feat: add API route for getting a single internship

backend/app/Http/Controllers/InternshipController.php

@@ -65,6 +65,33 @@ class InternshipController extends Controller
         return response()->json($internships);
     }
 
+    public function get(int $id) {
+        $user = auth()->user();
+
+        $internship = Internship::find($id);
+        
+        if(!$internship) {
+            return response()->json([
+                'message' => 'No such internship exists.'
+            ], 400);
+        }
+
+        if ($user->role !== 'ADMIN' && $internship->user_id !== $user->id) {
+            abort(403, 'Unauthorized');
+        }
+
+        $internship->company = Company::find($internship->company_id)->makeHidden(['created_at', 'updated_at']);
+        unset($internship->company_id);
+
+        $internship->contact = User::find($internship->company->contact)->makeHidden(['created_at', 'updated_at', 'email_verified_at']);
+        unset($internship->company->contact);
+        
+        $internship->status = InternshipStatus::whereColumn('internship_id', '=', $internship->id)->get()->first()->makeHidden(['created_at', 'updated_at', 'id']);
+        $internship->status->modified_by = User::find($internship->status->modified_by)->makeHidden(['created_at', 'updated_at', 'email_verified_at']);
+
+        return response()->json($internship);
+    }
+
     /**
      * Display a listing of the resource.
      */