<?php

declare(strict_types=1);

namespace App\Service;

use App\BusProNet\Constants;
use App\BusProNet\Model\Room;
use App\BusProNet\Model\Service;
use App\Form\Model\BookingCreateDto;
use App\Form\Model\BookingDtoInterface;
use App\Form\Model\ParticipantDto;

/**
 * Calculates pricing for booking components including rooms and services.
 *
 * This service provides comprehensive pricing calculations for the booking system,
 * handling room pricing based on quantities and service pricing per participant.
 * It returns structured pricing data for display in forms and summaries.
 */
class BookingPriceCalculatorService
{
    /**
     * Calculates comprehensive pricing breakdown for a booking.
     *
     * @param BookingDtoInterface $bookingDto The booking data to calculate pricing for
     *
     * @return array{rooms: array, services: array, grandTotal: float} Complete pricing breakdown
     */
    public function getPricingBreakdown(BookingDtoInterface $bookingDto): array
    {
        $roomPricing = $this->calculateRoomPricing($bookingDto);
        $servicePricing = $this->calculateServicePricing($bookingDto);
        $grandTotal = $this->calculateGrandTotal($bookingDto);

        return [
            'rooms' => $roomPricing,
            'services' => $servicePricing,
            'grandTotal' => $grandTotal,
        ];
    }

    /**
     * Calculates pricing for all selected rooms.
     *
     * @param BookingDtoInterface $bookingDto The booking data containing room selections
     *
     * @return array Array of room pricing data with labels, quantities, and totals
     */
    public function calculateRoomPricing(BookingDtoInterface $bookingDto): array
    {
        $roomPricing = [];

        if (false === $bookingDto instanceof BookingCreateDto) {
            return $roomPricing;
        }

        $selectedRooms = $bookingDto->getSelectedRooms();
        if (true === empty($selectedRooms)) {
            return $roomPricing;
        }

        foreach ($selectedRooms as $roomSelection) {
            $room = $this->getRoomById($bookingDto, $roomSelection->roomId);
            if (null === $room || null === $room->price) {
                continue;
            }

            $totalPrice = $roomSelection->quantity * $room->price;

            $roomPricing[] = [
                'roomId' => $room->id,
                'label' => $room->label,
                'quantity' => $roomSelection->quantity,
                'unitPrice' => $room->price,
                'totalPrice' => $totalPrice,
            ];
        }

        return $roomPricing;
    }

    /**
     * Calculates pricing for all selected services across all participants, grouped by subtype.
     *
     * @param BookingDtoInterface $bookingDto The booking data containing participants and their service selections
     *
     * @return array Array of service groups with each group containing services of the same subtype
     */
    public function calculateServicePricing(BookingDtoInterface $bookingDto): array
    {
        $participants = $bookingDto->getParticipants();

        if (true === empty($participants)) {
            return [];
        }

        // Aggregate service selections across all participants
        $serviceAggregation = [];

        foreach ($participants as $participant) {
            $this->aggregateParticipantServices($participant, $serviceAggregation);
        }

        // Add transportation services as separate line items (Zustieg, Rabatt, Parkplatz)
        $transportationItems = $this->aggregateTransportationServices($bookingDto);
        foreach ($transportationItems as $key => $transportationItem) {
            $serviceAggregation[$key] = $transportationItem;
        }

        // Group services by subtype and convert to pricing format
        return $this->groupServicesBySubtype($serviceAggregation);
    }

    /**
     * Calculates the grand total for the entire booking.
     *
     * @param BookingDtoInterface $bookingDto The booking data to calculate total for
     *
     * @return float The grand total price
     */
    public function calculateGrandTotal(BookingDtoInterface $bookingDto): float
    {
        $roomTotal = $this->calculateRoomTotal($bookingDto);
        $serviceTotal = $this->calculateServiceTotal($bookingDto);

        return $roomTotal + $serviceTotal;
    }

    /**
     * Calculates total price for all rooms.
     */
    public function calculateRoomTotal(BookingDtoInterface $bookingDto): float
    {
        $roomPricing = $this->calculateRoomPricing($bookingDto);

        return array_sum(array_column($roomPricing, 'totalPrice'));
    }

    /**
     * Calculates total price for all services.
     */
    public function calculateServiceTotal(BookingDtoInterface $bookingDto): float
    {
        $servicePricing = $this->calculateServicePricing($bookingDto);

        return array_sum(array_column($servicePricing, 'groupTotal'));
    }

    /**
     * Formats a price value for display with proper German formatting.
     *
     * @param float $price The price to format
     *
     * @return string Formatted price string (e.g., "123,45")
     */
    public function formatPrice(float $price): string
    {
        return number_format($price, 2, ',', '.');
    }

