# $Id$
# TeXLive::TLWinGoo.pm -# Windows nastiness
#
# Copyright 2008, 2009 Siep Kroonenberg, Norbert Preining
# This file is licensed under the GNU General Public License version 2
# or any later version.

# code for broadcast_env adapted from Win32::Env:
# Copyright 2006 Oleg "Rowaa[SR13]" V. Volkov, all rights reserved.
# This program is free software; you can redistribute it and/or modify it
# under the same terms as Perl itself.

package TeXLive::TLWinGoo;

=pod

=head1 NAME

C<TeXLive::TLWinGoo> -- Additional utilities for Windows

=head2 SYNOPSIS

  use TeXLive::TLWinGoo;

=head2 DIAGNOSTICS

  TeXLive::TLWinGoo::win_version;
  TeXLive::TLWinGoo::is_vista;
  TeXLive::TLWinGoo::admin;
  TeXLive::TLWinGoo::non_admin;
  TeXLive::TLWinGoo::reg_country;

=head2 ENVIRONMENT AND REGISTRY

  TeXLive::TLWinGoo::expand_string($s);
  TeXLive::TLWinGoo::global_tmpdir;
  TeXLive::TLWinGoo::get_system_path;
  TeXLive::TLWinGoo::get_user_path;
  TeXLive::TLWinGoo::win_which_dir($prog);
  TeXLive::TLWinGoo::setenv_reg($env_var, $env_data);
  TeXLive::TLWinGoo::unsetenv_reg($env_var);
  TeXLive::TLWinGoo::adjust_reg_path_for_texlive($action, $texbindir, $mode);
  TeXLive::TLWinGoo::register_extension($extension, $file_type);
  TeXLive::TLWinGoo::unregister_extension($extension);
  TeXLive::TLWinGoo::register_file_type($file_type, $command);
  TeXLive::TLWinGoo::unregister_file_type($file_type);

=head2 ACTIVATING CHANGES IMMEDIATELY

  TeXLive::TLWinGoo::broadcast_env;
  TeXLive::TLWinGoo::update_assocs;

=head2 SHORTCUTS

  TeXLive::TLWinGoo::desktop_path;
  TeXLive::TLWinGoo::add_desktop_shortcut($texdir, $name, $icon,
    $prog, $args, $batgui);
  TeXLive::TLWinGoo::add_menu_shortcut($place, $name, $icon,
    $prog, $args, $batgui);
  TeXLive::TLWinGoo::remove_desktop_shortcut($name);
  TeXLive::TLWinGoo::remove_menu_shortcut($place, $name);

=head2 UNINSTALLER

  TeXLive::TLWinGoo::create_uninstaller;
  TeXLive::TLWinGoo::unregister_uninstaller;

All exported functions return forward slashes.

=head2 DESCRIPTION

=over 4

=cut

BEGIN {
  use Exporter;
  use vars qw( @ISA @EXPORT $Registry);
  @ISA = qw( Exporter );
  @EXPORT = qw(
    &win_version
    &is_vista
    &admin
    &non_admin
    &reg_country
    &expand_string
    &global_tmpdir
    &get_system_path
    &get_user_path
    &setenv_reg
    &unsetenv_reg
    &adjust_reg_path_for_texlive
    &register_extension
    &unregister_extension
    &register_file_type
    &unregister_file_type
    &broadcast_env
    &update_assocs
    &shell_folder
    &desktop_path
    &add_desktop_shortcut
    &add_menu_shortcut
    &remove_desktop_shortcut
    &remove_menu_shortcut
    &create_uninstaller
    &unregister_uninstaller
  );
  # for testing also:
  @EXPORT_OK = qw(
    &admin_again
    &get_system_env
    &get_user_env
    &win_which_dir
    &global_tmpdir
    &is_a_texdir
    &tex_dirs_on_path
  );
  if ($^O=~/^MSWin(32|64)$/i) {
    require Win32::API;
    require Win32::TieRegistry;
    Win32::TieRegistry->import( qw( $Registry
      REG_SZ REG_EXPAND_SZ  KEY_READ KEY_WRITE KEY_ALL_ACCESS
         KEY_ENUMERATE_SUB_KEYS ) );
    $Registry->Delimiter('/');
    $Registry->ArrayValues(0);
    $Registry->FixSzNulls(1);
    require Win32::Shortcut;
    Win32::Shortcut->import( qw( SW_SHOWNORMAL SW_SHOWMINNOACTIVE ) );
  }
}

use TeXLive::TLUtils;
TeXLive::TLUtils->import( qw( mkdirhier ) );

use open qw(:utf8 :std);

my $is_win = $^O=~/^MSWin(32|64)$/i;

=pod

=back

=head2 DIAGNOSTICS

=over 4

=item C<win_version>

C<win_version> returns the Windows version number as stored in the
registry: 5.0 for Windows 2000, 5.1 for Windows XP and 6.0 for Vista.

