Refactor authorization helper to separate some methods

Methods regarding to role hierarchi are now delegated to a parent role helper.

src/Bundle/ChillMainBundle/Security/ParentRoleHelper.php

@@ -0,0 +1,71 @@
+<?php
+
+namespace Chill\MainBundle\Security;
+
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
+use Symfony\Component\Security\Core\Role\Role;
+use Symfony\Component\Security\Core\Role\RoleHierarchyInterface;
+
+/**
+ * Helper which traverse all role to find parents
+ */
+class ParentRoleHelper
+{
+    protected RoleHierarchyInterface $roleHierarchy;
+
+    /**
+     * The role in a hierarchy, given by the parameter
+     * `security.role_hierarchy.roles` from the container.
+     *
+     * @var string[]
+     */
+    protected array $hierarchy;
+
+    public function __construct(
+        RoleHierarchyInterface $roleHierarchy,
+        ParameterBagInterface $parameterBag
+    ) {
+        $this->roleHierarchy = $roleHierarchy;
+        $this->hierarchy     = $parameterBag->get('security.role_hierarchy.roles');
+    }
+
+    /**
+     * Return all the role which give access to the given role. Only the role
+     * which are registered into Chill are taken into account.
+     *
+     * @param string $role
+     * @return string[] the role which give access to the given $role
+     */
+    public function getParentRoles(string $role): array
+    {
+        $parentRoles = [];
+        // transform the roles from role hierarchy from string to Role
+        $roles = \array_keys($this->hierarchy);
+
+        foreach ($roles as $r) {
+            $childRoles = $this->roleHierarchy->getReachableRoleNames([$r]);
+
+            if (\in_array($role, $childRoles)) {
+                $parentRoles[] = $r;
+            }
+        }
+
+        return $parentRoles;
+    }
+
+    /**
+     * Test if a parent role may give access to a given child role
+     *
+     * @param string $childRole The role we want to test if he is reachable
+     * @param string $parentRole The role which should give access to $childRole
+     * @return bool true if the child role is granted by parent role
+     */
+    public function isRoleReached($childRole, $parentRole): bool
+    {
+        $reachableRoles = $this->roleHierarchy
+            ->getReachableRoleNames([$parentRole]);
+
+        return in_array($childRole, $reachableRoles);
+    }
+
+}