where_clause'      => $this->interval_query->get_sql_clause( 'where' ),
				'limit'             => $this->get_sql_clause( 'limit' ),
			);

			$unique_products            = $this->get_unique_product_count( $totals_query['from_clause'], $totals_query['where_time_clause'], $totals_query['where_clause'] );
			$totals[0]['products']      = $unique_products;
			$segmenter                  = new Segmenter( $query_args, $this->report_columns );
			$unique_coupons             = $this->get_unique_coupon_count( $totals_query['from_clause'], $totals_query['where_time_clause'], $totals_query['where_clause'] );
			$totals[0]['coupons_count'] = $unique_coupons;
			$totals[0]['segments']      = $segmenter->get_totals_segments( $totals_query, $table_name );
			$totals                     = (object) $this->cast_numbers( $totals[0] );

			$this->interval_query->add_sql_clause( 'select', $this->get_sql_clause( 'select' ) . ' AS time_interval' );
			$this->interval_query->add_sql_clause( 'left_join', $coupon_join );
			$this->interval_query->add_sql_clause( 'where_time', $where_time );
			$db_intervals = $wpdb->get_col(
				$this->interval_query->get_query_statement()
			); // phpcs:ignore cache ok, DB call ok, , unprepared SQL ok.

			$db_interval_count       = count( $db_intervals );
			$expected_interval_count = TimeInterval::intervals_between( $query_args['after'], $query_args['before'], $query_args['interval'] );
			$total_pages             = (int) ceil( $expected_interval_count / $params['per_page'] );

			if ( $query_args['page'] < 1 || $query_args['page'] > $total_pages ) {
				return $data;
			}

			$this->update_intervals_sql_params( $query_args, $db_interval_count, $expected_interval_count, $table_name );
			$this->interval_query->add_sql_clause( 'order_by', $this->get_sql_clause( 'order_by' ) );
			$this->interval_query->add_sql_clause( 'limit', $this->get_sql_clause( 'limit' ) );
			$this->interval_query->add_sql_clause( 'select', ", MAX(${table_name}.date_created) AS datetime_anchor" );
			if ( '' !== $selections ) {
				$this->interval_query->add_sql_clause( 'select', ', ' . $selections );
			}
			$intervals = $wpdb->get_results(
				$this->interval_query->get_query_statement(),
				ARRAY_A
			); // phpcs:ignore cache ok, DB call ok, unprepared SQL ok.

			if ( null === $intervals ) {
				return new \WP_Error( 'woocommerce_analytics_revenue_result_failed', __( 'Sorry, fetching revenue data failed.', 'woocommerce' ) );
			}

			if ( isset( $intervals[0] ) ) {
				$unique_coupons                = $this->get_unique_coupon_count( $intervals_query['from_clause'], $intervals_query['where_time_clause'], $intervals_query['where_clause'], true );
				$intervals[0]['coupons_count'] = $unique_coupons;
			}

			$data = (object) array(
				'totals'    => $totals,
				'intervals' => $intervals,
				'total'     => $expected_interval_count,
				'pages'     => $total_pages,
				'page_no'   => (int) $query_args['page'],
			);

			if ( TimeInterval::intervals_missing( $expected_interval_count, $db_interval_count, $params['per_page'], $query_args['page'], $query_args['order'], $query_args['orderby'], count( $intervals ) ) ) {
				$this->fill_in_missing_intervals( $db_intervals, $query_args['adj_after'], $query_args['adj_before'], $query_args['interval'], $data );
				$this->sort_intervals( $data, $query_args['orderby'], $query_args['order'] );
				$this->remove_extra_records( $data, $query_args['page'], $params['per_page'], $db_interval_count, $expected_interval_count, $query_args['orderby'], $query_args['order'] );
			} else {
				$this->update_interval_boundary_dates( $query_args['after'], $query_args['before'], $query_args['interval'], $data->intervals );
			}
			$segmenter->add_intervals_segments( $data, $intervals_query, $table_name );
			$this->create_interval_subtotals( $data->intervals );

			$this->set_cached_data( $cache_key, $data );
		}

		return $data;
	}

	/**
	 * Get unique products based on user time query
	 *
	 * @param string $from_clause       From clause with date query.
	 * @param string $where_time_clause Where clause with date query.
	 * @param string $where_clause      Where clause with date query.
	 * @return integer Unique product count.
	 */
	public function get_unique_product_count( $from_clause, $where_time_clause, $where_clause ) {
		global $wpdb;