=cut

my $windows_version = 0;

if ($is_win) {
  my $tempkey = $Registry->Open(
    "LMachine/software/Microsoft/Windows NT/CurrentVersion/",
    {Access => KEY_READ() });
  $windows_version = $tempkey -> { "/CurrentVersion" };
}

sub win_version { return $windows_version; }

=item C<is_vista>

C<is_vista> returns 1 if win_version is >= 6.0, otherwise 0.

=cut

sub is_vista { return $windows_version >= 6; }

# permissions with which we try to access the system environment

my $is_admin = 1;

sub sys_access_permissions {
  $is_admin ? KEY_ALL_ACCESS() : KEY_READ() | KEY_ENUMERATE_SUB_KEYS();
}

sub get_system_env {
  return $Registry -> Open(
    "LMachine/system/currentcontrolset/control/session manager/Environment/",
    {Access => sys_access_permissions()});
}

# $is_admin was set to true originally. With this value,
# sys-access_permissions returns full access permissions. If that
# doesn't work out then apparently we aren't administrator, so we
# set $is_admin to 0.

if ($is_win) {
  $is_admin = 0 if not get_system_env();
  debug("Configuring TLWinGoo for " .
    ($is_admin ? "admin" : "user") . "mode\n") if win32();
}

sub get_user_env {
  return $Registry -> Open("CUser/Environment", {Access => KEY_ALL_ACCESS()});
}

=pod

=item C<admin>

Returns admin status, admin implying having full read-write access
to the system environment.

=cut

sub admin { return $is_admin; }

=pod

=item C<non_admin>

Pretend not to have admin privileges, to enforce a user- rather than
a system install.

Currently only used for testing.

=cut

sub non_admin {
  debug("TLWinGoo: switching to user mode\n");
  $is_admin = 0;
}

# just for testing; doesn't check actual user permissions
sub admin_again {
  debug("TLWinGoo: switching to admin mode\n");
  $is_admin = 1;
}

=pod

=item C<reg_country>

Two-letter country code representing the locale of the current user

=cut

sub reg_country {
  my $value = $Registry -> {"CUser/Control Panel/International//Locale"};
  return 0 unless $value;
  # there might be trailing nulls on Vista
  $value =~ s/\x00*$//;
  $value = substr $value, -4;
  return 0 unless $value;
  my $lmkey = $Registry -> Open("HKEY_CLASSES_ROOT/MIME/Database/Rfc1766/",
                             {Access => KEY_READ()});
  return 0 unless $lmkey;
  $lm = $lmkey->{"/$value"};
  return 0 unless $lm;
  debug("found lang codes value = $value, lm = $lm...\n");
  if ($lm) {
    if ($lm =~ m/^zh-(tw|hk)$/i) {
      return ("zh-tw");
    } elsif ($lm =~ m/^zh/) {
      # for anything else starting with zh return, that is zh, zh-cn, zh-sg
      # and maybe something else
      return ("zh-cn");
    } else {
      return(substr $lm, 0, 2);
    }
  }
}

=pod

=back

=head2 ENVIRONMENT AND REGISTRY

Most settings can be made for a user and for the system. User
settings override system settings.

For admin users, the functions below affect both user- and system
settings. For non-admin users, only user settings are changed.

An exception is the search path: the effective searchpath consists
of the system searchpath in front concatenated with the user
searchpath at the back.

Note that in a roaming profile network setup, users take only user
settings with them to other systems, not system settings. In this
case, with a TeXLive on the network, a nonadmin install makes the
most sense.

=over 4

=item C<expand_string($s)>

This function replaces substrings C<%env_var%> with their current
values as environment variable and returns the result.

=cut

sub expand_string {
  my ($s) = @_;
  $s =~ s/%([^%;]+)%/$ENV{$1} ? $ENV{$1} : "%$1%"/eg;
  return $s;
}

=pod

=item C<global_tmpdir>

Returns the expanded value of C<%TEMP%> from the system environment,
usually C<%SystemRoot%/Temp>. This value is normally not available
from C<%ENV>.

