) {
    return;
  }

  my $defaultXStartup
  = ("#!/bin/sh\n\n".
    "unset SESSION_MANAGER\n".
    "unset DBUS_SESSION_BUS_ADDRESS\n".
    "OS=`uname -s`\n".
    "if [ \$OS = 'Linux' ]; then\n".
    "  case \"\$WINDOWMANAGER\" in\n".
    "    \*gnome\*)\n".
    "      if [ -e /etc/SuSE-release ]; then\n".
    "        PATH=\$PATH:/opt/gnome/bin\n".
    "        export PATH\n".
    "      fi\n".
    "      ;;\n".
    "  esac\n".
    "fi\n".
    "if [ -x /etc/X11/xinit/xinitrc ]; then\n".
    "  exec /etc/X11/xinit/xinitrc\n".
    "fi\n".
    "if [ -f /etc/X11/xinit/xinitrc ]; then\n".
    "  exec sh /etc/X11/xinit/xinitrc\n".
    "fi\n".
    "[ -r \$HOME/.Xresources ] && xrdb \$HOME/.Xresources\n".
    "xsetroot -solid grey\n".
    "xterm -geometry 80x24+10+10 -ls -title \"\$VNCDESKTOP Desktop\" &\n".
    "twm\n");

  $logger->warn("Creating default startup script $xstartupFile");
  open(XSTARTUP, ">$xstartupFile");
  print XSTARTUP $defaultXStartup;
  close(XSTARTUP);
  chmod 0755, "$xstartupFile";
}

sub DetectAndExportDisplay {
  # If the unix domain socket exists then use that (DISPLAY=:n) otherwise use
  # TCP (DISPLAY=host:n)

  if (-e "/tmp/.X11-unix/X$displayNumber" ||
    -e "/usr/spool/sockets/X11/$displayNumber")
  {
    $ENV{DISPLAY}= ":$displayNumber";
  } else {
    $ENV{DISPLAY}= "$host:$displayNumber";
  }
}

sub RunXstartup {
  $logger->warn("Starting applications specified in $xstartupFile");
  DetectAndExportDisplay();
  $ENV{VNCDESKTOP}= $desktopName;

  if ($opt{'-fg'}) {
    if (! $skipxstartup) {
      system("$xstartupFile >> " . quotedString($desktopLog) . " 2>&1");
    }
    if (IsXvncRunning()) {
      $opt{'-kill'} = ':'.$displayNumber;
      Kill();
    }
  } else {
    if ($opt{'-autokill'}) {
      if (! $skipxstartup) {
        system("($xstartupFile; $0 -kill :$displayNumber) >> "
          . quotedString($desktopLog) . " 2>&1 &");
      }
    } else {
      if (! $skipxstartup) {
        system("$xstartupFile >> " . quotedString($desktopLog)
          . " 2>&1 &");
      }
    }
  }
}

sub DetectBinariesDir {
  my $result = "";
  my $slashndx = rindex($0, "/");

  if($slashndx>=0) {
    $result = substr($0, 0, $slashndx+1);
  }
  if ($result =~ m!unix/!) {
    $result = "/usr/bin/";
  }

  return $result;
}

sub DetectFontPath {
  if (-d "/etc/X11/fontpath.d") {
    $fontPath = "catalogue:/etc/X11/fontpath.d";
  }

  @fontpaths = ('/usr/share/X11/fonts', '/usr/share/fonts', '/usr/share/fonts/X11/');
  if (! -l "/usr/lib/X11") {push(@fontpaths, '/usr/lib/X11/fonts');}
  if (! -l "/usr/X11") {push(@fontpaths, '/usr/X11/lib/X11/fonts');}
  if (! -l "/usr/X11R6") {push(@fontpaths, '/usr/X11R6/lib/X11/fonts');}
  push(@fontpaths, '/usr/share/fonts/default');

  @fonttypes = ('misc',
    '75dpi',
    '100dpi',
    'Speedo',
    'Type1');

  foreach $_fpath (@fontpaths) {
    foreach $_ftype (@fonttypes) {
      if (-f "$_fpath/$_ftype/fonts.dir") {
        if (! -l "$_fpath/$_ftype") {
          $defFontPath .= "$_fpath/$_ftype,";
        }
      }
    }
  }

  if ($defFontPath) {
    if (substr($defFontPath, -1, 1) eq ',') {
      chop $defFontPath;
    }
  }

  if (!defined($fontPath) || $fontPath eq "") {
    $fontPath = $defFontPath;
  }
}

sub ProcessCliOptions {
  Usage() if ($opt{'-help'} || $opt{'-h'} || $opt{'--help'});

  Kill() if ($opt{'-kill'});

  List() if ($opt{'-list'});

  # Uncomment this line if you want default geometry, depth and pixelformat
  # to match the current X display:
  # GetXDisplayDefaults();

  if ($opt{'-geometry'}) {
    $geometry = $opt{'-geometry'};
  }
  if ($opt{'-noxstartup'}) {
    $skipxstartup = 1;
  }
  if ($opt{'-xstartup'}) {
    $xstartupFile = $opt{'-xstartup'};
  }
  if ($opt{'-fp'}) {
    $fontPath = $opt{'-fp'};
    $fpArgSpecified = 1;
  }
  if ($opt{'-debug'}) {
    $debug = 1;
    delete $opt{'-debug'};
    $opt{'-Log'} = '*:stderr:100';
  }
  if ($opt{'-config'}) {
    @configFiles = split ",", $opt{'-config'};
    delete $opt{'-config'};
  }
  $testOutputTopic = $opt{'-test-output-topic'};
}

sub CreateDotVncDir {
  if (!(-e $vncUserDir)) {
    if (!mkdir($vncUserDir,0755)) {
      die "$prog: Could not create $vncUserDir.\n";
    }
  }
}

sub DeWasSelectedEarlier {
  -e $de_was_selected_file;
}

sub DeWasSpecifiedOnCommandLine {
  defined($opt{'-select-de'}) && $opt{'-select-de'} ne "1";
}

sub PromptingForDeWasRequestedOnCommandLine {
 return unless defined($opt{'-select-de'});

 $opt{'-select-de'} == 1;
}

sub WarnIfShouldPromptForDe {
  return unless shouldPromptUserToSelectDe();

