mint/api-v13/app/Http/Api/CourseApi.php

<?php

namespace App\Http\Api;

use App\Models\CourseMember;

class CourseApi
{
    public static function getStudentChannels($courseId)
    {
        $channels = [];
        $studentsChannel = CourseMember::where('course_id', $courseId)
            ->whereNotNull('channel_id')
            ->where('role', 'student')
            ->whereIn('status', ['joined', 'accepted', 'agreed'])
            ->select('channel_id')
            ->orderBy('created_at')
            ->get();
        foreach ($studentsChannel as $key => $channel) {
            $channels[] = $channel->channel_id;
        }

        return $channels;
    }

    public static function role($courseId, $userUid)
    {
        $role = CourseMember::where('course_id', $courseId)
            ->where('user_id', $userUid)
            ->where('is_current', true)
            ->value('role');

        return $role;
    }
}