PHP / Stripe payment

stripe-intent.php

<?php
// uses "stripe/stripe-php": "6.37.0",
// this is in the body of an API controller function that my stripe form posts to
// frontend uses https://js.stripe.com/v3/
// **the js posts a body with `payment_method_id` or `payment_intent_id` depending on the step of the process**
// this is captured as a property of $input


function the_post_method()
{
  $input = $this->getInput(); // gets the input JSON and converts to an object
  $stripe_settings = $this->config->item('stripe_settings');
  $secret_key = ($stripe_settings->mode === STRIPE_MODE_LIVE) ? $stripe_settings->live_secret_key : $stripe_settings->test_secret_key;

  \Stripe\Stripe::setApiKey($secret_key);

  try {
    $statementDescriptor = 'ACME temp descriptor 123';
  
  if(isset($input->payment_method_id))
  {
    $intent = \Stripe\PaymentIntent::create([
      'payment_method' => $input->payment_method_id,
      'amount' => round($orderData['grand_total'] * 100), // amount in pence 
      'currency' => 'gbp',
      'confirmation_method' => 'manual',
      'confirm' => true, //Set to true to attempt to confirm this PaymentIntent immediately
      'statement_descriptor' => $statementDescriptor    // add order number (need to get next order # first)
    ]);
  }

  if(isset($input->payment_intent_id))
  {
    $intent = \Stripe\PaymentIntent::retrieve($input->payment_intent_id);
    $intent->confirm(); 
    
    $invoice_id = '123';
    \Stripe\PaymentIntent::update(
      $input->payment_intent_id,
      ['metadata' => ['invoice_number' => 'INVOICE '.$invoice_id]]
    );
    
  }

  $this->return_success_output_json($orderNumber, $orderData, $approval_user_id, $intent);
   
  } catch (\Stripe\Error\Base $e) {
    return $this->fail('The payment failed: ' . $e->getMessage(), 500);
  }
  
}