  $logger->warn(<<WARNING);

Warning: the Desktop Environment to run wasn't selected, but prompting to select
a Desktop Environment was disabled.
WARNING
}

sub DeWasntSelectedYet() {
  !DeWasSelectedEarlier();
}

sub shouldPromptUserToSelectDe() {
  return 1 if DeWasntSelectedYet();

  PromptingForDeWasRequestedOnCommandLine();
}

sub SelectDe {
  $selectDeCmd = ConstructSelectDeCmd();
  system($selectDeCmd) == 0 || die("Failed to execute $selectDeCmd\n");
}

sub ConfigureDeToRun {
  if (DeWasSpecifiedOnCommandLine()) {
    SelectDe();
    return;
  }

  AskUserToChooseDeOrManualXstartup();
}

sub AskUserToChooseDeOrManualXstartup {
  return if IsDryRun();

  if (PromptingDisabled()) {
    WarnIfShouldPromptForDe();
    return;
  }
  return unless shouldPromptUserToSelectDe();

  ForgetSelectedDe();
  SelectDe();
}

sub ConstructSelectDeCmd {
  my $cmd = "$selectDeBin";
  my $specifiedDe = $opt{'-select-de'};

  if ($specifiedDe) {
    $cmd .= " --select-de";
    if ($specifiedDe ne "1") {
      $cmd .= " $specifiedDe";
    }
  }

  $cmd;
}

sub ForgetSelectedDe {
  unlink $de_was_selected_file;
}

sub DetectDisplayNumberFromCliArgs {
  if (@ARGV == 0) {
    return;
  }

  my $displayNumber;
  if ($ARGV[0] =~ /^:(\d+)$/) {
    $displayNumber = $1;
    shift(@ARGV);
    if (!CheckVncIsntRunningOnDisplay($displayNumber)) {
      die "A VNC server is already running as :$displayNumber\n";
    }
  }

  $displayNumber;
}

sub CheckCliOptionsForBeingValid {
  if (@ARGV == 0) {
    return;
  }

  if (! IsCliOption($ARGV[0])) {
    Usage();
  }
}

sub IsCliOption {
  my $arg = shift;

  ($arg =~ /^-/) || ($arg =~ /^\+/);
}

sub DisableLegacyVncAuth {
  # Disable vnc auth, kasmvnc uses https basic auth
  system("echo 'WrLNwLrcrxM=' | base64 -d > $vncUserDir/passwd");
}

sub TellUserToSetupUserAndPassword {
  if (AtLeastOneUserConfigured()) {
    return;
  }

  $logger->warn("\nYou need to create a KasmVNC user to access your desktops.\n");
  system($exedir."kasmvncpasswd $kasmPasswdFile");
  if (($? >> 8) != 0) {
    exit 1;
  }
}

sub DefaultKasmUsername {
  my $defaultUsername = $systemUser;
  return if ($users->userExists($defaultUsername));

  $defaultUsername;
}

sub PromptForUsernameToCreate {
  my $defaultKasmUsername = DefaultKasmUsername();
  my $prompt;

  if ($defaultKasmUsername) {
    $prompt = "Enter username (default: $defaultKasmUsername): ";
  } else {
    $prompt = "Enter username: ";
  }

  Prompt($prompt) || $defaultKasmUsername;
}

sub GuideUserToEnterUserToCreate {
  my $userToCreate;

  print(<<"NEEDTOCREATEUSER");

Let's create a user.

NEEDTOCREATEUSER

  while (1) {
    $userToCreate = PromptForUsernameToCreate();
    next if !defined($userToCreate) || $userToCreate =~ /^\s+$/;

    if ($users->userExists($userToCreate)) {
      say "User already exists: \"$userToCreate\"";
      next;
    }
    last;
  };

  $userToCreate;
}

sub GuideUserToSetupKasmPasswdUser {
  my $userToCreate = GuideUserToEnterUserToCreate();

  unless ($users->addUser($userToCreate, "w")) {
    die("\nFailed to setup user \"$userToCreate\"\n");
  }
  print("Created user \"$userToCreate\"\n");
}


sub AtLeastOneUserConfigured {
  $users->count() > 0;
}

sub MakeXCookie {
  # Make an X server cookie and set up the Xauthority file
  # mcookie is a part of util-linux, usually only GNU/Linux systems have it.
  my $cookie = `mcookie`;
  # Fallback for non GNU/Linux OS - use /dev/urandom on systems that have it,
  # otherwise use perl's random number generator, seeded with the sum
  # of the current time, our PID and part of the encrypted form of the password.
  if ($cookie eq "" && open(URANDOM, '<', '/dev/urandom')) {
    my $randata;
    if (sysread(URANDOM, $randata, 16) == 16) {
      $cookie = unpack 'h*', $randata;
    }
    close(URANDOM);
  }
  if ($cookie eq "") {
    srand(time+$$+unpack("L",`cat $vncUserDir/passwd`));
    for (1..16) {
      $cookie .= sprintf("%02x", int(rand(256)) % 256);
    }
  }

  return $cookie;
}

sub SetupXauthorityFile {
  my $cookie = MakeXCookie();

  open(XAUTH, "|xauth -f $xauthorityFile source -");
  print XAUTH "add $host:$displayNumber . $cookie\n";
  print XAUTH "add $host/unix:$displayNumber . $cookie\n";
  close(XAUTH);
}

sub UserSpecifiedArgsToCmd {
  my $cmd = "";

  foreach my $arg (@ARGV) {
    $cmd .= " " . quotedString($arg);
    noteXvncOption($arg) if $arg =~ /^-/;
  }

  $cmd;
}

sub ConstructXvncCmd {
  my $cmd = $exedir."Xvnc :$displayNumber";

  $cmd .= UserSpecifiedArgsToCmd();
  $cmd .= SwallowedArgsToCmd();
  $cmd .= ConfigToCmd();
  $cmd .= LegacyModeArgsToCmd();

