#!/usr/bin/perl 

# ======================================================================
# WebMonitor Standalone Module: mail
#
#                               CGI script for providing form and script
#                                to send mail to configured system users
#
# required files: mail.list
#                                     Text file with users nicknames and
#                                       email addresses in the format of
#                                             <nickname>:<email address>
#                      Keep "mail.list" in same directory as mail script
#                                 NOTE: you can even have group aliases!
#                                just separate the addresses with commas
#         Make sure you 'chmod 0644 mail.list' so the server can read it
#                             +-----------------------------------------
#                   Example:  |webmaster:admin@machine
#                             |john-doe:jdoe
#                             |carlos:cpero@ncsa.uiuc.edu
#                             |group:leader@domain.com,member@domain.com
#                             +-----------------------------------------
# ======================================================================
# Carlos A. Pero (cpero@ncsa.uiuc.edu)              last update  4/30/95
# ======================================================================
# Documentation for WebMonitor can be found at
#                          <URL:http://hoohoo.ncsa.uiuc.edu/webmonitor/>
# ======================================================================
# This code is in the public domain. Specifically, we give to the public
# domain all rights for future licensing of the source code, all resale
# rights, and all publishing rights.
# 
# We ask, but do not require, that the following message be included in
# all derived works:
# 
# Portions developed at the National Center for Supercomputing
# Applications at the University of Illinois at Urbana-Champaign.
# 
#
# THE UNIVERSITY OF ILLINOIS GIVES NO WARRANTY, EXPRESSED OR IMPLIED,
# FOR THE SOFTWARE AND/OR DOCUMENTATION PROVIDED, INCLUDING, WITHOUT
# LIMITATION, WARRANTY OF MERCHANTABILITY AND WARRANTY OF FITNESS FOR A
# PARTICULAR PURPOSE.
# ======================================================================
# This script can be referenced 2 ways for the best flexibility:
#
# DIRECTLY, <A HREF="/cgi-bin/mail?nickname">
# This will generate an email form for the person named in 'nickname',
# and if they exist in the 'mail.list' file.
# If no 'nickname' is specified in the QUERY_STRING when the script is
# first invoked, or the nickname cannot be found in the 'mail.list', 
# an email form with a SELECT box of all valid nicknames is generated.
# When the email form is submitted, it will call itself via method of POST,
# and send the email to the recipient, outputting a confirmation message.
# If the HTTP_REFERER was trasmitted when the script was first invoked,
# there will be a hyperlink available to go back to that page (such as
# the user's home page).
#
# FORWARDING RESULTS, <FORM METHOD="POST" ACTION="/cgi-bin/mail?nickname">
# This will forward the results from the FORM, which can exist anywhere,
# to the recipient specified by 'nickname'.  Since the 'nickname' is in
# the QUERY_STRING, the FORM *must* use the METHOD="POST", otherwise the
# recipient's nickname will be blown away.
# Users may want to include a:
#    <INPUT TYPE="hidden" NAME="next-url" VALUE="/~user/received.html">
# If this is present in the FORM input, the client will be redirected
# to this HTML file as a confirmation message instead of the default.
# In addition, the user can also define any of the following input names
# in their form to better customize the output mailed back to them.
#    <INPUT TYPE="hidden" NAME="subject" VALUE="My survey results">
#    <INPUT TYPE="hidden" NAME="from-name" VALUE="Average Web user">
#    <INPUT TYPE="hidden" NAME="from-email" VALUE="jdoe@domain.com">
# These values will then be used in the header of the email message.
# Otherwise, default values will be substituted.
# ======================================================================


########################################################################
########## Configurable variables ######################################

$SENDMAIL = '/usr/sbin/sendmail';
#                                   The location of your sendmail binary

## Also, make sure the first line of this script points
## to your PERL binary

########## Nothing else to change ######################################
########################################################################


$SCRIPT = $ENV{'SCRIPT_NAME'};

#### Do standard HTTP stuff ####
&cgi_receive;
&cgi_decode;
&cgi_header;

#### Output email form unless you are receiving FORM input already ####
&print_form unless keys %FORM;

#### Make sure required fields are filled out ####
if ($FORM{'nickname'}) {
    #### This section is for receiving from this form ####
    &error_blank_field('your name')  unless ($FORM{'from-name'});
    &error_blank_field('your email address in the form of <I>name@domain</I>') unless ($FORM{'from-email'} =~ /\@/);
    &error_blank_field('the subject of the message') unless ($FORM{'subject'});
    &error_blank_field('your message') unless ($FORM{'message'});
}
else {
    #### This section is for user's forms ####
    #### Such as ACTION="/cgi-bin/mail?carlos" to have results forwarded ####
    $FORM{'nickname'} = $ENV{'QUERY_STRING'};
}

