payment_init_php

<?php
// Include the configuration file
// require_once 'config.php';
// Include database connection file
include_once '../db_connection.php';
// Include the Stripe PHP library
require_once '../vendor/stripe/stripe-php/init.php'
// Set API key
\Stripe\Stripe::setApiKey(STRIPE_SECRET_API_KEY);
// Retrieve JSON from POST body
$jsonStr = file_get_contents('php://input');
$jsonObj = json_decode($jsonStr);
// Get user ID fron current SESSION
$userID = isset($_SESSION['loggedInUserID'])?$_SESSION['loggedInUserID']:0;

if ($jsonObj->request_type == 'create_customer_subscription') {
  $subscr_plan_id = !empty($jsonObj->subscr_plan_id)?$jsonObj->subscr_plan_id:'';
  $name = !empty($jsonObj->name)?$jsonObj->name:'';
  $email = !empty($jsonObj->email)?$jsonObj->email:'';

  // Fetch plan details fron the database
  $sqlQ = "SELECT `name`, `price`, `interval` FROM plans WHERE id=?";
  $stmt = $con->prepare($sqlQ);
  $stmt->bind_param("i", $subscr_plan_id);
  $stmt->execute();
  $stmt->bind_result($planName, $planPrice, $planInterval);
  $stmt->fetch();

  // Convert price to cents
  $planPriceCents = round($planPrice*100);

  // Add customer to Stripe
  try {
    $customer = \Stripe\Customer::create([
      'name' => $name,
      'email' => $email
    ]);
  } catch ( Exception $e ) {
    $api_error = $e->getMessage();
  }

  if (empty($api_error) && $customer) {
    // Create price with subscription info and interval
    try {
      $price = \Stripe\Price::create([
        'unit_amount' => $planPriceCents,
        'currency' => STRIPE_CURRENCY,
        'recurring' => ['interval' => $planInterval],
        'product_data' => ['name' => $planName],
      ]);
    } catch ( Exception $e ) {
      $api_error = $e->getMessage();
    }
    if (empty($api_error) && $price) {
      // Create a new subscription
      try {
        $subscription = \Stripe\Customer::create([
          'customer' => $customer->id,
          'items' => [[
              'price' => $price->id
            ]],
            'payment_behavior' => 'default_incomplete',
            'expand' => ['latest_invoice.payment_intent'],
        ]);
      } catch ( Exception $e ) {
        $api_error = $e->getMessage();
      }
      if (empty($api_error) && $subscription) {
        $output = [
          'subscriptionId' => $subscription->id,
          'clientSecret' => $subscription->latest_invoice->payment_intent->client_secret,
          'customerId' => $customer->id
        ];
        echo json_encode($output);
      }else{
        echo json_encode(['error' => $api_error]);
      }
    }else{
      echo json_encode(['error' => $api_error]);
    }
  }else{
    echo json_encode(['error' => $api_error]);
  }

}elseif ($jsonObj->request_type == 'payment_insert') {
  $payment_intent = !empty($jsonObj->payment_intent)?$jsonObj->payment_intent:'';
  $subscription_id = !empty($jsonObj->subscription_id)?$jsonObj->subscription_id:'';
  $customer_id = !empty($jsonObj->customer_id)?$jsonObj->customer_id:'';
  $subscr_plan_id = !empty($jsonObj->subscr_plan_id)?$jsonObj->subscr_plan_id:'';
  // Fetch plan details from the database
  $sqlQ = "SELECT `interval` FROM plans WHERE id=?";
  $stmt = $con->prepare($sqlQ);
  $stmt->bind_param("i", $subscr_plan_id);
  $stmt->execute();
  $stmt->bind_result($interval);
  $stmt->fetch();
  $planInterval = $interval;
  $stmt->close();
  // Retrieve customer info
  try {
    $customer = \Stripe\Customer::retrieve($customer_id);
  } catch ( Exception $e) {
    $api_error = $e->getMessage();
  }
  // Check whether the charge was successful
  if (!empty($payment_intent) && $payment_intent->status == 'succeeded') {
    // Retrieve subscription info
    try {
      $subscriptionData = \Stripe\Customer::retrieve($subscription_id);
    } catch ( Exception $e) {
      $api_error = $e->getMessage();
    }
    $payment_intent_id = $payment_intent->id;
    $paidAmount = $payment_intent->amount;
    $paidAmount = ($paidAmount/100);
    $paidCurrency = $payment_intent->currency;
    $payment_status = $payment_intent->status;

    $created = date("Y-m-d H:i:s", $payment_intent->created);
    $current_period_start = $current_period_end = '';
    if (!empty($subscriptionData)) {
      $created = date("Y-m-d H:i:s", $subscriptionData->created);
      $current_period_start = date("Y-m-d H:i:s", $subscriptionData->$current_period_start);
      $current_period_end = date("Y-m-d H:i:s", $subscriptionData->$current_period_end);
    }

    $customer_name = $customer_email ='';
    if (!empty($customer)) {
      $customer_name = !empty($customer->name)?$customer->name:'';
      $customer_email = !empty($customer->email)?$customer->email:'';

      if (!empty($customer_name)) {
        $name_arr = explode('', $customer_name);
        $first_name = !empty($name_arr[0])?$name_arr[0]:'';
        $last_name = !empty($name_arr[1])?$name_arr[1]:'';
      }
      // Insert user details if no exists in the DB users table
      if (empty($userID)) {
        $sqlQ = "INSERT INTO users (first_name, last_name, email) VALUES (?,?,?)";
        $stmt = $con->prepare($sqlQ);
        $stmt->bind_param("sss", $first_name, $last_name, $customer_email);
        $insertUser = $stmt->execute();

        if ($insertUser) {
          $userID = $stmt->insert_id;
        }
      }
    }
    // Check if any transaction  data exists already with the same TXN ID
    $sqlQ = "SELECT id FROM user_subscriptions WHERE stripe_payment_intent_id = ?";
    $stmt = $con->prepare($sqlQ);
    $stmt->bind_param("s", $payment_intent_id);
    $stmt->execute();
    $stmt->bind_result($id);
    $stmt->fetch();
    $prevPaymentID = $id;
    $stmt->close();

    $payment_id = 0;
    if (!empty($prevPaymentID)) {
      $payment_id = $prevPaymentID;
    }else{
      // Insert transaction data into the database
      $sqlQ = "INSERT INTO user_subscriptions (user_id, plan_id, stripe_subscription_id, stripe_customer_id, stripe_payment_intent_id,
      paid_amount, paid_amount_currency, plan_interval, customer_name, customer_email, created, plan_period_start, plan_period_end, status)
      VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?)";
      $stmt = $con->prepare($sqlQ);
      $stmt->bind_param("iisssdssssssss", $userID, $subscr_plan_id, $subscription_id, $customer_id, $payment_intent_id,
      $paidAmount, $paidCurrency, $planInterval, $customer_name, $customer_email, $created, $current_period_start,
      $current_period_end, $payment_status);
      $insert = $stmt->execute();

      if ($insert) {
        $payment_id = $stmt->insert_id;
        // Update subscription ID in users table
        $sqlQ = "UPDATE users SET subscription_id=? WHERE id=?";
        $stmt =$con->prepare($sqlQ);
        $stmt->bind_param("ii", $payment_id, $userID);
        $update = $stmt->execute();
      }
    }
    $output = [
      'payment_id' => base64_encode($payment_id)
    ];
    echo json_encode($output);
  }else{
    echo json_encode(['error' => 'Transaction has been failed!']);
  }
}

?>