<?php

namespace App\Services\Booking;

use App\Enums\AppointmentStatus;
use App\Models\Appointment;
use App\Models\AppointmentService;
use App\Models\Business;
use App\Models\CustomerProfile;
use App\Models\GuestAppointmentAccessToken;
use App\Models\Service;
use App\Services\Availability\AvailabilityService;
use App\Services\Notifications\NotificationService;
use App\Enums\NotificationType;
use Carbon\CarbonImmutable;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Str;
use RuntimeException;

class BookingService
{
    public function __construct(private readonly AvailabilityService $availability, private readonly NotificationService $notifications) {}

    /** @return array{appointment: Appointment, accessToken: string} */
    public function create(Business $business, array $input): array
    {
        $serviceIds = array_values(array_unique($input['serviceIds']));
        $services = Service::query()->where('businessId', $business->id)->whereIn('id', $serviceIds)->where('isActive', true)->get();
        if ($services->count() !== count($serviceIds)) {
            throw new RuntimeException('One or more selected services are no longer available.');
        }

        $start = CarbonImmutable::parse($input['startAt'])->setTimezone($business->timezone);
        $end = $start->addMinutes($services->sum('durationMinutes') + $services->sum('bufferBeforeMinutes') + $services->sum('bufferAfterMinutes'));
        $available = $this->availability->slots($business, $start, $serviceIds, $input['staffId'])->first(fn ($slot) => $slot['startAt'] === $start->toIso8601String());
        if (! $available) {
            throw new RuntimeException('That time has just been booked. Please choose another slot.');
        }

        $rawToken = Str::random(64);
        $appointment = DB::transaction(function () use ($business, $input, $services, $start, $end, $rawToken): Appointment {
            $conflict = Appointment::query()
                ->where('businessId', $business->id)
                ->where('staffId', $input['staffId'])
                ->whereNotIn('status', [AppointmentStatus::Cancelled->value, AppointmentStatus::NoShow->value])
                ->where('startAt', '<', $end->utc())
                ->where('endAt', '>', $start->utc())
                ->lockForUpdate()
                ->exists();
            if ($conflict) {
                throw new RuntimeException('That time has just been booked. Please choose another slot.');
            }

            $email = strtolower(trim($input['email']));
            $customer = CustomerProfile::query()->where('businessId', $business->id)->where('email', $email)->first();
            if (! $customer) $customer = new CustomerProfile(['businessId' => $business->id, 'email' => $email]);
            $customer->firstName = trim($input['firstName']);
            $customer->lastName = trim($input['lastName']);
            $customer->phone = trim($input['phone'] ?? '') ?: $customer->phone;
            $customer->isGuest = ! $customer->userId;
            $customer->save();
            $appointment = Appointment::create([
                'businessId' => $business->id,
                'customerId' => $customer->id,
                'staffId' => $input['staffId'],
                'status' => $business->bookingRule?->requireApproval ? AppointmentStatus::Pending : AppointmentStatus::Confirmed,
                'startAt' => $start->utc(),
                'endAt' => $end->utc(),
                'notes' => $input['notes'] ?? null,
            ]);
            foreach ($services as $service) {
                AppointmentService::create(['appointmentId' => $appointment->id, 'serviceId' => $service->id, 'priceAtBooking' => $service->price, 'durationAtBookingMinutes' => $service->durationMinutes]);
            }
            GuestAppointmentAccessToken::create(['appointmentId' => $appointment->id, 'tokenHash' => hash('sha256', $rawToken), 'expiresAt' => now()->addMonths(6)]);
            return $appointment;
        });

        $appointment->load(['customer', 'staff.user', 'services.service']);
        $notificationType = $appointment->status === AppointmentStatus::Pending ? NotificationType::BookingPendingApproval : NotificationType::BookingConfirmed;
        $this->notifications->create(
            $business,
            $notificationType,
            $appointment->status === AppointmentStatus::Pending
                ? 'Your booking request is waiting for the shop to approve.'
                : 'Your appointment is confirmed.',
            "booking-created:{$appointment->id}",
            $appointment->customer->userId,
            $appointment->customer->id,
            $appointment->id,
            "/book/confirmation",
            $business->name,
        );

        return ['appointment' => $appointment, 'accessToken' => $rawToken];
    }
}