#### Lookup email address based on 'nickname' ####
open (MAILNAMES, "mail.list") || die ("$SCRIPT: Can't open mail.list: $!\n");
while (<MAILNAMES>) {
    chop;
    ($nick, $addr) = split(/:/, $_);
    $ADDRESS{$nick} = $addr;
}
close (MAILNAMES);
&error_blank_field('the nickname of the recipient') unless ($ADDRESS{$FORM{'nickname'}});

#### Make sure all necessary variables for email message are filled in
($FORM{'subject'}) || ($FORM{'subject'} = "FORM results");
($FORM{'from-email'}) || ($FORM{'from-email'} = $ADDRESS{$FORM{'nickname'}});
($FORM{'from-name'}) || ($FORM{'from-name'} = "WebMonitor mail");

open (MAIL, "| $SENDMAIL $ADDRESS{$FORM{'nickname'}}") || die ("$SCRIPT: Can't open $mailprog: $!\n");
print MAIL "Reply-to: $FORM{'from-email'} ($FORM{'from-name'})\n";
print MAIL "From: $FORM{'from-email'} ($FORM{'from-name'})\n";
print MAIL "To: $ADDRESS{$FORM{'nickname'}}\n";
print MAIL "Subject: $FORM{'subject'}\n";
print MAIL "\n";
print MAIL "=============================================================\n";
print MAIL "NOTE:  This message was sent through the WebMonitor mail form\n";
print MAIL "=============================================================\n";
print MAIL "REMOTE HOST:        $ENV{'REMOTE_HOST'}\n";
print MAIL "REMOTE ADDRESS:     $ENV{'REMOTE_ADDR'}\n";
print MAIL "HTTP_USER_AGENT:    $ENV{'HTTP_USER_AGENT'}\n";
print MAIL "=============================================================\n";
print MAIL "\n";
if ($ENV{'QUERY_STRING'}) {
    &dump_values(FORM, MAIL);
}
else {
    print MAIL "$FORM{'message'}\n";
}
print MAIL "\n";
close (MAIL);

#### Now, redirect if "next-url" is included
if ($FORM{'next-url'}) {
    print "Location: $FORM{'next-url'}\n";
    print "\n";
    exit;
}

#### Prevent HTML output
foreach $key (keys %FORM) {
    $FORM{$key} =~ s/</\&lt;/g;
    $FORM{$key} =~ s/>/\&gt;/g;
}

#### Output confirmation message ####
print qq|<HTML><HEAD><TITLE>WebMonitor-Email Sent</TITLE></HEAD><BODY>\n|;
print qq|<H1>$ENV{'SERVER_NAME'} Email Sent</H1>\n|;
print qq|The following message has been sent.\n|;
print qq|You can now return to <A HREF="$FORM{'previous-url'}">where you were</A>.\n| if ($FORM{'previous-url'});
print qq|<HR>\n|;
print "<PRE>\n";
print "Reply-to: $FORM{'from-email'} ($FORM{'from-name'})\n";
print "From: $FORM{'from-email'} ($FORM{'from-name'})\n";
print "To: $ADDRESS{$FORM{'nickname'}}\n";
print "Subject: $FORM{'subject'}\n";
print "\n";
if ($ENV{'QUERY_STRING'}) {
    &dump_values(FORM, STDOUT);
}
else {
    print "$FORM{'message'}\n";
}
print "\n";
print "</PRE>\n";
print "</BODY>\n";
exit;

#####################################################################
#### SUBROUTINES ####################################################

sub error_blank_field {
    local($variable) = @_;
    print "\n" if ($FORM{'next-url'});
    print "<HTML><HEAD><TITLE>WebMonitor-Email Error</TITLE></HEAD><BODY>\n";
    print "<H1>Error!</H1>\n";
    print "You did not fill in $variable.\n";
    print "Please go back to the form and do so.\n";
    print "</BODY>\n";
    exit;
}

sub cgi_header {
    print "Content-type: text/html\n";
    print "\n" unless ($FORM{'next-url'});
}        

sub cgi_receive {
    if ($ENV{'REQUEST_METHOD'} eq "POST") {
        read(STDIN, $incoming, $ENV{'CONTENT_LENGTH'});
    }
    else {
        $incoming = $ENV{'QUERY_STRING'};
    }
}

sub cgi_decode {
    @pairs = split(/&/, $incoming);

    foreach (@pairs) {
        ($name, $value) = split(/=/, $_);

