<?php

namespace App\Observers;

use App\Models\Employee;
use Illuminate\Support\Facades\DB;

class EmployeeObserver
{
    public function creating(Employee $employee): void
    {
        if (filled($employee->employee_code)) {
            return;
        }

        $year = now()->format('Y');
        $prefix = "EMP-{$year}-";

        $employee->employee_code = DB::transaction(function () use ($prefix): string {
            $latestCode = Employee::withTrashed()
                ->where('employee_code', 'like', $prefix.'%')
                ->lockForUpdate()
                ->orderByDesc('employee_code')
                ->value('employee_code');

            $sequence = 1;

            if ($latestCode !== null) {
                $sequence = (int) substr($latestCode, strlen($prefix)) + 1;
            }

            return $prefix.str_pad((string) $sequence, 4, '0', STR_PAD_LEFT);
        });
    }
}