enablePlan() public method

public enablePlan ( $plan, $credit )
 /**
  * @return \Illuminate\Http\RedirectResponse
  */
 public function changePlan()
 {
     $user = Auth::user();
     $account = $user->account;
     $company = $account->company;
     $plan = Input::get('plan');
     $term = Input::get('plan_term');
     $numUsers = Input::get('num_users');
     $planDetails = $account->getPlanDetails(false, false);
     $newPlan = ['plan' => $plan, 'term' => $term, 'num_users' => $numUsers];
     $newPlan['price'] = Utils::getPlanPrice($newPlan);
     $credit = 0;
     if (!empty($planDetails['started']) && $plan == PLAN_FREE) {
         // Downgrade
         $refund_deadline = clone $planDetails['started'];
         $refund_deadline->modify('+30 days');
         if ($plan == PLAN_FREE && $refund_deadline >= date_create()) {
             if ($payment = $account->company->payment) {
                 $ninjaAccount = $this->accountRepo->getNinjaAccount();
                 $paymentDriver = $ninjaAccount->paymentDriver();
                 $paymentDriver->refundPayment($payment);
                 Session::flash('message', trans('texts.plan_refunded'));
                 \Log::info("Refunded Plan Payment: {$account->name} - {$user->email}");
             } else {
                 Session::flash('message', trans('texts.updated_plan'));
             }
         }
     }
     if (!empty($planDetails['paid']) && $plan != PLAN_FREE) {
         $time_used = $planDetails['paid']->diff(date_create());
         $days_used = $time_used->days;
         if ($time_used->invert) {
             // They paid in advance
             $days_used *= -1;
         }
         $days_total = $planDetails['paid']->diff($planDetails['expires'])->days;
         $percent_used = $days_used / $days_total;
         $credit = $planDetails['plan_price'] * (1 - $percent_used);
     }
     if ($newPlan['price'] > $credit) {
         $invitation = $this->accountRepo->enablePlan($newPlan, $credit);
         return Redirect::to('view/' . $invitation->invitation_key);
     } else {
         if ($plan != PLAN_FREE) {
             $company->plan_term = $term;
             $company->plan_price = $newPlan['price'];
             $company->num_users = $numUsers;
             $company->plan_expires = date_create()->modify($term == PLAN_TERM_MONTHLY ? '+1 month' : '+1 year')->format('Y-m-d');
         }
         $company->plan = $plan;
         $company->save();
         return Redirect::to('settings/account_management');
     }
 }