/**
  * Update the specified resource in storage.
  *
  * @param  \Illuminate\Http\Request  $request
  * @return \Illuminate\Http\Response
  */
 public function update(Request $request)
 {
     $video_id = $request['video_id'];
     $video = Video::find($video_id);
     $this->validate($request, ['title' => 'required|min:3', 'video-url' => 'required|min:3', 'description' => 'required|min:10', 'category' => 'required']);
     $haystacks = ['=', '/'];
     foreach ($haystacks as $haystack) {
         $video_url = substr(trim($request['video-url']), strrpos(trim($request['video-url']), $haystack, -1) + 1);
         if ($this->videoExist($video_url)) {
             $video->video_url = $video_url;
         }
     }
     $video->video_title = $request['title'];
     $video->video_category = $request['category'];
     $video->video_description = $request['description'];
     $video->save();
     return redirect()->back();
 }