woocommerce/includes/class-wc-discounts.php

380 lines
10 KiB
PHP

<?php
/**
* Discount calculation
*
* @author Automattic
* @package WooCommerce/Classes
* @version 3.2.0
* @since 3.2.0
*/
/**
* Discounts class.
*
* @todo this class will need to be called instead get_discounted_price, in the cart?
*/
class WC_Discounts {
/**
* An array of items to discount.
*
* @var array
*/
protected $items = array();
/**
* An array of discounts which have been applied to items.
*
* @var array
*/
protected $discounts = array();
/**
* An array of applied coupons codes and total discount.
*
* @var array
*/
protected $applied_coupons = array();
/**
* Precision so we can work in cents.
*
* @var int
*/
protected $precision = 1;
/**
* Constructor.
*
* @param array $items Items to discount.
*/
public function __construct( $items = array() ) {
$this->precision = pow( 10, wc_get_price_decimals() );
$this->set_items( $items );
}
/**
* Get items.
*
* @since 3.2.0
* @return object[]
*/
public function get_items() {
return $this->items;
}
/**
* Get discount by key without precision.
*
* @since 3.2.0
* @param string $key name of discount row to return.
* @return array
*/
public function get_discount( $key ) {
return isset( $this->discounts[ $key ] ) ? $this->remove_precision( $this->discounts[ $key ] ) : 0;
}
/**
* Get all discount totals with precision.
*
* @since 3.2.0
* @param bool $in_cents Should the totals be returned in cents, or without precision.
* @return array
*/
public function get_discounts( $in_cents = false ) {
return $in_cents ? $this->discounts : array_map( array( $this, 'remove_precision' ), $this->discounts );
}
/**
* Get discounted price of an item without precision.
*
* @since 3.2.0
* @param object $item Get data for this item.
* @return float
*/
public function get_discounted_price( $item ) {
return $this->remove_precision( $this->get_discounted_price_in_cents( $item ) );
}
/**
* Get discounted price of an item to precision (in cents).
*
* @since 3.2.0
* @param object $item Get data for this item.
* @return float
*/
public function get_discounted_price_in_cents( $item ) {
return $item->price - $this->discounts[ $item->key ];
}
/**
* Returns a list of applied coupons with name value pairs - name being
* the coupon code, and value being the total amount disounted.
*
* @since 3.2.0
* @return array
*/
public function get_applied_coupons() {
return array_map( array( $this, 'remove_precision' ), $this->applied_coupons );
}
/**
* Set cart/order items which will be discounted.
*
* @since 3.2.0
* @param array $items List items, normailised, by WC_Totals.
*/
public function set_items( $items ) {
$this->items = array();
$this->discounts = array();
$this->applied_coupons = array();
if ( ! empty( $items ) && is_array( $items ) ) {
$this->items = $items;
$this->discounts = array_fill_keys( array_keys( $items ), 0 );
}
uasort( $this->items, array( $this, 'sort_by_price' ) );
}
/**
* Apply a discount to all items using a coupon.
*
* @todo Coupon class has lots of WC()->cart calls and needs decoupling. This makes 'is valid' hard to use here.
* @todo is_valid_for_product accepts values - how can we deal with that?
*
* @since 3.2.0
* @param WC_Coupon $coupon Coupon object being applied to the items.
* @return bool True if applied.
*/
public function apply_coupon( $coupon ) {
if ( ! is_a( $coupon, 'WC_Coupon' ) ) {
return false;
}
if ( ! isset( $this->applied_coupons[ $coupon->get_code() ] ) ) {
$this->applied_coupons[ $coupon->get_code() ] = 0;
}
// @todo how can we support the old woocommerce_coupon_get_discount_amount filter?
// @todo is valid for product - filter items here and pass to function?
$items_to_apply = $this->get_items_to_apply_coupon( $coupon );
switch ( $coupon->get_discount_type() ) {
case 'percent' :
$this->applied_coupons[ $coupon->get_code() ] += $this->apply_percentage_discount( $items_to_apply, $coupon->get_amount() );
break;
case 'fixed_product' :
$this->applied_coupons[ $coupon->get_code() ] += $this->apply_fixed_product_discount( $items_to_apply, $coupon->get_amount() * $this->precision );
break;
case 'fixed_cart' :
$this->applied_coupons[ $coupon->get_code() ] += $this->apply_fixed_cart_discount( $items_to_apply, $coupon->get_amount() * $this->precision );
break;
}
}
/**
* Add precision (deep) to a price.
*
* @since 3.2.0
* @param int|array $value Value to remove precision from.
* @return float
*/
protected function add_precision( $value ) {
if ( is_array( $value ) ) {
foreach ( $value as $key => $subvalue ) {
$value[ $key ] = $this->add_precision( $subvalue );
}
} else {
$value = $value * $this->precision;
}
return $value;
}
/**
* Remove precision (deep) from a price.
*
* @since 3.2.0
* @param int|array $value Value to remove precision from.
* @return float
*/
protected function remove_precision( $value ) {
if ( is_array( $value ) ) {
foreach ( $value as $key => $subvalue ) {
$value[ $key ] = $this->remove_precision( $subvalue );
}
} else {
$value = wc_format_decimal( $value / $this->precision, wc_get_price_decimals() );
}
return $value;
}
/**
* Sort by price.
