Add a "top tag" section in Communities

app/widgets/Communities/Communities.php

@@ -4,6 +4,7 @@ use Movim\Widget\Base;
 
 use Respect\Validation\Validator;
 use App\Configuration;
+use Carbon\Carbon;
 
 include_once WIDGETS_PATH . 'Post/Post.php';
 
@@ -28,11 +29,27 @@ class Communities extends Base
             ->restrictNSFW()
             ->recents()
             ->orderBy('posts.published', 'desc')
-            ->where('open', true)
-            ->take(30)
-            ->get();
+            ->where('open', true);
 
-        $view->assign('posts', $posts);
+        $postsIds = $posts->take(200)->pluck('id')->toArray();
+
+        $tags = \App\Tag::whereIn('id', function ($query) use ($postsIds) {
+            $query->select('tag_id')
+                  ->fromSub(function ($query) use ($postsIds) {
+                      $query->selectRaw('tag_id, count(tag_id) as count')
+                            ->fromSub(function ($query) use ($postsIds) {
+                                $query->from('post_tag')
+                                      ->whereIn('post_id', $postsIds)
+                                      ->get();
+                            }, 'last_month')
+                            ->groupBy('tag_id')
+                            ->orderBy('count', 'desc')
+                            ->take(20);
+                  }, 'top');
+        })->get();
+
+        $view->assign('tags', $tags);
+        $view->assign('posts', $posts->take(30)->get());
         $view->assign('communities', $this->user->session->interestingCommunities()
             ->take(6)
             ->get());

app/widgets/Communities/_communities.tpl

@@ -1,3 +1,15 @@
+{if="$tags->isNotEmpty()"}
+    <ul class="list">
+        <li>
+            <p class="line normal">
+                {loop="$tags"}
+                    <a class="button flat narrow" href="{$c->route('tag', $value->name)}">#{$value->name}</a>
+                {/loop}
+            </p>
+        </li>
+    </ul>
+{/if}
+
 {if="!$communities->isEmpty()"}
 <ul class="list middle flex third active all">
     <li class="subheader block large">