Yeah the problem is in the file /includes/modules/order_totals/ot_qty_discount.php.
It seems to halve the difference between the qty_discount - tax and deduct this from the order total
... so 4268 - 426.80 = right answer 3841.20 but it goes on to then subtract ((426.80-349.20)/2) = 3802.40
(It also seems to ignore the Calculate Tax, Include Tax and Include Shipping settings in the qty_discount module itself...)
So, howabout backing up the file above (change extension to .bak) and trying this version:
Code:
<?php
/*
$Id: ot_qty_discount.php,v 1.41 2004-09-14 dreamscape Exp $
osCommerce, Open Source E-Commerce Solutions
http://www.oscommerce.com
Copyright (c) 2004 Josh Dechant
Protions Copyright (c) 2003 osCommerce
Released under the GNU General Public License
*/
class ot_qty_discount {
var $title, $output;
function ot_qty_discount() {
$this->code = 'ot_qty_discount';
$this->title = MODULE_QTY_DISCOUNT_TITLE;
$this->description = MODULE_QTY_DISCOUNT_DESCRIPTION;
$this->enabled = MODULE_QTY_DISCOUNT_STATUS;
$this->sort_order = MODULE_QTY_DISCOUNT_SORT_ORDER;
$this->include_shipping = MODULE_QTY_DISCOUNT_INC_SHIPPING;
$this->include_tax = MODULE_QTY_DISCOUNT_INC_TAX;
$this->calculate_tax = MODULE_QTY_DISCOUNT_CALC_TAX;
$this->output = array();
}
function process() {
global $order, $currencies, $ot_subtotal;
$od_amount = $this->calculate_discount($this->get_order_total());
if ($this->calculate_tax == 'true') $tod_amount = $this->calculate_tax_effect($od_amount);
if ($od_amount > 0) {
if (MODULE_QTY_DISCOUNT_RATE_TYPE == 'percentage') $title_ext = sprintf(MODULE_QTY_DISCOUNT_PERCENTAGE_TEXT_EXTENSION ,$this->calculate_rate($_SESSION['cart']->count_contents()));
$this->deduction = $od_amount+$tod_amount;
$this->output[] = array('title' => sprintf(MODULE_QTY_DISCOUNT_FORMATED_TITLE, $title_ext),
'text' => sprintf(MODULE_QTY_DISCOUNT_FORMATED_TEXT, $currencies->format($od_amount)),
'value' => $od_amount);
$order->info['total'] -= $this->deduction;
$order->info['tax'] -= $tod_amount;
if ($this->sort_order < $ot_subtotal->sort_order) $order->info['subtotal'] -= $this->deduction;
}
}
function calculate_discount($amount) {
global $qty_discount, $order_total_array;
$od_amount = 0;
if ((MODULE_QTY_DISCOUNT_DISABLE_WITH_COUPON == 'true') && (isset($_SESSION['cc_id']))) return $od_amount;
$qty_discount = $this->calculate_rate($_SESSION['cart']->count_contents());
if ($qty_discount > 0) {
if (MODULE_QTY_DISCOUNT_RATE_TYPE == 'percentage') {
$od_amount = tep_round((($amount*10)/10)*($qty_discount/100), 2);
} else {
$od_amount = tep_round((($qty_discount*10)/10), 2);
}
}
return $od_amount;
}
function calculate_rate($order_qty) {
$discount_rate = split("[:,]" , MODULE_QTY_DISCOUNT_RATES);
$size = sizeof($discount_rate);
for ($i=0, $n=$size; $i<$n; $i+=2) {
if ($order_qty >= $discount_rate[$i]) {
$qty_discount = $discount_rate[$i+1];
}
}
return $qty_discount;
}
function calculate_tax_effect($od_amount) {
global $order;
if (MODULE_QTY_DISCOUNT_RATE_TYPE == 'percentage') {
$tod_amount = 0;
reset($order->info['tax_groups']);
while (list($key, $value) = each($order->info['tax_groups'])) {
$god_amount = 0;
$tax_rate = tep_get_tax_rate_from_desc($key);
$net = ($tax_rate * $order->info['tax_groups'][$key]);
if ($net > 0) {
$god_amount = $this->calculate_discount($order->info['tax_groups'][$key]);
$tod_amount += $god_amount;
$order->info['tax_groups'][$key] = $order->info['tax_groups'][$key] - $god_amount;
}
}
} else {
$tod_amount = 0;
reset($order->info['tax_groups']);
while (list($key, $value) = each($order->info['tax_groups'])) {
$god_amount = 0;
$tax_rate = tep_get_tax_rate_from_desc($key);
