<?php
namespace Wbs24\Services;

use Bitrix\Main\Loader;
use Bitrix\Main\Data\Cache;
use Bitrix\Sale;

class Main 
{
    protected $settings;
    protected $ready = false;

    public function __construct()
    {
        $this->settings = $this->getSettings();

        if (
            true
            //&& Loader::includeModule('sale')
            //&& Loader::includeModule('iblock')
            //&& Loader::includeModule('catalog')
        ) {
            $this->ready = true;
        }
    }

    protected function getErrorIfNotReady()
    {
        $error = false;
        if (!$this->ready) {
            $error = [
                'error' => 'necessary modules are not installed',
            ];
        }

        return $error;
    }

    public function getJson($data)
    {
        $action = $data['action'] ?? false;
        $result = [
            'error' => 'invalid data',
        ];

        if ($errorNotReady = $this->getErrorIfNotReady()) {
            $action = false;
            $result = $errorNotReady;
        }

        switch ($action) {
            case 'getServices':
                $result = $this->getServices($data);
                break;
            case 'addToBasket':
                $result = $this->addToBasket($data);
                break;
            case 'delFromBasket':
                $result = $this->delFromBasket($data);
                break;
            case 'checkInBasket':
                $result = $this->checkInBasket($data);
                break;
            case 'delUnbound':
                $result = $this->delUnbound();
                break;
        }

        return json_encode($result);
    }

    protected function getSettings()
    {
        $settings = [];
        include_once($_SERVER['DOCUMENT_ROOT'].'/local/services/~settings.php');
        
        return $settings;
    }

    // GET SERVICES
    protected function getServices($data)
    {
        $productId = $data['productId'] ?? false;
        if (!$productId) return;

        $itemSectionId = $this->getItemSection($productId);
        $services = $this->getServicesByItemSection($itemSectionId);
        $preparedServices = $this->prepareServicesForResponse($services);

        return $preparedServices;
    }

    protected function getItemSection($itemId)
    {
        if (
            !$itemId
            && !empty($this->settings['productIblockId'])
        ) return false;

        $filter = [
            "IBLOCK_ID" => $this->settings['productIblockId'],
            "ACTIVE" => "Y",
            "ID" => $itemId,
        ];

        $select = [
            "ID",
            "IBLOCK_ID",
            "IBLOCK_SECTION_ID",
        ];
        $result = $this->getList($filter, $select, $this->settings['cacheSeconds']);
        $sectionId = $result[0]["IBLOCK_SECTION_ID"] ?: false;

        return $sectionId;
    }

    protected function getServicesByItemSection($itemSectionId)
    {

        if (
            !$itemSectionId
            && !empty($this->settings['servicesIblockId'])
            && !empty($this->settings['propertyCodeForSectionsLink'])
        ) return [];

        $filter = [
            "IBLOCK_ID" => $this->settings['servicesIblockId'], 
            "ACTIVE" => "Y", 
			//"AVAILABLE" => "Y",
            "PROPERTY_".$this->settings['propertyCodeForSectionsLink'] => $itemSectionId,
        ];
        $select = [
            "ID", 
            "IBLOCK_ID", 
            "NAME", 
            "SCALED_PRICE_".$this->getPriceId(),
        ];
        $services = $this->getList($filter, $select, $this->settings['cacheSeconds']);

        return $services;
    }

    protected function prepareServicesForResponse($services)
    {
        $preparedServices = [];
        foreach ($services as $service) {
            $preparedServices[] = [
                'id' => $service['ID'],
                'name' => $service['NAME'],
                'price' => round($service['SCALED_PRICE_'.$this->getPriceId()]),
            ];
        }

        return $preparedServices;
    }

    protected function getList($filter, $select = ["ID", "IBLOCK_ID", "NAME"], $cacheSeconds = false)
    {
        if ($cacheSeconds) {
            $cache = Cache::createInstance();
            $cacheKey = md5(print_r($filter, true).print_r($select, true));
            if ($cache->initCache($cacheSeconds, $cacheKey)) {
                return $cache->getVars();
            }
        }

        $list = [];
        if (Loader::includeModule('iblock')) {
            $result = \CIBlockElement::GetList(["SORT" => "ASC"], $filter, false, false, $select);
            while ($fields = $result->Fetch()) {
                $list[] = $fields;
            }
		}

        if ($cacheSeconds) {
            $cache->startDataCache();
            $cache->endDataCache($list);
        }

        return $list;
    }

    protected function getPriceId()
    {
        return $this->settings['priceId'] ?: 1;
    }

