package NetUseAdminWeb;

#    NetUseMod is a program to moderate Usenet posts via web interface.
#    Copyright (C) 2024  Salahuddin <salahuddin@member.fsf.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 <https://www.gnu.org/licenses/>.

use Dancer2;
use File::Copy 'move';
use HTML::Entities;

our $VERSION = '0.1';

my $post_to_usenet = 1;     # toggle for testing
my $usenet_host = 'YOUR_USENET_PROVIDER';
my $usenet_port = '119';    # production 536 ssl
my $rnews_location = '/usr/bin/rnews';
# set user and password in /etc/news/passwd.nntp
# to submit news to your newsgroup provider.

my $send_rec_ack = 1;
my $noreply_mail = 'no-reply@YOUR_DOMAIN';

my $mail_format = 'YOUR_HOME_DIR/NetUseMod/scripts/mail_format.sh';
my $admin_user = 'XXXXXXXX';
my $admin_pass = 'XXXXXXXX';

# example: /home/username/
my $dir_base = 'YOUR_HOME_DIR';
my $dir_incoming = 'incoming_news';
my $dir_processed = 'processed_news';
my $dir_rejected = 'rejected_news';


sub sendReceiveAck {
    my ($from, $subject, $description) = @_;
    system('echo "' . $description . '." | mail -s "Re: ' .  $subject . '" -r ' . $noreply_mail . ' \'' . $from . '\'');
}

sub postToNewsGroup {
    my $processed_dest_file = shift;
    system($rnews_location . ' -h ' . $usenet_host . ' -P ' . $usenet_port . ' -S ' . $usenet_host . ' < ' . $processed_dest_file);
}

sub formatNews {
    my ($filename, $processed_dest_file) = @_;
    system('cat ' . $filename . ' | ' . $mail_format . ' > ' . $processed_dest_file);
}

sub getFileData {
    my $filename = shift;
    if ($filename eq '') {
	return '';
    }
    open(FH, '<', $filename) or die $!;
    my $file_data = '';
    while(<FH>){
	$file_data .= $_;
    }
    close(FH);
    return $file_data;
}

hook before => sub {
    if (!session('user') &&
	request->path !~ m{^/login} ) {
        forward '/login', { requested_path => request->path };
    }
};

get '/' => sub {
    template 'index';
};

sub get_news_list {
    my $dir_type = shift;
    my $dirname = $dir_base . $dir_type . "/"; 
    opendir my($dh), $dirname or die "Couldn't open dir '$dirname': $!";
    my @files = readdir $dh;
    closedir $dh;
    # remve .. . entries.
    for(my $index = 0; $index <= $#files; $index++){
	if ($files[$index] eq '.') {
	    splice(@files, $index, 1);
	    #index value changed
	    last;
	}
    }
    for(my $index = 0; $index <= $#files; $index++){
	if ($files[$index] eq '..') {
	    splice(@files, $index, 1);
	    #index value changed
	    last;
	}
    }
    my %file_list;
    foreach(@files) {
        my $fh = $dirname . '/'	. $_;
        my $epoch_timestamp = (stat($fh))[8];
        my $timestamp       = localtime($epoch_timestamp);
        $file_list{$_} = $timestamp;
    }
    return %file_list;
}

get '/listincomingnews' => sub {
    my %file_list = get_news_list($dir_incoming);
    my $listnews = '';
    for(keys %file_list){
	$listnews .= "<tr>";
	$listnews .= '<td>' . $_ . '</td>';
	$listnews .= '<td>' . $file_list{$_} . '</td>';  # created time
	$listnews .= '<td><a href="/viewfile?filename=' . $_ . '&dirtype=' .$dir_incoming . '">view</a></td>';
	$listnews .= "</tr>";
    }
    template 'listnews', { listnews => $listnews };
};

get '/viewfile' => sub {
    my $filename_param = query_parameters->get('filename');
    my $dir_type = query_parameters->get('dirtype');
    my $filename = $dir_base . $dir_type . '/' .  $filename_param;
    my $file_data = '';
    $file_data = getFileData($filename);
    if ($file_data eq '') {
	template 'generic', { message => "emtpy" };
    }
    $file_data = encode_entities($file_data);
    $file_data =~ s/\n/<br>/g;
    my $accept_reject_html_block = '';
    if ($dir_type eq $dir_incoming) {
	my $accept_html_button = '<a href="/acceptnews?filename=' . $filename_param . '">Accept</a>';
	my $reject_html_button = '<a href="/rejectnews?filename=' . $filename_param . '">Reject</a>';
	$accept_reject_html_block = $accept_html_button . '&nbsp;&nbsp;' . $reject_html_button;
    }
    template 'viewnews', { file_data => $file_data, accept_reject_html_block => $accept_reject_html_block };
};

