<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */

namespace Zend\Permissions\Acl;

interface AclInterface
{
    /**
     * Returns true if and only if the Resource exists in the ACL
     *
     * The $resource parameter can either be a Resource or a Resource identifier.
     *
     * @param  Resource\ResourceInterface|string $resource
     * @return bool
     */
    public function hasResource($resource);

    /**
     * Returns true if and only if the Role has access to the Resource
     *
     * The $role and $resource parameters may be references to, or the string identifiers for,
     * an existing Resource and Role combination.
     *
     * If either $role or $resource is null, then the query applies to all Roles or all Resources,
     * respectively. Both may be null to query whether the ACL has a "blacklist" rule
     * (allow everything to all). By default, Zend\Permissions\Acl creates a "whitelist" rule (deny
     * everything to all), and this method would return false unless this default has
     * been overridden (i.e., by executing $acl->allow()).
     *
     * If a $privilege is not provided, then this method returns false if and only if the
     * Role is denied access to at least one privilege upon the Resource. In other words, this
     * method returns true if and only if the Role is allowed all privileges on the Resource.
     *
     * This method checks Role inheritance using a depth-first traversal of the Role registry.
     * The highest priority parent (i.e., the parent most recently added) is checked first,
     * and its respective parents are checked similarly before the lower-priority parents of
     * the Role are checked.
     *
     * @param  Role\RoleInterface|string            $role
     * @param  Resource\ResourceInterface|string    $resource
     * @param  string                               $privilege
     * @return bool
     */
    public function isAllowed($role = null, $resource = null, $privilege = null);
}
