CourseOpener.php

<?php

namespace App\Domain\Courses;

use App\Domain\Courses\Exam\ExamQuestion;
use App\Domain\Courses\Exam\ExamVersion;
use App\Exceptions\Courses\CourseCannotBeOpened;

class CourseOpener
{
    public function open(Course $course)
    {
        if($course->open)
        {
            throw new CourseCannotBeOpened('Course is open');
        }

        if(!$course->video_uploaded)
        {
            throw new CourseCannotBeOpened('Course should have video');
        }

        if($course->questions->count() < 3)
        {
            throw new CourseCannotBeOpened('Create at least 3 questions for the course exam before open it');
        }

        if($course->checklistItems->count() < 2)
        {
            throw new CourseCannotBeOpened('Create at least 2 checklist items for the course video exam before open it');
        }
        
        if($course->raters()->count() <= 0)
        {
	        throw new CourseCannotBeOpened('Assign at least 1 rater for this course');
        }

        if($this->shouldCreateNewExamVersion($course))
        {
            $course->exam_version_id = $this->createNewExamVersion($course)->id;
        }

        $course->open = true;
        $course->save();
    }
  
    //...
}