get '/listprocessednews' => sub {
    my %file_list = get_news_list($dir_processed);
    my $listnews = '';
    for(keys %file_list){
	$listnews .= "<tr>";
	$listnews .= '<td>' . $_ . '</td>';
	$listnews .= '<td>' . $file_list{$_} . '</td>';  # created time
	$listnews .= '<td><a href="/viewfile?filename=' . $_ . '&dirtype=' . $dir_processed . '">view</a></td>';
	$listnews .= "</tr>";
    }
    template 'listnews', { listnews => $listnews };
};

get '/listrejectednews' => sub {
    my %file_list = get_news_list($dir_rejected);
    my $listnews = '';
    for(keys %file_list){
	$listnews .= "<tr>";
	$listnews .= '<td>' . $_ . '</td>';
	$listnews .= '<td>' . $file_list{$_} . '</td>';  # created time
	$listnews .= '<td><a href="/viewfile?filename=' . $_ . '&dirtype=' . $dir_rejected . '">view</a></td>';
	$listnews .= "</tr>";
    }
    template 'listnews', { listnews => $listnews };
};

get '/acceptnews' => sub {
    my $filename_param = query_parameters->get('filename');
    my $filename = $dir_base . '/' . $dir_incoming . '/' . $filename_param;
    my $file_data = '';
    $file_data = getFileData($filename);
    if ($file_data eq '') {
	template 'generic', { message => "emtpy" };
    }
    $file_data = encode_entities($file_data);
    $file_data =~ s/\n/<br>/g;
    template 'acceptnews', { file_data => $file_data, filename_param => $filename_param };
};

post '/acceptnews' => sub {
    my $filename_param = body_parameters->get('filename_param');
    my $filename = $dir_base . '/' . $dir_incoming . '/' . $filename_param;
    my $dest_filename = $dir_base . '/' . $dir_processed . '/' . $filename_param;
    my $processed_dest_file = $dest_filename . '_processed';
    formatNews($filename, $processed_dest_file);
    if ($post_to_usenet eq 1) {
	postToNewsGroup($processed_dest_file);
    }
    move($filename, $dest_filename)or die "The move operation failed: $!";
    template 'generic', { message => 'Success' };
};

get '/rejectnews' => sub {
    my $filename_param = query_parameters->get('filename');
    my $filename = $dir_base . '/' . $dir_incoming . '/' . $filename_param;
    my $file_data = '';
    $file_data = getFileData($filename);
    if ($file_data eq '') {
	template 'generic', { message => "emtpy" };
    }
    $file_data = encode_entities($file_data);
    $file_data =~ s/\n/<br>/g;
    template 'rejectnews', { file_data => $file_data, filename_param => $filename_param };
};

sub parseFromAndSubject {
    my $message       = shift;
    my $from          = '';
    my $subject       = '';
    my @message_array = split(/\n/, $message);

    foreach(@message_array) {
        # first empty line
        if(/^$/) {
            last;
        }
        if( /^From: / ) {
            $from = $_;
            $from=~ s/^From: //i;
        } elsif( /^Subject: / ) {
            $subject = $_;
            $subject =~ s/^Subject: //i;
        }
    }
    # trim
    $from =~ s/^\s+|\s+$//g;
    $subject =~ s/^\s+|\s+$//g;
    return ($from, $subject);
}

post '/rejectnews' => sub {
    my $submitbutton = body_parameters->get('submitbutton');
    my $filename_param = body_parameters->get('filename_param');
    my $reject_reason = body_parameters->get('reject_reason');
    my $filename = $dir_base . '/' . $dir_incoming . '/' . $filename_param;
    my $dest_filename = $dir_base . '/' . $dir_rejected . '/' . $filename_param;

    if (index($submitbutton, 'Send reject notification') != -1) {
	# TODO: send notification
	if ($send_rec_ack eq 1) {
	    open(FH, '<', $filename) or die $!;
	    my $file_data = '';
	    while(<FH>){
		# first empty line
		if(/^$/) {
		    last;
		}
		$file_data .= $_;
	    }
	    close(FH);
	    my ($from, $subject) = parseFromAndSubject($file_data);
	    # TODO: check return value
	    sendReceiveAck($from, $subject, $reject_reason);
	}
    }
    # add error in error variable
    move($filename, $dest_filename)or die "The move operation failed: $!";

    my $message = 'Success';
    template 'generic', { message => $message };
};

get '/login' => sub {
    if (session('user')) {
	redirect '/';
    } else {
	template 'login', { path => param('requested_path') };
    }
};

post '/login' => sub {
    my $user_value = body_parameters->get('user');
    my $pass_value = body_parameters->get('pass');
    my $error_message = '';

    if($user_value eq $admin_user && $pass_value eq $admin_pass) {
	session user => $user_value;
	redirect body_parameters->get('path') || '/';
    } else {
	$error_message = 'Invalid login/password.';
    }

    if($error_message ne '') {
	return template 'generic', { message => $error_message};
    }
};

get '/logout' => sub {
    app->destroy_session;
    redirect '/';
};

true;