		$table_name = self::get_db_table_name();
		return $wpdb->get_var(
			"SELECT
					COUNT( DISTINCT {$wpdb->prefix}wc_order_product_lookup.product_id )
				FROM
					{$wpdb->prefix}wc_order_product_lookup JOIN {$table_name} ON {$wpdb->prefix}wc_order_product_lookup.order_id = {$table_name}.order_id
					{$from_clause}
				WHERE
					1=1
					{$where_time_clause}
					{$where_clause}"
		); // phpcs:ignore cache ok, DB call ok, unprepared SQL ok.
	}

	/**
	 * Get unique coupons based on user time query
	 *
	 * @param string $from_clause       From clause with date query.
	 * @param string $where_time_clause Where clause with date query.
	 * @param string $where_clause      Where clause with date query.
	 * @return integer Unique product count.
	 */
	public function get_unique_coupon_count( $from_clause, $where_time_clause, $where_clause ) {
		global $wpdb;

		$table_name = self::get_db_table_name();
		return $wpdb->get_var(
			"SELECT
					COUNT(DISTINCT coupon_id)
				FROM
					{$wpdb->prefix}wc_order_coupon_lookup JOIN {$table_name} ON {$wpdb->prefix}wc_order_coupon_lookup.order_id = {$table_name}.order_id
					{$from_clause}
				WHERE
					1=1
					{$where_time_clause}
					{$where_clause}"
		); // phpcs:ignore cache ok, DB call ok, unprepared SQL ok.
	}

	/**
	 * Add order information to the lookup table when orders are created or modified.
	 *
	 * @param int $post_id Post ID.
	 * @return int|bool Returns -1 if order won't be processed, or a boolean indicating processing success.
	 */
	public static function sync_order( $post_id ) {
		if ( 'shop_order' !== get_post_type( $post_id ) && 'shop_order_refund' !== get_post_type( $post_id ) ) {
			return -1;
		}

		$order = wc_get_order( $post_id );
		if ( ! $order ) {
			return -1;
		}

		return self::update( $order );
	}

	/**
	 * Update the database with stats data.
	 *
	 * @param WC_Order|WC_Order_Refund $order Order or refund to update row for.
	 * @return int|bool Returns -1 if order won't be processed, or a boolean indicating processing success.
	 */
	public static function update( $order ) {
		global $wpdb;
		$table_name = self::get_db_table_name();

		if ( ! $order->get_id() || ! $order->get_date_created() ) {
			return -1;
		}

		/**
		 * Filters order stats data.
		 *
		 * @param array $data Data written to order stats lookup table.
		 * @param WC_Order $order  Order object.
		 */
		$data = apply_filters(
			'woocommerce_analytics_update_order_stats_data',
			array(
				'order_id'           => $order->get_id(),
				'parent_id'          => $order->get_parent_id(),
				'date_created'       => $order->get_date_created()->date( 'Y-m-d H:i:s' ),
				'date_created_gmt'   => gmdate( 'Y-m-d H:i:s', $order->get_date_created()->getTimestamp() ),
				'num_items_sold'     => self::get_num_items_sold( $order ),
				'total_sales'        => $order->get_total(),
				'tax_total'          => $order->get_total_tax(),
				'shipping_total'     => $order->get_shipping_total(),
				'net_total'          => self::get_net_total( $order ),
				'status'             => self::normalize_order_status( $order->get_status() ),
				'customer_id'        => $order->get_report_customer_id(),
				'returning_customer' => $order->is_returning_customer(),
			),
			$order
		);

		$format = array(
			'%d',
			'%d',
			'%s',
			'%s',
			'%d',
			'%f',
			'%f',
			'%f',
			'%f',
			'%s',
			'%d',
			'%d',
		);

		if ( 'shop_order_refund' === $order->get_type() ) {
			$parent_order = wc_get_order( $order->get_parent_id() );
			if ( $parent_order ) {
				$data['parent_id'] = $parent_order->get_id();
				$format[]          = '%d';
			}
		} else {
			$data['returning_customer'] = self::is_returning_customer( $order );
		}

		// Update or add the information to the DB.
		$result = $wpdb->replace( $table_name, $data, $format );

		/**
		 * Fires when order's stats reports are updated.
		 *
		 * @param int $order_id Order ID.
		 */
		do_action( 'woocommerce_analytics_update_order_stats', $order->get_id() );

		// Check the rows affected for success. Using REPLACE can affect 2 rows if the row already exists.
		return ( 1 === $result || 2 === $result );
	}

	/**
	 * Deletes the order stats when an order is deleted.
	 *
	 * @param int $post_id Post ID.
	 */
	public static function delete_order( $post_id ) {
		global $wpdb;
		$order_id = (int) $post_id;

		if ( 'shop_order' !== get_post_type( $order_id ) && 'shop_order_refund' !== get_post_type( $order_id ) ) {
			return;
		}