  $cmd .= " >> " . quotedString($desktopLog) . " 2>&1";

  return $cmd;
}

sub LegacyModeArgsToCmd {
  my %legacyOptions = (
    -rfbauth => "$vncUserDir/passwd",
    -rfbport => 5901,
    -rfbwait => 30000
  );
  my @cmd = ();

  while(my($optionName, $optionArg) = each %legacyOptions) {
    next if WasOptionSpecifiedViaCli($optionName);

    my $optionText = "$optionName " . quotedString($optionArg);
    push(@cmd, $optionText);
    noteXvncOption($optionName);
  }

  my $legacyCmd = join " ", @cmd;
  " $legacyCmd";
}

sub noteXvncOption {
  my $optionName = shift;

  $addedXvncOptions{$optionName} = 1;
}

sub WasOptionSpecifiedViaCli {
  my $optionName = shift;

  $addedXvncOptions{$optionName};
}

sub SwallowedArgsToCmd {
  my @swallowedOptions = qw(-fp -interface -websocketPort -Log);
  my @optionsInCliFormat = map { SwallowedOptionToCLI($_) } @swallowedOptions;
  " " . join " ", @optionsInCliFormat;
}

sub SwallowedOptionToCLI {
  my $optionName = shift;

  return unless ($opt{$optionName});

  noteXvncOption($optionName);
  "$optionName " . quotedString($opt{$optionName});
}

sub StartXvncAndRecordPID {
  system("$cmd & echo \$! >$pidFile");
}

sub DeleteLogLeftFromPreviousXvncRun {
  unlink($desktopLog);
}

sub StartXvncWithSafeFontPath {
  if ($fpArgSpecified) {
    $logger->warn("\nWARNING: The first attempt to start Xvnc failed, probably because the font");
    $logger->warn("path you specified using the -fp argument is incorrect.  Attempting to");
    $logger->warn("determine an appropriate font path for this system and restart Xvnc using");
    $logger->warn("that font path ...");
  } else {
    $logger->warn("\nWARNING: The first attempt to start Xvnc failed, possibly because the font");
    $logger->warn("catalog is not properly configured.  Attempting to determine an appropriate");
    $logger->warn("font path for this system and restart Xvnc using that font path ...");
  }
  $cmd =~ s@-fp [^ ]+@@;
  $cmd .= " -fp $defFontPath" if ($defFontPath);
  StartXvncAndRecordPID();
}

sub IsXvncRunning {
  IsProcessRunning(`cat $pidFile`);
}

sub WarnUserXvncNotStartedAndExit {
  $logger->warn("Could not start Xvnc.\n");
  unlink $pidFile;
  open(LOG, "<$desktopLog");
  while (<LOG>) { print; }
  close(LOG);
  die "\n";
}

sub WaitForXvncToRespond {
  my $sleepSlice = 0.1;
  my $sleptFor = 0;
  my $sleepLimit = 3;

  until (IsXvncResponding() || $sleptFor >= $sleepLimit) {
    sleep($sleepSlice);
    $sleptFor += $sleepSlice;
  }
}

sub IsXvncResponding {
  `xdpyinfo -display :$displayNumber >/dev/null 2>&1`;
  $? == 0;
}

sub UsingSafeFontPath {
  $fontPath eq $defFontPath
}

sub CreateUserConfigIfNeeded {
  my $configFilename = "$vncUserDir/kasmvnc.yaml";
  if (-e $configFilename) {
    return;
  }

  $logger->warn("Creating default config $configFilename");
  open(VNCUSERCONFIG, ">$configFilename");
  print VNCUSERCONFIG $defaultConfig;
  close(VNCUSERCONFIG);
  chmod 0644, "$configFilename";
}

sub PrintKasmUsers {
  $logger->warn("\nUsers configured:");
  $logger->warn($users->toString());
  $logger->warn("");
}

sub CheckWeCanRunInThisEnvironment {
  $exedir = DetectBinariesDir();
  CheckRequiredDependenciesArePresent();
}

sub DefineFilePathsAndStuff {
  #
  # Global variables.  You may want to configure some of these for
  # your site
  #

  $geometry = "1024x768";

  $vncUserDir = "$ENV{HOME}/.vnc";
  $vncUserConfig = "$vncUserDir/config";
  $kasmPasswdFile = "$ENV{HOME}/.kasmpasswd";

  $selectDeBin = DetectSelectDeBin();
  $de_was_selected_file="$ENV{HOME}/.vnc/.de-was-selected";

  $KasmVNC::Users::vncPasswdBin = $exedir . "kasmvncpasswd";
  $KasmVNC::Users::logger = $logger;

  $vncSystemConfigDir = "/etc/kasmvnc";
  if ($ENV{KASMVNC_DEVELOPMENT}) {
    $vncDefaultsConfig = "/src/unix/kasmvnc_defaults.yaml";
    $vncSystemConfig = "/src/unix/kasmvnc.yaml";
  } else {
    $vncDefaultsConfig = "/usr/share/kasmvnc/kasmvnc_defaults.yaml";
    $vncSystemConfig = "$vncSystemConfigDir/kasmvnc.yaml";
  }

  $vncUserConfig = "$ENV{HOME}/.vnc/kasmvnc.yaml";
  @configFiles = ($vncDefaultsConfig, $vncSystemConfig, $vncUserConfig);
  $defaultWebsocketPort = 8443;

  $skipxstartup = 0;
  $xauthorityFile = $ENV{XAUTHORITY} // "$ENV{HOME}/.Xauthority";

  $xstartupFile = $vncUserDir . "/xstartup";
  $defaultConfig = <<TEXT;
logging:
  log_writer_name: all
  log_dest: logfile
  level: 100
TEXT
  %appSettings = ();
  %addedXvncOptions = ();

  chop($host = `uname -n`);
  chop($hostIPs = `hostname -i`);
  @hostIPs = split ' ', $hostIPs;

  chop($systemUser = `whoami`);