        $name  =~ tr/+/ /;
        $value =~ tr/+/ /;
        $name  =~ s/%([A-F0-9][A-F0-9])/pack("C", hex($1))/gie;
        $value =~ s/%([A-F0-9][A-F0-9])/pack("C", hex($1))/gie;

        #### Strip out semicolons unless for special character
        $value =~ s/;/$$/g;
        $value =~ s/&(\S{1,6})$$/&\1;/g;
        $value =~ s/$$/ /g;

        $value =~ s/\|/ /g;
        $value =~ s/^!/ /g; ## Allow exclamation points in sentences

        #### Skip blank text entry fields
        next if ($value eq "");

        #### Check for "assign-dynamic" field names
        #### Mainly for on-the-fly input names, especially checkboxes
        if ($name =~ /^assign-dynamic/) {
            $name = $value;
            $value = "on";
        }

	#### Allow for multiple values of a single name
        $FORM{$name} .= ", " if ($FORM{$name});

        $FORM{$name} .= $value;
    }
}

sub dump_values {
    local($env, $handle) = @_;
    eval "\@keys = keys \%$env";
    eval "\@values = values \%$env";
    ($handle eq "STDOUT") && (print $handle "<PRE>\n");
    while ($#keys >= 0) {
	$key = pop(@keys);
	$value = pop(@values);
	if ($value =~ /[\cM\n]/) {
	    print $handle "($key)\n";
	    print $handle "-" x 70, "\n", $value, "-" x 70, "\n";
	}
	else {
            print $handle "($key)  $value\n";
	}
    }
    ($handle eq "STDOUT") && (print $handle "</PRE>\n");

}

sub print_form {
    #### Assign path_info and query_string if necessary
    #### $path_info = "";

    open (MAILNAMES, "mail.list") || die ("$SCRIPT: Can't open mail.list: $!\n");
    while (<MAILNAMES>) {
	chop;
	($nickname, $address) = split(/:/, $_);
	$ADDRESS{$nickname} = $address;
    }
    close (MAILNAMES);

    print qq|<HTML><HEAD><TITLE>WebMonitor-Email Form</TITLE></HEAD><BODY>\n|;
    print qq|<H1>$ENV{'SERVER_NAME'} <A HREF="http://hoohoo.ncsa.uiuc.edu/webmonitor/module-mail.html">Email Form</A></H1>\n|;
    print qq|<FORM METHOD="POST" ACTION="$SCRIPT$path_info$query_string">\n|;
    print qq|<HR>\n|;
    print qq|<INPUT TYPE="submit" VALUE="Send Email"> to |;


    if ($ADDRESS{$ENV{'QUERY_STRING'}}) {
	print qq|<B>$ENV{'QUERY_STRING'}</B> <I>($ADDRESS{$ENV{'QUERY_STRING'}})</I>\n|;
	print qq|<INPUT TYPE="hidden" NAME="nickname" VALUE="$ENV{'QUERY_STRING'}">\n|;
    }
    else {
	print qq|<SELECT NAME="nickname">\n|;
	print qq|<OPTION>Select name...\n|;
        foreach $nickname (sort keys %ADDRESS) {
	    print qq|<OPTION>$nickname\n|;
        }
        print qq|</SELECT>\n|;
    }


    print qq|<HR>\n|;
    print qq|<PRE>|;
    print qq|    Your Name: <INPUT NAME="from-name" SIZE="30">\n|;
    print qq|Email Address: <INPUT NAME="from-email" SIZE="30">\n|;
    print qq|      Subject: <INPUT NAME="subject" SIZE="40">    <INPUT TYPE="reset" VALUE="Clear Message">\n|;
    print qq|</PRE>\n|;
    print qq|<TEXTAREA NAME="message" ROWS="15" COLS="70"></TEXTAREA>\n|;
    print qq|<INPUT TYPE="hidden" NAME="previous-url" VALUE="$ENV{'HTTP_REFERER'}">\n|;
    print qq|</FORM>\n|;
    print qq|</BODY>\n|;

    exit;
}