<?php

declare(strict_types=1);

namespace App\Observers;

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

/**
 * Updates the artwork creator's reactions_received_count when
 * a reaction is added or removed.
 */
class ArtworkReactionObserver
{
    public function __construct(
        private readonly UserStatsService $userStats,
    ) {}

    public function created(ArtworkReaction $reaction): void
    {
        $creatorId = $this->creatorId($reaction->artwork_id);
        if ($creatorId) {
            $this->userStats->incrementReactionsReceived($creatorId);
        }

        // The reactor is "active"
        $this->userStats->ensureRow($reaction->user_id);
        $this->userStats->setLastActiveAt($reaction->user_id);
    }

    public function deleted(ArtworkReaction $reaction): void
    {
        $creatorId = $this->creatorId($reaction->artwork_id);
        if ($creatorId) {
            $this->userStats->decrementReactionsReceived($creatorId);
        }
    }

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

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