  DetectFontPath();
}

sub limitVncModeOptions {
  my $self = shift;
  my $protocol = ConfigValue("network.protocol");

  return 1 if isBlank($protocol) || $protocol eq "http";

  my @allowedVncModeOptions = qw(network.protocol
    server.advanced.x_authority_file legacy.desktop_name
    server.advanced.x_font_path desktop.resolution.width);
  first { $self->hasKey($_) } @allowedVncModeOptions;
}

sub DefineConfigToCLIConversion {
  $KasmVNC::CliOption::fetchValueSub = \&ConfigValue;
  $KasmVNC::ConfigKey::fetchValueSub = \&ConfigValue;

  my $regionValidator = KasmVNC::PatternValidator->new({
    pattern => qr/^(-)?\d+(%)?$/,
    errorMessage => "must be an integer or percentage"
  });
  my $clipboardSizeValidator = KasmVNC::PatternValidator->new({
    pattern => qr/^(unlimited|\d+)$/,
    errorMessage => "must be 'unlimited' or a number"
  });
  my $autoNumberValidator = KasmVNC::PatternValidator->new({
    pattern => qr/^(auto|\d+)$/,
    errorMessage => "must be 'auto' or a number"
  });
  my $secondsValidator = KasmVNC::PatternValidator->new({
    pattern => qr/^(never|\d+)$/,
    errorMessage => "must be a number or 'never'"
  });
  my $allConfigKeysValidatorSub = sub {
    my @allConfigKeys = map { $_->configKeyNames() } @xvncOptions;

    KasmVNC::EnumValidator->new({
      allowedValues => [flatten(@allConfigKeys)]
    })
  };
  KasmVNC::CliOption::beforeIsActive(\&limitVncModeOptions);
  my $ipv4_regexp = '((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}';
  my $ipv6_regexp = '(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))';

  @xvncOptions = (
    KasmVNC::CliOption->new({
        name => 'geometry',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "desktop.resolution.width",
            type => KasmVNC::ConfigKey::INT
          }),
          KasmVNC::ConfigKey->new({
            name => "desktop.resolution.height",
            type => KasmVNC::ConfigKey::INT
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $width = $self->{'desktop.resolution.width'};
          my $height = $self->{'desktop.resolution.height'};
          if (defined($width) && defined($height)) {
            return $width . "x" . $height;
          }

          $geometry;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'AcceptSetDesktopSize',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "desktop.allow_resize",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'depth',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "desktop.pixel_depth",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(16 24 32)]
            })
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          $value || $depth;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'noWebsocket',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.protocol",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(http vnc)]
            })
          })
        ],
        isActiveSub => sub {
          my $self = shift;
          my $protocol = $self->{"network.protocol"};
          return unless defined($protocol);

          $protocol eq "vnc";
        },
        deriveValueSub => sub { 1 }
    }),
    KasmVNC::CliOption->new({
        name => 'websocketPort',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.websocket_port",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(auto|\d+)$/,
              errorMessage => "must be one a number or 'auto'"
            }),
          })
        ],
        deriveValueSub => sub {
          my $self = shift;

          my $value = $self->configValue();
          if ($value eq 'auto' || !defined($value)) {
            return GenerateWebsocketPortFromDisplayNumber();
          }

          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'interface',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.interface",
            type => KasmVNC::ConfigKey::ANY
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'UseIPv4',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.use_ipv4",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'UseIPv6',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.use_ipv6",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'cert',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.ssl.pem_certificate",
            type => KasmVNC::ConfigKey::ANY
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'key',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.ssl.pem_key",
            type => KasmVNC::ConfigKey::ANY
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'sslOnly',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.ssl.require_ssl",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'AlwaysShared',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "user_session.session_type",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(shared exclusive)]
            })
          })
        ],
        deriveValueSub => sub {
          1;
        },
        isActiveSub => sub {
          my $self = shift;
          my $sessionType =  $self->configValue();
          return unless defined($sessionType);

          $sessionType eq "shared";
        }
    }),
    KasmVNC::CliOption->new({
        name => 'DisconnectClients',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "user_session.new_session_disconnects_existing_exclusive_session",
            type => KasmVNC::ConfigKey::ANY
          })
        ],
        deriveValueSub => sub {
          my $self = shift;

          $self->configValue() eq "true" ? 1 : 0;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'NeverShared',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "user_session.session_type",
            type => KasmVNC::ConfigKey::ANY
          })
        ],
        deriveValueSub => sub {
          1;
        },
        isActiveSub => sub {
          my $self = shift;
          my $sessionType =  $self->configValue();
          return unless defined($sessionType);

          $sessionType eq "exclusive";
        },
    }),
    KasmVNC::CliOption->new({
        name => 'QueryConnect',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "user_session.concurrent_connections_prompt",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'IdleTimeout',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "user_session.idle_timeout",
            validator => $secondsValidator
          })
        ],
        deriveValueSub => \&deriveSeconds
    }),
    KasmVNC::CliOption->new({
        name => 'RemapKeys',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "keyboard.remap_keys",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^0x[[:xdigit:]]+->0x[[:xdigit:]]+$/,
              errorMessage => "must be in the format 0x<hex_number>->0x<hex_number>"
            }),
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'AvoidShiftNumLock',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "keyboard.ignore_numlock",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'RawKeyboard',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "keyboard.raw_keyboard",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'AcceptPointerEvents',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "pointer.enabled",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'Log',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "logging.log_writer_name",
            type => KasmVNC::ConfigKey::ANY
          }),
          KasmVNC::ConfigKey->new({
            name => "logging.log_dest",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(logfile syslog)]
            })
          }),
          KasmVNC::ConfigKey->new({
            name => "logging.level",
            type => KasmVNC::ConfigKey::INT
          })
        ],
        deriveValueSub => sub {
          my $self = shift;

          my $writerName = $self->{"logging.log_writer_name"};
          if ($writerName eq "all") {
            $writerName = "*";
          }

          my $log_dest = $self->{"logging.log_dest"};
          if ($log_dest eq "logfile") {
            $log_dest = "stdout";
          }
          my $level = $self->{"logging.level"};