    // BASKET
    protected function addToBasket($data)
    {
        if (!Loader::includeModule('sale') && !Loader::includeModule('catalog')) return;

        $productId = $data['productId'] ?? false;
        if (!$productId) return;
        $serviceId = $data['serviceId'] ?? false;
        if (!$serviceId) return;

        $basket = $this->getBasket();
        $item = $basket->createItem('catalog', $serviceId);
        $item->setFields([
            'QUANTITY' => 1,
            'CURRENCY' => \Bitrix\Currency\CurrencyManager::getBaseCurrency(),
            'LID' => \Bitrix\Main\Context::getCurrent()->getSite(),
            'PRODUCT_PROVIDER_CLASS' => 'CCatalogProductProvider',
        ]);

        $basketPropertyCollection = $item->getPropertyCollection();
        $basketPropertyCollection->setProperty([
            [
               'NAME' => 'ID родительского товара',
               'CODE' => 'SERVICEOFPRODUCTID', // свойство должно быть в списке параметра корзины OFFERS_PROPS
               'VALUE' => $productId,
               'SORT' => 100,
            ],
        ]);

        $basket->save();

        return ['result' => 'success'];
    }

    protected function delFromBasket($data)
    {
        if (!Loader::includeModule('sale') && !Loader::includeModule('catalog')) return;

        $productId = $data['productId'] ?? false;
        if (!$productId) return;
        $serviceId = $data['serviceId'] ?? false;
        if (!$serviceId) return;

        list($basket, $item) = $this->getBasketAndItemWithService($productId, $serviceId);
        if ($item) {
            $item->delete();
            $basket->save();
        }

        return ['result' => 'success'];
    }

    protected function checkInBasket($data)
    {
        if (!Loader::includeModule('sale') && !Loader::includeModule('catalog')) return;

        $productId = $data['productId'] ?? false;
        if (!$productId) return;
        $serviceId = $data['serviceId'] ?? false;
        if (!$serviceId) return;

        list($basket, $item) = $this->getBasketAndItemWithService($productId, $serviceId);

        return ['result' => ($item ? 'exist' : 'not_exist')];
    }

    protected function delUnbound()
    {
        if (!Loader::includeModule('sale') && !Loader::includeModule('catalog')) return;

        $needRecalc = false;
        $basket = $this->getBasket();
        $productIds = [];
        $serviceIdsToBasketItemIds = [];
        $unboundItemIds = [];

        foreach ($basket as $item) {
            $itemProductId = $item->getProductId();
            $itemParentProductId = $this->getParentProductId($item);
            $itemId = $item->getId();

            if ($itemParentProductId) {
                $productIdsToBasketItemIds[$itemParentProductId][] = $itemId;
            } else {
                $productIds[] = $itemProductId;
            }
        }

        $unboundItemIds = $this->getUnboundItemsIds($productIds, $productIdsToBasketItemIds);

        foreach ($basket as $item) {
            $itemId = $item->getId();

            if (in_array($itemId, $unboundItemIds)) {
                $item->delete();
                $needRecalc = true;
            }
        }

        if ($needRecalc) {
            $basket->save();
        }

        return [
            'result' => ($needRecalc ? 'recalc' : 'success'),
        ];
    }

    protected function getBasketAndItemWithService($productId, $serviceId)
    {
        $basket = $this->getBasket();
        foreach ($basket as $item) {
            $itemProductId = $item->getProductId();
            $itemParentProductId = $this->getParentProductId($item);

            if (
                $itemProductId == $serviceId 
                && $itemParentProductId == $productId
            ) {
                return [$basket, $item];
            }
        }

        return [$basket, false];
    }

    protected function getParentProductId(&$item)
    {
        $basketPropertyCollection = $item->getPropertyCollection(); 
        $itemPropertyValues = $basketPropertyCollection->getPropertyValues();
        $itemParentProductId = $itemPropertyValues['SERVICEOFPRODUCTID']['VALUE'] ?? false;

        return $itemParentProductId;
    }

    protected function getUnboundItemsIds($productIds, $productIdsToBasketItemIds)
    {
        $unboundItemIds = [];

        foreach ($productIdsToBasketItemIds as $itemParentProductId => $itemIds) {
            if (!in_array($itemParentProductId, $productIds)) {
                foreach ($itemIds as $itemId) $unboundItemIds[] = $itemId;
            }
        }

        return $unboundItemIds;
    }

    protected function getBasket()
    {
        $basket = Sale\Basket::loadItemsForFUser(Sale\Fuser::getId(), \Bitrix\Main\Context::getCurrent()->getSite());

        return $basket;
    }
}