first commit

app/Http/Controllers/CommentController.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\Document;
+use App\Models\User;
+use Illuminate\Http\Request;
+
+class CommentController extends Controller
+{
+    public function store(Request $request, Document $document)
+    {
+        $comment = $document->comments()->create([
+            'user_id' => auth()->id(),
+            'content' => $request->content,
+            'parent_id' => $request->parent_id
+        ]);
+        
+        $this->processMentions($comment);
+        
+        return back();
+    }
+    
+    private function processMentions(Comment $comment)
+    {
+        preg_match_all('/@([\w\-]+)/', $comment->content, $matches);
+        
+        foreach ($matches[1] as $username) {
+            $user = User::where('username', $username)->first();
+            if ($user) {
+                $user->notify(new MentionNotification($comment));
+            }
+        }
+    }
+}