<?php

declare(strict_types=1);

namespace App\Observers;

use App\Models\ArtworkFavourite;
use App\Services\UserStatsService;
use Illuminate\Support\Facades\DB;

/**
 * Updates the artwork creator's favorites_received_count and last_active_at
 * whenever a favourite is added or removed.
 */
class ArtworkFavouriteObserver
{
    public function __construct(
        private readonly UserStatsService $userStats,
    ) {}

    public function created(ArtworkFavourite $favourite): void
    {
        $creatorId = $this->creatorId($favourite->artwork_id);
        if ($creatorId) {
            $this->userStats->incrementFavoritesReceived($creatorId);
        }
    }

    public function deleted(ArtworkFavourite $favourite): void
    {
        $creatorId = $this->creatorId($favourite->artwork_id);
        if ($creatorId) {
            $this->userStats->decrementFavoritesReceived($creatorId);
        }
    }

    private function creatorId(int $artworkId): ?int
    {
        $id = DB::table('artworks')
            ->where('id', $artworkId)
            ->value('user_id');

        return $id !== null ? (int) $id : null;
    }
}