<?php
declare(strict_types=1);

/**
 * Zahlungsart "PayPal Checkout (Orders v2 / REST)".
 *
 * Neues, eigenstaendiges Modul – laeuft parallel zum Legacy-NVP-Modul
 * (PaypalPaymentMethod) und teilt sich mit ihm KEINEN Code.
 *
 * Aktivierung ueber einen eigenen Eintrag in `payment_methods` mit
 * module = 'paypalrest'. Der Cashdesk instanziiert dann automatisch diese
 * Klasse (ucfirst('paypalrest').'PaymentMethod' => PaypalrestPaymentMethod).
 *
 * Flow: after_order() legt die PayPal-Order an und leitet den Kunden zur
 * Approve-URL weiter. Der Rueckweg laeuft NICHT ueber den Cashdesk (der ist auf
 * das Legacy-Modul verdrahtet), sondern ueber /core/paypal_v2/return.php.
 */

require_once __DIR__ . '/../paypal_v2/Config.php';
require_once __DIR__ . '/../paypal_v2/PayPalClient.php';
require_once __DIR__ . '/../paypal_v2/Orders.php';
require_once __DIR__ . '/../paypal_v2/Gateway.php';

class PaypalrestPaymentMethod
{
    private $base_object;
    private $layout_object;

    private $customer_data;
    private $shipping_address;
    private $billing_address;
    private $shoppingcart;
    private $payment_method;
    private $shipping_method;
    private $gift_certificate;
    private $order_id;

    public function __construct($base_object, $layout_object)
    {
        $this->base_object   = $base_object;
        $this->layout_object = $layout_object;

        $this->customer_data    = false;
        $this->shipping_address = false;
        $this->billing_address  = false;
        $this->shoppingcart     = false;
        $this->payment_method   = false;
        $this->shipping_method  = false;
        $this->gift_certificate = false;
        $this->order_id         = false;
    }

    public function set_data($customer, $shipping, $billing, $shoppingcart, $delivery, $payment, $order_id = false)
    {
        $this->customer_data    = $customer;
        $this->shipping_address = $shipping;
        $this->billing_address  = $billing;
        $this->shoppingcart     = $shoppingcart;
        $this->payment_method   = $delivery;
        $this->shipping_method  = $payment;
        $this->order_id         = $order_id;
    }

    public function set_gift_certificate($gift_certificate)
    {
        $this->gift_certificate = $gift_certificate;
    }

    public function set_order_id($order_id)
    {
        $this->order_id = $order_id;
    }

    /** Vom Cashdesk vor dem Speichern aufgerufen. Kein Fehler => leere Rueckgabe. */
    public function before_order($argument = null)
    {
        return '';
    }

    public function during_order($argument = null)
    {
        return '';
    }

    /**
     * Nach dem Speichern des Auftrags: PayPal-Order anlegen und weiterleiten.
     *
     * @param  float|false $order_total Bruttosumme des Auftrags
     * @return string HTML-Fallback (nur, wenn keine Weiterleitung moeglich war)
     */
    public function after_order($order_total = false)
    {
        $charged = (float) $order_total;

        // Gutschein wie im Legacy-Modul vom zu zahlenden Betrag abziehen
        if ($this->gift_certificate && isset($this->gift_certificate->with_vat)) {
            $charged -= (float) $this->gift_certificate->with_vat;
        }

        try {
            $gateway     = new \PaypalV2\Gateway($this->base_object);
            $order_number = $this->resolve_order_number((int) $this->order_id);
            $approve_url = $gateway->createOrderAndGetApprovalUrl((int) $this->order_id, $charged, $order_number);
        } catch (\Throwable $e) {
            \error_log('PayPal v2 after_order: ' . $e->getMessage());
            return $this->render_error('Beim Initialisieren von PayPal ist ein Fehler aufgetreten.');
        }

        // Bevorzugt harte Weiterleitung (an dieser Stelle sind noch keine Header gesendet).
        if (!\headers_sent()) {
            \header('Location: ' . $approve_url);
            exit;
        }

        // Fallback: Button/Meta-Refresh im Template
        $this->layout_object->assign('call', 'payment_open');
        $this->layout_object->assign('paypal_link', $approve_url);
        return $this->layout_object->_fetch('content_cash_desk/paypalrest.tpl');
    }

    /** Wird vom Cashdesk fuer dieses Modul NICHT aufgerufen (Return laeuft ueber return.php). */
    public function change_order()
    {
        return '';
    }

    // ---------------------------------------------------------------- intern

    private function resolve_order_number(int $order_id): string
    {
        $db  = $this->base_object->db;
        $res = $db->query('SELECT order_number FROM orders WHERE id=' . $order_id . ' LIMIT 1');
        if ($res && $res->num_rows > 0) {
            return (string) $res->fetch_object()->order_number;
        }
        return (string) $order_id;
    }

    private function render_error(string $message): string
    {
        $this->layout_object->assign('call', 'payment_error');
        $this->layout_object->assign('message', $message);
        return $this->layout_object->_fetch('content_cash_desk/paypalrest.tpl');
    }
}