ent(),
			'needs_shipping'          => $cart->needs_shipping(),
			'has_calculated_shipping' => $has_calculated_shipping,
			'fees'                    => $this->get_item_responses_from_schema( $this->fee_schema, $cart->get_fees() ),
			'totals'                  => (object) $this->prepare_currency_response(
				[
					'total_items'        => $this->prepare_money_response( $cart->get_subtotal(), wc_get_price_decimals() ),
					'total_items_tax'    => $this->prepare_money_response( $cart->get_subtotal_tax(), wc_get_price_decimals() ),
					'total_fees'         => $this->prepare_money_response( $cart->get_fee_total(), wc_get_price_decimals() ),
					'total_fees_tax'     => $this->prepare_money_response( $cart->get_fee_tax(), wc_get_price_decimals() ),
					'total_discount'     => $this->prepare_money_response( $cart->get_discount_total(), wc_get_price_decimals() ),
					'total_discount_tax' => $this->prepare_money_response( $cart->get_discount_tax(), wc_get_price_decimals() ),
					'total_shipping'     => $has_calculated_shipping ? $this->prepare_money_response( $cart->get_shipping_total(), wc_get_price_decimals() ) : null,
					'total_shipping_tax' => $has_calculated_shipping ? $this->prepare_money_response( $cart->get_shipping_tax(), wc_get_price_decimals() ) : null,

					// Explicitly request context='edit'; default ('view') will render total as markup.
					'total_price'        => $this->prepare_money_response( $cart->get_total( 'edit' ), wc_get_price_decimals() ),
					'total_tax'          => $this->prepare_money_response( $cart->get_total_tax(), wc_get_price_decimals() ),
					'tax_lines'          => $this->get_tax_lines( $cart ),
				]
			),
			'errors'                  => $cart_errors,
			'payment_requirements'    => $this->extend->get_payment_requirements(),
			self::EXTENDING_KEY       => $this->get_extended_data( self::IDENTIFIER ),
		];
	}

	/**
	 * Get tax lines from the cart and format to match schema.
	 *
	 * @param \WC_Cart $cart Cart class instance.
	 * @return array
	 */
	protected function get_tax_lines( $cart ) {
		$cart_tax_totals = $cart->get_tax_totals();
		$tax_lines       = [];

		foreach ( $cart_tax_totals as $cart_tax_total ) {
			$tax_lines[] = array(
				'name'  => $cart_tax_total->label,
				'price' => $this->prepare_money_response( $cart_tax_total->amount, wc_get_price_decimals() ),
			);
		}

		return $tax_lines;
	}

	/**
	 * Get cart validation errors.
	 *
	 * @param \WC_Cart $cart Cart class instance.
	 * @return array
	 */
	protected function get_cart_errors( $cart ) {
		$controller    = new CartController();
		$item_errors   = array_filter(
			$controller->get_cart_item_errors(),
			function ( WP_Error $error ) {
				return $error->has_errors();
			}
		);
		$coupon_errors = $controller->get_cart_coupon_errors();

		return array_values( array_map( [ $this->error_schema, 'get_item_response' ], array_merge( $item_errors, $coupon_errors ) ) );
	}
}