          "$writerName:$log_dest:$level";
        }
    }),
    KasmVNC::CliOption->new({
        name => 'BlacklistThreshold',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "security.brute_force_protection.blacklist_threshold",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'BlacklistTimeout',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "security.brute_force_protection.blacklist_timeout",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_Region',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.visible_region.top",
            validator => $regionValidator
          }),
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.visible_region.left",
            validator => $regionValidator
          }),
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.visible_region.right",
            validator => $regionValidator
          }),
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.visible_region.bottom",
            validator => $regionValidator
          }),
        ],
        deriveValueSub => sub {
          my $self = shift;

          join ",", ($self->{"data_loss_prevention.visible_region.left"},
            $self->{"data_loss_prevention.visible_region.top"},
            $self->{"data_loss_prevention.visible_region.right"},
            $self->{"data_loss_prevention.visible_region.bottom"}
          );
        }
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_RegionAllowClick',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.visible_region.concealed_region.allow_click_down",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_RegionAllowRelease',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.visible_region.concealed_region.allow_click_release",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_ClipDelay',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.clipboard.delay_between_operations",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(none|\d+)$/,
              errorMessage => "must be 'none' or a number in milliseconds"
            }),
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          if ($value eq "none") {
            $value = 0;
          }
          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'SendCutText',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.clipboard.server_to_client.enabled",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_ClipSendMax',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.clipboard.server_to_client.size",
            validator => $clipboardSizeValidator
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          if ($value eq "unlimited") {
            $value = 0;
          }
          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'SendPrimary',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.clipboard.server_to_client.primary_clipboard_enabled",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'AcceptCutText',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.clipboard.client_to_server.enabled",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_ClipAcceptMax',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.clipboard.client_to_server.size",
            validator => $clipboardSizeValidator
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          if ($value eq "unlimited") {
            $value = 0;
          }
          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'AcceptKeyEvents',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.keyboard.enabled",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_KeyRateLimit',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.keyboard.rate_limit",
            validator => $clipboardSizeValidator
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          if ($value eq "unlimited") {
            $value = 0;
          }
          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_Log',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.logging.level",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(off info verbose)]
            })
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'FrameRate',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.max_frame_rate",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DynamicQualityMin',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.rect_encoding_mode.min_quality",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'DynamicQualityMax',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.rect_encoding_mode.max_quality",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'TreatLossless',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.rect_encoding_mode.consider_lossless_quality",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'RectThreads',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.rect_encoding_mode.rectangle_compress_threads",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(auto|\d+)$/,
              errorMessage => "must be 'auto' or a number in milliseconds"
            }),
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          if ($value eq "auto") {
            $value = 0;
          }
          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'JpegVideoQuality',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.jpeg_quality",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'WebpVideoQuality',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.webp_quality",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'MaxVideoResolution',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.max_resolution.width",
            type => KasmVNC::ConfigKey::INT
          }),
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.max_resolution.height",
            type => KasmVNC::ConfigKey::INT
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          $self->{'encoding.video_encoding_mode.max_resolution.width'} . "x"
            . $self->{'encoding.video_encoding_mode.max_resolution.height'};
        }
    }),
    KasmVNC::CliOption->new({
        name => 'VideoTime',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.enter_video_encoding_mode.time_threshold",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'VideoArea',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.enter_video_encoding_mode.area_threshold",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(\d+%)$/,
              errorMessage => "must be a number, followed by %"
            }),
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $value = $self->configValue();
          $value =~ s/%$//;

          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'VideoOutTime',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.exit_video_encoding_mode.time_threshold",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'PrintVideoArea',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.logging.level",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(off info)]
            })
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $value = $self->configValue();
          switch($value) {
            case 'off' { return 0 }
            case 'info' { return 1 }
          }

          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'VideoScaling',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.video_encoding_mode.scaling_algorithm",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(nearest bilinear progressive_bilinear)]
            })
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $value = $self->configValue();
          switch($value) {
            case 'nearest' { return 0 }
            case 'bilinear' { return 1 }
            case 'progressive_bilinear' { return 2 }
          }

          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'CompareFB',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.compare_framebuffer",
            validator => KasmVNC::EnumValidator->new({
              allowedValues => [qw(off always auto)]
            })
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $value = $self->configValue();
          switch($value) {
            case 'off' { return 0 }
            case 'always' { return 1 }
            case 'auto' { return 2 }
          }

          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'ZlibLevel',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.zrle_zlib_level",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(auto|[0-9])$/,
              errorMessage => "must be 'auto' or a number in 0..9"
            }),
          })
        ],
        isActiveSub => sub {
          $self = shift;

          my $value = $self->configValue();
          isPresent($value) && $value ne "auto";
        }
    }),
    KasmVNC::CliOption->new({
        name => 'ImprovedHextile',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.hextile_improved_compression",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'httpd',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.http.httpd_directory",
            type => KasmVNC::ConfigKey::ANY
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'http-header',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.http.headers",
            type => KasmVNC::ConfigKey::ANY
          })
        ],
        toStringSub => sub {
          $self = shift;

          my @values = @{ listify($self->configValues()) };

          my $valuesStr = "";
          foreach $value (@values) {
            $valuesStr = $valuesStr . "-http-header '$value' "
          }
          chop($valuesStr);
          return $valuesStr;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'IgnoreClientSettingsKasm',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "runtime_configuration.allow_client_to_override_kasm_server_settings",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $value = $self->configValue();

          switch($value) {
            case 'true' {
              $value = 0;
            }
            case 'false' {
              $value = 1;
            }
          }

          $value;
      }
    }),
    KasmVNC::CliOption->new({
        name => 'fp',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.advanced.x_font_path",
            type => KasmVNC::ConfigKey::ANY
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $value = $self->configValue();
          return $value if isPresent($value) && $value ne 'auto';

          $fontPath;
        },
        isActiveSub => sub {
          my $self = shift;

          my $value = $self->configValue();
          return 1 if isPresent($value) && $value ne 'auto';

          $fontPath;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'KasmPasswordFile',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.advanced.kasm_password_file",
            type => KasmVNC::ConfigKey::ANY
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'MaxDisconnectionTime',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.auto_shutdown.no_user_session_timeout",
            validator => $secondsValidator
          })
        ],
        deriveValueSub => \&deriveSeconds
    }),
    KasmVNC::CliOption->new({
        name => 'MaxConnectionTime',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.auto_shutdown.active_user_session_timeout",
            validator => $secondsValidator
          })
        ],
        deriveValueSub => \&deriveSeconds
    }),
    KasmVNC::CliOption->new({
        name => 'MaxIdleTime',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.auto_shutdown.inactive_user_session_timeout",
            validator => $secondsValidator
          })
        ],
        deriveValueSub => \&deriveSeconds
    }),
    KasmVNC::CliOption->new({
        name => 'auth',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "server.advanced.x_authority_file",
            type => KasmVNC::ConfigKey::ANY
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my $value = $self->configValue();
          return $value if isPresent($value) && $value ne 'auto';

