<?php

declare(strict_types=1);

namespace App\Form\Model;

use App\BusProNet\Constants;
use App\BusProNet\Model\Booking;
use App\BusProNet\Model\Travel;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Context\ExecutionContextInterface;

/**
 * Unified DTO for both booking creation and editing workflows.
 *
 * This DTO consolidates the previously separate BookingCreateDto and BookingEditDto
 * into a single class that handles both modes. All service selections are stored
 * in participant DTOs regardless of mode, ensuring consistent data structure and
 * simplifying pricing calculations, field handlers, and template rendering.
 */
class BookingDto
{
    public const MODE_CREATE = 'create';
    public const MODE_EDIT = 'edit';

    public int $currentStep = 1;

    /**
     * @var array<int, RoomSelectionDto>
     */
    #[Assert\Valid]
    public array $roomSelections = [];

    /**
     * @var array<int, ParticipantDto>
     */
    #[Assert\Valid]
    public array $participants = [];

    #[Assert\Choice(
        choices: [Constants::PAYMENT_METHOD_TRANSFER, Constants::PAYMENT_METHOD_DEBIT],
        message: 'Bitte wählen Sie eine gültige Zahlungsart.'
    )]
    public ?string $paymentMethod = Constants::PAYMENT_METHOD_TRANSFER;

    public ?BankAccountDto $bankAccount = null;

    public ?int $agencyId = null;

    /**
     * Booking status code for API submission.
     * Values: 'F' (Final/Frei), 'A' (Anfrage/Inquiry).
     */
    public string $bookingStatus = 'F';

    /**
     * Reference to booking entity (only populated in edit mode).
     */
    public ?Booking $booking = null;

    /**
     * Timestamp of last session update (for staleness detection).
     * Updated automatically by BookingService::saveBookingDto().
     */
    public ?\DateTimeImmutable $lastSessionUpdate = null;

    /**
     * Fingerprint of the booking state when loaded from API (edit mode only).
     * This property stores the original state and is never updated after initial load.
     * Used to detect unsaved changes in edit mode by comparing with current state.
     */
    public ?string $originalFingerprint = null;

    public function __construct(public Travel $travel, public int $hotelId)
    {
    }

    public function getMode(): string
    {
        return null !== $this->booking ? self::MODE_EDIT : self::MODE_CREATE;
    }

    /**
     * @return array<int, RoomSelectionDto>
     */
    public function getSelectedRooms(): array
    {
        // In edit mode, rooms are fixed - return empty array
        if (self::MODE_EDIT === $this->getMode()) {
            return [];
        }

        return array_filter($this->roomSelections, function (RoomSelectionDto $roomSelection) {
            return 0 < $roomSelection->quantity;
        });
    }

    public function getParticipants(): array
    {
        return $this->participants;
    }

    public function hasParticipant(int $index): bool
    {
        return isset($this->participants[$index]);
    }

    public function getParticipant(int $index): ?ParticipantDto
    {
        return $this->participants[$index] ?? null;
    }

    /**
     * Determines if this is a family booking based on participant age distribution.
     *
     * A family booking is defined as:
     * - 1 or 2 participants aged 18 or older (adults)
     * - At least 1 participant younger than 18 (children)
     */
    public function isFamilyBooking(): bool
    {
        $adults = 0;
        $children = 0;

        $travelStartDate = $this->travel->dateFrom;

        foreach ($this->participants as $participant) {
            $age = $participant->getAge($travelStartDate);

            if (null === $age) {
                continue;
            }

            if ($age >= 18) {
                ++$adults;
            } else {
                ++$children;
            }
        }

        return ($adults >= 1 && $adults <= 2) && ($children >= 1);
    }

    public function isCanceled(): bool
    {
        return null !== $this->booking && 'S' === $this->booking->status;
    }

    public function isOption(): bool
    {
        return null !== $this->booking && 'O' === $this->booking->status;
    }

    #[Assert\Callback(callback: 'validateRoomSelection', groups: ['booking_create_step_1'])]
    public function validateRoomSelection(ExecutionContextInterface $context): void
    {
        $selectedRooms = $this->getSelectedRooms();

        if (0 === count($selectedRooms)) {
            $context->buildViolation('Bitte mindestens ein Zimmer/Bett auswählen')
                ->addViolation();
        }
    }

    #[Assert\Callback]
    public function validateBankAccount(ExecutionContextInterface $context): void
    {
        if (Constants::PAYMENT_METHOD_DEBIT !== $this->paymentMethod) {
            return;
        }

        if (null === $this->bankAccount) {
            $context->buildViolation('Bitte geben Sie Ihre Bankverbindung an.')
                ->atPath('bankAccount')
                ->addViolation();

            return;
        }

        if (null === $this->bankAccount->iban || '' === trim($this->bankAccount->iban)) {
            $context->buildViolation('Bitte geben Sie Ihre IBAN ein.')
                ->atPath('bankAccount.iban')
                ->addViolation();
        }

        if (null === $this->bankAccount->accountHolder || '' === trim($this->bankAccount->accountHolder)) {
            $context->buildViolation('Bitte geben Sie den Kontoinhaber ein.')
                ->atPath('bankAccount.accountHolder')
                ->addViolation();
        }

        if (false === $this->bankAccount->sepaMandateAccepted) {
            $context->buildViolation('Bitte akzeptieren Sie das SEPA-Mandat.')
                ->atPath('bankAccount.sepaMandateAccepted')
                ->addViolation();
        }
    }
}