=cut

if ($is_win) {
  $global_tmp = expand_string(get_system_env()->{'TEMP'}) if $is_win;
}

my $global_tmp = "/tmp";

sub global_tmpdir { return $global_tmp; }

sub is_a_texdir {
  my $d = shift;
  $d =~ s/\\/\//g;
  $d = $d . '/' unless $d =~ m!/$!;
  # don't consider anything under %systemroot% a texdir
  my $sr = uc($ENV{'SystemRoot'});
  $sr =~ s/\\/\//g;
  $sr = $sr . '/' unless $sr =~ m!/$!;
  return 0 if index($d, $sr)==0;
  foreach $p qw(luatex.exe mktexlsr.exe pdftex.exe tex.exe xetex.exe) {
    return 1 if (-e $d.$p);
  }
  return 0;
}

=pod

=item C<get_system_path>

Returns unexpanded system path, as stored in the registry, but with
forward slashes.

=cut

sub get_system_path {
  my $value = get_system_env() -> {'/Path'};
  $value =~ s/\\/\//g;
  # Remove terminating zero bytes; there may be several, at least
  # under w2k, and the FixSzNulls option only removes one.
  $value =~ s/[\s\x00]+$//;
  return $value;
}

=pod

=item C<get_user_path>

Returns unexpanded user path, as stored in the registry, but with
forward slashes. The user path often does not exist, and is rarely
expandable.

=cut

sub get_user_path {
  my $value = get_user_env() -> {'/Path'};
  return "" if not $value;
  $value =~ s/\\/\//g;
  $value =~ s/[\s\x00]+$//;
  return $value;
}

=pod

=item C<win_which_dir>

More or less the same as which, except that 1. it returns a
directory, 2. it consults the path stored in the registry rather
than the path of the current process, and 3. it assumes that the
filename includes an extension. Currently only used for testing.

=cut

sub win_which_dir {
  my $prog = shift;
  my $d;
  # first check system path
  my $path = expand_string(get_system_path());
  my $user_path = expand_string(get_user_path());
  $path = $path . ';' . $user_path if $user_path;
  foreach $d (split (';',$path)) {
    $d =~ s/\/$//;
    return $d if -e $d.'/'.$prog;
  }
  return 0;
}

=pod

=item C<setenv_reg($env_var, $env_data[, $mode]);>

Set an environment variable $env_var to $env_data.

$mode="user": set for current user. $mode="system": set for all
users. Default: both if admin, current user otherwise.

=cut

sub setenv_reg {
  my $env_var = shift;
  my $env_data = shift;
  my $mode = @_ ? shift : "default";
  die "setenv_reg: Invalid mode $mode"
    if ($mode ne "user" and $mode ne "system" and $mode ne "default");
  die "setenv_reg: mode 'system' only available for admin"
    if ($mode eq "system" and !$is_admin);
  my $env;
  if ($mode ne "system") {
    my $env = get_user_env();
    $env->ArrayValues(1);
    $env->{'/'.$env_var} =
       [ $env_data, ($env_data =~ /%/) ? REG_EXPAND_SZ : REG_SZ ];
  }
  if ($mode ne "user" and $is_admin) {
    $env = get_system_env();
    $env->ArrayValues(1);
    $env->{'/'.$env_var} =
       [ $env_data, ($env_data =~ /%/) ? REG_EXPAND_SZ : REG_SZ ];
  }
}

=pod

=item C<unsetenv_reg($env_var[, $mode]);>

Unset an environment variable $env_var

=cut

sub unsetenv_reg {
  my $env_var = shift;
  my $env = get_user_env();
  my $mode = @_ ? shift : "default";
  #print "Unsetenv_reg: unset $env_var with mode $mode\n";
  die "unsetenv_reg: Invalid mode $mode"
    if ($mode ne "user" and $mode ne "system" and $mode ne "default");
  die "unsetenv_reg: mode 'system' only available for admin"
    if ($mode eq "system" and !$is_admin);
  delete get_user_env()->{'/'.$env_var} if $mode ne "system";
  delete get_system_env()->{'/'.$env_var} if ($mode ne "user" and $is_admin);
}

=pod

=item C<tex_dirs_on_path($path)>

Returns tex directories found on the search path.
A directory is a TeX directory if it contains tex.exe or
pdftex.exe.

