Using Stripe PHP API to create functions with meaningful outputs and using them in controller

ci_stripe_helper.php

<?php

# Sachethana Pathirage
# git clone https://github.com/stripe/stripe-php into helpers folder
# load the function using $this->load->helper('ci_stripe_helper');
# tested on CodeIgniter V3.0.0

include("stripe-php-master/init.php");

$stripe = array(
    "secret_key" => "sk_test_XXX",
    "publishable_key" => "pk_test_XXX"
);

\Stripe\Stripe::setApiKey($stripe['secret_key']);

function stripe2_createCustomer($email, $token, $plan)
{
    return $customer = \Stripe\Customer::create(array(
        'email' => $email,
        'card' => $token,
        'plan' => $plan
    ));
}

function stripe2_getCustomer($customer_id)
{
    return \Stripe\Customer::retrieve($customer_id);
}

function stripe2_isAccountActive($customer_id)
{
    $customer = stripe2_getCustomer($customer_id);
    if (isset($customer['subscriptions']['data'][0]['ended_at'])) {
        if ($customer['subscriptions']['data'][0]['ended_at'] == null) {
            return true;
        }
    }
    return false;
}

function stripe2_addCard($customer_id, $token)
{
    $customer = \Stripe\Customer::retrieve($customer_id);
    return $customer->sources->create(array(
        "source" => $token
    ));
}

function stripe2_removeCard($customer_id, $token)
{
    $customer = \Stripe\Customer::retrieve($customer_id);
    return $customer->sources->retrieve($token)->delete();
}

function stripe2_changeplan($customer_id, $plan, $subscription_id)
{
    $subscription = \Stripe\Subscription::retrieve($subscription_id);
    $itemID       = $subscription->items->data[0]->id;
    return \Stripe\Subscription::update($subscription_id, array(
        "items" => array(
            array(
                "id" => $itemID,
                "plan" => $plan
            )
        )
    ));
    
}

//cancel subscription
function stripe2_unsubscribe($customer_id, $subscription_id)
{
    $at_period_end = TRUE;
    $sub           = \Stripe\Subscription::retrieve($subscription_id);
    return $sub->cancel(array(
        'at_period_end' => $at_period_end
    ));
}

?>

Example.php

<?
require(APPPATH.'/libraries/REST_Controller.php');
# Example controller
class Example extends REST_Controller{
	function __construct() {
        parent::__construct();
        $this->load->model('Security_model');
        $this->load->model('Accounts_model');
        $this->load->helper('string');
        $this->load->helper('ci_stripe_helper');
    }

    # Example GET method
    public function heartbeat_get(){
        $token = $this->input->get_request_header('Token', TRUE);
        $username = strtolower($this->input->get_request_header('Username', TRUE));
        $session = $this->Security_model->validate_session($token);
        if($session != FALSE && $username){
            $user_to_login = $this->Account_model->get_user($Username);
            if($user_to_login==FALSE){
                $this->response(array(
                    "Message"=>"We can't find your account. Please login again.",
                    "Action"=>"logout",
                    "Status"=>false,
                    "Timestamp" => date('m-d-Y H:i:s')
                ));
                exit;
            }
            if($user_to_login['Active'] != 1){
                $this->response(array(
                    "Message"=>"Your AppName account is not active.",
                    "Action"=>"logout",
                    "Status"=>false,
                    "Timestamp" => date('m-d-Y H:i:s')); 
                exit;
            }
            if(isset($user_to_login['stripe_user'])){
                //stripe handles it's own errors :)
                $this->response(array(
                    "Status"=>true,
                    "Active"=>stripe2_isAccountActive($user_to_login['stripe_user']),
                    "Timestamp" => date('m-d-Y H:i:s'))); 
            }else{
                $this->response(
                    array(
                        "Message"=>"You haven't subscribed to any plans in AppName. Please login again to select a plan.",
                        "Action"=>"subscribe",
                        "Status"=>false,
                        "Timestamp" => date('m-d-Y H:i:s')
                    ));
            }
        }else{
            $this->response(array(
                "Message"=>"Your session has expired. You need to login again",
                "Action"=>"logout",
                "Status"=>false,
                "Timestamp" => date('m-d-Y H:i:s'));
        }
    }
}
?>