<?php

declare(strict_types=1);

namespace KupShop\PreordersBundle\Service;

use KupShop\I18nBundle\Entity\Currency;
use KupShop\I18nBundle\Util\PriceConverter;
use KupShop\KupShopBundle\Context\ContextManager;
use KupShop\KupShopBundle\Context\CurrencyContext;
use KupShop\KupShopBundle\Context\EmptiableContext;
use KupShop\KupShopBundle\Context\LanguageContext;
use KupShop\KupShopBundle\Context\PriceLevelContext;
use KupShop\KupShopBundle\Context\UserContext;
use KupShop\KupShopBundle\Exception\InvalidArgumentException;
use KupShop\KupShopBundle\Util\Contexts;
use KupShop\KupShopBundle\Util\Price\TotalPrice;
use KupShop\OrderingBundle\Util\Purchase\PurchaseUtil;
use KupShop\PreordersBundle\Entity\Preorder;
use KupShop\PreordersBundle\Entity\UserPreorder;
use KupShop\PricelistBundle\Context\PricelistContext;
use Query\Operator;

class DynamicContexts
{
    /**
     * @var array<int, string> Mapping of pricelist IDs to currency (cache in case of multiple calls to activatePreorder)
     */
    private array $pricelistCurrenciesCache = [];

    public function __construct(
        private readonly ContextManager $contextManager,
        private readonly PurchaseUtil $purchaseUtil,
        private readonly PreorderUtil $listUtil,
        private readonly PricelistContext $pricelistContext,
        private readonly PriceConverter $priceConverter,
    ) {
    }

    /**
     * @template T of mixed
     *
     * @param callable(): T $callback
     *
     * @return T
     *
     * @throws InvalidArgumentException
     */
    public function withDynamicPrices(Preorder $preorder, array $items, callable $callback)
    {
        $contexts = array_merge(
            $this->getBaseContexts($preorder),
            $this->getDynamicContexts($preorder, $items),
        );

        return $this->contextManager->activateContexts($contexts, $callback);
    }

    /**
     * @template T of mixed
     *
     * @param callable(): T $callback
     *
     * @return T
     *
     * @throws InvalidArgumentException
     */
    public function withBasePrices(Preorder $preorder, callable $callback)
    {
        $contexts = $this->getBaseContexts($preorder);

        return $this->contextManager->activateContexts($contexts, $callback);
    }

    protected function getBaseContexts(Preorder $preorder, ?\User $user = null): array
    {
        $contexts = [];
        if ($user) {
            $contexts[UserContext::class] = $user;
        }

        if (PreorderUtil::fieldIsComposedOfDigits($preorder, 'id_pricelist')) {
            $contexts[PricelistContext::class] = (int) $preorder['id_pricelist'];
        } else {
            $contexts[PricelistContext::class] = ContextManager::FORCE_EMPTY;
        }

        if (PreorderUtil::fieldIsComposedOfDigits($preorder, 'id_price_level')) {
            $contexts[PriceLevelContext::class] = (int) $preorder['id_price_level'];
        } else {
            $contexts[PriceLevelContext::class] = ContextManager::FORCE_EMPTY;
        }

        return $contexts;
    }

    /**
     * @throws InvalidArgumentException
     */
    private function getDynamicContexts(Preorder $preorder, array $items = []): array
    {
        $contexts = [];

        // Pokud nemáme nastaveny dynamické ceny, tak není potřeba již volat výpočet total price
        if (!$preorder->hasDynamicPrice()) {
            return $contexts;
        }

        /* @var TotalPrice $total */
        $this->withBasePrices($preorder, function () use ($items, &$total) {
            $productList = $this->listUtil->getPreorderProductList($items);
            $purchaseState = PreorderUtil::toPurchaseState($productList->getProducts());

            $total = $this->purchaseUtil->recalculateTotalPrices($purchaseState)
                ->getTotalPrice();
        });

