sub _instantiate_pp_nvp {
  my $self = shift;

  if(defined($self->{'pp_nvp'}) && $self->{'pp_nvp'}->isa('Business::PayPal::NVP')){ return; }
  my $pp_branch;
  if($self->{'cfg'}->param("paypal.pp_use_sandbox")){
    $pp_branch = 'test';
  } else {
    $pp_branch = 'live';
  }

  $self->{'pp_nvp'} = Business::PayPal::NVP->new(
      Version => '57.0',
         test => {
            user => $self->{'cfg'}->param("paypal.pp_sandbox_username"),
             pwd => $self->{'cfg'}->param("paypal.pp_sandbox_password"),
             sig => $self->{'cfg'}->param("paypal.pp_sandbox_signature")
                 },
         live => {
            user => $self->{'cfg'}->param("paypal.pp_username"),
             pwd => $self->{'cfg'}->param("paypal.pp_password"),
             sig => $self->{'cfg'}->param("paypal.pp_signature")
                 },
       branch => $pp_branch );

  return;
}

sub _SetExpressCheckout {
  my $self = shift;
  my $fields = shift;

  my $gross_sales = $self->_compute_invoice($fields);

  $self->_instantiate_pp_nvp();
  $fields->{'AMT'} = $gross_sales;
  $fields->{'DESC'} = $self->{'cfg'}->param("inventory.product_name");
  $fields->{'CURRENCYCODE'} = 'USD';
  $fields->{'PAYMENTACTION'} = 'Sale';
  $fields->{'RETURNURL'} = $self->{'cfg'}->param("paypal.pp_return_url");
  $fields->{'CANCELURL'} = $self->{'cfg'}->param("paypal.pp_cancel_url");
  $fields->{'VERSION'} = $self->{'cfg'}->param("paypal.pp_api_version");
  $fields->{'METHOD'} = 'SetExpressCheckout';
  $fields->{'REQCONFIRMSHIPPING'} = '0';
  $fields->{'ADDROVERRIDE'} = '0';
  $fields->{'NOSHIPPING'} = '0';
  $fields->{'ALLOWNOTE'} = '0';
  $fields->{'LOCALECODE'} = 'US';
  $fields->{'HDRBORDERCOLOR'} = $self->{'cfg'}->param("paypal.pp_hdrbordercolor");
  $fields->{'HDRBACKCOLOR'} = $self->{'cfg'}->param("paypal.pp_hdrbackcolor");
  $fields->{'PAYFLOWCOLOR'} = $self->{'cfg'}->param("paypal.pp_payflowcolor");
  # $fields->{'SOLUTIONTYPE'} = 'Mark';
  # $fields->{'LANDINGPAGE'} = 'Login';
  # $fields->{'CHANNELTYPE'} = 'Merchant';

  my %response = $self->{'pp_nvp'}->SetExpressCheckout( %{$fields} );
  # $self->log('DEBUG','->get_paypal_token_nvp() says API server said: ',\%response);
  my %details = $self->{'pp_nvp'}->GetExpressCheckoutDetails( 'Token' => $response{'TOKEN'} );
  $self->{'paypal_details'} = \%details;
  # $self->log('DEBUG','Express Checkout Details include: ',$self->{'paypal_details'});

  return %details;
}

sub _GetExpressCheckoutDetails {
  my $self = shift;
  my $token = shift;

  $self->_instantiate_pp_nvp();
  my %response;
  $response{'TOKEN'} = $token;
  my %details = $self->{'pp_nvp'}->GetExpressCheckoutDetails( 'Token' => $response{'TOKEN'} );
  $self->{'paypal_details'} = \%details;
  print STDERR '->_GetExpressCheckoutDetails() says the details are: ' . Dumper(\%details);

  return \%details;
}

sub _DoExpressCheckoutPayment {
  my $self = shift;
  # my $fields = shift;
  # return unless(defined($self->{'paypal_details'}));
  # $self->log('DEBUG','$ymd->DoExpressCheckoutPayment got these incoming arguments: ',$fields);

  # my $gross_sales = $self->_compute_invoice($fields);
  $self->_instantiate_pp_nvp();

  my %args = (
          token => $self->{'s'}->param('token'),
          TOKEN => $self->{'s'}->param('token'),
        PayerID => $self->{'s'}->param('payerid'),
        PAYERID => $self->{'s'}->param('payerid'),
#           AMT => '1.00',
            AMT => $self->{'s'}->{'AMT'},
#    OrderTotal => '1.00',
     OrderTotal => $self->{'s'}->{'AMT'},
   CURRENCYCODE => 'USD',
  PAYMENTACTION => 'Sale',
         METHOD => 'DoExpressCheckoutPayment'
             );

  print STDERR 'DoExpressCheckoutPayment got these arguments: ' . Dumper(\%args);
  my %response = $self->{'pp_nvp'}->DoExpressCheckoutPayment( %args );
  print STDERR 'DoExpressCheckoutPayment responds: ' . Dumper(\%response);


  if($response{'ACK'} eq 'Success' && defined($response{'TRANSACTIONID'})){
    my $sql = $self->{'cfg'}->param("sql.insert_pp_transaction");
    my $sth = $self->{'dbh'}->prepare($sql);
    $sth->execute(
         $response{'TRANSACTIONID'},
         $response{'TOKEN'},
         $response{'ACK'},
         $response{'PAYMENTSTATUS'},
         $response{'AMT'},
         $response{'FEEAMT'},
         $response{'TAXAMT'},
         $response{'CURRENCYCODE'},
         $response{'PAYMENTTYPE'},
         $response{'TRANSACTIONTYPE'},
         $response{'REASONCODE'},
         $response{'PENDINGREASON'},
         $response{'ORDERTIME'},
         $response{'TIMESTAMP'},
         $response{'VERSION'},
         $response{'BUILD'},
         $response{'CORRELATIONID'} );
  }

  return \%response;
}