#!/usr/bin/perl

###############################################################################
##
## The URL Access Notifier
##
## This CGI will send an e-mail when it will be accessed
## It is good to be called like an image from inside a web page this way:
##
## <img src="http://host.net/cgi-bin/notify?Resource+name" width=1 height=1>
##
##
##
## Distributed under the terms of the GPL as found at 
##
##       http://www.gnu.org/licenses/gpl.txt
##
##
## This software home page:
##
##	http://avi.alkalay.net/software/notify/
##
##
##
## Copyright (C) 2001 by Avi Alkalay
##
##  Avi Alkalay
## <avi@alkalay.net>
##  19 Aug 2001
##  Made in Brazil
##

##
## Changelog
##
## * Sat Sep 22 06:18:01 BRST 2001 Avi Alkalay <avi@alkalay.net>
##   - 1.91
##   - Added 'redirect' support
## * Sun Aug 19 2001 Avi Alkalay <avi@alkalay.net>
##   - 1.9
##   - First public clean release
##

use strict;
use CGI qw(:push :standard :cgi);
$|=1;
my $defaultTo="aviram\@yahoo.com";
#my $defaultTo="aviram\@br.ibm.com";
my $defaultFrom="notifier\@alkalay.net";
my $signature="URL Access Notifier";
my $version="1.91";
my $home="http://avi.alkalay.net/software/notify/";

###############################################################################
##
## getCGIContext
##
## Uses the CGI.pm library to get parameters passed via the form or URL.
## Returns a hash containing the values needed by the program.
##
###############################################################################
sub getCGIContext {
	my $query=new CGI;
	my %input;

	$input{time}=localtime();
	$input{remoteHost}=$query->remote_host();
	$input{virtualHost}=$query->virtual_host();
	#$input{referer}=$query->referer();
	$input{referer}=$query->param('referer');
	$input{userAgent}=$query->http('User-agent');
	$input{identifier}=$query->param('id');
	$input{to}=$query->param('to');
	$input{from}=$query->param('from');
	$input{redir}=$query->param('redir');

	if ($input{referer} eq "") {
		$input{referer}=$query->referer();
	}

	if ($input{referer} eq "") {
		$input{referer}="Direct Access";
	}

	if ($input{identifier} eq "") {
		$input{identifier}=join(" ",@ARGV);
	}

	if ($input{to} eq "") {
		$input{to}=$defaultTo;
	}

	if ($input{from} eq "") {
		$input{from}=$defaultFrom;
	}

	# Calculate a very simple hash to get the cookie
	$input{hash}=$input{identifier};
	$input{hash}=~s/[ \.]//g;
	$input{times}=$query->cookie(-name=>"notify.$input{hash}");

	if ($input{identifier}) {
		$input{times}+=1;
		$input{cookie}=$query->cookie(-name=>"notify.$input{hash}",
			-value=>$input{times},
			-domain=>$input{virtualHost},
			-expires=>'+3y',
			-path=>"/");
	}

	return %input;
}



###############################################################################
##
## sendMIMEEmail
##
## Build and send a MIME message
##
###############################################################################
sub sendMIMEEmail {
	my (%cgiContext)=@_;
	my $SENDMAIL="/usr/sbin/sendmail -t";
	#my $SENDMAIL="/tmp/log -t";
	my $boundary="____________________" . rand();

	$boundary=~s/\.//g;
	
	open(MAIL,"| $SENDMAIL -f \"$cgiContext{from}\"");
	print MAIL <<EOF;
From: $cgiContext{from}
To: $cgiContext{to}
X-Mailer: $signature $version $home
Organization: Alkalay dot Net
MIME-Version: 1.0
Subject: $cgiContext{identifier}
Content-Type: multipart/alternative; boundary="$boundary"

--$boundary
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

EOF
	print MAIL genTXTOutput(%cgiContext);
	print MAIL <<EOF;

--$boundary
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit

EOF
	print MAIL genHTMLOutput(%cgiContext);
	print MAIL <<EOF;


--$boundary--

.
EOF
	close(MAIL);
}



###############################################################################
##
## genTXTOutput
##
## Creates the report in plain text format
##
###############################################################################
sub genTXTOutput {
	my (%cgiContext)=@_;
	my $output;
	my $tempOut;
	my $var;
	my $nameSize;

	$output=<<EOF;
URL ACCESS NOTIFY

The resource identified by "$cgiContext{identifier}" was accessed.



