getCourseLessonByEnrollment.ts

async findOneByEnrollment({ accountId, userId, courseId, courseVersionId, lessonId }) {
    const [enrolment] = await this.knex('enrollments')
      .where({
        user_id: userId
      })
      .andWhere({
        account_id: accountId
      })
      .andWhere({
        course_id: courseId
      })
      .andWhere({
        course_version_id: courseVersionId
      });

    if (!enrolment) {
      throw new Error('No enrollment found');
    }

    if ((new Date(enrolment.start_date) > new Date())) {
      throw new Error('Enrollment not started');
    }

    if (enrolment.end_date && (new Date() > new Date(enrolment.end_date))) {
      throw new Error('Enrollment expired');
    }

    const [lesson] = await this.knex('course_lessons')
      .andWhere({
        account_id: accountId
      })
      .andWhere({
        course_id: courseId
      })
      .andWhere({
        course_version_id: courseVersionId
      })
      .andWhere({
        id: lessonId
      });

    if (lesson.status === 'draft') {
      throw new Error('Lesson not available');
    }

    return lesson;
  }