add controllers, servoices

app/Services/ClassPreparation/ClassPreparationContextService.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Services\ClassPreparation;
+
+use App\Models\Configuration;
+use Illuminate\Support\Facades\DB;
+
+class ClassPreparationContextService
+{
+    /** cache for roster presence per term */
+    private array $rosterPresenceCache = [];
+
+    public function getSchoolYear(): string
+    {
+        return (string) (Configuration::getConfig('school_year') ?? '');
+    }
+
+    public function getSemester(): string
+    {
+        return (string) (Configuration::getConfig('semester') ?? '');
+    }
+
+    public function hasRosterForSemester(string $schoolYear, string $semester): bool
+    {
+        $year = trim((string) $schoolYear);
+        $sem = trim((string) $semester);
+        if ($year === '' || $sem === '') {
+            return false;
+        }
+
+        $key = sprintf('sem:%s:%s', $year, $sem);
+        if (array_key_exists($key, $this->rosterPresenceCache)) {
+            return $this->rosterPresenceCache[$key];
+        }
+
+        $cnt = DB::table('student_class')
+            ->where('school_year', $year)
+            ->where('semester', $sem)
+            ->count();
+
+        $this->rosterPresenceCache[$key] = $cnt > 0;
+        return $this->rosterPresenceCache[$key];
+    }
+}