Product::purchase_message()

	public function purchase_message() {
		$preorder = $this->availability() === Availability::PREORDER;
		if ( ! $preorder ) {
			return '';
		}
		$source  = $this->get_source_data();
		$date    = isset( $source->preorder_release_date ) ? strtotime( $source->preorder_release_date ) : 0;
		$message = isset( $source->preorder_message ) ? $source->preorder_message : '';
		$message = str_replace( '%%DATE%%', '%s', $message );

		$default_message   = __( 'Available for pre-order.', 'bigcommerce' );
		$default_with_date = __( 'Available for pre-order. Expected release date is %s.', 'bigcommerce' );

		if ( empty( $date ) && strpos( $message, '%s' ) !== false ) {
			$message = '';
		}

		if ( empty( $message ) ) {
			$message = empty( $date ) ? $default_message : $default_with_date;
		}

		$date_string = $date ? date_i18n( get_option( 'date_format', 'Y-m-d' ), $date ) : '';

		return sprintf( $message, $date_string );
	}