h_stats['stats'] ) ) {
				// Combine all the stats, and keep the resize and send conversion settings separately.
				$stats['size_before'] += ! empty( $smush_stats['stats']['size_before'] ) ? $smush_stats['stats']['size_before'] : 0;
				$stats['size_after']  += ! empty( $smush_stats['stats']['size_after'] ) ? $smush_stats['stats']['size_after'] : 0;
			}

			$stats['count_images'] = 0;
			if ( isset( $smush_stats['sizes'] ) && is_array( $smush_stats['sizes'] ) ) {
				foreach ( $smush_stats['sizes'] as $image_stats ) {
					$stats['count_images'] += $image_stats->size_before !== $image_stats->size_after ? 1 : 0;
				}
			}

			$stats['count_supersmushed'] += ! empty( $smush_stats['stats'] ) && $smush_stats['stats']['lossy'] ? 1 : 0;

			// Add resize saving stats.
			if ( ! empty( $resize_savings ) ) {
				// Add resize and conversion savings.
				$stats['savings_resize'] += ! empty( $resize_savings['bytes'] ) ? $resize_savings['bytes'] : 0;
				$stats['size_before']    += ! empty( $resize_savings['size_before'] ) ? $resize_savings['size_before'] : 0;
				$stats['size_after']     += ! empty( $resize_savings['size_after'] ) ? $resize_savings['size_after'] : 0;
				$stats['count_resize']   += 1;
			}

			// Add conversion saving stats.
			if ( ! empty( $conversion_savings ) ) {
				// Add resize and conversion savings.
				$stats['savings_conversion'] += ! empty( $conversion_savings['bytes'] ) ? $conversion_savings['bytes'] : 0;
				$stats['size_before']        += ! empty( $conversion_savings['size_before'] ) ? $conversion_savings['size_before'] : 0;
				$stats['size_after']         += ! empty( $conversion_savings['size_after'] ) ? $conversion_savings['size_after'] : 0;
			}
			$stats['count_smushed'] += 1;
		}

		return $stats;
	}

	/**
	 * Set pro savings stats if not premium user.
	 *
	 * For non-premium users, show expected average savings based
	 * on the free version savings.
	 */
	public function set_pro_savings() {
		// No need this already premium.
		if ( WP_Smush::is_pro() ) {
			return;
		}

		// Initialize.
		$this->stats['pro_savings'] = array(
			'percent' => 0,
			'savings' => 0,
		);

		// Default values.
		$savings       = $this->stats['percent'] > 0 ? $this->stats['percent'] : 0;
		$savings_bytes = $this->stats['human'] > 0 ? $this->stats['bytes'] : '0';
		$orig_diff     = 2.22058824;
		if ( ! empty( $savings ) && $savings > 49 ) {
			$orig_diff = 1.22054412;
		}
		// Calculate Pro savings.
		if ( ! empty( $savings ) ) {
			$savings       = $orig_diff * $savings;
			$savings_bytes = $orig_diff * $savings_bytes;
		}

		// Set pro savings in global stats.
		if ( $savings > 0 ) {
			$this->stats['pro_savings'] = array(
				'percent' => number_format_i18n( $savings, 1 ),
				'savings' => size_format( $savings_bytes, 1 ),
			);
		}
	}

	/**
	 * Smush and Resizing Stats Combined together.
	 *
	 * @param array $smush_stats     Smush stats.
	 * @param array $resize_savings  Resize savings.
	 *
	 * @return array Array of all the stats
	 */
	public function combined_stats( $smush_stats, $resize_savings ) {
		if ( empty( $smush_stats ) || empty( $resize_savings ) ) {
			return $smush_stats;
		}

		// Initialize key full if not there already.
		if ( ! isset( $smush_stats['sizes']['full'] ) ) {
			$smush_stats['sizes']['full']              = new stdClass();
			$smush_stats['sizes']['full']->bytes       = 0;
			$smush_stats['sizes']['full']->size_before = 0;
			$smush_stats['sizes']['full']->size_after  = 0;
			$smush_stats['sizes']['full']->percent     = 0;
		}