=cut

sub tex_dirs_on_path {
  my ($path) = @_;
  my ($d, $d_exp);
  my @texdirs = ();
  foreach $d (split (';', $path)) {
    $d_exp = expand_string($d);
    if (is_a_texdir($d_exp)) {
      # tlwarn("Possibly conflicting [pdf]TeX program found at $d_exp\n");
      push(@texdirs, $d_exp);
    };
  }
  return @texdirs;
}

=pod

=item C<adjust_reg_path_for_texlive($action, $tlbindir, $mode)>

Edit system or user PATH variable in the registry.
Adds or removes (depending on $action) $tlbindir directory
to system or user PATH variable in the registry (depending on $mode).

=cut

sub adjust_reg_path_for_texlive {
  my ($action, $tlbindir, $mode) = @_;
  die("Unknown path action: $action\n")
    if ($action ne 'add') and ($action ne 'remove');
  die("Unknown path mode: $mode\n")
    if ($mode ne 'system') and ($mode ne 'user');
  debug("Warning: [pdf]tex program not found in $tlbindir\n")
    if (!is_a_texdir($tlbindir));
  my $path = ($mode eq 'system') ? get_system_path() : get_user_path();
  $tlbindir =~ s!/!\\!g;
  my $tlbindir_short = uc(short_name($tlbindir));
  my ($d, $d_short, @newpath);
  my $tex_dir_conflict = 0;
  foreach $d (split (';', $path)) {
    $d_short = uc(short_name(expand_string($d)));
    $d_short =~ s!/!\\!g;
    ddebug("adjust_reg: compar $d_short with $tlbindir_short\n");
    if ($d_short ne $tlbindir_short) {
      push(@newpath, $d);
      $tex_dir_conflict += is_a_texdir($d);
    }
  }
  if ($action eq 'add') {
    if ($tex_dir_conflict) {
      debug("Warning: conflicting [pdf]tex found on the $mode path in $d; appending texlive bin dir to the front.");
      unshift(@newpath, $tlbindir);
    } else {
      push(@newpath, $tlbindir);
    }
  }
  if (@newpath) {
    debug("TLWinGoo: adjust_reg_path_for_texlive: calling setenv_reg in $mode\n");
    setenv_reg("Path", join(';', @newpath), $mode);
  } else {
    debug("TLWinGoo: adjust_reg_path_for_texlive: calling unsetenv_reg in $mode\n");
    unsetenv_reg("Path", $mode);
  }
  if (($action eq 'add') and ($mode eq 'user') and tex_dirs_on_path(get_system_path())) {
    debug("Warning: conflicting [pdf]tex found on the system path in $d; not fixable in user mode.");
    return 1;
  }
  return 0;
}

# delete a registry key recursively.
# the key parameter should be a string, not a registry object.
# We shall use this with file types.

sub reg_delete_recurse {
  my $parent = shift;
  my $childname = shift;
  ddebug("Deleting $childname regkey\n");
  if ($childname !~ '^/') { # subkey
    my $child = $parent->Open ($childname, {Access => KEY_ALL_ACCESS()});
    return unless $child;
    foreach my $v (keys %$child) {
      if ($v =~ '^/') { # value
        delete $child->{$v};
      } else { # subkey
        reg_delete_recurse ($child, $v);
      }
    }
    delete $child->{'/'};
  }
  delete $parent->{$childname};
}

=pod

=item C<register_extension($mode, $extension, $file_type)>

Add registry entry to associate $extension with $file_type. Slashes
are flipped where necessary.

If $mode is 0, nothing is actually done. If $mode is 1, only not-present
keys of keys that are matching the given key are (re)created. If $mode
is 2 then keys are (re)created in any case.

=cut

sub register_extension {
  my $mode = shift;
  return if ($mode == 0);

  my $extension = shift;
  $extension = '.'.$extension unless $extension =~ /^\./; # ensure leading dot
  $extension = uc($extension);

  my $file_type = shift;
  debug("Linking $extension to $file_type\n");
  my ($classes_key, $k);

