Initial SS4 upgrade work

.gitignore

@@ -0,0 +1 @@
+/.idea/

_config/config.yml

@@ -1,13 +1,22 @@
 ---
 Name: masqueradeconfig
 ---
-Member:
+SilverStripe\Admin\SecurityAdmin:
   extensions:
-    - MasqueradeMemberExtension
-SecurityAdmin:
+    - DHensby\SilverStripeMasquerade\Extensions\SecurityAdminExtension
+SilverStripe\Security\Member:
   extensions:
-    - MasqueradeSecurityAdminExtension
-LeftAndMain:
-  extra_requirements_css:
-    masquerade/css/masquerade.css:
-      media: screen
+    - DHensby\SilverStripeMasquerade\Extensions\MemberExtension
+---
+Name: masquerademiddleware
+After:
+  - '#coresecurity'
+---
+SilverStripe\Core\Injector\Injector:
+  SilverStripe\Control\Director:
+    properties:
+      Middlewares:
+        MasqueradeMiddleware: '%$DHensby\SilverStripeMasquerade\Control\MasqueradeMiddleware'
+SilverStripe\Security\MemberAuthenticator\LogoutHandler:
+  extensions:
+    - DHensby\SilverStripeMasquerade\Extensions\LogoutHandlerExtension

composer.json

@@ -1,13 +1,17 @@
 {
     "name": "dhensby/silverstripe-masquerade",
     "description": "SilverStripe module to allow you to masquerade as other users",
-    "type": "silverstripe-module",
+    "type": "silverstripe-vendormodule",
     "require": {
-        "php": "^5.3.3 || ^7",
-        "silverstripe/framework": "^3.1.0"
+        "silverstripe/framework": "^4"
     },
     "require-dev": {
-        "phpunit/phpunit": "^3 || ^4 || ^5"
+        "phpunit/phpunit": "^5.7"
+    },
+    "autoload": {
+        "psr-4": {
+            "DHensby\\SilverStripeMasquerade\\": "src/"
+        }
     },
     "license": "ISC",
     "authors": [
@@ -18,9 +22,8 @@
     ],
     "extra": {
         "branch-alias": {
-            "master-dev": "0.x-dev"
-        },
-        "installer-name": "masquerade"
+            "dev-master": "1.x-dev"
+        }
     },
     "prefer-stable": true,
     "minimum-stability": "dev"

src/Control/MasqueradeMiddleware.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace DHensby\SilverStripeMasquerade\Control;
+
+use SilverStripe\Control\HTTPRequest;
+use SilverStripe\Control\Middleware\HTTPMiddleware;
+use SilverStripe\Security\Member;
+use SilverStripe\Security\Security;
+
+class MasqueradeMiddleware implements HTTPMiddleware
+{
+    public function process(HTTPRequest $request, callable $delegate)
+    {
+        $session = $request->getSession();
+        if ($session->isStarted() && $id = $session->get('masqueradingAs')) {
+            $member = Member::get()->byID($id);
+            if ($member) {
+                Security::setCurrentUser($member);
+            }
+        }
+
+        return $delegate($request);
+    }
+}

src/Extensions/LogoutHandlerExtension.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace DHensby\SilverStripeMasquerade\Extensions;
+
+use SilverStripe\Control\Controller;
+use SilverStripe\Control\Director;
+use SilverStripe\Control\HTTPRequest;
+use SilverStripe\Control\HTTPResponse;
+use SilverStripe\Core\Extension;
+use SilverStripe\Security\Security;
+
+class LogoutHandlerExtension extends Extension
+{
+    public function beforeLogout()
+    {
+        /** @var HTTPRequest $request */
+        $request = $this->owner->getRequest();
+        $session = $request->getSession();
+
+        // If we're currently masquerading, we only want to stop masquerading, not *actually* log out
+        if ($session->get('masqueradingAs')) {
+            $session->clear('masqueradingAs');
+            $session->save($request);
+            $response = $this->redirectAfterLogout();
+            $response->output();
+            exit;
+        }
+    }
+
+    /**
+     * Copied verbatim from LogoutHandler::redirectAfterLogout()
+     *
+     * @return HTTPResponse
+     */
+    protected function redirectAfterLogout()
+    {
+        $backURL = $this->owner->getBackURL();
+        if ($backURL) {
+            return $this->owner->redirect($backURL);
+        }
+
+        $link = Security::config()->get('login_url');
+        $referer = $this->owner->getReturnReferer();
+        if ($referer) {
+            $link = Controller::join_links($link, '?' . http_build_query([
+                'BackURL' => Director::makeRelative($referer)
+            ]));
+        }
+
+        return $this->owner->redirect($link);
+    }
+}