transaction_webhook.php

public function transaction_charge(){
        log_message('debug','Event charge.success from paystack');
        // Retrieve the request's body
        $input = @file_get_contents("php://input");
        // only a post with paystack signature header gets our attention
        if ((strtoupper($_SERVER['REQUEST_METHOD']) != 'POST' ) || !array_key_exists('HTTP_X_PAYSTACK_SIGNATURE', $_SERVER) ){ 
            exit();
        }
        
        define('PAYSTACK_SECRET_KEY',$this->private_key);
        // validate event do all at once to avoid timing attack
        if($_SERVER['HTTP_X_PAYSTACK_SIGNATURE'] !== hash_hmac('sha512', $input, PAYSTACK_SECRET_KEY)){
            exit();
        }
        http_response_code(200);
        // parse event (which is json string) as object
        // Do something - that will not take long - with $event
        $event = json_decode($input);
        
        //update transaction status
        //update users payment status
        if($event->event == "charge.success"){
             log_message('debug','Entered successs');
             //TODO: get transaction reference and work with it
             $reference = $event->data->reference;
             //with the transaction $reference, check if the transaction has already been marked as successful,
             // if not, then credit agent wallet and mark as successful.
   
        }
        exit();
    }