Access information:
                           Access time: $cgiContext{time}
                      User Remote Host: $cgiContext{remoteHost}
Times this user accessed this resource: $cgiContext{times}
                  User Agent signature: $cgiContext{userAgent}
                        User came from: $cgiContext{referer}
		    User recirected to: $cgiContext{redir}
                          Virtual Host: $cgiContext{virtualHost}




Other HTTP Session envrionment variables:
EOF

	foreach $var (keys(%ENV)) {
		$nameSize=length($var) if (length($var)>$nameSize);
	}

	foreach $var (sort(keys(%ENV))) {
		#$tempOut=" " x $nameSize-length($var),"$var=$ENV{$var}\n";
		$output=join("",$output," " x ($nameSize-length($var)),"$var=$ENV{$var}\n");
	}

	$output=join("",$output,<<EOF);
________________________________________________________________________
$signature $version by Avi Alkalay <avi at alkalay.net>
$home
EOF
	return $output;
}




###############################################################################
##
## genHTMLOutput
##
## Creates the report in HTML format
##
###############################################################################
sub genHTMLOutput {
	my (%cgiContext)=@_;
	my $output;
	my $tempOut;
	my $var;

	$output=<<EOF;
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
  <title>Notify</title>
</head>
<body bgcolor=white style="font:8pt verdana">
<u><b><big><big>URL Access Notify</big></big></b></u><br>
<br>
<br>
The resource identified by "<b><u><font color="red">$cgiContext{identifier}</font></u></b>" was accessed.<br>
<br>
<b>Access information:</b><br>
<table bgcolor=blue><tr><td>
<table cellpadding="1" cellspacing="0" border="0" bgcolor="#ddffbb">
  <tbody style="font:8pt verdana">
    <tr valign="Top">
      <td valign="Top" align="Right" height="30%" nowrap="true"><b>Access time:</b></td>
      <td valign="Middle">$cgiContext{time}</td>
    </tr>
    <tr valign="Top">
      <td valign="Top" align="Right" height="30%" nowrap="true"><b>User Remote Host:</b></td>
      <td valign="Middle">$cgiContext{remoteHost}</td>
    </tr>
    <tr valign="Top">
      <td valign="Top" align="Right" height="30%" nowrap="true"><b>Times this user<br>accessed this resource:</b></td>
      <td valign="Bottom">$cgiContext{times}</td>
    </tr>
    <tr valign="Top">
      <td valign="Top" align="Right" height="30%" nowrap="true"><b>User Agent signature:</b></td>
      <td valign="Middle">$cgiContext{userAgent}</td>
    </tr>
    <tr valign="Top">
      <td valign="Top" align="Right" height="30%" nowrap="true"><b>User came from:</b></td>
      <td valign="Middle">$cgiContext{referer}</td>
    </tr>
    <tr valign="Top">
      <td valign="Top" align="Right" height="30%" nowrap="true"><b>User redirected to:</b></td>
      <td valign="Middle">$cgiContext{redir}</td>
    </tr>
    <tr valign="Top">
      <td valign="Top" align="Right" height="30%" nowrap="true"><b>Virtual Host:</b></td>
      <td valign="Middle">$cgiContext{virtualHost}</td>
    </tr>
  </tbody>
</table>
</td></tr></table>
<br>
<br>
<b>Other HTTP Session environment variables:</b><br>
<table bgcolor=blue><tr><td>
<table cellpadding="1" cellspacing="0" border="0" bgcolor="#ddffbb">
  <tbody style="font:8pt verdana">
EOF

	foreach $var (sort(keys(%ENV))) {
		$tempOut=<<EOF;
    <tr valign="Top">
      <td valign="Middle" align="Right" nowrap="true"><font color="#777777">$var</font></td>
      <td valign="Middle"><b>=</b></td>
      <td valign="Middle" nowrap="true"><font color="#777777">$ENV{$var}</font></td>
    </tr>
EOF
		$output=join("",$output,$tempOut);
	}

	$output=join("",$output,<<EOF);
  </tbody>
</table>
</td></tr></table>
<hr align="Left" width="100%" size="0"><small>$signature $version by Avi Alkalay &lt;<u>avi at alkalay.net</u>&gt;<br>
<a href="$home">$home</a></small>
</body>
</html>
EOF
	return $output;
}




###############################################################################
##
## Main block
##
## Just call above functions in a special order.
##
###############################################################################

# Get the parameters pre-processed by CGI.pm
my %cgiContext=getCGIContext();

if ($cgiContext{redir} eq "") {
	print header(-type=>"image/gif",-cookie=>$cgiContext{cookie},-size=>0);
} else {
	print redirect($cgiContext{redir});
}
sendMIMEEmail(%cgiContext);
close(STDOUT);