<?php

use Bitrix\Main\Loader;
use Bitrix\Main\SystemException;
use Bitrix\Main\Web\Json;

define('STATISTIC_SKIP_ACTIVITY_CHECK', 'true');

require $_SERVER['DOCUMENT_ROOT'].'/bitrix/modules/main/include/prolog_before.php';
include_once 'const.php';

try {
    if (!Loader::includeModule('iblock') || !Loader::includeModule('aspro.allcorp3')) {
        throw new SystemException('Error include module');
    }

    if (!include_once ($_SERVER['DOCUMENT_ROOT'].SITE_TEMPLATE_PATH.'/vendor/php/solution.php')) {
        throw new SystemException('Error include solution constants');
    }

    $application = Bitrix\Main\Application::getInstance();
    $request = $application->getContext()->getRequest();
    $request->addFilter(new Bitrix\Main\Web\PostDecodeFilter());
    $session = $application->getSession();

    $action = $request->get('action');
    $type = $request->get('type');
    if (check_bitrix_sessid() && $action) {
        $arItems = [];
        switch ($action) {
            case 'compare':
                $iblockID = trim(htmlspecialcharsbx($request->get('IBLOCK_ID')));
                $isSKU = $iblockID == TSolution::getFrontParametrValue('CATALOG_SKU_IBLOCK_ID');
                if ($isSKU) {
                    $iblockID = TSolution::getFrontParametrValue('CATALOG_IBLOCK_ID');
                }

                if ($type === 'multiple') {
                    $arItems = (array)$request->get('items');
                    if ($iblockID && $arItems) {
                        foreach ($arItems as $arItem) {
                            $itemID = trim(htmlspecialcharsbx($arItem['ID']));

                            $catalogCompareList = $session->get('CATALOG_COMPARE_LIST');
                            $catalogCompareList[$iblockID]['ITEMS'][$itemID] = CIBlockElement::GetByID($itemID)->Fetch();

                            $session->set('CATALOG_COMPARE_LIST', $catalogCompareList);
                        }

                        $arItems = array_keys($_SESSION['CATALOG_COMPARE_LIST'][$iblockID]['ITEMS']);
                    } else {
                        throw new SystemException('Not enought parameters');
                    }
                } else {
                    $itemID = trim(htmlspecialcharsbx($request->get('ID')));
                    if ($iblockID && $itemID) {
                        if (
                            $session->has('CATALOG_COMPARE_LIST')
                            && !empty($session->get('CATALOG_COMPARE_LIST'))
                            && !empty($session['CATALOG_COMPARE_LIST'][$iblockID])
                            && array_key_exists($itemID, $session['CATALOG_COMPARE_LIST'][$iblockID]['ITEMS'])
                        ) {
                            unset($session['CATALOG_COMPARE_LIST'][$iblockID]['ITEMS'][$itemID]);
                        } else {
                            $catalogCompareList = $session->get('CATALOG_COMPARE_LIST');
                            $catalogCompareList[$iblockID]['ITEMS'][$itemID] = CIBlockElement::GetByID($itemID)->Fetch();

                            $session->set('CATALOG_COMPARE_LIST', $catalogCompareList);
                        }

                        $arItems = array_keys($session['CATALOG_COMPARE_LIST'][$iblockID]['ITEMS']);
                    } else {
                        throw new SystemException('Not enought parameters');
                    }
                }

                break;
        }
    }

    if (!isset($arItems)) {
        throw new SystemException('Not enought parameters');
    }
} catch (SystemException $error) {
    exit(Json::encode(['error' => $error->getMessage()]));
}

exit(Json::encode(['status' => 'OK', 'items' => $arItems]));