public function get_chart_legend() {

		if ( empty( $this->show_categories ) ) {
			return array();
		}

		$legend = array();
		$index  = 0;

		foreach ( $this->show_categories as $category ) {

			$category    = get_term( $category, 'product_cat' );
			$total       = 0;
			$product_ids = $this->get_products_in_category( $category->term_id );

			foreach ( $product_ids as $id ) {

				if ( isset( $this->item_sales[ $id ] ) ) {
					$total += $this->item_sales[ $id ];
				}
			}

			$legend[] = array(
				/* translators: 1: total items sold 2: category name */
				'title'            => sprintf( __( '%1$s sales in %2$s', 'woocommerce' ), '<strong>' . wc_price( $total ) . '</strong>', $category->name ),
				'color'            => isset( $this->chart_colours[ $index ] ) ? $this->chart_colours[ $index ] : $this->chart_colours[0],
				'highlight_series' => $index,
			);

			$index++;
		}

		return $legend;
	}