Managing Many-to-Many Relationships with attach, detach, sync

<?php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use App\Models\Role; // Assuming Role model exists

class User extends Model
{
    public function roles()
    {
        return $this->belongsToMany(Role::class);
    }
}

// Usage example in a controller or service:
// $user = User::find(1);
// $adminRole = Role::where('name', 'admin')->first();
// $editorRole = Role::where('name', 'editor')->first();
// $viewerRole = Role::where('name', 'viewer')->first();

// Attach a single role
// $user->roles()->attach($adminRole->id);

// Attach multiple roles (e.g., if user has no roles yet)
// $user->roles()->attach([$adminRole->id, $editorRole->id]);

// Detach a single role
// $user->roles()->detach($adminRole->id);

// Detach multiple roles
// $user->roles()->detach([$editorRole->id, $viewerRole->id]);

// Sync roles: adds new roles, removes old ones not in list, keeps existing ones
// If the user currently has roles [1, 2, 3] and you sync [2, 4],
// role 1 and 3 will be detached, role 4 will be attached, role 2 will remain.
// $user->roles()->sync([$adminRole->id, $viewerRole->id]);

// Sync with pivot data (e.g., for a 'role_user' pivot table with 'assigned_at' column)
// $user->roles()->sync([
//     $adminRole->id => ['assigned_at' => now()],
//     $viewerRole->id,
// ]);