$net = ($tax_rate * $order->info['tax_groups'][$key]);
if ($net>0) {
$god_amount = ($tax_rate/100)*$od_amount;
$tod_amount += $god_amount;
$order->info['tax_groups'][$key] = $order->info['tax_groups'][$key] - $god_amount;
}
}
}
return $tod_amount;
}
function get_order_total() {
global $order;
$order_total = $order->info['total'];
if ($this->include_tax == 'false') $order_total = ($order_total - $order->info['tax']);
if ($this->include_shipping == 'false') $order_total = ($order_total - $order->info['shipping_cost']);
return $order_total;
}
function check() {
if (!isset($this->check)) {
$check_query = tep_db_query("select configuration_value from " . TABLE_CONFIGURATION . " where configuration_key = 'MODULE_QTY_DISCOUNT_STATUS'");
$this->check = tep_db_num_rows($check_query);
}
return $this->check;
}
function keys() {
return array('MODULE_QTY_DISCOUNT_STATUS', 'MODULE_QTY_DISCOUNT_SORT_ORDER', 'MODULE_QTY_DISCOUNT_DISABLE_WITH_COUPON', 'MODULE_QTY_DISCOUNT_RATE_TYPE', 'MODULE_QTY_DISCOUNT_RATES', 'MODULE_QTY_DISCOUNT_INC_SHIPPING', 'MODULE_QTY_DISCOUNT_INC_TAX', 'MODULE_QTY_DISCOUNT_CALC_TAX');
}
function install() {
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) values ('Display Quantity Discount', 'MODULE_QTY_DISCOUNT_STATUS', 'true', 'Do you want to enable the quantity discount module?', '6', '1','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, date_added) values ('Sort Order', 'MODULE_QTY_DISCOUNT_SORT_ORDER', '2', 'Sort order of display.', '6', '2', now())");
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) values ('Disable If Coupon Used', 'MODULE_QTY_DISCOUNT_DISABLE_WITH_COUPON', 'true', 'Do you want to disable the quantity discount module if a discount coupon is being used by the user?', '6', '3','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Discount Rate Type', 'MODULE_QTY_DISCOUNT_RATE_TYPE', 'percentage', 'Choose the type of discount rate - percentage or flat rate', '6', '4','tep_cfg_select_option(array(\'percentage\', \'flat rate\'), ', now())");
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, date_added) values ('Discount Rates', 'MODULE_QTY_DISCOUNT_RATES', '10:5,20:10', 'The discount is based on the total number of items. Example: 10:5,20:10.. 10 or more items get a 5% or $5 discount; 20 or more items receive a 10% or $10 disount; depending on the rate type.', '6', '5', now())");
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Include Shipping', 'MODULE_QTY_DISCOUNT_INC_SHIPPING', 'false', 'Include Shipping in calculation', '6', '6', 'tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Include Tax', 'MODULE_QTY_DISCOUNT_INC_TAX', 'false', 'Include Tax in calculation.', '6', '7','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Calculate Tax', 'MODULE_QTY_DISCOUNT_CALC_TAX', 'true', 'Re-calculate Tax on discounted amount.', '6', '8','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
}
function remove() {
tep_db_query("delete from " . TABLE_CONFIGURATION . " where configuration_key in ('" . implode("', '", $this->keys()) . "')");
}
}
////
// Get tax rate from tax description
if (!function_exists(tep_get_tax_rate_from_desc)) {
function tep_get_tax_rate_from_desc($tax_desc) {
$tax_query = tep_db_query("select tax_rate from " . TABLE_TAX_RATES . " where tax_description = '" . $tax_desc . "'");
$tax = mysql_fetch_assoc($tax_query);
return $tax['tax_rate'];
}
}
?>
You'll need to remove and install the qty_discount module in OT again.
I'd also use a simplier example in the cart - maybe just one taxable item at $10 net - so it's easier to figure the total out.
Simon