woothemes/woocommerce

<?php
/**
 * Cart fees API.
 *
 * Developers can add fees to the cart via WC()->cart->fees_api() which will reference this class.
 *
 * We suggest using the action woocommerce_cart_calculate_fees hook for adding fees.
 *
 * @package WooCommerce\Classes
 * @version 3.2.0
 */

defined( 'ABSPATH' ) || exit;

/**
 * WC_Cart_Fees class.
 *
 * @since 3.2.0
 */
final class WC_Cart_Fees {

    /**
     * An array of fee objects.
     *
     * @var object[]
     */
    private $fees = array();

    /**
     * Reference to cart object.
     *
     * @since 3.2.0
     * @var WC_Cart
     */
    private $cart;

    /**
     * New fees are made out of these props.
     *
     * @var array
     */
    private $default_fee_props = array(
        'id'        => '',
        'name'      => '',
        'tax_class' => '',
        'taxable'   => false,
        'amount'    => 0,
        'total'     => 0,
    );

    /**
     * Constructor. Reference to the cart.
     *
     * @since 3.2.0
     * @throws Exception If missing WC_Cart object.
     * @param WC_Cart $cart Cart object.
     */
    public function __construct( &$cart ) {
        if ( ! is_a( $cart, 'WC_Cart' ) ) {
            throw new Exception( 'A valid WC_Cart object is required' );
        }

        $this->cart = $cart;
    }

    /**
     * Register methods for this object on the appropriate WordPress hooks.
     */
    public function init() {}

    /**
     * Add a fee. Fee IDs must be unique.
     *
     * @since 3.2.0
     * @param array $args Array of fee properties.
     * @return object Either a fee object if added, or a WP_Error if it failed.
     */
    public function add_fee( $args = array() ) {
        $fee_props            = (object) wp_parse_args( $args, $this->default_fee_props );
        $fee_props->name      = $fee_props->name ? $fee_props->name : __( 'Fee', 'woocommerce' );
        $fee_props->tax_class = in_array( $fee_props->tax_class, array_merge( WC_Tax::get_tax_classes(), WC_Tax::get_tax_class_slugs() ), true ) ? $fee_props->tax_class : '';
        $fee_props->taxable   = wc_string_to_bool( $fee_props->taxable );
        $fee_props->amount    = wc_format_decimal( $fee_props->amount );

        if ( empty( $fee_props->id ) ) {
            $fee_props->id = $this->generate_id( $fee_props );
        }

        if ( array_key_exists( $fee_props->id, $this->fees ) ) {
            return new WP_Error( 'fee_exists', __( 'Fee has already been added.', 'woocommerce' ) );
        }

        $this->fees[ $fee_props->id ] = $fee_props;

        return $this->fees[ $fee_props->id ];
    }

    /**
     * Get fees.
     *
     * @return array
     */
    public function get_fees() {
        uasort( $this->fees, array( $this, 'sort_fees_callback' ) );

        return $this->fees;
    }

    /**
     * Set fees.
     *
     * @param object[] $raw_fees Array of fees.
     */
    public function set_fees( $raw_fees = array() ) {
        $this->fees = array();

        foreach ( $raw_fees as $raw_fee ) {
            $this->add_fee( $raw_fee );
        }
    }

    /**
     * Remove all fees.
     *
     * @since 3.2.0
     */
    public function remove_all_fees() {
        $this->set_fees();
    }

    /**
     * Sort fees by amount.
     *
     * @param stdClass $a Fee object.
     * @param stdClass $b Fee object.
     * @return int
     */
    protected function sort_fees_callback( $a, $b ) {
        /**
         * Filter sort fees callback.
         *
         * @since 3.8.0
         * @param int Sort order, -1 or 1.
         * @param stdClass $a Fee object.
         * @param stdClass $b Fee object.
         */
        return apply_filters( 'woocommerce_sort_fees_callback', $a->amount > $b->amount ? -1 : 1, $a, $b );
    }

    /**
     * Generate a unique ID for the fee being added.
     *
     * @param string $fee Fee object.
     * @return string fee key.
     */
    private function generate_id( $fee ) {
        return sanitize_title( $fee->name );
    }
}