		// Full Image.
		if ( ! empty( $smush_stats['sizes']['full'] ) ) {
			$smush_stats['sizes']['full']->bytes       = ! empty( $resize_savings['bytes'] ) ? $smush_stats['sizes']['full']->bytes + $resize_savings['bytes'] : $smush_stats['sizes']['full']->bytes;
			$smush_stats['sizes']['full']->size_before = ! empty( $resize_savings['size_before'] ) && ( $resize_savings['size_before'] > $smush_stats['sizes']['full']->size_before ) ? $resize_savings['size_before'] : $smush_stats['sizes']['full']->size_before;
			$smush_stats['sizes']['full']->percent     = ! empty( $smush_stats['sizes']['full']->bytes ) && $smush_stats['sizes']['full']->size_before > 0 ? ( $smush_stats['sizes']['full']->bytes / $smush_stats['sizes']['full']->size_before ) * 100 : $smush_stats['sizes']['full']->percent;

			$smush_stats['sizes']['full']->size_after = $smush_stats['sizes']['full']->size_before - $smush_stats['sizes']['full']->bytes;

			$smush_stats['sizes']['full']->percent = round( $smush_stats['sizes']['full']->percent, 1 );
		}

		return $this->total_compression( $smush_stats );
	}

	/**
	 * Combine Savings from PNG to JPG conversion with smush stats
	 *
	 * @param array $stats               Savings from Smushing the image.
	 * @param array $conversion_savings  Savings from converting the PNG to JPG.
	 *
	 * @return Object|array Total Savings
	 */
	public function combine_conversion_stats( $stats, $conversion_savings ) {
		if ( empty( $stats ) || empty( $conversion_savings ) ) {
			return $stats;
		}

		foreach ( $conversion_savings as $size_k => $savings ) {
			// Initialize Object for size.
			if ( empty( $stats['sizes'][ $size_k ] ) ) {
				$stats['sizes'][ $size_k ]              = new stdClass();
				$stats['sizes'][ $size_k ]->bytes       = 0;
				$stats['sizes'][ $size_k ]->size_before = 0;
				$stats['sizes'][ $size_k ]->size_after  = 0;
				$stats['sizes'][ $size_k ]->percent     = 0;
			}

			if ( ! empty( $stats['sizes'][ $size_k ] ) && ! empty( $savings ) ) {
				$stats['sizes'][ $size_k ]->bytes       = $stats['sizes'][ $size_k ]->bytes + $savings['bytes'];
				$stats['sizes'][ $size_k ]->size_before = $stats['sizes'][ $size_k ]->size_before > $savings['size_before'] ? $stats['sizes'][ $size_k ]->size_before : $savings['size_before'];
				$stats['sizes'][ $size_k ]->percent     = ! empty( $stats['sizes'][ $size_k ]->bytes ) && $stats['sizes'][ $size_k ]->size_before > 0 ? ( $stats['sizes'][ $size_k ]->bytes / $stats['sizes'][ $size_k ]->size_before ) * 100 : $stats['sizes'][ $size_k ]->percent;
				$stats['sizes'][ $size_k ]->percent     = round( $stats['sizes'][ $size_k ]->percent, 1 );
			}
		}

		return $this->total_compression( $stats );
	}

	/**
	 * Iterate over all the size stats and calculate the total stats
	 *
	 * @param array $stats  Stats array.
	 *
	 * @return mixed
	 */
	public function total_compression( $stats ) {
		$stats['stats']['size_before'] = 0;
		$stats['stats']['size_after']  = 0;
		$stats['stats']['time']        = 0;

		foreach ( $stats['sizes'] as $size_stats ) {
			$stats['stats']['size_before'] += ! empty( $size_stats->size_before ) ? $size_stats->size_before : 0;
			$stats['stats']['size_after']  += ! empty( $size_stats->size_after ) ? $size_stats->size_after : 0;
			$stats['stats']['time']        += ! empty( $size_stats->time ) ? $size_stats->time : 0;
		}

