/* Función para agregar varios productos a la vez por url */
function woocommerce_maybe_add_multiple_products_to_cart() {
// Asegúrate que WooCommerce está instalado, el parametro query add-to-cart existe y contiene al menos una coma.
if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
    return;
}

// Eliminar el hook de WooCommerce, ya que es inútil (no maneja múltiples productos).
remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );

$product_ids = explode( ',', $_REQUEST['add-to-cart'] );
$quantities = explode( ',', $_REQUEST['quantities'] );

$count       = count( $product_ids );
$number      = 0;

foreach ( $product_ids as $product_id ) {
    if ( ++$number === $count ) {
        // Ok, último punto, enviémoslo de nuevo al método add_to_cart_action de woocommerce para su manejo.
        $_REQUEST['add-to-cart'] = $product_id;

        return WC_Form_Handler::add_to_cart_action();
    }

    $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
    $was_added_to_cart = false;
    $adding_to_cart    = wc_get_product( $product_id );

    if ( ! $adding_to_cart ) {
        continue;
    }

    $add_to_cart_handler = apply_filters( 'woocommerce_add_to_cart_handler', $adding_to_cart->product_type, $adding_to_cart );

    /*
     * Lo siento... si quieres productos no simples, utiliza la segunda versión de este código.
     *
     * Relacionado: WooCommerce ha establecido los siguientes métodos como privados:
     * WC_Form_Handler::add_to_cart_handler_variable(),
     * WC_Form_Handler::add_to_cart_handler_grouped(),
     * WC_Form_Handler::add_to_cart_handler_simple()
     *
     * ¿Por qué tienes que ser así WooCommerce?
     */
    if ( 'simple' !== $add_to_cart_handler ) {
        continue;
    }
//         $_REQUEST['quantity'] = ! empty( $id_and_quantity[1] ) ? absint( $id_and_quantity[1] ) : 1;
$_REQUEST['quantity'] = ! empty( $quantities[$number] ) ? absint( $quantities[$number] ) : 1;
    $quantity          = empty( $quantities[$number - 1] ) ? 1 : wc_stock_amount(  $quantities[$number - 1] );
//     $quantity          = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( $_REQUEST['quantity'] );
    $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity );

    if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity ) ) {
        wc_add_to_cart_message( array( $product_id => $quantity ), true );
    }
}
}

 // Se dispara antes de la llamada de retorno de WC_Form_Handler::add_to_cart_action.
 add_action( 'wp_loaded',        'woocommerce_maybe_add_multiple_products_to_cart', 15 );
// eliminar el aviso de "añadido a la cesta".
add_filter( 'wc_add_to_cart_message_html', '__return_false' );

// Asegúrate que WooCommerce está instalado, el parametro query add-to-cart existe y contiene al menos una coma.
if ( ! class_exists( 'WC_Form_Handler' ) || empty( $_REQUEST['add-to-cart'] ) || false === strpos( $_REQUEST['add-to-cart'], ',' ) ) {
    return;
}

remove_action( 'wp_loaded', array( 'WC_Form_Handler', 'add_to_cart_action' ), 20 );

$product_ids = explode( ',', $_REQUEST['add-to-cart'] );
$quantities = explode( ',', $_REQUEST['quantities'] );
$count       = count( $product_ids );
$number      = 0;

foreach ( $product_ids as $product_id ) {
    if ( ++$number === $count ) {
        // Ok, último punto, enviémoslo de nuevo al método add_to_cart_action de woocommerce para su procesamiento.
        $_REQUEST['add-to-cart'] = $product_id;

        return WC_Form_Handler::add_to_cart_action();
    }

    $product_id        = apply_filters( 'woocommerce_add_to_cart_product_id', absint( $product_id ) );
    $was_added_to_cart = false;

    $adding_to_cart    = wc_get_product( $product_id );

    if ( ! $adding_to_cart ) {
        continue;
    }

    if ( $adding_to_cart->is_type( 'simple' ) ) {
        $_REQUEST['quantity'] = ! empty( $quantities[$number] ) ? absint( $quantities[$number] ) : 1;
        $quantity          = empty( $quantities[$number - 1] ) ? 1 : wc_stock_amount(  $quantities[$number - 1] );
        // la cantidad se aplica a todos los productos atm
        //$quantity          = empty( $_REQUEST['quantity'] ) ? 1 : wc_stock_amount( $_REQUEST['quantity'] );
        $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity );

        if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity ) ) {
            wc_add_to_cart_message( array( $product_id => $quantity ), true );
        }

