feat: enhance leadership management by adding role assignment and revocation for lecturers

app/Services/Admin/Master/DepartmentService.php

@@ -4,6 +4,7 @@
 
 use App\Models\Department;
 use App\Models\DepartmentLeadership;
+use App\Models\Lecturer;
 use Illuminate\Contracts\Pagination\LengthAwarePaginator;
 use Illuminate\Database\Eloquent\Collection;
 
@@ -57,23 +58,53 @@ private function syncLeadership(Department $department, ?int $lecturerId, ?strin
             ->first();
 
         if (! $lecturerId) {
-            $currentLeader?->update(['ended_at' => now()]);
+            if ($currentLeader) {
+                $currentLeader->update(['ended_at' => now()]);
+                $this->revokeKaprodiRoleIfNoLongerLeading($currentLeader->lecturer_id);
+            }
 
             return;
         }
 
         if ($currentLeader && $currentLeader->lecturer_id === $lecturerId) {
             $currentLeader->update(['started_at' => $startedAt ?? $currentLeader->started_at]);
+            $this->grantKaprodiRole($lecturerId);
 
             return;
         }
 
-        $currentLeader?->update(['ended_at' => now()]);
+        if ($currentLeader) {
+            $currentLeader->update(['ended_at' => now()]);
+            $this->revokeKaprodiRoleIfNoLongerLeading($currentLeader->lecturer_id);
+        }
 
         $department->leaderships()->create([
             'lecturer_id' => $lecturerId,
             'started_at' => $startedAt ?? now(),
         ]);
+
+        $this->grantKaprodiRole($lecturerId);
+    }
+
+    private function grantKaprodiRole(int $lecturerId): void
+    {
+        $user = Lecturer::find($lecturerId)?->user;
+
+        if ($user && ! $user->hasRole('kaprodi')) {
+            $user->assignRole('kaprodi');
+        }
+    }
+
+    private function revokeKaprodiRoleIfNoLongerLeading(int $lecturerId): void
+    {
+        $stillLeadsAnyDepartment = DepartmentLeadership::query()
+            ->where('lecturer_id', $lecturerId)
+            ->whereNull('ended_at')
+            ->exists();
+
+        if (! $stillLeadsAnyDepartment) {
+            Lecturer::find($lecturerId)?->user?->removeRole('kaprodi');
+        }
     }
 
     public function delete(Department $department): bool