ioseo()->helpers->validateIp( $ip ) ? $ip : __( '(Invalid IP)', 'all-in-one-seo-pack' );
			if ( ! $this->allowBot() ) {
				if ( $track ) {
					$userAgent = $_SERVER['HTTP_USER_AGENT'];
					// Translators: 1 - The IP address. 2 - The user agent.
					$this->track( sprintf( __( 'Blocked bot with IP %1$s -- matched user agent %2$s found in blocklist.', 'all-in-one-seo-pack' ), $ip, $userAgent ) );
				}
				status_header( 503 );
				exit;
			} elseif ( $blockReferer && $this->isBadReferer() ) {
				status_header( 503 );
				if ( $track ) {
					$referer = ! empty( $_SERVER['HTTP_REFERER'] ) ? esc_url_raw( wp_unslash( $_SERVER['HTTP_REFERER'] ) ) : '';
					// Translators: 1 - The IP address. 2 - The referer.
					$this->track( sprintf( __( 'Blocked bot with IP %1$s -- matched referer %2$s found in blocklist.', 'all-in-one-seo-pack' ), $ip, $referer ) );
				}
				status_header( 503 );
				exit;
			}
		}
	}

	/**
	 * Get the size of the log file.
	 *
	 * @since 4.0.0
	 *
	 * @return integer The size of the log file.
	 */
	public function getLogSize() {
		$uploadDirectory = wp_upload_dir();
		$logDirectory    = $uploadDirectory['basedir'] . '/aioseo/logs/';
		$filePath        = $logDirectory . 'aioseo-bad-bot-blocker.log';
		$fs              = aioseo()->core->fs;
		if ( $fs->exists( $filePath ) ) {
			return $fs->size( $filePath );
		}

		return 0;
	}

	/**
	 * Clears the log for the bad bot blocker.
	 *
	 * @since 4.0.0
	 *
	 * @return integer The file size.
	 */
	public function clearLog() {
		$uploadDirectory = wp_upload_dir();
		$logDirectory    = $uploadDirectory['basedir'] . '/aioseo/logs/';
		$filePath        = $logDirectory . 'aioseo-bad-bot-blocker.log';
		$fs              = aioseo()->core->fs;
		if ( $fs->exists( $filePath ) ) {
			$fs->putContents( $filePath, '' );
		}

		return $this->getLogSize();
	}

	/**
	 * Returns the bot list.
	 *
	 * @since 4.0.0
	 *
	 * @return array The bot list.
	 */
	public function getBotList() {
		return $this->botList;
	}

	/**
	 * Returns the referer list.
	 *
	 * @since 4.0.0
	 *
	 * @return array The referer list.
	 */
	public function getRefererList() {
		return $this->refererList;
	}

	/**
	 * Whether or not to allow the bot through.
	 *
	 * @since 4.0.0
	 *
	 * @return boolean True if this is a good bot and we can allow it through.
	 */
	private function allowBot() {
		$allow = true;
		if ( ! $this->isGoodBot() && $this->isBadBot() && ! is_user_logged_in() ) {
			$allow = false;
		}

		return apply_filters( 'aioseo_allow_bot', $allow );
	}

	/**
	 * Is this a good bot?
	 *
	 * @see  Original code, thanks to Sean M. Brown.
	 * @link http://smbrown.wordpress.com/2009/04/29/verify-googlebot-forward-reverse-dns/
	 *
	 * @since 4.0.0
	 *
	 * @return boolean True if this is a good bot.
	 */
	private function isGoodBot() {
		$botList = [
			'Yahoo! Slurp' => 'crawl.yahoo.net',
			'googlebot'    => '.googlebot.com',
			'msnbot'       => 'search.msn.com',
		];
		$botList = apply_filters( 'aioseo_good_bot_list', $botList );
		if ( ! empty( $botList ) ) {
			if ( ! isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
				return false;
			}
			$ua  = $_SERVER['HTTP_USER_AGENT'];
			$uas = $this->prepareList( $botList );
			if ( preg_match( '/' . $uas . '/i', $ua ) ) {
				$ip           = $_SERVER['REMOTE_ADDR'];
				$hostname     = gethostbyaddr( $ip );
				$ipByHostName = gethostbyname( $hostname );
				if ( $ipByHostName === $ip ) {
					$hosts = array_values( $botList );
					foreach ( $hosts as $k => $h ) {
						$hosts[ $k ] = preg_quote( $h ) . '$';
					}
					$hosts = join( '|', $hosts );
					if ( preg_match( '/' . $hosts . '/i', $hostname ) ) {
						return true;
					}
				}
			}
		}

		return false;
	}

	/**
	 * Is this a bad bot?
	 *
	 * @since 4.0.0
	 *
	 * @return boolean True if it is a bad bot.
	 */
	private function isBadBot() {
		$botList = aioseo()->options->deprecated->tools->blocker->custom->enable
			? explode( "\n", aioseo()->options->deprecated->tools->blocker->custom->bots )
			: $this->botList;
		$botList = apply_filters( 'aioseo_bad_bot_list', $botList );
		if ( ! empty( $botList ) ) {
			if ( ! isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
				return false;
			}
			$ua  = $_SERVER['HTTP_USER_AGENT'];
			$uas = $this->prepareList( $botList );
			if ( preg_match( '/' . $uas . '/i', $ua ) ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Is this a bad referer?
	 *
	 * @since 4.0.0
	 *
	 * @return boolean True if this is a bad referer.
	 */
	private function isBadReferer() {
		$refererList = aioseo()->options->deprecated->tools->blocker->custom->enable
			? explode( "\n", aioseo()->options->deprecated->tools->blocker->custom->referer )
			: $this->refererList;
		$refererList = apply_filters( 'aioseo_bad_referer_list', $refererList );

		if ( ! empty( $refererList ) && ! empty( $_SERVER ) && ! empty( $_SERVER['HTTP_REFERER'] ) ) {
			$referer = esc_url_raw( wp_unslash( $_SERVER['HTTP_REFERER'] ) );
			$regex   = $this->prepareList( $refererList );
			if ( preg_match( '/' . $regex . '/i', $referer ) ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Quote List for Regex
	 *
	 * @since 4.0.0
	 *
	 * @param        $list
	 * @param string $quote
	 * @return string
	 */
	private function prepareList( $list, $quote = '/' ) {
		$regex = '';
		$cont  = 0;
		foreach ( $list as $l ) {
			$trim_l = trim( $l );
			if ( ! empty( $trim_l ) ) {
				if ( $cont ) {
					$regex .= '|';
				}
				$cont   = 1;
				$regex .= preg_quote( trim( $l ), $quote );
			}
		}

		return $regex;
	}

	/**
	 * Tracks the bad bot that was blocked.
	 *
	 * @since 4.0.0
	 *
	 * @param  string $message The message to log.
	 * @return void
	 */
	public function track( $message ) {
		if ( $this->log ) {
			$this->log->info( $message );
		}
	}
}