1_before.php

<?php

public static function masspay($data)
{
	$ci = get_instance();
	$ci->load->library('zip');
	$ci->load->helper('download');
	
	// sort by payment_site then payment_job
	$sorted_data = $ci->db->select('wufoo_id')
	                      ->where_in('wufoo_id', $data['selected'])
	                      ->order_by('payment_site')
	                      ->order_by('payment_job')
	                      ->group_by('wufoo_id')
	                      ->get(Wufoo::INVOICE_TABLE)
	                      ->result();
	
	$txt_data = array();
	
	foreach ($sorted_data as $record) {
		$id = $record->wufoo_id;
		$entry = $ci->db->get_where(Wufoo::INVOICE_TABLE, array('wufoo_id' => $id, 'department' => ucfirst($data['department'])))->row();
		
		$reference = htmlspecialchars_decode($entry->payment_site.'|'.$entry->payment_job.'|'.$entry->wufoo_id);
		
		// split the files for different payemnt methods and currencies
		$entry_type = "{$entry->payment_method}_{$entry->payment_currency}";
		
		// Paypal and MB have different mass pay file structures
		switch ($entry->payment_method) {
			case 'Paypal':
				$entry_data = array(
					$entry->payment_email,
					$entry->payment_amount,
					$entry->payment_currency,
					$reference,
				);
			break;
			
			case 'Moneybookers':
				$entry_data = array(
					$entry->payment_email,
					$entry->payment_currency,
					$entry->payment_amount,
					$reference,
				);
			break;
			
			default:
			break;
		}
		
		// putting the data together
		isset($txt_data[$entry_type]) or $txt_data[$entry_type] = '';
		$txt_data[$entry_type] .= implode("\t", $entry_data)."\n";
	}
	
	$filename = implode('_', array(
		'masspay',
		$data['department'],
		mktime(),
	));
	
	// create a zip, or just output the txt directly?
	if (count($txt_data) > 1) {
		foreach ($txt_data as $payment_method => $txt_file) {
			$ci->zip->add_data(implode('_', array(
				'masspay',
				$data['department'],
				$payment_method,
				mktime(),
			)).'.txt', $txt_file);
		}
		$ci->zip->download(implode('_', array(
			'masspay',
			$data['department'],
			mktime(),
		)).'.zip');
	} else {
		force_download(implode('_', array(
			'masspay',
			$data['department'],
			key($txt_data),
			mktime(),
		)).'.txt', array_shift($txt_data));
	}
}

2_after.rb

module MassPay
  class << self
    def build(params)
      temp_file = Tempfile.new("mass_pay-#{Time.now.to_i}")
      
      Zip::ZipOutputStream.open(temp_file.path) do |zip|
        fetch_entries(params[:ids]).each do |entry_group|
          group, entries = entry_group
          content = entries.join("\n")
          
          zip.put_next_entry("#{group}.txt")
          zip.puts(content)
        end
      end
      
      temp_file.close
      temp_file.path
    end
    
    protected
    
    def fetch_entries(invoice_ids)
      files = {}
      
      Invoice.where(:id => invoice_ids).all.each do |invoice|
        files[:"#{invoice.payment_service.name}_#{invoice.payment_currency.code}"] ||= []
        files[:"#{invoice.payment_service.name}_#{invoice.payment_currency.code}"] << format(invoice)
      end
      
      files
    end
    
    def format(invoice)
      format = case invoice.payment_service.name
        when "Paypal"
          [invoice.payment_email, invoice.amount, invoice.payment_currency.code, reference_text_for(invoice)]
        when "Moneybookers"
          [invoice.payment_email, invoice.payment_currency.code, invoice.amount, reference_text_for(invoice)]
      end
      
      format.join("\t")
    end
    
    def reference_text_for(invoice)
      [invoice.site.name, invoice.job.name, invoice.id].join("|")
    end
  end
end