#!/usr/bin/perl

use LWP::UserAgent;

print "Content-type: text/plain\n\n";



# read post from PayPal system and add 'cmd'
read (STDIN, $query, $ENV{'CONTENT_LENGTH'});
$query .= '&cmd=_notify-validate';
 
# post back to PayPal system to validate
$ua = LWP::UserAgent->new(ssl_opts => { verify_hostname => 1 });

# when testing change sandbox url here
$req = HTTP::Request->new('POST', 'https://www.paypal.com/cgi-bin/webscr');

$req->content_type('application/x-www-form-urlencoded');

# and here

$req->header(Host => 'www.paypal.com');
$req->content($query);
$res = $ua->request($req);
 
# split posted variables into pairs
@pairs = split(/&/, $query);
$count = 0;
foreach $pair (@pairs) {
 ($name, $value) = split(/=/, $pair);
 $value =~ tr/+/ /;
 $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
 $variable{$name} = $value;
 $count++;
}
 
# assign posted variables to local variables
$item_name = $variable{'item_name'};
$item_number = $variable{'item_number'};
$payment_status = $variable{'payment_status'};
$payment_amount = $variable{'mc_gross'};
$payment_currency = $variable{'mc_currency'};
$txn_id = $variable{'txn_id'};
$receiver_email = $variable{'receiver_email'};
$payer_email = $variable{'payer_email'};

$custom = $variable{'custom'};
 
if ($res->is_error) {
 # HTTP error
 # do whatever necessary
 print "ERROR: http_error! (Not sure what this is)\n";
 $ipnerror = "http_error";
 &error1;
 
}
elsif ($res->content eq 'VERIFIED') {
 print "PayPal responded VERIFIED.\n";
 # check the $payment_status=Completed
 if ($payment_status ne "Completed") {
  # do whatever necessary
  print "Payment status was not Completed.\n";
   $ipnerror = "Payment status was not completed.";
 &error1;
  
 }
 
 

 
 # check that $receiver_email is your Primary PayPal email
 elsif ($receiver_email ne "info\@email.com") {
  # do whatever necessary
  print "Receiver email was incorrect.\n";
    $ipnerror = "Receiver email was incorrect";
    &error1;
  
 }
 

 
 
 # process payment
 else {
  # everything ok, update your database
  # split 4 passthrough variables in "custom", separated by comma (',')
  # change separator char if necessary
  print "Everything should be ok.\n";
  my ($user1, $user2, $user3) = split(/,/, $custom, 3);
  
  

  my $response = $ua->post('http://www.mydomain.com/cgi-bin/add-listing.pl', {
    'USER1' => $user1,
    'USER2' => $user2,
    'USER3' => $user3,
    'RESULT' => '0' } );
  
  
  unless ($response->is_success) {
   print "Posting to add-listing.pl failed.\n";
   $ipnerror = "Posting to add-listing.pl failed.";
   &error1;
   # request failed
  }
  # parse server response
  my $resdec = $response->decoded_content;
 }
}
elsif ($res->content eq 'INVALID') {
 # log for manual investigation
 # do whatever necessary
 print "PayPal responded INVALID. (Probably means it didn't get called from Paypal.)\n";
     $ipnerror = "PayPal responded INVALID. (Probably means it didn't get called from Paypal.)";
     &error1;
}
else {
 # error
 # do whatever necessary
 print "Unexpected response from PayPal.\n";
      $ipnerror = "Unexpected response from PayPal.";
     &error1;
}




sub error1 {
$notify_admin2 = "1"; #1=yes, 0=no
$mailprog = "/usr/sbin/sendmail";


if ($notify_admin2 eq "1") {
    # send mail with activate link to admin
		open (MAIL, "|$mailprog info\@email.com") || die "Can't open $mailprog!\n";
		print MAIL "From: $sitename <admin\@email.com>\n";
		print MAIL "Reply-to: $sitename <admin\@email.com>\n";
		print MAIL "To: info@email.com\n";
		print MAIL "Subject: IPN Handler Error\n";
		print MAIL "Content-type: text/plain\n";
		print MAIL "There was an IPN Handler error.\n\n";
		print MAIL "Error: $ipnerror\n\n";
                print MAIL "User1: $user1\n";
                print MAIL "User2: $user2\n";
		print MAIL "User3: $user3\n";
		print MAIL "This email sent by ipn-handler.pl. \n\n";
		close (MAIL);
}
} #end sub


print "Done\n";