feat: add external API for updating internship status to DEFENDED

backend/app/Http/Controllers/ExternalApiController.php

@@ -2,9 +2,14 @@
 
 namespace App\Http\Controllers;
 
+use App\Enums\InternshipStatus;
+use App\Mail\InternshipStatusUpdated;
+use App\Models\Internship;
+use App\Models\InternshipStatusData;
 use App\Models\User;
 use Illuminate\Http\Request;
 use Laravel\Sanctum\Sanctum;
+use Mail;
 
 class ExternalApiController extends Controller
 {
@@ -48,8 +53,50 @@ class ExternalApiController extends Controller
         return response()->noContent();
     }
 
-    public function update_internship_status(int $id)
+    public function update_internship_status(Request $request, $id)
     {
-        // TODO: Implement in SCRUM-65
+        $user = $request->user();
+        $internship = Internship::find($id);
+
+        if (!$internship) {
+            return response()->json([
+                'message' => 'No such internship exists.'
+            ], 400);
+        }
+
+        $currentStatus = $internship->status->status;
+
+        $request->validate([
+            'status' => ['required', 'string', 'uppercase', 'in:DEFENDED,NOT_DEFENDED'],
+            'note' => ['required', 'string', 'min:1']
+        ]);
+
+        if ($currentStatus !== InternshipStatus::CONFIRMED_BY_ADMIN) {
+            return response()->json([
+                "error" => "Expected current status to be 'CONFIRMED_BY_ADMIN', but it was '$currentStatus->value' instead",
+            ], 422);
+        }
+
+        $newStatus = InternshipStatusData::make([
+            'internship_id' => $id,
+            'status' => $request->status,
+            'note' => $request->note,
+            'changed' => now(),
+            'modified_by' => $user->id,
+        ]);
+
+        Mail::to($internship->student)
+            ->sendNow(new InternshipStatusUpdated(
+                $internship,
+                $user->name,
+                $internship->student->name,
+                $internship->company->name,
+                $currentStatus,
+                $request->enum('status', InternshipStatus::class),
+                $request->note
+            ));
+
+        $newStatus->save();
+        return response()->noContent();
     }
 }