fix parent pages and teachers and admin

app/Models/TeacherClass.php

@@ -5,6 +5,7 @@ namespace App\Models;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
 
 class TeacherClass extends BaseModel
 {
@@ -162,6 +163,70 @@ class TeacherClass extends BaseModel
             ->all();
     }
 
+    /**
+     * Distinct section identifiers this teacher can access, expanded across legacy
+     * `classSection.id` PKs and `classSection.class_section_id` business codes.
+     *
+     * @return list<int>
+     */
+    public static function distinctAccessibleSectionIdsForTeacher(int $userId): array
+    {
+        $sectionIds = static::distinctSectionIdsForTeacher($userId);
+        if ($sectionIds === []) {
+            return [];
+        }
+
+        $expanded = [];
+
+        if (Schema::hasTable('classSection')) {
+            $codeRows = DB::table('classSection')
+                ->select('id', 'class_section_id')
+                ->whereIn('class_section_id', $sectionIds)
+                ->get();
+            $matchedRawIds = [];
+
+            foreach ($codeRows as $row) {
+                $matchedRawIds[(int) $row->class_section_id] = true;
+                foreach ([(int) $row->id, (int) $row->class_section_id] as $sectionId) {
+                    if ($sectionId > 0) {
+                        $expanded[$sectionId] = true;
+                    }
+                }
+            }
+
+            $unmatchedSectionIds = array_values(array_filter(
+                $sectionIds,
+                static fn (int $sectionId): bool => ! isset($matchedRawIds[$sectionId]),
+            ));
+
+            $pkRows = $unmatchedSectionIds === []
+                ? collect()
+                : DB::table('classSection')
+                    ->select('id', 'class_section_id')
+                    ->whereIn('id', $unmatchedSectionIds)
+                    ->get();
+
+            foreach ($pkRows as $row) {
+                foreach ([(int) $row->id, (int) $row->class_section_id] as $sectionId) {
+                    if ($sectionId > 0) {
+                        $expanded[$sectionId] = true;
+                    }
+                }
+            }
+        }
+
+        foreach ($sectionIds as $sectionId) {
+            if (! isset($expanded[(int) $sectionId])) {
+                $expanded[(int) $sectionId] = true;
+            }
+        }
+
+        $ids = array_map('intval', array_keys($expanded));
+        sort($ids);
+
+        return $ids;
+    }
+
     /** legacy: getClassSectionsByTeacherId() */
     public static function getClassSectionsByTeacherId(int $teacherId): array
     {