		$stats['stats']['bytes'] = ! empty( $stats['stats']['size_before'] ) && $stats['stats']['size_before'] > $stats['stats']['size_after'] ? $stats['stats']['size_before'] - $stats['stats']['size_after'] : 0;

		if ( ! empty( $stats['stats']['bytes'] ) && ! empty( $stats['stats']['size_before'] ) ) {
			$stats['stats']['percent'] = ( $stats['stats']['bytes'] / $stats['stats']['size_before'] ) * 100;
		}

		return $stats;
	}

	/**
	 * Get all the attachment meta, sum up the stats and return
	 *
	 * @param bool $force_update     Whether to forcefully update the cache.
	 *
	 * @return array|bool|mixed
	 */
	private function global_stats( $force_update = false ) {
		$stats = get_option( 'smush_global_stats' );

		// Remove id from global stats stored in db.
		if ( ! $force_update && $stats && ! empty( $stats ) && isset( $stats['size_before'] ) ) {
			if ( isset( $stats['id'] ) ) {
				unset( $stats['id'] );
			}

			return $stats;
		}

		global $wpdb;

		$smush_data = array(
			'size_before'  => 0,
			'size_after'   => 0,
			'percent'      => 0,
			'human'        => 0,
			'bytes'        => 0,
			'total_images' => 0,
		);

		$offset       = 0;
		$supersmushed = 0;
		$query_next   = true;

		while ( $query_next ) {
			$global_data = $wpdb->get_results(
				$wpdb->prepare(
					"SELECT post_id, meta_value FROM {$wpdb->postmeta} WHERE meta_key=%s LIMIT %d, %d",
					Modules\Smush::$smushed_meta_key,
					$offset,
					$this->query_limit
				)
			); // Db call ok; no-cache ok.

			// If we didn't got any results.
			if ( ! $global_data ) {
				break;
			}

			foreach ( $global_data as $data ) {
				// Skip attachment, if not in attachment list.
				if ( ! in_array( $data->post_id, $this->attachments, true ) ) {
					continue;
				}

				$smush_data['id'][] = $data->post_id;
				if ( ! empty( $data->meta_value ) ) {
					$meta = maybe_unserialize( $data->meta_value );
					if ( ! empty( $meta['stats'] ) ) {

						// Check for lossy compression.
						if ( true === $meta['stats']['lossy'] ) {
							$supersmushed++;
						}

						// If the image was optimised.
						if ( ! empty( $meta['stats'] ) && $meta['stats']['size_before'] >= $meta['stats']['size_after'] ) {
							// Total Image Smushed.
							$smush_data['total_images'] += ! empty( $meta['sizes'] ) ? count( $meta['sizes'] ) : 0;
							$smush_data['size_before']  += ! empty( $meta['stats']['size_before'] ) ? (int) $meta['stats']['size_before'] : 0;
							$smush_data['size_after']   += ! empty( $meta['stats']['size_after'] ) ? (int) $meta['stats']['size_after'] : 0;
						}
					}
				}
			}

			$smush_data['bytes'] = $smush_data['size_before'] - $smush_data['size_after'];

			// Update the offset.
			$offset += $this->query_limit;

			// Compare the Offset value to total images.
			if ( ! empty( $this->total_count ) && $this->total_count <= $offset ) {
				$query_next = false;
			}
		}

