Laravel in 2026: Modern Patterns, Lessons & Architectural Evolution

<?php

declare(strict_types=1);

namespace App\Services\Wallet;

use App\Models\Wallet;
use App\Models\Transaction;
use Illuminate\Support\Facades\DB;

final class AtomicWalletCreditService
{
    public function credit(int $userId, float $amount, string $reference): Transaction
    {
        return DB::transaction(function () use ($userId, $amount, $reference): Transaction {
            $wallet = Wallet::where('user_id', $userId)->lockForUpdate()->firstOrFail();
            $existing = Transaction::where('reference', $reference)->first();
            if ($existing) return $existing;

            $wallet->increment('balance', $amount);
            return Transaction::create([
                'wallet_id' => $wallet->id,
                'user_id' => $userId,
                'amount' => $amount,
                'type' => 'credit',
                'reference' => $reference,
                'balance_after' => $wallet->balance,
            ]);
        });
    }
}