    /**
     * Formats a price with Euro symbol for display.
     *
     * @param float $price The price to format
     *
     * @return string Formatted price string with Euro symbol (e.g., "€123,45")
     */
    public function formatPriceWithSymbol(float $price): string
    {
        return '€'.$this->formatPrice($price);
    }

    /**
     * Aggregates all transportation-related services and pricing into separate line items.
     *
     * Creates separate entries for:
     * - Zustieg: Sum of all pickup prices and base transportation costs (positive and negative)
     * - Parkplatz: Sum of all parking service prices
     *
     * Note: Transportation discounts will be handled generically by groupServicesBySubtype as "Beförderung - Rabatt"
     *
     * @param BookingDtoInterface $bookingDto The booking data containing participants
     *
     * @return array Array of transportation line items (Zustieg, Parkplatz)
     */
    private function aggregateTransportationServices(BookingDtoInterface $bookingDto): array
    {
        $participants = $bookingDto->getParticipants();

        $pickupTotal = 0.0;     // All pickup prices and base transportation costs
        $parkingTotal = 0.0;    // Parking service costs

        $pickupParticipants = 0;
        $parkingParticipants = 0;

        foreach ($participants as $participant) {
            $participantPickupCost = 0.0;
            $participantParkingCost = 0.0;

            // Transportation service pricing (outbound)
            if (null !== $participant->transportationOutbound && null !== $participant->transportationOutbound->price) {
                $participantPickupCost += $participant->transportationOutbound->price;
            }

            // Transportation service pricing (inbound)
            if (null !== $participant->transportationInbound && null !== $participant->transportationInbound->price) {
                $participantPickupCost += $participant->transportationInbound->price;
            }

            // Pickup pricing (outbound)
            if (null !== $participant->pickupOutbound && null !== $participant->pickupOutbound->price) {
                $participantPickupCost += $participant->pickupOutbound->price;
            }

            // Pickup pricing (inbound)
            if (null !== $participant->pickupInbound && null !== $participant->pickupInbound->price) {
                $participantPickupCost += $participant->pickupInbound->price;
            }

            // Parking service pricing
            if (null !== $participant->parkingService && null !== $participant->parkingService->price) {
                $participantParkingCost += $participant->parkingService->price;
            }

            // Aggregate participant totals (count participants who have any transportation costs)
            if (0.0 !== $participantPickupCost) {
                $pickupTotal += $participantPickupCost;
                ++$pickupParticipants;
            }
            if ($participantParkingCost > 0) {
                $parkingTotal += $participantParkingCost;
                ++$parkingParticipants;
            }
        }

        $transportationItems = [];

        // Add pickup entry (if any transportation/pickup costs exist)
        if (0.0 !== $pickupTotal) {
            $transportationItems['transportation_pickup'] = [
                'serviceId' => 'transportation_pickup',
                'label' => 'Zustieg',
                'unitPrice' => null,
                'participantCount' => $pickupParticipants,
                'totalPrice' => $pickupTotal,
                'subType' => 'transportation',
            ];
        }

        // Add parking entry (only if positive costs)
        if ($parkingTotal > 0) {
            $transportationItems['transportation_parking'] = [
                'serviceId' => 'transportation_parking',
                'label' => 'Parkplatz',
                'unitPrice' => null,
                'participantCount' => $parkingParticipants,
                'totalPrice' => $parkingTotal,
                'subType' => 'transportation',
            ];
        }

        return $transportationItems;
    }

    /**
     * Groups services by their subtypes for display, separating positive costs and discounts.
     *
     * Creates separate entries for positive costs and negative costs (discounts) within each service group.
     * For example: "Kurse" and "Kurse - Rabatt" if there are both positive and negative priced course services.
     *
     * @param array $serviceAggregation Aggregated service data
     *
     * @return array Grouped services by subtype with separate discount entries
     */
    private function groupServicesBySubtype(array $serviceAggregation): array
    {
        $groupedServices = [];

        // First pass: separate positive and negative prices by subtype
        $servicesBySubtypeAndSign = [];

        foreach ($serviceAggregation as $serviceData) {
            if (0.0 === $serviceData['totalPrice']) {
                continue; // Skip zero-price services
            }

            $subType = $serviceData['subType'] ?? 'other';

            // Normalize rental subtypes to avoid duplicate sections
            if (true === in_array($subType, Constants::TOKEN_RENTALS, true)) {
                $subType = 'rentals'; // Normalize all rental subtypes to a single key
            }

