<?php

declare(strict_types=1);

namespace App\Service;

use App\BusProNet\Model\Insurance;
use App\Form\Model\BookingDto;

/**
 * Single source of truth for "the applicant could still upgrade to a family insurance".
 *
 * Participants are entered one card at a time, applicant first, so at the moment the
 * applicant has to pick an insurance the family constellation is not yet known and no
 * family insurance can be offered. Only the applicant may hold a family insurance, so
 * without a standing hint the opportunity is silently lost once the dependents' dates
 * of birth make the booking eligible.
 *
 * This is deliberately a derived predicate rather than a one-time event: it stays true
 * for as long as the applicant can still act on it and disappears by itself once they
 * switch to a family insurance, deliberately pick something else while eligible, or the
 * constellation stops qualifying.
 */
class FamilyInsuranceAvailabilityChecker
{
    public function __construct(
        private readonly InsuranceManager $insuranceService,
        private readonly BookingPriceCalculator $priceCalculatorService,
    ) {
    }

    /**
     * Whether the applicant should be pointed at a family insurance they cannot have
     * chosen earlier.
     *
     * Requires `applicantInsuranceChosenWhileFamilyIneligible` - i.e. the standing choice
     * was actually made before family insurance was possible - so an applicant who was
     * offered a family insurance and picked something else is not nagged about it.
     */
    public function isFamilyInsuranceUpgradeAvailable(BookingDto $bookingDto): bool
    {
        if (false === $bookingDto->applicantInsuranceChosenWhileFamilyIneligible) {
            return false;
        }

        $applicant = $bookingDto->getParticipant(0);

        if (null === $applicant || null === $applicant->insurance || true === $applicant->insurance->familyInsurance) {
            return false;
        }

        return $this->hasEligibleFamilyInsurance($bookingDto);
    }

    /**
     * Checks whether a family insurance is actually eligible right now - not just whether
     * the participant composition qualifies as a family booking, but whether a selectable
     * family insurance product actually matches the current total booking price.
     */
    public function hasEligibleFamilyInsurance(BookingDto $bookingDto): bool
    {
        if (false === $bookingDto->isFamilyBooking()) {
            return false;
        }

        $applicant = $bookingDto->getParticipant(0);
        if (null === $applicant) {
            return false;
        }

        $selectableInsurances = $this->insuranceService->getSelectableInsurances($bookingDto->travel);
        $familyInsurances = array_values(array_filter($selectableInsurances, static fn (Insurance $i) => true === $i->familyInsurance));

        if ([] === $familyInsurances) {
            return false;
        }

        $totalPrice = $this->priceCalculatorService->calculateTotalBookingPriceExcludingInsurance($bookingDto);

        return [] !== $this->insuranceService->getEligibleInsurances($familyInsurances, $applicant, $bookingDto, $totalPrice);
    }
}