How to Adapt WooCommerce Reports for a Multi Currency Shop

A multi currency shop breaks WooCommerce reports quietly: totals in different currencies get added together as if they were the same number.

• open file wp-content\plugins\woocommerce\includes\admin\reports\class-wc-admin-report.php
• find there public function get_order_report_data
• on the same end of the function before code return $result; drop code:

  $result = apply_filters('woocs_reports_get_order_report_query', $result, $args);

• open functions.php file of your current wp theme and on the same bottom of the file drop the next code:

  add_filter('woocs_reports_get_order_report_query', function($result, $args) {
  
      if (is_array($result) AND isset($result[0]->total_sales))
      {
          global $wpdb;
          global $WOOCS;
          $range = '7day';
          if (isset($_GET['range']))
          {
              $range = $_GET['range'];
          }
          $start_date = '';
          $end_date = date('Y-m-d 23:59:59');
          switch ($range)
          {
              case 'custom':
                  $start_date = $_GET['start_date'];
                  break;
              case '7day':
                  $start_date = date('Y-m-d 00:00:00', time() - 7 * DAY_IN_SECONDS);
                  break;
              case 'month':
                  $start_date = date('Y-m-01 00:00:00');
                  break;
              case 'year':
                  $start_date = date('Y-01-01 00:00:00');
                  break;
  
              default:
                  $start_date = date('Y-m-d 00:00:00', time() - 7 * DAY_IN_SECONDS);
                  break;
          }
          $order_status = "wc-" . implode('","wc-', $args['order_status']);
          //***
          $sql = $wpdb->prepare('SELECT ID FROM ' . $wpdb->posts . ' WHERE post_type=%s AND post_status IN("' . $order_status . '") AND post_date >= %s AND post_date < %s', 'shop_order', $start_date, $end_date);
          $tmp = $wpdb->get_results($sql, ARRAY_N);        
          $orders = array();
          $result = array();
          if (!empty($tmp))
          {
              foreach ($tmp as $v)
              {
                  $orders[] = $v[0];
              }
  
              $result = array();
              $currencies = $WOOCS->get_currencies();
              foreach ($orders as $order_id)
              {
                  $tmp = array();
                  $order = new WC_Order($order_id);
  
                  $_order_currency = get_post_meta($order_id, '_order_currency', true);                
                  $order_rate = get_post_meta($order_id, '_woocs_order_rate', true);                
                  if (!$order_rate)
                  {
                      if (isset($currencies[$_order_currency]))
                      {
                          $order_rate = $currencies[$_order_currency]['rate'];
                      } else
                      {
                          continue;
                      }
                  }                
                  
                  if ($_order_currency != $WOOCS->default_currency)
                  {
                      $tmp['total_sales'] = $WOOCS->back_convert(get_post_meta($order_id, '_order_total', true), $order_rate, 4);
                      $tmp['total_shipping'] = $WOOCS->back_convert(get_post_meta($order_id, '_order_shipping', true), $order_rate, 4);
                      $tmp['total_tax'] = $WOOCS->back_convert(get_post_meta($order_id, '_order_tax', true), $order_rate, 4);
                      $tmp['total_shipping_tax'] = $WOOCS->back_convert(get_post_meta($order_id, '_order_shipping_tax', true), $order_rate, 4);
                  } else
                  {
                      $tmp['total_sales'] = get_post_meta($order_id, '_order_total', true);
                      $tmp['total_shipping'] = get_post_meta($order_id, '_order_shipping', true);
                      $tmp['total_tax'] = get_post_meta($order_id, '_order_tax', true);
                      $tmp['total_shipping_tax'] = get_post_meta($order_id, '_order_shipping_tax', true);
                  }
                  
                  $tmp['post_date'] = $order->order_date;
                  $result[] = (object) $tmp;
              }
          }
      }
  
      return $result;
  }, 10, 2);