#!/usr/bin/perl -w

use strict;
use warnings;
use CGI qw(:standard :cgi-lib);
$CGI::POST_MAX=102400;  $CGI::DISABLE_UPLOADS = 1;
require Mail::Send;
use Fcntl ':flock'; # import LOCK_* constants

#################### GLOBAL SETUP #################################
# Parameter name manipulation, helps prevent some spam
my $nameParam = 'fdsf43';
my $phoneParam = 'xf3f3';
my $floodTime = 120; # flood protection timeout in seconds
my $floodTries = 1; # flood protection - number of requests that are allowed to be sent
my $floodFile = 'flood.ip';
my $sendEmail = 0; # should we send request e-mail?
my $emailAddress = 'callbackscript@example.com'; # to which address should we be sending requests?
my $emailSubject = 'Call Request'; # what e-mail subject should we use?
my $backButtonMessage = 'Please hit your browser\'s <em>Back</em> button and correct this.';
my $userHost = remote_host(); # store user's IP
my $q = new CGI;

printHTML(qq|<strong>Name</strong> field is required. $backButtonMessage|) if !defined($q->param($nameParam)) or $q->param($nameParam) eq 'Name';
printHTML(qq|<strong>Phone number</strong> field is required. $backButtonMessage|) if !defined($q->param($nameParam)) or $q->param($phoneParam) eq 'Phone number';
printHTML(qq|<strong>Name</strong> field may <strong>not</strong> be longer than <strong>100</strong> characters. $backButtonMessage|) 
	if length($q->param($nameParam)) > 100;
printHTML(qq|<strong>Phone number</strong> field may <strong>not</strong> be longer than <strong>100</strong> characters. $backButtonMessage|)
	if length($q->param($phoneParam)) > 100;

my %userInfo = ( 'host' => remote_host(),
				'name' => $q->param($nameParam),
				'phone number' => $q->param($phoneParam),
				'request time' => scalar (localtime(time)));
if (checkFlood($userInfo{'host'}))
{
	if (defined($q->param('ajax')))
	{
		printHTTPHeaders();
		print "FLOOD";
		exit;
	}
	printHTML('You have already submitted your request. We will call you as soon as possible. Thank you.');
}

if ($sendEmail) { sendMail(); }
else {testScript(); }

if (defined($q->param('ajax')))
{
	printHTTPHeaders();
	print "OK";
	exit;	
}

printHTML('Your request has been submitted. We will call you as soon as possible. Thank you.');


sub testScript
{
	printHTMLError ("Failed to open `test` file: $!") unless open TEST_FILE, ">", 'test';
	print TEST_FILE <<EMAIL_BODY;
Call back request (E.Create):
----------------------------------------
	From: $userInfo{'name'}
	Phone number: $userInfo{'phone number'}
---------------------------------------
	IP Address: $userInfo{'host'}
	Request was sent at: $userInfo{'request time'} 
EMAIL_BODY
	close TEST_FILE;
}

sub sendMail
{
	my $msg = new Mail::Send;
	$msg->to($emailAddress);
	$msg->subject($emailSubject . " from $userInfo{'name'} [" . localtime()  . "]");
	my $fh = $msg->open('sendmail'); 
	print $fh <<EMAIL_BODY;
Call back request (E.Create):
----------------------------------------
	From: $userInfo{'name'}
	Phone number: $userInfo{'phone number'}
---------------------------------------
	IP Address: $userInfo{'host'}
	Request was sent at: $userInfo{'request time'} 
EMAIL_BODY
	$fh->close;         # complete the message and send it	
}

sub checkFlood
{
	my $userHost = shift;
	my $noFlood = 0; my $yesFlood = 1;
	my $separator = ':sep:';
	
	return $noFlood
		unless open FLOOD_FILE, "<", $floodFile;
	my $userFloodCount = 0;
	my @floodData = ();
	while(<FLOOD_FILE>)
	{
		chomp;
		my ($ip, $time) = split /\Q$separator\E/, $_, 2;
		push @floodData, {'ip' => $ip, 'time' => $time }
			unless (time() - $time) > $floodTime;
		$userFloodCount++
			if $ip eq $userHost
				and (time() - $time) < $floodTime;
	}
	push @floodData, { 'ip' => $userHost, 'time' => time() }
		if $userFloodCount <= $floodTries;
	close FLOOD_FILE;
	return $noFlood
		unless open FLOOD_FILE, ">", $floodFile;
	flock(FLOOD_FILE, LOCK_EX);
	seek(FLOOD_FILE, 0, 2);
	foreach my $flooder(@floodData)
	{
		print FLOOD_FILE $flooder->{'ip'} . $separator . $flooder->{'time'} . $/;
	}
	flock(FLOOD_FILE, LOCK_UN);
	close FLOOD_FILE;
	return $yesFlood
		if $userFloodCount >= $floodTries;
	return $noFlood;
}

sub printHTMLError
{
	my $message = shift;
	printHTTPHeaders();
	print <<END_HTML;
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
	<title>Fatal Server Error</title>
</head>
<body>
	<h1>Fatal Server Error</h1>
	<p>A server error has occured ( $message ). Try again later. We apologize for the inconvenience.</p>
</body>
</html>
END_HTML
	exit;
}

sub printHTML
{
	my $message = shift;
	printHTTPHeaders();
	print <<END_HTML;
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
	<title>Foo Bar Baz</title>
</head>
<body>
	<h1>SENT</h1>
</body>

END_HTML
 	exit;
}

sub printHTTPHeaders
{
	print "Content-type: text/html\n\n";
}