class Item
{
    /**
     * Master object
     *
     * @var Master
     */
    private $master;

    /**
     * Contains methods for checking stock, etc.
     *
     * @var Validation
     */
    public $guards;

    /**
     * Sets up `Item`
     *
     * @author Evan D Shaw <evandanielshaw@gmail.com>
     * @param Master $master
     * @return void
     */
    public function __construct(Master $master) {
        $this->master = $master;
        $this->guards = new Validation($master);
    }

    /**
     * Adds an item to wishlist given a set of params
     *
     * @important
     * @author Evan D Shaw <evandanielshaw@gmail.com>
     * @param int    $post_id
     * @param string $sku **MUST** be urldecoded
     * @param array  $item_option
     * @param string $advance
     * @return GenericError|true
     */
    public function addToWishlist($post_id, $sku, $item_option = [], $advance = '') {
        $exists = $this->guards->itemExists($post_id, $sku);
        if ($exists instanceof GenericError) {
            return $exists;
        }

        if (!defined('WCEX_WIDGET_CART')) {
            if (!empty($item_option)) {
                // by default we use `wcex_widget_cart`'s way of serializing option data but multi-select
                // option values are serialized differently when not using `wcex_widget_cart`. Because of this,
                // we have to transform multi-select option values when `wcex_widget_cart` is not being used.
                $item_option = self::convertWidgetCartItemOptionPayloadToWelcartDefault($item_option, $post_id, $sku);
            }

            // By default, Welcart serializes with the encoded SKU. `wcex_widget_cart` serializes with the decoded SKU.
            $sku = urlencode($sku);
        }

        $opterror = $this->guards->requiredOptionsProvided($post_id, $sku, $item_option);
        if ($opterror instanceof GenericError) {
            return $opterror;
        }

        $tempcart = new \usces_cart();
        if (!empty($item_option)) {
            // we are forced to set $_POST at runtime here since `in_serialize` uses $_POST internally
            $_POST['itemOption'] = $item_option;
        }
        $tempcart->in_serialize($post_id, $sku);
        unset($_POST['itemOption']);
        if (!empty($advance)) {
            $advance = $tempcart->wc_serialize($advance);
        }

        $hookargs = [
            'post_id' => $post_id,
            'sku' => $sku,
            'item_option' => $item_option,
            'advance' => $advance,
        ];

        $customerror = apply_filters('wcexwl_filter_item_add_to_wishlist_custom_validation', null, $hookargs);
        if ($customerror !== null) {
            return $customerror;
        }

        $serial = apply_filters('wcexwl_filter_item_add_to_wishlist_serial', $tempcart->serial, $hookargs);

        // check if logged in after all other checks pass so that we can add the item
        // to the wishlist automatically after a successful login
        $isloggedin = $this->guards->isLoggedIn();
        if ($isloggedin instanceof GenericError) {
            $isloggedin->setData($serial);
            return $isloggedin;
        }

        $res = CRUD::executeAddToWishlist($post_id, $sku, $serial, $advance);
        if ($res === false) {
            return $this->master->estore->getErrorResponse(Store::INTERNAL_SERVER_ERROR);
        }

        return true;
    }

    /**
     * Given an item option array formatted the same way as WCEX Widget Cart, this method
     * transforms the values that differ from Welcart's default handling of item option data
     * so that no discrepancies exist between cart and wishlist items that are identical.
     *
     * @author Evan D Shaw <evandanielshaw@gmail.com>
     * @param array  $item_option
     * @param int    $post_id
     * @param string $sku **MUST** be urldecoded
     * @return array
     */
    public static function convertWidgetCartItemOptionPayloadToWelcartDefault($item_option, $post_id, $sku) {
        global $usces;

        $ioptkeys = $usces->get_itemOptionKey($post_id, true);
        if ($ioptkeys) {
            foreach ($ioptkeys as $key => $value) {
                $optValues = $usces->get_itemOptions(urldecode($value), $post_id);
                if (1 == $optValues['means']) { // multiselect
                    if (!empty($item_option[$post_id][$sku][$value])) {
                        $item_option[$post_id][$sku][$value] = explode(',', $item_option[$post_id][$sku][$value][0]);
                    }
                }
            }
        }

        if (isset($item_option[$post_id][$sku])) {
            $item_option[$post_id][urlencode($sku)] = $item_option[$post_id][$sku];
            if ($sku !== urlencode($sku)) {
                // remove after encoding and replacing, if necessary
                unset($item_option[$post_id][$sku]);
            }
        }

        return $item_option;
    }

    /**
     * Adds an item to wishlist with `$_POST` values
     *
     * @important
     * @author Evan D Shaw <evandanielshaw@gmail.com>
     * @return GenericError|string
     */
    public function postToWishlist() {
        $requiredFields = ['postId', 'sku'];
        foreach ($requiredFields as $field) {
            if (empty($_POST[$field])) {
                $emessage = $this->master->estore->getErrorCodeMap()[Store::UNKNOWN_ERROR]->message;
                return $this->master->estore->getErrorResponse(Store::REQUIRED_FIELDS_MISSING, [$field], [$emessage]);
            }
        }

        $post_id = (int)$_POST['postId'];
        $sku = (string)$_POST['sku'];
        $item_option = isset($_POST['itemOption']) ? $_POST['itemOption'] : [];
        $advance = isset($_POST['advance']) ? $_POST['advance'] : '';

        $added = $this->addToWishlist($post_id, $sku, $item_option, $advance);
        if ($added !== true) {
            return $added;
        }

        if ($_SERVER['HTTP_REFERER']) {
            $_SESSION['usces_previous_url'] = esc_url($_SERVER['HTTP_REFERER']);
        } else {
            $_SESSION['usces_previous_url'] = str_replace('https://', 'http://', get_home_url()) . '/';
        }

        return 'success';
    }
}