API Pix no WooCommerce

<?php
/**
 * Plugin Name: Pix pela API da xFlow (exemplo)
 */
defined( 'ABSPATH' ) || exit;

add_action( 'before_woocommerce_init', function () {
    if ( class_exists( \Automattic\WooCommerce\Utilities\FeaturesUtil::class ) ) {
        \Automattic\WooCommerce\Utilities\FeaturesUtil::declare_compatibility( 'custom_order_tables', __FILE__, true );
    }
} );

add_action( 'plugins_loaded', function () {
    if ( class_exists( 'WC_Payment_Gateway' ) ) {
        require __DIR__ . '/class-wc-gateway-xflow-pix.php';
    }
} );

add_filter( 'woocommerce_payment_gateways', function ( $gateways ) {
    $gateways[] = 'WC_Gateway_Xflow_Pix';
    return $gateways;
} );

add_action( 'woocommerce_thankyou_xflow_pix', 'xflow_pix_pagina_do_pedido' );
add_action( 'woocommerce_api_xflow_pix_webhook', 'xflow_pix_webhook' );

function xflow_pix_api( string $metodo, string $caminho, ?array $corpo = null, ?string $chave = null ): array {
    $headers = array(
        'Authorization' => 'Basic ' . base64_encode( XFLOW_PUBLIC_KEY . ':' . XFLOW_SECRET_KEY ),
        'Content-Type'  => 'application/json',
    );
    if ( $chave ) {
        $headers['Idempotency-Key'] = $chave;
    }
    $res = wp_remote_request( 'https://app.xflowpayments.com/api/v1' . $caminho, array(
        'method'  => $metodo,
        'headers' => $headers,
        'body'    => $corpo ? wp_json_encode( $corpo ) : null,
        'timeout' => 30,
    ) );
    // Em falha de rede, o status vem 0 e o corpo vazio.
    return array(
        'status' => (int) wp_remote_retrieve_response_code( $res ),
        'body'   => json_decode( wp_remote_retrieve_body( $res ), true ) ?? array(),
    );
}

<?php
// class-wc-gateway-xflow-pix.php
class WC_Gateway_Xflow_Pix extends WC_Payment_Gateway {

    public function __construct() {
        $this->id           = 'xflow_pix';
        $this->method_title = 'Pix (API xFlow)';
        $this->has_fields   = true;
        $this->form_fields  = array(
            'enabled' => array( 'title' => 'Ativar', 'type' => 'checkbox', 'label' => 'Ativar Pix', 'default' => 'no' ),
            'title'   => array( 'title' => 'Título', 'type' => 'text', 'default' => 'Pix' ),
        );
        $this->init_settings();
        $this->title = $this->get_option( 'title' );

        add_action( 'woocommerce_update_options_payment_gateways_' . $this->id, array( $this, 'process_admin_options' ) );
    }

    public function payment_fields() {
        echo '<p><label for="xflow_documento">CPF ou CNPJ</label>
              <input id="xflow_documento" name="xflow_documento" type="text" inputmode="numeric"></p>';
    }

    private function documento(): string {
        return preg_replace( '/\D/', '', (string) wp_unslash( $_POST['xflow_documento'] ?? '' ) );
    }

    public function validate_fields() {
        if ( ! in_array( strlen( $this->documento() ), array( 11, 14 ), true ) ) {
            wc_add_notice( 'Informe um CPF ou CNPJ válido para pagar com Pix.', 'error' );
            return false;
        }
        return true;
    }

    public function process_payment( $order_id ) {
        $order    = wc_get_order( $order_id );
        $centavos = (int) round( (float) $order->get_total() * 100 );

        $res = xflow_pix_api( 'POST', '/charges', array(
            'amountCents'        => $centavos,
            'customer'           => array(
                'name'     => $order->get_formatted_billing_full_name(),
                'email'    => $order->get_billing_email(),
                'document' => $this->documento(),
            ),
            'description'        => 'Pedido #' . $order->get_order_number(),
            'external_reference' => (string) $order->get_id(),
        ), 'woo-' . $order->get_id() . '-' . $centavos );

        if ( empty( $res['body']['id'] ) ) {
            $order->add_order_note( 'xFlow: ' . wp_json_encode( $res['body'] ) );
            wc_add_notice( 'Não foi possível gerar o Pix agora. Tente de novo.', 'error' );
            return array( 'result' => 'failure' );
        }

        $order->update_meta_data( '_xflow_charge_id', $res['body']['id'] );
        $order->update_status( 'on-hold', 'Aguardando pagamento Pix.' ); // também salva o meta
        WC()->cart->empty_cart();

        return array( 'result' => 'success', 'redirect' => $this->get_return_url( $order ) );
    }
}

function xflow_pix_pagina_do_pedido( $order_id ) {
    $order = wc_get_order( $order_id );
    if ( ! $order || $order->is_paid() ) {
        return;
    }
    $c = xflow_pix_api( 'GET', '/charges/' . rawurlencode( (string) $order->get_meta( '_xflow_charge_id' ) ) )['body'];

    $status = $c['status'] ?? '';
    if ( 'pending' !== $status ) {
        echo 'paid' === $status ? '<p>Pagamento recebido.</p>' : '<p>Este código Pix não está mais disponível. Fale com a loja.</p>';
        return;
    }
    printf(
        '<h2>Pague com Pix</h2><img src="%s" alt="QR Code Pix" width="240" height="240"><textarea readonly rows="4">%s</textarea>',
        esc_attr( $c['pix']['qrCodeBase64'] ),
        esc_textarea( $c['pix']['copyPaste'] )
    );
}

function xflow_pix_webhook() {
    $raw      = file_get_contents( 'php://input' );
    $esperado = 'sha256=' . hash_hmac( 'sha256', $raw, XFLOW_WEBHOOK_SECRET );
    if ( ! hash_equals( $esperado, $_SERVER['HTTP_X_WEBHOOK_SIGNATURE'] ?? '' ) ) {
        status_header( 401 );
        exit;
    }

    $evento = json_decode( $raw, true );
    $data   = $evento['data'] ?? array();

    if ( 'transaction.paid' === ( $evento['event'] ?? '' ) && true === ( $data['livemode'] ?? null ) ) {
        $order = wc_get_order( (int) ( $data['external_reference'] ?? 0 ) );
        $ok    = $order
            && $order->get_meta( '_xflow_charge_id' ) === ( $data['id'] ?? '' )
            && (int) round( (float) $order->get_total() * 100 ) === (int) ( $data['amount'] ?? 0 );

        if ( $ok && ! $order->is_paid() ) {
            $order->payment_complete( $data['pix']['endToEnd'] ?? $data['id'] );
        }
    }

    status_header( 200 );
    exit;
}