<?php

declare(strict_types=1);

namespace App\Service;

use App\Form\Model\BookingDto;
use App\Form\Model\ParticipantDto;

/**
 * Generates fingerprints of booking state for change detection in edit mode.
 *
 * Creates SHA-256 hashes of all mutable booking data to detect unsaved changes.
 * Used by EditController to determine if user modifications need to be saved.
 * Also provides data extraction for draft persistence.
 */
class BookingFingerprintService
{
    /**
     * Generates a fingerprint (hash) of all mutable booking data.
     *
     * The fingerprint includes payment details and all participant data including
     * personal information, addresses, body dimensions, room assignments, and service selections.
     */
    public function generateFingerprint(BookingDto $bookingDto, bool $logData = false): string
    {
        return hash('sha256', serialize($this->extractUserData($bookingDto)));
    }

    /**
     * Extracts all user-editable data from a BookingDto as a serializable array.
     *
     * This method captures all data that represents user input: personal information,
     * addresses, body dimensions, service selections, voucher codes, and payment details.
     * The resulting array can be used for fingerprint generation or draft persistence.
     *
     * @param BookingDto $bookingDto The booking DTO to extract data from
     *
     * @return array Serializable array of all user-editable data
     */
    public function extractUserData(BookingDto $bookingDto): array
    {
        $data = [
            'paymentMethod' => $bookingDto->paymentMethod,
            'bankAccount' => [
                'iban' => $bookingDto->bankAccount?->iban,
                'accountHolder' => $bookingDto->bankAccount?->accountHolder,
            ],
            'participants' => [],
        ];

        foreach ($bookingDto->participants as $index => $participant) {
            $data['participants'][$index] = $this->extractParticipantData($participant);
        }

        return $data;
    }

    /**
     * Extracts user-editable data from a single participant.
     *
     * @param ParticipantDto $participant The participant to extract data from
     *
     * @return array Serializable array of participant data
     */
    private function extractParticipantData(ParticipantDto $participant): array
    {
        return [
            'personalData' => [
                'firstName' => $participant->firstName,
                'lastName' => $participant->lastName,
                'dateOfBirth' => $participant->dateOfBirth?->format('Y-m-d'),
                'email' => $participant->email,
                'mobile' => $participant->mobile,
                'gender' => $participant->gender,
                'nationality' => $participant->nationality,
            ],
            'address' => [
                'street' => $participant->address?->street,
                'postCode' => $participant->address?->postCode,
                'city' => $participant->address?->city,
                'country' => $participant->address?->country,
            ],
            'bodyDimensions' => [
                'height' => $participant->height,
                'weight' => $participant->weight,
                'shoeSize' => $participant->shoeSize,
            ],
            'roomAssignment' => [
                'assignedRoomId' => $participant->assignedRoomId,
                'remarksRoom' => $participant->remarksRoom,
            ],
            'licensePlate' => $participant->licensePlate,
            'services' => [
                'skiPass' => $participant->skiPass?->id,
                'courses' => $this->normalizeServiceArray($participant->courses),
                'board' => $this->normalizeServiceArray($participant->board),
                'rentals' => $this->normalizeServiceArray($participant->rentals),
                'rentalInsurance' => $participant->rentalInsurance?->id,
                'additionalServices' => $this->normalizeServiceArray($participant->additionalServices),
                'transportationOutbound' => $participant->transportationOutbound?->id,
                'transportationInbound' => $participant->transportationInbound?->id,
                'pickup' => $participant->pickup?->id,
                'parking' => $participant->parking,
                'insurance' => $participant->insurance?->id,
                'bulkInsuranceBooking' => $participant->bulkInsuranceBooking,
            ],
            'vouchers' => [
                'purchaseVoucherCode' => $participant->purchaseVoucherCode,
                'promoVoucherCode' => $participant->promoVoucherCode,
            ],
        ];
    }

    /**
     * Normalizes a service array to ensure consistent fingerprinting.
     *
     * Extracts service IDs, sorts them, and returns a simple indexed array.
     * This ensures that associative arrays, indexed arrays, and different orders
     * all produce the same fingerprint as long as the same services are present.
     *
     * @param array $services Array of Service objects
     *
     * @return array Sorted array of service IDs
     */
    private function normalizeServiceArray(array $services): array
    {
        $ids = array_map(fn ($s) => $s->id, $services);
        sort($ids);

        return array_values($ids);
    }

    /**
     * Checks if the booking has unsaved changes in edit mode.
     *
     * Compares the current state fingerprint with the original fingerprint
     * that was set when the booking was loaded from the API.
     */
    public function isDirty(BookingDto $bookingDto): bool
    {
        if (BookingDto::MODE_EDIT !== $bookingDto->getMode()) {
            return false;
        }

        if (null === $bookingDto->originalFingerprint) {
            return false;
        }

        $currentFingerprint = $this->generateFingerprint($bookingDto);

        return $bookingDto->originalFingerprint !== $currentFingerprint;
    }
}