<?php
// file commerce_discounts.rules.inc

function commerce_discounts_rules_condition_info() {
  $conditions = array();

  $conditions['commerce_discounts_order_balance_comparison'] = array(
    'label' => t('Subtotal comparison'),
    'parameter' => array(
      'commerce_order' => array(
        'type' => 'commerce_order',
        'label' => t('Order'),
        'description' => t('The order whose balance should be compared (calculated as the order total minus completed payment amounts).'),
      ),
      'operator' => array(
        'type' => 'text',
        'label' => t('Operator'),
        'description' => t('The comparison operator.'),
        'optional' => TRUE,
        'default value' => '<=',
        'options list' => 'commerce_numeric_comparison_operator_options_list',
        'restriction' => 'input',
      ),
      'value' => array(
        'type' => 'text',
        'label' => t('Value'),
        'description' => t('The value to compare against the order balance. An order balance less than or equal to 0 indicates the order has been paid in full.'),
        'default value' => '0',
      ),
    ),
    'group' => t('Commerce Payment'),
    'callbacks' => array(
      'execute' => 'commerce_discounts_rules_compare_balance',
    ),
  );


  return $conditions;
}

/**
 * Condition callback: checks the unpaid balance of an order.
 */
function commerce_discounts_rules_compare_balance($order, $operator, $value) {
  // Check the balance of the order.
  //$balance = commerce_payment_order_balance($order);

  $subtotal = 0;
  $i = 0;
  foreach ($order->commerce_line_items['und'] as $line_item_id) {
    //dsm($line_item_id , '$line_item_id');
    $line_item =  commerce_line_item_load($line_item_id['line_item_id']);
    $i++;
    //dsm($line_item, 'line item ' . $i);
    if($line_item->type == 'product') {
      $subtotal += $line_item->commerce_total['und'][0]['data']['components'][0]['price']['amount'];
    }
  }
  //dsm($order, '$ordeer');
  //dsm($balance, 'balance');
  //dsm($subtotal, '$subtotal');
  // If the balance was incalculable, set the balance to the order total.
//  if ($balance === FALSE) {
//    $balance = entity_metadata_wrapper('commerce_order', $order)->commerce_order_total->value();
//  }

  // Make a quantity comparison based on the operator.
  switch ($operator) {
    case '<':
      return $subtotal < $value;
    case '<=':
      return $subtotal <= $value;
    case '=':
      return $subtotal == $value;
    case '>=':
      return $subtotal >= $value;
    case '>':
      return $subtotal > $value;
  }

  return FALSE;
}