        // convert currency of total price to default preorder's price-list's currency
        if ($pricelistId = $preorder['id_pricelist'] ?? false) {
            /** @var Currency $currency */
            $currency = $this->contextManager->activateContexts(
                [PricelistContext::class => $pricelistId],
                fn () => $this->pricelistContext->getActive()->getCurrency(),
            );

            if ($total->getCurrency()->getId() !== $currency->getId()) {
                $total = $this->priceConverter->convertPrice(
                    $total->getCurrency(),
                    $currency,
                    $total->getPriceWithoutVat(),
                );
            }
        }

        if (method_exists($total, 'getPriceWithoutVat')) {
            $total = $total->getPriceWithoutVat();
        }

        if ($idPriceLevel = $preorder->getPriceLevelID($total)) {
            $contexts[PriceLevelContext::class] = $idPriceLevel;
        }
        if ($idPricelist = $preorder->getPricelistID($total)) {
            $contexts[PricelistContext::class] = $idPricelist;
        }

        return $contexts;
    }

    /**
     * @template T of mixed
     *
     * @param (callable(): T)|null $callback
     *
     * @return T
     *
     * @throws InvalidArgumentException
     */
    public function activateUserPreorder(UserPreorder $userPreorder, ?callable $callback = null)
    {
        $contexts = array_merge(
            $this->getBaseContexts($userPreorder->getPreorder()),
            $this->getDynamicContexts($userPreorder->getPreorder(), $userPreorder->getItems()),
        );

        $customData = $userPreorder->getCustomData();

        if ($lang = $customData->get('language') ?? false) {
            $contexts[LanguageContext::class] = $lang;
        }

        if ($currency = $customData->get('currency') ?? false) {
            $contexts[CurrencyContext::class] = $currency;
        }

        if ($callback) {
            return $this->contextManager->activateContexts($contexts, $callback);
        }

        foreach ($contexts as $class => $id) {
            Contexts::get($class)?->activate($id === null ? null : (string) $id);
        }

        return null;
    }

    /**
     * @template T of mixed
     *
     * @param (callable(): T)|null $callback
     *
     * @return T
     *
     * @throws InvalidArgumentException
     */
    public function activatePreorder(Preorder $preorder, ?\User $user, ?callable $callback = null)
    {
        $contexts = $this->getBaseContexts($preorder, $user);

        if ($user) {
            $contexts = array_merge(
                $contexts,
                $this->getDynamicContexts($preorder, $preorder->getItemsByUser($user)),
            );
        }

        // Activate the appropriate currency in case of the preorder having a different currency than the site.
        // E.g. user is on the czech site with CZK, but the preorder pricelist is EUR -> prices displayed in CZK,
        // but total price is calculated based on the pricelist = EUR values with Kč.
        // "Appropriate currency" = currency of the default pricelist in preorder settings.
        if (null !== ($priceListId = $preorder->getPricelistID())) {
            $currency = $this->getCurrencyFromPricelist($priceListId);

            if ($currency) {
                $contexts[CurrencyContext::class] = $currency;
            }
        }

        if ($callback) {
            return $this->contextManager->activateContexts($contexts, $callback);
        }

        foreach ($contexts as $class => $id) {
            $context = Contexts::get($class);

            switch ($id) {
                case ContextManager::FORCE_EMPTY:
                    if (!($context instanceof EmptiableContext)) {
                        throw new \LogicException('cannot force non-emptiable context to be empty');
                    }

                    $context->forceEmpty();
                    break;

                case null:
                    $context->clearCache();
                    break;

                default:
                    $context->activate(is_int($id) ? (string) $id : $id);
            }
        }

        return null;
    }

    private function getCurrencyFromPricelist(int $pricelistId): ?string
    {
        if (!array_key_exists($pricelistId, $this->pricelistCurrenciesCache)) {
            $currency = sqlQueryBuilder()->select('currency')
                ->from('pricelists')
                ->andWhere(Operator::equals(['id' => $pricelistId]))
                ->execute()
                ->fetchOne();

            $this->pricelistCurrenciesCache[$pricelistId] = $currency ?: null;
        }

        return $this->pricelistCurrenciesCache[$pricelistId];
    }
}