  $extension = lc($extension);
  if ($is_admin) {
    $classes_key = $Registry -> Open("LMachine/Software/Classes/",
      {Access => KEY_ALL_ACCESS()}) or die "Cannot open classpath";
  } else {
    $classes_key = $Registry -> Open("CUser/Software/Classes/",
        {Access => KEY_ALL_ACCESS()});
  }


  my $do_create_key = 0;

  if ($mode == 1) {
    if (defined($classes_key->{$extension})) {
      if (defined($classes_key->{$extension}->{'/'})) {
        if ($classes_key->{$extension}->{'/'} eq $file_type) {
          debug("register_extension: already same key $extension $file_type present, recreate it\n");
          $do_create_key = 1;
        } else {
          debug("register_extension: old foreign key" . $classes_key->{$extension}->{'/'} . " found, not changing\n");
        }
      }
    } else {
      debug("register_extension: old key $extension not found, recreating it\n");
      $do_create_key = 1;
    }
  } elsif ($mode == 2) {
    $do_create_key = 1;
  } else {
    die "Unknown mode $mode for register_extension";
  }

  if ($do_create_key) {
    $k = $classes_key->CreateKey($extension);
    $k -> ArrayValues(0);
    $k -> {"/"} = $file_type;
    if (admin()) {
      # delete possibly conflicting value from HKCU/software
      $classes_key = $Registry -> Open("CUser/Software/Classes/",
          {Access => KEY_ALL_ACCESS()});
      delete $classes_key -> {$extension};
    }
  }
}

=pod

=item C<unregister_extension($mode, $extension, $filetype)>

Reversal of register_extension.

=cut

sub unregister_extension {
  my $mode = shift;
  return if ($mode == 0);

  # we don't error check; we just do the best we can.
  my $extension = shift;
  my $filetype = shift;
  $extension = '.'.$extension unless $extension =~ /^\./; # ensure leading dot
  $extension = uc($extension);
  debug("unregistering $extension\n");

  my $classes_key;

  my $HKLMclasses_key = $Registry -> Open("LMachine/Software/Classes/",
    {Access => KEY_ALL_ACCESS()});
  my $HKCUclasses_key = $Registry -> Open("CUser/Software/Classes/",
    {Access => KEY_ALL_ACCESS()});
  if (admin()) {
    $classes_key = $HKLMclasses_key;
  } else {
    $classes_key = $HKCUclasses_key;
  }
  if ($classes_key) {
    my $do_remove_key = 0;
    if ($mode == 1) {
      if (defined($classes_key->{$extension})) {
        if (defined($classes_key->{$extension}->{'/'})) {
          if ($classes_key->{$extension}->{'/'} eq $filetype) {
            debug("unregister_extension: correct key/value $extension/$filetype found, removing\n");
            $do_remove_key = 1;
          } else {
            debug("unregister_extension: foreign value for $extension found, keeping it\n");
          }
        } else {
          $do_remove_key = 1;
        }
      } else {
        # nothing necessary, this key wasn't found
      }
    } elsif ($mode == 2) {
      $do_remove_key = 1;
    } else {
      die "Unknown mode $mode for unregister_extension";
    }

    if ($do_remove_key) {
      reg_delete_recurse ($classes_key, $extension."/");
      if (admin()) {
        if ($HKCUclasses_key) {
          reg_delete_recurse ($HKCUclasses_key, $extension."/");
        } else {
          debug("Cannot open HKCU classes for write\n");
        }
      }
    }
  } else {
    if (admin()) {
      debug("Cannot open HKLM classes for write\n");
    } else {
      debug("Cannot open HKCU classes for write\n");
    }
  }
}

=pod

=item C<register_file_type($file_type, $command)>

Add registry entries to associate $file_type with $command. Slashes
are flipped where necessary. Double quotes should be added by the
caller if necessary.

=cut

sub register_file_type {
  my $file_type = shift;
  my $command = shift;
  $command =~s/\//\\/g;
  debug ("Linking $file_type to $command\n");
  my ($classes_key, $k);

  if ($is_admin) {
    $classes_key = $Registry -> Open("LMachine/Software/Classes/",
      {Access => KEY_ALL_ACCESS()}) or die "Cannot open classpath";
    $k = $classes_key->CreateKey($file_type."/Shell/Open/Command/");
    $k -> {"/"} = $command;
    $k -> ArrayValues(0);
    # delete possibly conflicting values from HKCU/software
    $classes_key = $Registry -> Open("CUser/Software/Classes/",
        {Access => KEY_ALL_ACCESS()});
    reg_delete_recurse($classes_key, $file_type);
  } else {
    $classes_key = $Registry -> Open("CUser/Software/Classes/",
        {Access => KEY_ALL_ACCESS()});
    $k = $classes_key->CreateKey($file_type."/Shell/Open/Command/");
    $k -> ArrayValues(0);
    $k -> {"/"} = $command;
  }
}

=pod

=item C<unregister_file_type($file_type)>

Reversal of register_script_type.