            $isDiscount = $serviceData['totalPrice'] < 0;

            // Create separate buckets for positive costs and discounts
            $bucketKey = $subType.($isDiscount ? '_discount' : '_regular');

            if (false === isset($servicesBySubtypeAndSign[$bucketKey])) {
                $servicesBySubtypeAndSign[$bucketKey] = [
                    'subType' => $subType,
                    'isDiscount' => $isDiscount,
                    'services' => [],
                    'total' => 0.0,
                    'participantCount' => 0,
                ];
            }

            $servicesBySubtypeAndSign[$bucketKey]['services'][] = $serviceData;
            $servicesBySubtypeAndSign[$bucketKey]['total'] += $serviceData['totalPrice'];
            $servicesBySubtypeAndSign[$bucketKey]['participantCount'] += $serviceData['participantCount'];
        }

        // Second pass: create display groups
        foreach ($servicesBySubtypeAndSign as $bucketData) {
            $baseGroupName = $this->getGroupNameForSubtype($bucketData['subType']);
            $groupName = $bucketData['isDiscount'] ? $baseGroupName.' - Rabatt' : $baseGroupName;

            $groupedServices[] = [
                'groupName' => $groupName,
                'services' => $bucketData['services'],
                'groupTotal' => $bucketData['total'],
            ];
        }

        return $groupedServices;
    }

    /**
     * Maps service subtypes to user-friendly group names.
     */
    private function getGroupNameForSubtype(string $subType): string
    {
        $groupMapping = [
            Constants::TOKEN_COURSES => 'Kurse',
            Constants::TOKEN_SKI_PASS => 'Skipässe',
            Constants::TOKEN_ADDITIONAL => 'Zusatzleistungen',
            Constants::TOKEN_BOARD => 'Verpflegung',
            Constants::TOKEN_RENTAL_INSURANCE => 'Leihmaterial-Versicherung',
            'transportation' => 'Beförderung',
            'rentals' => 'Leihmaterial', // Normalized rental subtype
        ];

        // Handle rentals array (keep for backward compatibility with non-normalized subtypes)
        if (true === in_array($subType, Constants::TOKEN_RENTALS, true)) {
            return 'Leihmaterial';
        }

        return $groupMapping[$subType] ?? 'Sonstige Leistungen';
    }

    /**
     * Aggregates service selections from a single participant into the service aggregation array.
     */
    private function aggregateParticipantServices(ParticipantDto $participant, array &$serviceAggregation): void
    {
        // Handle single service selections (skiPass, rentalInsurance)
        if (null !== $participant->skiPass && null !== $participant->skiPass->price) {
            $this->addToServiceAggregation($serviceAggregation, $participant->skiPass, 1);
        }

        if (null !== $participant->rentalInsurance && null !== $participant->rentalInsurance->price) {
            $this->addToServiceAggregation($serviceAggregation, $participant->rentalInsurance, 1);
        }

        // Handle multiple service selections
        $multipleServiceArrays = [
            'courses' => $participant->courses,
            'additionalServices' => $participant->additionalServices,
            'board' => $participant->board,
            'rentals' => $participant->rentals,
        ];

        foreach ($multipleServiceArrays as $serviceArray) {
            if (true === is_array($serviceArray)) {
                foreach ($serviceArray as $service) {
                    if ($service instanceof Service && null !== $service->price) {
                        $this->addToServiceAggregation($serviceAggregation, $service, 1);
                    }
                }
            }
        }
    }

    /**
     * Adds a service to the aggregation array, incrementing count and updating total price.
     */
    private function addToServiceAggregation(array &$serviceAggregation, Service $service, int $quantity): void
    {
        $serviceKey = $service->id.'_'.$service->label;

        if (false === isset($serviceAggregation[$serviceKey])) {
            $serviceAggregation[$serviceKey] = [
                'serviceId' => $service->id,
                'label' => $service->label,
                'unitPrice' => $service->price,
                'participantCount' => 0,
                'totalPrice' => 0.0,
                'subType' => $service->subType,
            ];
        }

        $serviceAggregation[$serviceKey]['participantCount'] += $quantity;
        $serviceAggregation[$serviceKey]['totalPrice'] += $service->price * $quantity;
    }

    /**
     * Retrieves a room by ID from the booking's travel data.
     */
    private function getRoomById(BookingCreateDto $bookingDto, ?int $roomId): ?Room
    {
        if (null === $roomId) {
            return null;
        }

        foreach ($bookingDto->travel->rooms as $room) {
            if ($room->id === $roomId) {
                return $room;
            }
        }

        return null;
    }
}