		// Add directory smush image bytes.
		if ( ! empty( $this->dir_stats['bytes'] ) && $this->dir_stats['bytes'] > 0 ) {
			$smush_data['bytes'] += $this->dir_stats['bytes'];
		}
		// Add directory smush image total size.
		if ( ! empty( $this->dir_stats['orig_size'] ) && $this->dir_stats['orig_size'] > 0 ) {
			$smush_data['size_before'] += $this->dir_stats['orig_size'];
		}
		// Add directory smush saved size.
		if ( ! empty( $this->dir_stats['image_size'] ) && $this->dir_stats['image_size'] > 0 ) {
			$smush_data['size_after'] += $this->dir_stats['image_size'];
		}
		// Add directory smushed images.
		if ( ! empty( $this->dir_stats['optimised'] ) && $this->dir_stats['optimised'] > 0 ) {
			$smush_data['total_images'] += $this->dir_stats['optimised'];
		}

		// Resize Savings.
		$smush_data['resize_count']   = $this->get_savings( 'resize', false, false, true );
		$resize_savings               = $this->get_savings( 'resize', false );
		$smush_data['resize_savings'] = ! empty( $resize_savings['bytes'] ) ? $resize_savings['bytes'] : 0;

		// Conversion Savings.
		$conversion_savings               = $this->get_savings( 'pngjpg', false );
		$smush_data['conversion_savings'] = ! empty( $conversion_savings['bytes'] ) ? $conversion_savings['bytes'] : 0;

		if ( ! isset( $smush_data['bytes'] ) || $smush_data['bytes'] < 0 ) {
			$smush_data['bytes'] = 0;
		}

		// Add the resize savings to bytes.
		$smush_data['bytes']       += $smush_data['resize_savings'];
		$smush_data['size_before'] += $resize_savings['size_before'];
		$smush_data['size_after']  += $resize_savings['size_after'];

		// Add Conversion Savings.
		$smush_data['bytes']       += $smush_data['conversion_savings'];
		$smush_data['size_before'] += $conversion_savings['size_before'];
		$smush_data['size_after']  += $conversion_savings['size_after'];

		if ( $smush_data['size_before'] > 0 ) {
			$smush_data['percent'] = ( $smush_data['bytes'] / $smush_data['size_before'] ) * 100;
		}

		// Round off percentage.
		$smush_data['percent'] = round( $smush_data['percent'], 1 );

		// Human-readable format.
		$smush_data['human'] = size_format(
			$smush_data['bytes'],
			( $smush_data['bytes'] >= 1024 ) ? 1 : 0
		);

		// Setup Smushed attachment IDs.
		$this->smushed_attachments = ! empty( $smush_data['id'] ) ? $smush_data['id'] : '';

		// Super Smushed attachment count.
		$this->super_smushed = $supersmushed;

		// Remove ids from stats.
		unset( $smush_data['id'] );

		// Update cache.
		update_option( 'smush_global_stats', $smush_data, false );

		return $smush_data;
	}

	/**
	 * Returns remaining count
	 *
	 * @return int
	 */
	private function remaining_count() {
		$resmush_count   = count( $this->resmush_ids );
		$remaining_count = $this->total_count - $this->smushed_count - $this->skipped_count;

		// Just a failsafe - can't have remaining value be a negative value.
		$remaining_count = $remaining_count > 0 ? $remaining_count : 0;

		// Check if the resmush count is equal to remaining count.
		if ( $resmush_count > 0 && ( $resmush_count !== $this->smushed_count || 0 === absint( $remaining_count ) ) ) {
			return $resmush_count + $remaining_count;
		}

		return $remaining_count;
	}

	/**
	 * Return the number of skipped attachments.
	 *
	 * @since 3.0
	 *
	 * @param bool $force  Force data refresh.
	 *
	 * @return array
	 */
	private function skipped_count( $force ) {
		$images = wp_cache_get( 'skipped_images', 'wp-smush' );
		if ( ! $force && $images ) {
			return $images;
		}

		global $wpdb;
		$images = $wpdb->get_col( "SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key='wp-smush-ignore-bulk'" ); // Db call ok.
		wp_cache_set( 'skipped_images', $images, 'wp-smush' );

		return $images;
	}

}