          $xauthorityFile;
        },
        isActiveSub => sub { 1; }
    }),
    KasmVNC::CliOption->new({
        name => 'desktop',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "legacy.desktop_name",
            type => KasmVNC::ConfigKey::ANY
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          if (isBlank($value) || $value eq "default") {
            $desktopName = DefaultDesktopName();
            return $desktopName;
          }

          $desktopName = $value;
        },
        isActiveSub => sub { 1; }
     }),
     KasmVNC::CliOption->new({
        name => 'AllowOverride',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "runtime_configuration.allow_override_standard_vnc_server_settings",
            type => KasmVNC::ConfigKey::BOOLEAN
          }),
          KasmVNC::ConfigKey->new({
            name => "runtime_configuration.allow_override_list",
            validator => $allConfigKeysValidatorSub
          })
        ],
        deriveValueSub => sub {
          $self = shift;

          my @overrideList = @{
            listify($self->{'runtime_configuration.allow_override_list'})
          };

          my @cliOptionList = map { cliOptionForConfigKey($_) } @overrideList;
          @cliOptionList = map { $_->{name} } @cliOptionList;

          join ",", @cliOptionList;
        },
        isActiveSub => sub {
          $self = shift;

          my $allowOverride = $self->{'runtime_configuration.allow_override_standard_vnc_server_settings'};
          return unless defined($allowOverride);

          $allowOverride eq "true";
        }
    }),
    KasmVNC::CliOption->new({
        name => 'DLP_ClipTypes',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "data_loss_prevention.clipboard.allow_mimetypes",
            type => KasmVNC::ConfigKey::ANY
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'QueryConnectTimeout',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "user_session.concurrent_connections_prompt_timeout",
            type => KasmVNC::ConfigKey::INT
          })
        ]
    }),
    KasmVNC::CliOption->new({
        name => 'PublicIP',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.udp.public_ip",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(auto|$ipv4_regexp|$ipv6_regexp)$/,
              errorMessage => "must be 'auto' or a valid IPv4 or IPv6 address"
            }),
          })
        ],
        isActiveSub => sub {
          $self = shift;

          my $value = $self->configValue();
          isPresent($value) && $value ne 'auto';
        }
    }),
    KasmVNC::CliOption->new({
        name => 'udpFullFrameFrequency',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "encoding.full_frame_updates",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(none|\d+)$/,
              errorMessage => "must be 'none' or an integer"
            }),
          })
        ],
        deriveValueSub => sub {
          my $self = shift;
          my $value = $self->configValue();

          if ($value eq "none") {
            $value = 0;
          }
          $value;
        }
    }),
    KasmVNC::CliOption->new({
        name => 'udpPort',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.udp.port",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(auto|\d+)$/,
              errorMessage => "must be 'auto' or an integer"
            }),
          })
        ],
        isActiveSub => sub {
          $self = shift;

          my $value = $self->configValue();
          isPresent($value) && $value ne 'auto';
        }
    }),
    KasmVNC::CliOption->new({
        name => 'StunServer',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "network.udp.stun_server",
            validator => KasmVNC::PatternValidator->new({
              pattern => qr/^(auto|\S+)$/,
              errorMessage => "must be 'auto' or an IP address/hostname"
            }),
          })
        ],
        isActiveSub => sub {
          $self = shift;

          my $value = $self->configValue();
          isPresent($value) && $value ne 'auto';
        }
    }),
    KasmVNC::CliOption->new({
        name => 'hw3d',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "desktop.gpu.hw3d",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ],
        deriveValueSub => sub {
          undef;
        },
        isActiveSub => sub {
          my $self = shift;

          $self->configValue() eq 'true';
        }
    }),
    KasmVNC::CliOption->new({
        name => 'drinode',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "desktop.gpu.drinode",
            type => KasmVNC::ConfigKey::ANY
          })
        ]
    }),
  );

  %cliArgMap = map { ("-" . $_->{name}) => $_ } @xvncOptions;
  %configKeyToXvncOptionMap = map {
    my $option = $_;

    map { $_->{name} => $option } @{ $option->{configKeys} };
  } @xvncOptions;
  # my $xvncDoc = "./Xvnc.md";
  # open(FH, '<', $xvncDoc) or die $!;

  # while(<FH>){
  #   if (m/\* \*\*-(\w+)/) {
  #     my $optionName = $1;
  #     if ($optionName) {
  #       $optionName = "-$optionName";
  #       my $cliOption = $cliArgMap{$optionName};
  #       if ($cliOption) {
  #         my @keys = @{ $cliOption->configKeyNames() };
  #         say '### ' . join(", ", @keys);
  #       }
  #     }
  #   }
  #   print $_;
  # }

  # close(FH);
  # exit 0;
}

sub PromptingAllowed {
  $appSettings{prompt}
}

sub PromptingDisabled {
  !PromptingAllowed();
}

sub cliOptionForConfigKey {
  my $configKey = shift;

  my $cliOptionForConfigKey = first { $_->hasKey($configKey) } @xvncOptions;
}

sub deriveSeconds {
  my $self = shift;

  my $value = $self->configValue();
  return 0 if $value eq 'never';

  $value;
}

sub deriveFromConfigAndLocalCli {
  my $self = shift;

  my $cliOptionName = "-" . $self->{name};
  my $cliOptionValue = $opt{$cliOptionName};
  my $configValue = deriveBoolean($self->configValue());

  return $configValue unless defined($cliOptionValue);

  $cliOptionValue;
}

sub ParseAndProcessCliOptions {
  my @supportedOptions = ("-geometry",1,"-kill",1,"-help",0,"-h",0,"--help",0,"-fp",1,"-list",0,"-fg",0,"-autokill",0,"-noxstartup",0,"-xstartup",1,"-select-de",OPTIONAL_ARG_VALUE, "-interface", REQUIRED_ARG_VALUE, '-debug', NO_ARG_VALUE, '-websocketPort', REQUIRED_ARG_VALUE, "-dry-run", NO_ARG_VALUE, '-config', REQUIRED_ARG_VALUE, '-test-output-topic', REQUIRED_ARG_VALUE, '-prompt', REQUIRED_ARG_VALUE);
  @vncserverOptions = (
    KasmVNC::CliOption->new({
        name => 'prompt',
        configKeys => [
          KasmVNC::ConfigKey->new({
            name => "command_line.prompt",
            type => KasmVNC::ConfigKey::BOOLEAN
          })
        ],
        deriveValueSub => \&deriveFromConfigAndLocalCli
    })
  );
  ParseOptionsAndRemoveMatchesFromARGV(@supportedOptions);
  ProcessCliOptions();
  CheckGeometryAndDepthAreSensible();