=cut

sub unregister_file_type {
  # we don't error check; we just do the best we can.
  my $file_type = shift;
  debug ("unregistering $file_type\n");

  my $classes_key = $Registry -> Open("CUser/Software/Classes/",
    {Access => KEY_ALL_ACCESS()});
  if ($classes_key) {
    reg_delete_recurse ($classes_key, $file_type."/");
  } else {
    tlwarn("Cannot open HKCU classes for write\n");
  }
  if ($is_admin) {
    $classes_key = $Registry -> Open("LMachine/Software/Classes/",
    {Access => KEY_ALL_ACCESS()});
    if ($classes_key) {
      reg_delete_recurse ($classes_key, $file_type."/");
    } else {
    debug ("Cannot open HKLM classes for write\n");
    }
    #reg_delete_recurse ($classes_key, $file_type);
  }
}

=pod

=back

=head2 ACTIVATING CHANGES IMMEDIATELY

=over 4

=item C<broadcast_env>

Broadcasts system message that enviroment has changed. This only has
an effect on newly-started programs, not on running programs and the
processes they spawn.

=cut

sub broadcast_env() {
  use constant HWND_BROADCAST	=> 0xffff;
  use constant WM_SETTINGCHANGE	=> 0x001A;
  my $result = "";
  my $SendMessage;
  debug("Broadcasting \"Enviroment settings changed\" message...\n");
  #$SendMessage = new Win32::API('user32', 'SendMessage', 'LLPP', 'L');
  #$result = $SendMessage->Call(HWND_BROADCAST, WM_SETTINGCHANGE,
  #    0, 'Environment') if $SendMessage;
  $SendMessage = new Win32::API('user32', 'SendMessageTimeout', 'LLPPLLP', 'L');
  my $ans = "12345678"; # room for dword
  $result = $SendMessage->Call(HWND_BROADCAST, WM_SETTINGCHANGE,
      0, 'Environment', 0, 2000, $ans) if $SendMessage;
  debug("Broadcast complete; result: $result.\n");
}

=pod

=item C<update_assocs>

Notifies the system that filetypes have changed.

=cut

sub update_assocs() {
  use constant SHCNE_ASSOCCHANGED	=> 0x8000000;
  use constant SHCNF_IDLIST =>	0;
  my $update_fu = new Win32::API('shell32', 'SHChangeNotify', 'LIPP', 'V');
  if ($update_fu) {
    debug("Notifying changes in filetypes...\n");
    $update_fu->Call (SHCNE_ASSOCCHANGED, SHCNF_IDLIST, 0, 0);
    debug("Done notifying\n");
  } else {
    debug("No update_fu\n");
  }
}

=pod

=back

=head2 SHORTCUTS

=cut

# short path names

my $shortfu;
if ($^O=~/^MSWin(32|64)$/i) {
  $shortfu = new Win32::API('kernel32', 'GetShortPathName', 'PPN', 'N');
}

sub short_name {
  my ($fname) = @_;
  return $fname unless $is_win;
  my $buffer = (' ' x 260);
  my $slength = $shortfu->Call($fname, $buffer, 260);
  if ($slength>0) { return substr $buffer, 0, $slength; }
  else { return ''; }
}

=pod

=over 4

=item C<shell_folder>

Location of shell `special folders'; $user_name is the name
to look for in user mode, $admin_name is the name for admin mode,
e.g. `Desktop' and `Common Desktop'. The default for $admin_name is
'Common .$user_name

=cut

sub shell_folder {
  my ($user_name, $admin_name) = @_;
  $admin_name = 'Common '.$user_name unless ($admin_name or !$user_name);
  my ($shell_key, $sh_folder);
  if (admin()) {
    return 0 unless $admin_name;
    $shell_key = $Registry->Open(
    "LMachine/software/microsoft/windows/currentversion/explorer/shell folders/",
      {Access => KEY_READ});
    $sh_folder = short_name($shell_key -> {"/$admin_name"});
  } else {
    $shell_key = $Registry->Open(
    "CUser/software/microsoft/windows/currentversion/explorer/shell folders/",
      {Access => KEY_READ});
    $sh_folder = short_name($shell_key -> {"/$user_name"});
  }
  $sh_folder =~ s!\\!/!g;
  return $sh_folder;
}