		// Retrieve customer details before the order is deleted.
		$order       = wc_get_order( $order_id );
		$customer_id = absint( CustomersDataStore::get_existing_customer_id_from_order( $order ) );

		// Delete the order.
		$wpdb->delete( self::get_db_table_name(), array( 'order_id' => $order_id ) );
		/**
		 * Fires when orders stats are deleted.
		 *
		 * @param int $order_id Order ID.
		 * @param int $customer_id Customer ID.
		 */
		do_action( 'woocommerce_analytics_delete_order_stats', $order_id, $customer_id );

		ReportsCache::invalidate();
	}


	/**
	 * Calculation methods.
	 */

	/**
	 * Get number of items sold among all orders.
	 *
	 * @param array $order WC_Order object.
	 * @return int
	 */
	protected static function get_num_items_sold( $order ) {
		$num_items = 0;

		$line_items = $order->get_items( 'line_item' );
		foreach ( $line_items as $line_item ) {
			$num_items += $line_item->get_quantity();
		}

		return $num_items;
	}

	/**
	 * Get the net amount from an order without shipping, tax, or refunds.
	 *
	 * @param array $order WC_Order object.
	 * @return float
	 */
	protected static function get_net_total( $order ) {
		$net_total = floatval( $order->get_total() ) - floatval( $order->get_total_tax() ) - floatval( $order->get_shipping_total() );
		return (float) $net_total;
	}

	/**
	 * Check to see if an order's customer has made previous orders or not
	 *
	 * @param array $order WC_Order object.
	 * @return bool
	 */
	public static function is_returning_customer( $order ) {
		$customer_id = \Automattic\WooCommerce\Admin\API\Reports\Customers\DataStore::get_existing_customer_id_from_order( $order );

		if ( ! $customer_id ) {
			return false;
		}

		$oldest_orders = \Automattic\WooCommerce\Admin\API\Reports\Customers\DataStore::get_oldest_orders( $customer_id );

		if ( empty( $oldest_orders ) ) {
			return false;
		}

		$first_order       = $oldest_orders[0];
		$second_order      = isset( $oldest_orders[1] ) ? $oldest_orders[1] : false;
		$excluded_statuses = self::get_excluded_report_order_statuses();

		// Order is older than previous first order.
		if ( $order->get_date_created() < wc_string_to_datetime( $first_order->date_created ) &&
			! in_array( $order->get_status(), $excluded_statuses, true )
		) {
			self::set_customer_first_order( $customer_id, $order->get_id() );
			return false;
		}

		// The current order is the oldest known order.
		$is_first_order = (int) $order->get_id() === (int) $first_order->order_id;
		// Order date has changed and next oldest is now the first order.
		$date_change = $second_order &&
			$order->get_date_created() > wc_string_to_datetime( $first_order->date_created ) &&
			wc_string_to_datetime( $second_order->date_created ) < $order->get_date_created();
		// Status has changed to an excluded status and next oldest order is now the first order.
		$status_change = $second_order &&
			in_array( $order->get_status(), $excluded_statuses, true );
		if ( $is_first_order && ( $date_change || $status_change ) ) {
			self::set_customer_first_order( $customer_id, $second_order->order_id );
			return true;
		}

		return (int) $order->get_id() !== (int) $first_order->order_id;
	}

	/**
	 * Set a customer's first order and all others to returning.
	 *
	 * @param int $customer_id Customer ID.
	 * @param int $order_id Order ID.
	 */
	protected static function set_customer_first_order( $customer_id, $order_id ) {
		global $wpdb;
		$orders_stats_table = self::get_db_table_name();

		$wpdb->query(
			$wpdb->prepare(
				"UPDATE ${orders_stats_table} SET returning_customer = CASE WHEN order_id = %d THEN false ELSE true END WHERE customer_id = %d",
				$order_id,
				$customer_id
			)
		);
	}

	/**
	 * Initialize query objects.
	 */
	protected function initialize_queries() {
		$this->clear_all_clauses();
		unset( $this->subquery );
		$this->total_query = new SqlQuery( $this->context . '_total' );
		$this->total_query->add_sql_clause( 'from', self::get_db_table_name() );

		$this->interval_query = new SqlQuery( $this->context . '_interval' );
		$this->interval_query->add_sql_clause( 'from', self::get_db_table_name() );
		$this->interval_query->add_sql_clause( 'group_by', 'time_interval' );
	}
}