Add admin-only email: gambit to look up users by email

src/Core/Search/SearchServiceProvider.php

@@ -40,7 +40,9 @@ class SearchServiceProvider extends AbstractServiceProvider
             ->needs('Flarum\Core\Search\GambitManager')
             ->give(function (Container $app) {
                 $gambits = new GambitManager($app);
-                $gambits->setFulltextGambit('Flarum\Core\Search\User\Gambits\FulltextGambit');
+
+                $gambits->setFulltextGambit('Flarum\Core\Search\User\Gambit\FulltextGambit');
+                $gambits->add('Flarum\Core\Search\User\Gambit\EmailGambit');
 
                 $app->make('events')->fire(
                     new ConfigureUserGambits($gambits)

src/Core/Search/User/Gambit/EmailGambit.php

@@ -0,0 +1,66 @@
+<?php
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Core\Search\User\Gambit;
+
+use Flarum\Core\Search\User\UserSearch;
+use Flarum\Core\Repository\UserRepository;
+use Flarum\Core\Search\AbstractRegexGambit;
+use Flarum\Core\Search\AbstractSearch;
+use LogicException;
+
+class EmailGambit extends AbstractRegexGambit
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected $pattern = 'email:(.+)';
+
+    /**
+     * @var UserRepository
+     */
+    protected $users;
+
+    /**
+     * @param \Flarum\Core\Repository\UserRepository $users
+     */
+    public function __construct(UserRepository $users)
+    {
+        $this->users = $users;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function apply(AbstractSearch $search, $bit)
+    {
+        if (! $search->getActor()->isAdmin()) {
+            return false;
+        }
+
+        return parent::apply($search, $bit);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function conditions(AbstractSearch $search, array $matches, $negate)
+    {
+        if (! $search instanceof UserSearch) {
+            throw new LogicException('This gambit can only be applied on a UserSearch');
+        }
+
+        $email = trim($matches[1], '"');
+
+        $user = $this->users->findByEmail($email);
+
+        $search->getQuery()->where('id', $negate ? '!=' : '=', $user->id);
+    }
+}

src/Core/Search/User/Gambit/FulltextGambit.php

@@ -8,7 +8,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Flarum\Core\Search\User\Gambits;
+namespace Flarum\Core\Search\User\Gambit;
 
 use Flarum\Core\Repository\UserRepository;
 use Flarum\Core\Search\AbstractSearch;