sub desktop_path() {
  return shell_folder('Desktop');
  #my ($shell_key, $deskpath);
  #if (admin()) {
  #  $shell_key = $Registry->Open(
  #  "LMachine/software/microsoft/windows/currentversion/explorer/shell folders/",
  #    {Access => KEY_READ});
  #  $deskpath = short_name($shell_key -> {"/Common Desktop"});
  #} else {
  #  $shell_key = $Registry->Open(
  #  "CUser/software/microsoft/windows/currentversion/explorer/shell folders/",
  #    {Access => KEY_READ});
  #  $deskpath = short_name($shell_key -> {"/Desktop"});
  #}
  #$deskpath =~ s!\\!/!g;
  #return $deskpath;
}

sub menu_path() {
  return shell_folder('Programs', 'Common Programs');
  #my ($shell_key, $menupath);
  #if (admin()) {
  #  $shell_key = $Registry->Open(
  #  "LMachine/software/microsoft/windows/currentversion/explorer/shell folders/",
  #    {Access => KEY_READ});
  #  $menupath = short_name($shell_key -> {"/Common Programs"});
  #} else {
  #  $shell_key = $Registry->Open(
  #  "CUser/software/microsoft/windows/currentversion/explorer/shell folders/",
  #    {Access => KEY_READ});
  #  $menupath = short_name($shell_key -> {"/Programs"});
  #}
  #$menupath =~ s!\\!/!g;
  #return $menupath;
}

=pod

=item C<add_desktop_shortcut($name, $icon, $prog, $args, $batgui)>

Add a desktop shortcut, with name $name and icon $icon, pointing to
program $prog with parameters $args (a string).  Use a non-null
batgui parameter if the shortcut starts a gui program via a
batchfile. Then the inevitable command prompt will be hidden
rightaway, leaving only the gui program visible.

=cut

sub add_desktop_shortcut {
  my ($name, $icon, $prog, $args, $batgui) = @_;

  # create shortcut
  my ($shc, $shpath, $shfile);
  $shc = new Win32::Shortcut();
  $shc->{'IconLocation'} = $icon if -f $icon;
  $shc->{'Path'} = $prog;
  $shc->{'Arguments'} = $args;
  $shc->{'ShowCmd'} = $batgui ? SW_SHOWMINNOACTIVE : SW_SHOWNORMAL;
  $shfile = desktop_path().'/'.$name.'.lnk';
  $shc->Save($shfile);
}

=pod

=item C<add_menu_shortcut($place, $name, $icon,
  $prog, $args, $batgui)>

Add a menu shortcut at place $place (relative to Start/Programs),
with name $name and icon $icon, pointing to program $prog with
parameters $args. See above for batgui.

=cut

sub add_menu_shortcut {
  my ($place, $name, $icon, $prog, $args, $batgui) = @_;
  $place =~ s!\\!/!g;

  my ($shc, $shpath, $shfile);
  $shc = new Win32::Shortcut();
  $shc->{'IconLocation'} = $icon if -f $icon;
  $shc->{'Path'} = $prog;
  $shc->{'Arguments'} = $args;
  $shc->{'ShowCmd'} = $batgui ? SW_SHOWMINNOACTIVE : SW_SHOWNORMAL;
  $shpath = $place;
  $shpath =~ s!\\!/!g;
  $shpath = '/'.$shpath unless $shpath =~ m!^/!;
  $shpath = menu_path().$shpath;
  if ((-e $shpath) and not (-d $shpath)) {
    next; # fail silently and don't worry about it
  } elsif (not (-d $shpath)) {
    mkdirhier($shpath);
    return unless -d $shpath;
  }
  $shfile = $shpath.'/'.$name.'.lnk';
  $shc->Save($shfile);
}

=pod

=item C<remove_desktop_shortcut($name)>

For uninstallation of an individual package.

=cut

sub remove_desktop_shortcut {
  my $name = shift;
  unlink desktop_path().'/'.$name.'.lnk';
}

=pod

=item C<remove_menu_shortcut($place, $name)>

For uninstallation of an individual package.

=cut

sub remove_menu_shortcut {
  my $place = shift;
  my $name = shift;
  $place =~ s!\\!/!g;
  $place = '/'.$place unless $place =~ m!^/!;
  unlink menu_path().$place.'/'.$name.'.lnk';
}

=pod

=back

=head2 UNINSTALLER

=over 4

=item C<create_uninstaller>

Writes registry entries for add/remove programs which  reference
the uninstaller script and creates uninstaller batchfiles to finish
the job.

