CourseWork/app/Services/FileService.php

<?php

namespace App\Services;

use App\Models\Grade;
use Barryvdh\DomPDF\Facade\Pdf;
use Illuminate\Support\Facades\Auth;

class FileService
{
    public function exportSubjects()
    {
        $listSubjects = collect();
        $student = Auth::user()->userable;
        $subjects = $student->grade->subjects;
        $teachers = $student->grade->teachers;

        $teachers->each(function ($teacher) use ($subjects, $listSubjects) {
            $teacher->subjects->each(function ($subject) use ($subjects, $listSubjects, $teacher) {
                if ($subjects->contains($subject)) {
                    $listSubjects->push(['subject' => $subject->name, 'teacher' => $teacher->fio]);
                }
            });
        });

        return Pdf::loadView('subjects.pdf', ['subjects' => $listSubjects])->download('Предметы.pdf');
    }

    public function exportStudents(Grade $grade)
    {
        $excellentStudents = $this->getMinScore($grade, 5);
        $goodStudents = $this->getMinScore($grade, 4);

        return Pdf::loadView('grades.list-students', [
            'excellentStudents' => $excellentStudents,
            'goodStudents' => $goodStudents,
        ])->download('Студенты.pdf');
    }

    public function getMinScore(Grade $grade, $minScore)
    {
        return $grade->students->filter(function ($student) use ($minScore) {
            return $student->lessons->min('pivot.score') == $minScore;
        });
    }

}