# Copyright (C) 2015  Matt Adams <opensource@radicaldynamic.com>
# Copyright (C) 2006  Matthias Dietrich <md (at) plusw (.) de>
# Copyright (C) 2005  Mathias Dahl <mathias . dahl at gmail dot com>
# Copyright (C) 2005  Alex Schroeder <alex@emacswiki.org>
#
# This program 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 3 of the License, or
# (at your option) any later version.
#
# This program 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, see <http://www.gnu.org/licenses/>.

# This module offers the possibility to restrict viewing of "hidden"
# pages to only editors or admins. The restriction may be based
# on a pattern matching the page id or to a membership to a certain
# page cluster.

use strict;
use v5.10;

AddModuleDescription('hiddenpages.pl', 'Hidden Pages Extension');

our ($HiddenCluster, $HideEditorPages, $HideAdminPages, $HideRegExEditor, $HideRegExAdmin);

# $HiddenCluster is a cluster name for hidden pages. Default
# is pages in the cluster "HiddenPage". You can override this
# value in your config file.

$HiddenCluster = 'HiddenPage';

# $Hide*Pages sets the access level to hidden pages:
#  0 = Hidden pages visible to all
#  1 = Password required
# You can override this value in your config file.
# NOTE: Pages for Editors are also visible to Admins!

$HideEditorPages = 1;
$HideAdminPages = 1;

# $HideRegEx* are regular expressions to find hidden pages. Default is pages
# ending with "HiddenE" for editors and "Hidden" for admins. You can override
# this value in your config file.

$HideRegExEditor = 'HiddenE$';
$HideRegExAdmin = 'Hidden$';

*OldOpenPage = \&OpenPage;
*OpenPage = \&NewOpenPage;

sub NewOpenPage {
  # Get page id/name sent in to OpenPage
  my ($id) = @_;

  # Shield the Private pages
  my $hidden = 0;

  # Check for match of HiddenPages
  if ($id and $id =~ /$HideRegExEditor/) {
    $hidden = "edi";
  } elsif ($id and $id =~ /$HideRegExAdmin/) {
    $hidden = "adi";
  }

  my $action = lc(GetParam('action', ''));

  if ($action ne 'rc' && $action ne 'search') {
    # Check the different levels of access
    if ($hidden eq "edi" && $HideEditorPages == 1 && (!UserIsEditor() && !UserIsAdmin())) {
      ReportError(T("Only Editors are allowed to see this hidden page."), "401 Not Authorized");
    } elsif ($hidden eq "adi" && $HideAdminPages == 1 && !UserIsAdmin()) {
      ReportError(T("Only Admins are allowed to see this hidden page."), "401 Not Authorized");
    }
  }

  # Give control back to OpenPage()
  OldOpenPage(@_);
}