<?php

declare(strict_types=1);

namespace Domain\Services;

use Carbon\CarbonImmutable;
use Carbon\CarbonInterface;
use Domain\Builders\OrderBuilder;
use Domain\Builders\OrderBuilderCompleted;
use Domain\Builders\OrderBuilderWithBasket;
use Domain\Enums\OrderTunnelStep;
use Domain\Exceptions\OrderTunnel\MissingOrderBuilderException;
use Domain\Exceptions\OrderTunnel\OrderLimitExceededException;
use Domain\Exceptions\OrderTunnel\WeeklyLimitExceededException;
use Domain\Models\Entities\Basket;
use Domain\Models\Entities\Order;
use Domain\Models\Entities\Shop;
use Domain\Models\Entities\Shopper;
use Domain\Models\ValueObjects\Entities\ShopperId;
use Domain\Models\ValueObjects\PickupTimeSlot;
use Domain\Policies\CustomerOrderLimitPolicy;
use Domain\Ports\Repositories\OrderRepository;
use Domain\Ports\Repositories\ShopperRepository;
use Domain\Ports\Repositories\ShopRepository;
use Domain\Ports\Services\EmployeeStatisticsService;
use Domain\Ports\Services\OrderBuilderSessionManager;
use Domain\Ports\Services\TransactionManager;
use Shared\DDD\DomainEventDispatcher;

class OrderTunnelService
{
    private const TIMESLOTS_DAY_TARGET = 28;

    public function __construct(
        private readonly BasketService $basketService,
        private readonly DomainEventDispatcher $eventDispatcher,
        private readonly ShopperService $shopperService,
        private readonly OrderBuilderSessionManager $orderBuilderSessionManager,
        private readonly PickupSchedulingService $pickupService,
        private readonly OrderRepository $orderRepository,
        private readonly CustomerOrderLimitPolicy $orderLimitPolicy,
        private readonly TransactionManager $transactionManager,
        private readonly ShopRepository $shopRepository,
        private readonly ShopperRepository $shopperRepository,
        private readonly OrderService $orderService,
        private readonly EmployeeStatisticsService $employeeStatisticsService,
    ) {
    }

    public function hasValidBasket(): bool
    {
        return $this->basketService->getBasket()->countItems() > 0;
    }

    public function canAccessStep(OrderTunnelStep $step): bool
    {
        $builder = $this->orderBuilderSessionManager->get();

        $hasValidBasket = $this->hasValidBasket();

        return match ($step) {
            OrderTunnelStep::REVIEW       => $hasValidBasket,
            OrderTunnelStep::BOOKING      => $this->hasValidBasket() && $builder !== null && $builder->isFromBasket(),
            OrderTunnelStep::CONFIRMATION => $this->hasValidBasket() && $builder !== null && $builder->isCompleted(),
        };
    }

    /**
     * Resolve the shop assigned to a customer.
     *
     * @throws \UnexpectedValueException If no shop can be resolved.
     */
    public function getShopForCustomer(ShopperId $customerId): Shop
    {
        return $this->shopperService->getShopFor($customerId)
            ?? throw new \UnexpectedValueException(
                "No shop found for customer '{$customerId->value}'"
            );
    }

    /** @return array<int, PickupTimeSlot> */
    public function getAvailableTimeSlots(Shop $shop): array
    {
        return $this->pickupService->getTimeSlotsFor(
            $shop,
            $this->getTimeslotsUntil()
        );
    }

    public function initializeFromBasket(Basket $basket, ShopperId $customerId): void
    {
        /** @var OrderBuilder $builder */
        $builder = OrderBuilder::fromBasket($basket, $customerId);

        $this->orderBuilderSessionManager->save($builder);
    }

    /**
     * @throws \Domain\Exceptions\OrderTunnel\MissingOrderBuilderException
     */
    public function getBuilderFromBasketOrFail(): OrderBuilderWithBasket
    {
        $builder = $this->orderBuilderSessionManager->get();

        if ($builder === null || ! $builder->isFromBasket()) {
            throw new MissingOrderBuilderException();
        }