    } else {

        $variation_id       = empty( $_REQUEST['variation_id'] ) ? '' : absint( wp_unslash( $_REQUEST['variation_id'] ) );
        $quantity           = empty( $quantities[$number - 1] ) ? 1 : wc_stock_amount( wp_unslash( $quantities[$number - 1] ) ); // WPCS: sanitization ok.
        $missing_attributes = array();
        $variations         = array();
        $adding_to_cart     = wc_get_product( $product_id );

        if ( ! $adding_to_cart ) {
          continue;
        }

        // Si el $product_id era de hecho un ID de variables, actualiza las variables.
        if ( $adding_to_cart->is_type( 'variation' ) ) {
          $variation_id   = $product_id;
          $product_id     = $adding_to_cart->get_parent_id();
          $adding_to_cart = wc_get_product( $product_id );

          if ( ! $adding_to_cart ) {
            continue;
          }
        }

        // Recoge los atributos contabilizados.
        $posted_attributes = array();

        foreach ( $adding_to_cart->get_attributes() as $attribute ) {
          if ( ! $attribute['is_variation'] ) {
            continue;
          }
          $attribute_key = 'attribute_' . sanitize_title( $attribute['name'] );

          if ( isset( $_REQUEST[ $attribute_key ] ) ) {
            if ( $attribute['is_taxonomy'] ) {
              // Don't use wc_clean as it destroys sanitized characters.
              $value = sanitize_title( wp_unslash( $_REQUEST[ $attribute_key ] ) );
            } else {
              $value = html_entity_decode( wc_clean( wp_unslash( $_REQUEST[ $attribute_key ] ) ), ENT_QUOTES, get_bloginfo( 'charset' ) ); // WPCS: sanitization ok.
            }

            $posted_attributes[ $attribute_key ] = $value;
          }
        }

        // No utilizar wc_clean ya que destruye los caracteres limpios.
        if ( empty( $variation_id ) ) {
          $data_store   = WC_Data_Store::load( 'product' );
          $variation_id = $data_store->find_matching_product_variation( $adding_to_cart, $posted_attributes );
        }

        // ¿Tenemos una ID de variable?
        if ( empty( $variation_id ) ) {
          throw new Exception( __( 'Please choose product options…', 'woocommerce' ) );
        }

        // Comprueba que los datos que tenemos son válidos.
        $variation_data = wc_get_product_variation_attributes( $variation_id );

        foreach ( $adding_to_cart->get_attributes() as $attribute ) {
          if ( ! $attribute['is_variation'] ) {
            continue;
          }

          // Get valid value from variation data.
          $attribute_key = 'attribute_' . sanitize_title( $attribute['name'] );
          $valid_value   = isset( $variation_data[ $attribute_key ] ) ? $variation_data[ $attribute_key ]: '';

          /**
          * Si el valor del atributo fue publicado, comprueba si es válido.
          *
          * Si no se contabilizó ningún atributo, sólo error si la variación tiene un atributo 'any' que requiere un valor.
           */
          if ( isset( $posted_attributes[ $attribute_key ] ) ) {
            $value = $posted_attributes[ $attribute_key ];

            // Allow if valid or show error.
            if ( $valid_value === $value ) {
              $variations[ $attribute_key ] = $value;
            } elseif ( '' === $valid_value && in_array( $value, $attribute->get_slugs() ) ) {
              // Si los valores válidos están vacíos, intentará de una variación "cualquiera" para obtener todos los valores posibles.
              $variations[ $attribute_key ] = $value;
            } else {
              throw new Exception( sprintf( __( 'Invalid value posted for %s', 'woocommerce' ), wc_attribute_label( $attribute['name'] ) ) );
            }
          } elseif ( '' === $valid_value ) {
            $missing_attributes[] = wc_attribute_label( $attribute['name'] );
          }
        }
        if ( ! empty( $missing_attributes ) ) {
          throw new Exception( sprintf( _n( '%s is a required field', '%s are required fields', count( $missing_attributes ), 'woocommerce' ), wc_format_list_of_items( $missing_attributes ) ) );
        }

      $passed_validation = apply_filters( 'woocommerce_add_to_cart_validation', true, $product_id, $quantity, $variation_id, $variations );

      if ( $passed_validation && false !== WC()->cart->add_to_cart( $product_id, $quantity, $variation_id, $variations ) ) {
        wc_add_to_cart_message( array( $product_id => $quantity ), true );
      }
    }
}