=cut

sub create_uninstaller {
  my ($tdfw, $tdwfw, $tdsvfw, $tdscfw) = @_;
  # TEXDIR, TEXDIRW, TEXMFSYSVAR, TEXMFSYSCONFIG
  $tdfw =~ s![\\/]$!!;
  my $td = $tdfw;
  $td =~ s!/!\\!g;

  $tdwfw =~ s![\\/]$!!;
  my $tdw = $tdwfw;
  $tdw =~ s!/!\\!g;

  $tdsvfw =~ s![\\/]$!!;
  my $tdsv = $tdsvfw;
  $tdsv =~ s!/!\\!g;

  $tdscfw =~ s![\\/]$!!;
  my $tdsc = $tdscfw;
  $tdsc =~ s!/!\\!g;

  my $uninst_key = $Registry -> Open((admin() ? "LMachine" : "CUser") .
    "/software/microsoft/windows/currentversion/",
    {Access => KEY_ALL_ACCESS()});
  my $k = $uninst_key->CreateKey("uninstall/TeXLive/");
  $k->{"/DisplayName"} = "TeXLive ".$::texlive_release;
  $k->{"/UninstallString"} = "\"$tdw\\tlpkg\\installer\\uninst.bat\"";
  $k->{'/DisplayVersion'} = $::texlive_release;
  $k->{'/URLInfoAbout'} = "http://www.tug.org/texlive";

  mkdirhier("$tdwfw/tlpkg/installer"); # wasn't this done yet?
  if (open UNINST, ">$tdwfw/tlpkg/installer/uninst.bat") {
    print UNINST <<UNEND;
\@echo off
rem This should not be necessary, but sometimes it is:
path $td\\tlpkg\\tlperl\\bin;$td\\bin\\win32;%path%
set PERL5LIB=$td\\tlpkg\\tlperl\\lib
perl.exe \"$td\\texmf\\scripts\\texlive\\uninstall-win32.pl\"
if errorlevel 1 exit
copy \"$tdw\\tlpkg\\installer\\uninst2.bat\" \"\%TEMP\%\"
rem pause
\"\%TEMP\%\\uninst2.bat\"
UNEND
;
  close UNINST;
  } else {
    warn "Cannot open $tdwfw/tlpkg/installer/uninst.bat for append";
  }

  if (open UNINST2, ">$tdwfw/tlpkg/installer/uninst2.bat") {
    print UNINST2 <<UNEND2 if ($td eq $tdw);
rmdir /s /q \"$td\\texmf-dist\"
rmdir /s /q \"$td\\texmf-doc\"
rmdir /s /q \"$td\\texmf\"
rmdir /s /q \"$td\\readme-html.dir\"
rmdir /s /q \"$td\\readme-txt.dir\"
rmdir /s /q \"$td\\bin\"
rmdir /s /q \"$td\\tlpkg\"
del /q \"$td\\README.*\"
del /q \"$td\\LICENSE.*\"
del /q \"$td\\doc.html\"
del \"$td\\index.html\"
del \"$td\\texmf.cnf\"
UNEND2
;
    print UNINST2 <<UNEND2;
rmdir /s /q \"$tdsv\"
rmdir /s /q \"$tdsc\"
rmdir /s /q \"$tdw\\temp\"
rmdir /s /q \"$tdw\\tlpkg\"
del \"$tdw\\install-tl.log\"
del \"$tdw\\texlive.profile\" 2>nul
del \"$tdw\\release-texlive.txt\"
set test=
for \%\%f in (\"$tdw\\*.*\") do \@set test=nonempty
if x\%test\%==x rd \"$tdw\"
\@echo Done uninstalling TeXLive.
rem \@pause
del %0
UNEND2
;
    close UNINST2;
  } else {
    warn "Cannot open $tdwfw/tlpkg/installer/uninst2.bat for writing";
  }
}

=pod

=item C<unregister_uninstaller>

Removes TeXLive from Add/Remove Programs.

=cut

sub unregister_uninstaller {
  my $regkey_uninst;
  $regkey_uninst = $Registry->Open(
    "CUser/software/microsoft/windows/currentversion/uninstall/",
    {Access => KEY_ALL_ACCESS()});
  reg_delete_recurse($regkey_uninst, 'texlive/') if $regkey_uninst;
  return unless admin();
  $regkey_uninst = $Registry->Open(
    "LMachine/software/microsoft/windows/currentversion/uninstall/",
    {Access => KEY_ALL_ACCESS()});
  reg_delete_recurse($regkey_uninst, 'texlive/') if $regkey_uninst;
}

=pod

=back

=cut

# needs a terminal 1 for require to succeed!
1;

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