  $displayNumber = DetectDisplayNumberFromCliArgs();
  if (!defined($displayNumber)) {
    $displayNumber = GetLowestAvailableDisplayNumber();
  }
  CheckCliOptionsForBeingValid();
}

sub CheckBrowserHostDefined {
  return if IsDryRun();

  scalar DeduceBrowserHosts() > 0 || \
    die "-interface has no default value and wasn't passed by user";
}

sub DefaultDesktopName {
  "$host:$displayNumber ($systemUser)";
}

sub GenerateWebsocketPortFromDisplayNumber {
  $defaultWebsocketPort + $displayNumber;
}

sub LoadUsers {
  $users = KasmVNC::Users->loadFrom($kasmPasswdFile);
}

sub EnsureAtLeastOneKasmUserExists {
  return if IsDryRun();

  LoadUsers();

  unless (PromptingAllowed()) {
    return unless $users->is_empty();

    $logger->warn(<<TEXT);
No users configured and prompting is prohitibed, exiting.
Use vncpasswd(1) to add a user or enable command_line.prompt in config.
TEXT
    exit 1;
  }

  return if AtLeastOneUserWithWriteAccessConfigured();

  GuideUserToAddWritePermissionsToExistingUser();
  $users->reload();
}

sub GuideUserToAddWritePermissionsToExistingUser {
  my @options = ();

  my @users = sort $users->users();
  foreach my $user (@users) {
    my $name = $user->name();
    push(@options, KasmVNC::TextOption->new({
        description =>
          "Provide user '$name' with write access",
        callback => sub {
          $users->addPermissions($name, "w");
          say "Added write permissions for user '$name'";
        }
    }));
  }
  push(@options, KasmVNC::TextOption->new({
      description => "Create a new user with write access",
      callback => sub {
        GuideUserToSetupKasmPasswdUser();
        $users->reload();
      }
  }));
  push(@options, KasmVNC::TextOption->new({
      description => "Start KasmVNC without a user with write access"
  }));

  my $banner = <<"NEEDTOADDWRITEPERMISSIONS";

In order to control your desktop, you need a KasmVNC user with write
permissions. Select what action to take:
NEEDTOADDWRITEPERMISSIONS

  my $option = askUserToChooseOption(
    banner => $banner,
    prompt => 'Provide selection number',
    options => \@options,
  );

  &{ $option->callback() }();
}

sub AtLeastOneUserWithWriteAccessConfigured {
  $users->findByPermissions("w") > 0;
}

sub ShouldPrintTopic {
  my $topic = shift;

  return 1 unless ($testOutputTopic);
  return 1 if ($testOutputTopic eq "all");

  $topic eq $testOutputTopic;
}

sub SupportedAbsoluteKeys {
  my @supportedAbsoluteKeys =
    map { $_->configKeyNames() } @allCliOptions;
  @supportedAbsoluteKeys = flatten(@supportedAbsoluteKeys);
  my %result = map { $_ => 1 } @supportedAbsoluteKeys;

  \%result;
}

sub SupportedSectionsFromAbsoluteKey {
  my $absoluteKey = shift;
  my @sections = ();

  return @sections unless ($absoluteKey =~ /\./);

  while ($absoluteKey =~ /\./) {
    $absoluteKey =~ s/\.[^\.]+$//;
    push @sections, $absoluteKey;
  }
  push @sections, $absoluteKey;

  @sections;
}

sub StartXvncOrExit {
  $cmd = ConstructXvncCmd();
  CheckForUnsupportedConfigKeys();
  CheckSslCertReadable();
  say $cmd if ($debug || IsDryRun()) && ShouldPrintTopic("xvnc-cmd");

  exit(0) if IsDryRun();

  CheckBrowserHostDefined();
  DeleteLogLeftFromPreviousXvncRun();
  StartXvncAndRecordPID();
  WaitForXvncToRespond();

  if (!IsXvncRunning() && !UsingSafeFontPath())  {
    StartXvncWithSafeFontPath();
    WaitForXvncToRespond();
  }

  unless (IsXvncRunning()) {
    WarnUserXvncNotStartedAndExit();
  }
}

sub WaitForTimeLimitOrSubReturningTrue {
  my ($timeLimit, $sub) = @_;
  my $sleepSlice = 0.05;
  my $sleptFor = 0;

  until (&$sub() || $sleptFor >= $timeLimit) {
    sleep($sleepSlice);
    $sleptFor += $sleepSlice;
  }
}

sub IsProcessRunning {
  my $pid = shift;
  unless ($pid) { return 0 };

  kill 0, $pid;
}

sub DefineLogAndPidFilesForDisplayNumber {
  $desktopLog = "$vncUserDir/$host:$displayNumber.log";
  $pidFile = "$vncUserDir/$host:$displayNumber.pid";
}

sub PrepareLoggingAndXvncKillingFramework {
  CreateDotVncDir();
  DefineLogAndPidFilesForDisplayNumber();
}

sub AllowXProgramsToConnectToXvnc {
  SetupXauthorityFile();
}

sub PrintLogFilenameAndConfiguredUsersAndStuff {
  $logger->warn("\nNew '$desktopName' desktop is $host:$displayNumber");
  PrintKasmUsers();
  $logger->warn("Log file is $desktopLog\n");
}

sub PrintBrowserUrl {
  my $browserUrls = ConstructBrowserUrl();
  $logger->warn("\nPaste this url in your browser:\n$browserUrls");
}

sub IsAllInterfaces {
  my $interface = shift;

