#!/usr/bin/perl -w

# Usage: sendit.pl <textfile> <email-addresses> <name-for-success-list> <delay>
#        and it expects a file called smtppwd.txt in a location specified
#        below. The <delay> between msgs is in seconds, and the delaly used is
#        up to 150% of that time, averaging 125% of the seconds value.
# Example:  sendit.pl advisormsg.txt advisors.contacts.csv adv.mailed17Jun 4
#
# David Harris, Version of 28 Sep 2005 pm 4:00

use Net::SMTP;
use Authen::SASL;

# Read SMTP servername|account|passwd|delay|debugFlag from an outside file that
# can be changed to use different outgoing SMTP systems, perhaps on different
# friends' machines.  The file name and location can be customized here:
open(SMTPPWD, 'C:/htdocs/smtppwd.txt') or die "Couldn't open smtppwd.txt";
chomp($lineread = <SMTPPWD>);     # Reads just first line.
close(SMTPPWD);
# Breaks into 5 substrings at |'s:
($servername, $smtpacct, $passwd, $debugFlag)
        = split /\|/, $lineread, 4;
# 0 for $debugFlag sets NO debugging.

# Check the number of arguments on the command line:
if ($#ARGV+1 != 4) {
  die "sendit.pl needs textfile, emails file, successes file,
  and delayseconds as arguments";
  };
  
# Check existence of the textfile and email listing file:
(open TXTMSG, "<$ARGV[0]") or die "sendit.pl textmsg file not found.\n";
(open EMAILS, "<$ARGV[1]") or die "sendit.pl emails file not found.\n";
# And file to report successful sendings:
(open SUCCESSES, ">$ARGV[2]") or die "sendit.pl: successes/out file not opened.\n";
# And delay-time base number (up to 50% of it will be randomly added to it):
# Thus a value of 48 sec. will average 1 msg/minute, 8 => 8 to 12 sec, averaging
#  10 sec, etc.
$delayseconds = "$ARGV[3]";


#Read the internal documentation from the TXTMSG template file, and throw
# the internal documentation away:
THRUDOCS: while ($lineread = <TXTMSG>) {
  last THRUDOCS if ($lineread =~ /^----------------------+$/);
}

# Read in the lines that give the substitution target fields,
# like TTTTT=1 and FFFFF=2 etc. (which tell which strings are targets to
# be substituted in the text message farther down in the TXTMSG file)
# followed by an '=' sign and the number of the field (column) to
# substitute from each line of the EMAILS file.

# IF there isn't at least one line of such substitutions, then there will
# not be any variation in the emails sent to, so don't use this program but
# just send an ordinary email to a single (set of) persons.

$linenum = 0;
while ($lineread = <TXTMSG>) {
  chomp $lineread;
  if ($lineread =~ /\w+=\d+/) {
     ($substit[$linenum], $subsfield[$linenum]) = split /=/, $lineread, 2;
     $linenum++;
  } elsif ($lineread =~ /^M+$/) {
     last;
  }
    else { die "MMMMMM...MMMMM line not found.\n";}
}


$msglines = 0;
# Read in the substitutable lines from the textfile opened above:
while ($lineread = <TXTMSG>) {
# The mail stuff wraps the lines if needed.
$messagearray[$msglines] = $lineread;
$msglines++;    # The array grows and this index is used below.
};
close(TXTMSG);

$emailnumber = 1;  # Counter of emails sent, for output near end
# Do the rest of this program once for each non-empty line in EMAILS file
while ((chomp($email = <EMAILS>)) && (length($email) > 2)) {
  # Put fields into array.
  @fields = split /\|/, $email;

  # Now @messagearray has the text with the targets embedded,
  #     @substit has the images of the targets,
  #     @subsfield has the numbers of the fields that are  used, and
  #     @fields has the fields OF THIS PARTICULAR EMAIL FILE LINE
  #        to put in place of the targets.

  # Make the 'Date:' string for this particular email
  ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
                  localtime(time-(0*3600)-3);  # Future time zone correction?
  $weekday = (Sun,Mon,Tue,Wed,Thu,Fri,Sat)[$wday];
  $monthname = (Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec)[$mon];
  $yr2000 = $year+1900;
  if (length($mday) == 1) {
    $mday = '0'.$mday;
    }
  if (length($hour) == 1) {
    $hour = '0'.$hour;
    }
  if (length($min) == 1) {
    $min = '0'.$min;
    }
  if (length($sec) == 1) {
    $sec = '0'.$sec;
    }
  $datestr = "$weekday, $mday $monthname $yr2000 $hour\:$min\:$sec +0000\n";

  # Activate the SMTP link:
  if ($debugFlag eq '0') {
    $smtp = Net::SMTP->new( Host => $servername,
                            Timeout => 120 );
    die "Couldn't connect to server" unless $smtp ;
  } else {
    $smtp = Net::SMTP->new( Host => $servername,
                            Timeout => 120,
                            Debug => 1 );     # Non-zero says DO debugging.
    die "Couldn't connect to server with debugging" unless $smtp ;
  }
  $smtp->auth($smtpacct,$passwd);  # Authentication!

  #Start of substitutable message, as stored in array by code above
  for ($j = 0; $j < $msglines; $j++) {  # Step thru stored lines
    $linetosend = $messagearray[$j];
    for ($i = 0; $i < $linenum; $i++) {  #For this line, make substitutions
      # Make a substitution as often as needed in 1 line:
      ($linetosend = $linetosend) =~ s/$substit[$i]/$fields[$subsfield[$i]-1]/g;
    }
    # Special calls for the first 3 lines:
    SWITCH: {
    if ($j == 0) { $smtp->mail($linetosend);      last SWITCH; }
    if ($j == 1) { $smtp->recipient($linetosend); last SWITCH; }
# Blank line then the computed date:
    if ($j == 2) { $smtp->data();                 last SWITCH; }
# All further lines:
    if ($linetosend =~ m/^From: /) {
      $smtp->datasend("Date: $datestr");  # Emit computed date
    }
    $smtp->datasend($linetosend);
    }
  }
  $smtp->dataend();
  $smtp->quit;
  # Write the emails.txt line that was successfully written, and its number:
  print SUCCESSES "$emailnumber|$email\n" ;
  $emailnumber++ ;
   # Sends one email per line of the EMAILS file.
  
  # Let some seconds elapse: the specified time plus randomly to 50% more:
  sleep $delayseconds + int(rand $delayseconds/2);
}
close (SUCCESSES); # After all sent