takeone-youtube-clone/app/Models/Comment.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Comment extends Model
{
    protected $fillable = [
        'video_id',
        'user_id',
        'parent_id',
        'body',
    ];

    // Relationships
    public function video()
    {
        return $this->belongsTo(Video::class);
    }

    public function user()
    {
        return $this->belongsTo(User::class);
    }

    public function parent()
    {
        return $this->belongsTo(Comment::class, 'parent_id');
    }

    public function replies()
    {
        return $this->hasMany(Comment::class, 'parent_id')->latest();
    }

    public function likes()
    {
        return $this->hasMany(CommentLike::class);
    }

    // Get mentioned users from comment body
    public function getMentionedUsers()
    {
        preg_match_all('/@(\w+)/', $this->body, $matches);
        if (empty($matches[1])) {
            return collect();
        }
        return User::whereIn('username', $matches[1])->get();
    }

    // Parse mentions and make them clickable
    public function getParsedBodyAttribute()
    {
        $body = e($this->body);
        $body = preg_replace('/@(\w+)/', '<a href="/channel/$1" class="user-mention">@$1</a>', $body);
        return $body;
    }
}