        /** @var OrderBuilderWithBasket $builder */
        return $builder;
    }

    /**
     * @throws \Domain\Exceptions\OrderTunnel\MissingOrderBuilderException
     */
    public function getBuilderCompletedOrFail(): OrderBuilderCompleted
    {
        $builder = $this->orderBuilderSessionManager->get();

        if ($builder === null || ! $builder->isCompleted()) {
            throw new MissingOrderBuilderException();
        }

        /** @var OrderBuilderCompleted $builder */
        return $builder;
    }

    /**
     * Validate that the selected date matches an available slot and apply it to the builder.
     *
     * @param  array<int, PickupTimeSlot>  $availableSlots
     */
    public function applyTimeSlot(
        OrderBuilderWithBasket $builder,
        Shop $shop,
        CarbonInterface $selectedDate,
        array $availableSlots
    ): ?PickupTimeSlot {
        $matchedSlot = null;
        foreach ($availableSlots as $ts) {
            if ($selectedDate->isSameDay($ts->getAt())) {
                $matchedSlot = $ts;
                break;
            }
        }

        if ($matchedSlot === null) {
            return null;
        }

        /** @var OrderBuilder $completed */
        $completed = $builder->withPickupTimeSlot($shop->id(), $matchedSlot);

        $this->orderBuilderSessionManager->save($completed);

        return $matchedSlot;
    }

    /** @throws \Domain\Exceptions\OrderTunnel\OrderLimitExceededException */
    public function assertBasketAmountWithinLimit(Basket $basket): void
    {
        $this->orderLimitPolicy->assertCanPlaceOrder($basket->totalTaxIncluded());
    }

    /** @throws \Domain\Exceptions\OrderTunnel\WeeklyLimitExceededException */
    public function assertBasketWeeklyAmountWithinLimitFor(
        Shopper $shopper,
        Basket $withBasket,
        \DateTimeInterface $atDate
    ): void {
        $startOfWeek = CarbonImmutable::instance($atDate)->startOfWeek(CarbonInterface::MONDAY);
        $endOfWeek   = CarbonImmutable::instance($atDate)->endOfWeek(CarbonInterface::SUNDAY);

        $weekTotal = $this->employeeStatisticsService->getWeeklyTotalForEmployee(
            $shopper->matricule,
            $startOfWeek,
            $endOfWeek
        );

        $this->orderLimitPolicy->assertCanPlaceWeeklyOrder($withBasket->totalTaxIncluded(), $weekTotal);
    }

    /**
     * @throws WeeklyLimitExceededException
     * @throws OrderLimitExceededException
     */
    public function finalizeOrder(OrderBuilderCompleted $builder): Order
    {
        $shopperId      = $builder->getShopperId();
        $basket         = $this->basketService->revalidateBasket($builder->getBasket());
        $pickupTimeSlot = $builder->getPickupTimeSlot();
        $shopId         = $builder->getShopId();
        $shopper        = $this->shopperRepository->getByIdOrFail($shopperId);

        $this->assertBasketAmountWithinLimit($basket);
        $this->assertBasketWeeklyAmountWithinLimitFor(
            $shopper,
            $basket,
            $pickupTimeSlot->getAt()
        );

        return $this->transactionManager->execute(function () use ($basket, $shopId, $shopper, $pickupTimeSlot) {
            $shop = $this->shopRepository->find($shopId);
            if (! $shop) {
                throw new \DomainException("Shop with id '{$shopId->value}' not found.");
            }

            $order = $this->orderService->createOrderFromBasket(
                $basket,
                $pickupTimeSlot,
                $shopper,
                $shop
            );

            $this->orderRepository->persist($order);

            $this->eventDispatcher->dispatch($order->toPlacedEvent());

            $this->basketService->empty();
            $this->orderBuilderSessionManager->clear();

            return $order;
        });
    }

    private function getTimeslotsUntil(): CarbonInterface
    {
        return CarbonImmutable::now()->addDays(self::TIMESLOTS_DAY_TARGET);
    }
}