laravel iteration adding amount on parent - php

Question

I mean, I have a referral system which is every parent_id has parent and the parent_id of that parent until it gets to the last parent which is the Senior.
Given that a user has purchased an item and it is successful, now I am calling the insertEarnings function to insert the corresponding amount to his parent_id, if his parent_id is Junior his parent_id will get 100.
This is how the question begin, what if his parent doesn't have a rank meaning not active, the amount to be insert to his parent_id will go through the next rank which is the Premium so the Premium will no have 250 total, after that proceed the normal insertion of the amount to the parent_id of Premium which is the Advanced- he will get the corresponding amount which is 200, because the rank below him which is the Premium is existing, the insertion will go through until it gets to the last rank which is the Senior
Imagine that it is looping through the parent until it gets to the last rank - Senior.
The ranks are in order
Junior
Premium
Advanced
Senior
Ranks with their corresponding amount value
Junior - 100
Premium - 150
Advanced - 200
Senior - 250
Users table
+------+------------+-------------+------------+
| id | username | parent_id | rank |
+------+------------+-------------+------------+
| 1 | john | NULL | Senior |
| 2 | jane | 1 | Advanced |
| 3 | josh | 2 | Premium |
| 4 | joey | 3 | Junior |
| 5 | jade | 4 | Basic |
+----------------------------------------------+
Code
$user_id = 5; // jade
$parent_id = 4;
// call the function to insert the earnings
self::insertEarnings($user_id,$parent_id);
private function insertEarnings($user_id,$parent_id) {
if ($parent_id > 0) {
$user_parent = $parent_id;
$has_parent = true;
// start iteration
while($has_parent == true){
$account = User::where('id',$user_parent)->first();
$amount = 0;
if ($account->rank == "Junior" ) {
$amount = 100;
} elseif ($account->rank == "Premium") {
$amount = 150;
// for example this user/parent does not exist the amount(150) for him will be added to the next rank which is the Advance
} elseif ($account->rank == "Advanced") {
$amount = 200;
} elseif ($account->rank == "Senior") {
$amount = 250;
// set to false to stop the iteration
$has_parent = false;
}
$earnings = new Earnings;
$earnings->user_id = $account->id;
$earnings->amount = $amount;
$earnings->save();
$next_parent = User::where('id',$user_parent)->first();
$user_parent = $next_parent->parent_id;
if($user_parent == 0){
$has_parent = false;
}
}
}
}
The $user_id is not used in this example, but there's a use to that that didn't included in the question because that is not the main problem.