clrghouz/app/Policies/SystemPolicy.php

<?php

namespace App\Policies;

use Illuminate\Auth\Access\HandlesAuthorization;

use App\Models\{System,User};

class SystemPolicy
{
	use HandlesAuthorization;

	/**
	 * Determine whether the user can create the model.
	 *
	 * A user can create a system if it doesnt exist.
	 *
	 * @param User $user
	 * @param System $system
	 * @return bool
	 */
	public function create(User $user, System $system): bool
	{
		// Site Admins can always create
		// If it doesnt exist, then a user can create it.
		return ($user->isAdmin() || (! $system->exists));
	}

	/**
	 * Can the user register this system
	 *
	 * @param User $user
	 * @param System $system
	 * @return bool
	 */
	public function register(User $user,System $system): bool
	{
		return ! $system->users->count() || $system->users->has($user);
	}

	/**
	 * Determine whether the user can update the model.
	 *
	 * A user can update a system if they are the user of it and it has no addresses.
	 * If it has addresses, at least one of the addresses must have been validated.
	 * (The assumption is, if a system has multiple addresses, they would be valid, or an admin can remove them.)
	 *
	 * @param User $user
	 * @param System $system
	 * @return bool
	 */
	public function update(User $user, System $system): bool
	{
		// Site Admins can always edit
		if ($user->isAdmin())
			return TRUE;

		// If it doesnt exist, then its a false.
		if (! $system->exists)
			return FALSE;

		return $system->users->contains($user)
			&& (($system->addresses->count() === 0) || ($system->addresses->where('validated',TRUE)->count()));
	}
}