BookStack/app/Actions/CommentRepo.php

<?php namespace BookStack\Actions;

use BookStack\Entities\Entity;
use League\CommonMark\CommonMarkConverter;

/**
 * Class CommentRepo
 */
class CommentRepo
{

    /**
     * @var Comment $comment
     */
    protected $comment;


    public function __construct(Comment $comment)
    {
        $this->comment = $comment;
    }

    /**
     * Get a comment by ID.
     */
    public function getById(int $id): Comment
    {
        return $this->comment->newQuery()->findOrFail($id);
    }

    /**
     * Create a new comment on an entity.
     */
    public function create(Entity $entity, string $text, ?int $parent_id): Comment
    {
        $userId = user()->id;
        $comment = $this->comment->newInstance();

        $comment->text = $text;
        $comment->html = $this->commentToHtml($text);
        $comment->created_by = $userId;
        $comment->updated_by = $userId;
        $comment->local_id = $this->getNextLocalId($entity);
        $comment->parent_id = $parent_id;

        $entity->comments()->save($comment);
        return $comment;
    }

    /**
     * Update an existing comment.
     */
    public function update(Comment $comment, string $text): Comment
    {
        $comment->updated_by = user()->id;
        $comment->text = $text;
        $comment->html = $this->commentToHtml($text);
        $comment->save();
        return $comment;
    }

    /**
     * Delete a comment from the system.
     */
    public function delete(Comment $comment)
    {
        $comment->delete();
    }

    /**
     * Convert the given comment markdown text to HTML.
     */
    public function commentToHtml(string $commentText): string
    {
        $converter = new CommonMarkConverter([
            'html_input' => 'strip',
            'max_nesting_level' => 10,
            'allow_unsafe_links' => false,
        ]);

        return $converter->convertToHtml($commentText);
    }

    /**
     * Get the next local ID relative to the linked entity.
     */
    protected function getNextLocalId(Entity $entity): int
    {
        $comments = $entity->comments(false)->orderBy('local_id', 'desc')->first();
        return ($comments->local_id ?? 0) + 1;
    }
}