// ==================== GRADE LEVEL ROUTES ====================

    /**
     * List all subjects for a grade level
     *
     * @param GradeLevel $gradeLevel
     * @return JsonResponse
     */
    public function indexSubjects(GradeLevel $gradeLevel): JsonResponse
    {
        $subjects = $this->service->getSubjectsForGradeLevel($gradeLevel);

        return response()->json($subjects);
    }

    /**
     * Attach a subject to a grade level
     *
     * @param GradeLevel $gradeLevel
     * @param Request $request
     * @return JsonResponse
     */
    public function attachSubject(GradeLevel $gradeLevel, Request $request): JsonResponse
    {
        $validated = $request->validate([
            'subject_id' => 'required|uuid|exists:subject,id',
        ]);

        $this->service->attachSubject($gradeLevel, $validated['subject_id']);

        return response()->json(
            [
                'message' => 'Subject attached successfully',
                'grade_level_id' => $gradeLevel->id,
                'subject_id' => $validated['subject_id'],
            ],
            201
        );
    }

    /**
     * Detach a subject from a grade level
     *
     * @param GradeLevel $gradeLevel
     * @param string $subjectId
     * @return JsonResponse
     */
    public function detachSubject(GradeLevel $gradeLevel, string $subjectId): JsonResponse
    {
        $this->service->detachSubject($gradeLevel, $subjectId);

        return response()->json(
            [
                'message' => 'Subject detached successfully',
                'grade_level_id' => $gradeLevel->id,
                'subject_id' => $subjectId,
            ]
        );
    }

    /**
     * Attach multiple subjects at once
     *
     * @param GradeLevel $gradeLevel
     * @param Request $request
     * @return JsonResponse
     */
    public function attachMultipleSubjects(GradeLevel $gradeLevel, Request $request): JsonResponse
    {
        $validated = $request->validate([
            'subject_ids' => 'required|array|min:1',
            'subject_ids.*' => 'required|uuid|exists:subject,id',
        ]);

        $attached = $this->service->attachMultipleSubjects($gradeLevel, $validated['subject_ids']);

        return response()->json(
            [
                'message' => 'Subjects attached successfully',
                'grade_level_id' => $gradeLevel->id,
                'attached_count' => count($attached),
                'subject_ids' => $attached,
            ],
            201
        );
    }

    /**
     * Sync subjects (replace all with new list)
     *
     * @param GradeLevel $gradeLevel
     * @param Request $request
     * @return JsonResponse
     */
    public function syncSubjects(GradeLevel $gradeLevel, Request $request): JsonResponse
    {
        $validated = $request->validate([
            'subject_ids' => 'required|array',
            'subject_ids.*' => 'required|uuid|exists:subject,id',
        ]);

        $result = $this->service->syncSubjects($gradeLevel, $validated['subject_ids']);

        return response()->json(
            [
                'message' => 'Subjects synced successfully',
                'grade_level_id' => $gradeLevel->id,
                'attached' => $result['attached'],
                'detached' => $result['detached'],
                'updated' => $result['updated'],
            ]
        );
    }
}