*
* @param array $a First element.
* @param array $b Second element.
* @return int
*/
protected function sort_by_price( $a, $b ) {
$price_1 = $a->price * $a->quantity;
$price_2 = $b->price * $b->quantity;
if ( $price_1 === $price_2 ) {
return 0;
}
return ( $price_1 < $price_2 ) ? 1 : -1;
}
/**
* Filter out all products which have been fully discounted to 0.
* Used as array_filter callback.
*
* @param object $item Get data for this item.
* @return bool
*/
protected function filter_products_with_price( $item ) {
return $this->get_discounted_price_in_cents( $item ) > 0;
}
/**
* Get items which the coupon should be applied to.
*
* @param object $coupon Coupon object.
* @return array
*/
protected function get_items_to_apply_coupon( $coupon ) {
$items_to_apply = array();
$limit_usage_qty = 0;
$applied_count = 0;
if ( null !== $coupon->get_limit_usage_to_x_items() ) {
$limit_usage_qty = $coupon->get_limit_usage_to_x_items();
}
foreach ( $this->items as $item ) {
if ( 0 === $this->get_discounted_price_in_cents( $item ) ) {
continue;
}
if ( ! $coupon->is_valid_for_product( $item->product ) && ! $coupon->is_valid_for_cart() ) { // @todo is this enough?
continue;
}
if ( $limit_usage_qty && $applied_count > $limit_usage_qty ) {
break;
}
if ( $limit_usage_qty && $item->quantity > ( $limit_usage_qty - $applied_count ) ) {
$limit_to_qty = absint( $limit_usage_qty - $applied_count );
$item->price = ( $item->price / $item->quantity ) * $limit_to_qty;
$item->quantity = $limit_to_qty; // Lower the qty so the discount is applied less.
}
if ( 0 >= $item->quantity ) {
continue;
}
$items_to_apply[] = $item;
$applied_count += $item->quantity;
}
return $items_to_apply;
}
/**
* Apply a discount amount to an item and ensure it does not go negative.
*
* @since 3.2.0
* @param object $item Get data for this item.
* @param int $discount Amount of discount.
* @return int Amount discounted.
*/
protected function add_item_discount( &$item, $discount ) {
$discounted_price = $this->get_discounted_price_in_cents( $item );
$discount = $discount > $discounted_price ? $discounted_price : $discount;
$this->discounts[ $item->key ] = $this->discounts[ $item->key ] + $discount;
return $discount;
}
/**
* Apply percent discount to items.
*
* @since 3.2.0
* @param array $items_to_apply Array of items to apply the coupon to.
* @param int $amount Amount of discount.
* @return int total discounted in cents
*/
protected function apply_percentage_discount( $items_to_apply, $amount ) {
$total_discounted = 0;
foreach ( $items_to_apply as $item ) {
$total_discounted += $this->add_item_discount( $item, $amount * ( $this->get_discounted_price_in_cents( $item ) / 100 ) );
}
return $total_discounted;
}
/**
* Apply fixed product discount to items.
*
* @since 3.2.0
* @param array $items_to_apply Array of items to apply the coupon to.
* @param int $discount Amount of discout.
* @return int total discounted in cents
*/
protected function apply_fixed_product_discount( $items_to_apply, $discount ) {
$total_discounted = 0;
foreach ( $items_to_apply as $item ) {
$total_discounted += $this->add_item_discount( $item, $discount * $item->quantity );
}
return $total_discounted;
}
/**
* Apply fixed cart discount to items.
*
* @since 3.2.0
* @param array $items_to_apply Array of items to apply the coupon to.
* @param int $cart_discount Fixed discount amount to apply.
* @return int total discounted in cents
*/
protected function apply_fixed_cart_discount( $items_to_apply, $cart_discount ) {
$items_to_apply = array_filter( $items_to_apply, array( $this, 'filter_products_with_price' ) );
if ( ! $item_count = array_sum( wp_list_pluck( $items_to_apply, 'quantity' ) ) ) {
return 0;
}
$per_item_discount = floor( $cart_discount / $item_count ); // round it down to the nearest cent number.
$amount_discounted = 0;
if ( $per_item_discount > 0 ) {
foreach ( $items_to_apply as $item ) {
$amount_discounted += $this->add_item_discount( $item, $per_item_discount * $item->quantity );
}
/**
* If there is still discount remaining, repeat the process.
*/
if ( $amount_discounted > 0 && $amount_discounted < $cart_discount ) {
$amount_discounted += $this->apply_fixed_cart_discount( $items_to_apply, $cart_discount - $amount_discounted );
}
} elseif ( $cart_discount > 0 ) {
/**
* Deal with remaining fractional discounts by splitting it over items
* until the amount is expired, discounting 1 cent at a time.
*/
foreach ( $items_to_apply as $item ) {
for ( $i = 0; $i < $item->quantity; $i ++ ) {
$amount_discounted += $this->add_item_discount( $item, 1 );
if ( $amount_discounted >= $cart_discount ) {
break 2;
}
}
if ( $amount_discounted >= $cart_discount ) {
break;
}
}
}
return $amount_discounted;
}
}