  $interface eq "0.0.0.0";
}

sub DeduceBrowserHosts {
  my @browserHosts;
  my $interface = $opt{"-interface"} || $optFromConfig{"-interface"};

  if (IsAllInterfaces($interface)) {
    @browserHosts = @hostIPs;
  } else {
    @browserHosts = ($interface);
  }

  @browserHosts;
}

sub ConstructBrowserUrl {
  my @browserHosts = DeduceBrowserHosts();
  my $browserPort = $opt{"-websocketPort"} || $optFromConfig{"-websocketPort"};

  my @urls = map { "https://$_:$browserPort" } @browserHosts;
  join "\n", @urls;
}

sub IsThisSystemBinary {
  $0 =~ m!^/usr!;
}

sub DetectSelectDeBin {
  if (IsThisSystemBinary()) {
    "/usr/lib/kasmvncserver/select-de.sh";
  } else {
    LocalSelectDePath();
  }
}

sub LocalSelectDePath {
  my $dirname = dirname($0);
  "$dirname/../builder/startup/deb/select-de.sh";
}

sub IsDryRun {
  $opt{"-dry-run"};
}

sub LoadConfig {
  my $filename = shift;

  return if IsConfigOptionalAndNotReadable($filename);

  my $config = KasmVNC::Config->new({ filename => $filename });

  $config;
}

sub FailIfConfigNotReadable {
  my $config = shift;

  -r $config || die "Couldn't load config: $config";
}

sub IsConfigOptionalAndNotReadable {
  my $config = shift;

  $config eq $vncUserConfig && ! -r $config;
}

sub TrimEmptyNodes {
  my $config = shift;
  my @supportedSections = @{ listify(SupportedSections()) };
  my @sectionsToCheck = reverse sort @supportedSections;

  foreach my $section (@sectionsToCheck) {
    if ($config->isEmpty($section)) {
      $config->delete($section);
    }
  }
}

sub ConfigValue {
  my ($absoluteKey, $configRef) = @_;
  $configRef ||= $mergedConfig;

  return $configRef->get($absoluteKey);
}

sub DerivedValue {
  my $absoluteKey = shift;

  $configKeyToXvncOptionMap{$absoluteKey}->toValue();
}

sub LoadConfigs {
  @allCliOptions = (@xvncOptions, @vncserverOptions);

  my @configs = map { LoadConfig $_ } @configFiles;
  foreach my $config (@configs) {
    TrimEmptyNodes($config);
  }
  $mergedConfig = KasmVNC::Config::merge(@configs);
}

sub SupportedSections {
  my %supportedAbsoluteKeys = %{ SupportedAbsoluteKeys() };
  my @supportedSections = map { SupportedSectionsFromAbsoluteKey($_) }
    (keys %supportedAbsoluteKeys);
  @supportedSections = uniq(flatten(@supportedSections));

  @supportedSections;
}

sub EmptySectionsDefinedInConfig {
  my @supportedSections = @{ listify(SupportedSections()) };
  my %configAbsoluteKeys = %{ ConfigAbsoluteKeys() };

  my @emptySections = grep($configAbsoluteKeys{$_} && isBlank(ConfigValue($_)),
    @supportedSections);
  uniq @emptySections;
}

sub ConfigAbsoluteKeys {
  my %configAbsoluteKeys = map { $_ => 1 }
    (ConfigToAbsoluteKeyList("", $mergedConfig->{data}));
  \%configAbsoluteKeys;
}

sub CheckForUnsupportedConfigKeys {
  my %supportedAbsoluteKeys = %{ SupportedAbsoluteKeys() };
  my @configAbsoluteKeys = ConfigToAbsoluteKeyList("", $mergedConfig->{data});
  my @unsupportedAbsoluteKeys =
    grep(!defined($supportedAbsoluteKeys{$_}), @configAbsoluteKeys);

  return if (scalar @unsupportedAbsoluteKeys == 0);

  if (ShouldPrintTopic("validation")) {
    $logger->warn("Unsupported config keys found:");
    $logger->warn(join("\n", @unsupportedAbsoluteKeys));
    $logger->warn();
  }

  exit 1;
}

sub ConstructOptFromConfig{
  my %result;

  foreach my $cliOption (values %cliArgMap) {
    my $cliArg = "-$cliOption->{name}";
    next if WasOptionSpecifiedViaCli($cliArg);

    my $optionValue = $cliOption->toValue();
    next unless defined($cliOption->toString());

    $result{$cliArg} = $optionValue;
  }

  \%result;
}

sub ConfigToCmd {
  ValidateConfig();
  %optFromConfig = %{ ConstructOptFromConfig() };

  my @cmd = map { $cliArgMap{$_}->toString() } (keys %optFromConfig);
  my $cmdStr = " " . join " ", @cmd;

  return $cmdStr;
}

sub ValidateConfig {
  foreach my $cliOption (@allCliOptions) {
    ValidateCliOption($cliOption);
  }
}

sub ValidateCliOption {
  my $cliOption = $_[0];

  return if ($cliOption->isValid());

  if (ShouldPrintTopic("validation")) {
    $logger->warn("config errors:");
    $logger->warn($cliOption->errorMessages());
    $logger->warn();
  }

  exit 1;
}

sub ConfigToAbsoluteKeyList {
  my $keyPrefix = $_[0];
  my %configPart = %{ $_[1] };

  my @absoluteKeys;

  foreach my $key (keys %configPart) {
    my $absoluteKey;
    if ($keyPrefix) {
      $absoluteKey = "$keyPrefix.$key";
    } else {
      $absoluteKey = $key;
    }

    if (!defined($configPart{$key})) {
      push @absoluteKeys, $absoluteKey;
      next;
    }

    if (ref $configPart{$key} ne "HASH") {
      push @absoluteKeys, $absoluteKey;
      next;
    }

    push @absoluteKeys,
      ConfigToAbsoluteKeyList($absoluteKey, \% { $configPart{$key} });
  }

  @absoluteKeys;
}

sub ActivateConfigToCLIConversion {
  foreach my $option (@xvncOptions){
    $option->activate();
  }
}

sub SetAppSettingsFromConfigAndCli {
  foreach my $option (@vncserverOptions) {
    my $value = $option->deriveValue();

    $appSettings{$option->{name}} = $value;
  }
}

sub InitLogger {
  $logger = KasmVNC::Logger->new();
}