nihonbuzz-academy/app/Http/Controllers/CertificateController.php

<?php

namespace App\Http\Controllers;

use App\Models\Course;
use App\Models\UserProgress;
use Illuminate\Http\Request;
use Inertia\Inertia;
use Barryvdh\DomPDF\Facade\Pdf; // Optional if we want PDF download, for now just view

class CertificateController extends Controller
{
    public function show(Request $request, string $courseSlug)
    {
        $user = $request->user();
        $course = Course::where('slug', $courseSlug)->withCount('lessons')->firstOrFail();

        // Check if course is fully completed
        // Count completed lessons vs total lessons
        $completedCount = UserProgress::where('user_id', $user->id)
            ->whereIn('lesson_id', $course->lessons()->pluck('id'))
            ->whereNotNull('completed_at')
            ->count();

        $totalLessons = $course->lessons_count ?? 0;
        $progress = ($totalLessons > 0) ? ($completedCount / $totalLessons) * 100 : 0;

        // Strict check: Must be 100% complete
        if ($progress < 100) {
             return redirect()->route('courses.index')->with('error', 'Selesaikan semua materi untuk klaim sertifikat.');
        }

        return Inertia::render('Certificates/Show', [
            'course' => $course,
            'student' => $user,
            'date' => now()->translatedFormat('d F Y'),
            'certificate_id' => 'NB-' . strtoupper(substr($course->slug, 0, 3)) . '-' . $user->id . '-' . date('ymd'),
        ]);
    }
}