Business::MaxMind::HTTPBase - Base class for accessing HTTP web services

package Business::MaxMind::HTTPBase;

use 5.006; # we use the utf8 pragma now.
           # Older perl installations should use 1.50

use strict;

require Exporter;
use AutoLoader qw(AUTOLOAD);
use vars qw($VERSION $API_VERSION);

use LWP::UserAgent;
use URI::Escape;

$VERSION = '1.51';
$API_VERSION = join('/','Perl',$VERSION);

# we have two servers main servers.
# if possible use minfraud3 it is the fastest followed by minfraud1
# minfraud2 should only used if you have a good reason
my @defaultservers = qw/minfraud3.maxmind.com minfraud1.maxmind.com minfraud2.maxmind.com/;

sub new {
  my $i = 0;
  my ($class) = shift;
  if ($class eq 'Business::MaxMind::HTTPBase') {
    die "Business::MaxMind::HTTPBase is an abstract class - use a subclass instead";
  }
  my $self = { @_ };
  bless $self, $class;
  for my $server (@defaultservers){
    $self->{servers}->[$i] = $server;
    $i++;
  }
  unless ($self->{wsIpaddrRefreshTimeout}) {
    $self->{wsIpaddrRefreshTimeout} = 18000;  # default of 5 hours timeout
  }
  $self->{wsIpaddrCacheFile} ||= '/tmp/maxmind.ws.cache';
  $self->{ua} = LWP::UserAgent->new;
  $self->_init;
  return $self;
}

sub getServers {
  return [ @{ $_[0]->{servers} || [] } ];
}

sub setServers {
  my ( $self, $serverarrayref ) = @_;
  $self->{servers} = [@$serverarrayref];
}

sub writeIpAddressToCache {
  my ($self, $filename, $ipstr) = @_;
  my $datetime = time();
  open my $fh, ">$filename" or return;
  print $fh $ipstr . "\n";
  print $fh $datetime . "\n";
}

sub readIpAddressFromCache {
  my ($self) = @_;
  my $ipstr;
  my $datetime;
  if (-s $self->{wsIpaddrCacheFile} ) {
    open my $fh, $self->{wsIpaddrCacheFile};
    $ipstr = <$fh>;
    chomp($ipstr);
    $datetime = <$fh>;
    chomp($datetime);
  }

  unless ($ipstr && (time() - $datetime <= $self->{wsIpaddrRefreshTimeout})) {
    # refresh cached IP addresses if no IP address in file, or if refresh timeout expired
    if (my $tryIpstr = $self->readIpAddressFromWeb($ipstr)) {
      $ipstr = $tryIpstr;
    } else {
      if ($self->{debug}) {
	print STDERR "Warning, unable to get ws_ipaddr from www.maxmind.com\n";
      }
    }
    # we write to cache whether or not we were able to get $tryIpStr, since
    # in case DNS goes down, we don't want to check app/ws_ipaddr over and over
    $self->writeIpAddressToCache($self->{wsIpaddrCacheFile}, $ipstr);
  }
  return $ipstr;
}

sub readIpAddressFromWeb {
  my ($self) = @_;
  my $request = HTTP::Request->new('GET', "http://www.maxmind.com/app/ws_ipaddr");
  if ($self->{"timeout"} > 0) {
    $self->{ua}->timeout($self->{"timeout"});  
  }

  my $response = $self->{ua}->request($request);
  if ($response->is_success) {
    my $content = $response->content;
    chomp($content);
    if ($content =~ m!^(?:\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3};)*\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$!) {
      # is comma separated string of IP addresses
      return $content;
    }
  }
}

sub query {
  my ($self) = @_;
  my $s = $self->{servers};
  my $ipstr;
  my $datetime;

  unless ($self->{useDNS}) {
    $ipstr = $self->readIpAddressFromCache;
  }
  if ($ipstr) {
    my @ipaddr = split(";",$ipstr);
    for my $ip (@ipaddr) {
      my $result = $self->querySingleServer($ip);
      return $result if $result;
    }
  }
  for my $server (@$s) {
    my $result = $self->querySingleServer($server);
    return $result if $result;
  }
  return 0;
}

sub input {
  my $self = shift;
  my %vars = @_;
  while (my ($k, $v) = each %vars) {
    unless (exists $self->{allowed_fields}->{$k}) {
      die "invalid input $k - perhaps misspelled field?";
    }
    $self->{queries}->{$k} = $self->filter_field($k, $v);
  }
}

# sub-class should override this if it needs to filter inputs
sub filter_field {
  my ($self, $name, $value) = @_;
  return $value;
}

sub output {
  my $self = shift;
  return $self->{output};
}

# if possible send the escaped string as latin1 for backward compatibility.
# That makes a difference for chars 128..255
# otherwise use utf8 encoding.
#
sub _mm_uri_escape {
  return uri_escape($_[0]) if $] < 5.007;
  return utf8::downgrade( my $t = $_[0], 1 ) ?   uri_escape($_[0]) :  uri_escape_utf8($_[0]) ;
}

sub querySingleServer {
  my ($self, $server) = @_;
  my $url = ($self->{isSecure} ? 'https' : 'http') . '://' . $server . '/' .
      $self->{url};
  my $check_field = $self->{check_field};
  my $queries = $self->{queries};
  my $query_string = join('&', map { "$_=" . _mm_uri_escape($queries->{$_}) } keys %$queries);
  $query_string .= "&clientAPI=$API_VERSION";
  if ($self->{"timeout"} > 0) {
    $self->{ua}->timeout($self->{"timeout"});
  }
  my $request = HTTP::Request->new('POST', $url);
  $request->content_type('application/x-www-form-urlencoded');
  $request->content($query_string);
  if ($self->{debug}) {
    print STDERR "sending HTTP::Request: " . $request->as_string;
  }
  my $response = $self->{ua}->request($request);
  if ($response->is_success) {
    my $content = $response->content;
    my @kvpair = split(';',$content);
    my %output;
    for my $kvp (@kvpair) {
      my ($key, $value) = split('=',$kvp,2);
      $output{$key} = $value;
    }
    unless (exists $output{$check_field}) {
      return 0;
    }
    $self->{output} = \%output;
    return 1;
  } else {
    if ($self->{debug}) {
      print STDERR "Error querying $server code: " . $response->code;
    }
    return 0;
  }
}

1;
__END__