Send an email to the user with a link to the personal data export file

function wp_privacy_send_personal_data_export_email( $request_id ) {
	// Get the request.
	$request = wp_get_user_request( $request_id );

	if ( ! $request || 'export_personal_data' !== $request->action_name ) {
		return new WP_Error( 'invalid_request', __( 'Invalid request ID when sending personal data export email.' ) );
	}

	// Localize message content for user; fallback to site default for visitors.
	if ( ! empty( $request->user_id ) ) {
		$locale = get_user_locale( $request->user_id );
	} else {
		$locale = get_locale();
	}

	$switched_locale = switch_to_locale( $locale );

	/** This filter is documented in wp-includes/functions.php */
	$expiration      = apply_filters( 'wp_privacy_export_expiration', 3 * DAY_IN_SECONDS );
	$expiration_date = date_i18n( get_option( 'date_format' ), time() + $expiration );

	$exports_url      = wp_privacy_exports_url();
	$export_file_name = get_post_meta( $request_id, '_export_file_name', true );
	$export_file_url  = $exports_url . $export_file_name;

	$site_name = wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES );
	$site_url  = home_url();

	/**
	 * Filters the recipient of the personal data export email notification.
	 * Should be used with great caution to avoid sending the data export link to wrong emails.
	 *
	 * @since 5.3.0
	 *
	 * @param string          $request_email The email address of the notification recipient.
	 * @param WP_User_Request $request       The request that is initiating the notification.
	 */
	$request_email = apply_filters( 'wp_privacy_personal_data_email_to', $request->email, $request );

	$email_data = array(
		'request'           => $request,
		'expiration'        => $expiration,
		'expiration_date'   => $expiration_date,
		'message_recipient' => $request_email,
		'export_file_url'   => $export_file_url,
		'sitename'          => $site_name,
		'siteurl'           => $site_url,
	);

	/* translators: Personal data export notification email subject. %s: Site title. */
	$subject = sprintf( __( '[%s] Personal Data Export' ), $site_name );

	/**
	 * Filters the subject of the email sent when an export request is completed.
	 *
	 * @since 5.3.0
	 *
	 * @param string $subject    The email subject.
	 * @param string $sitename   The name of the site.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request           User request object.
	 *     @type int             $expiration        The time in seconds until the export file expires.
	 *     @type string          $expiration_date   The localized date and time when the export file expires.
	 *     @type string          $message_recipient The address that the email will be sent to. Defaults
	 *                                              to the value of `$request->email`, but can be changed
	 *                                              by the `wp_privacy_personal_data_email_to` filter.
	 *     @type string          $export_file_url   The export file URL.
	 *     @type string          $sitename          The site name sending the mail.
	 *     @type string          $siteurl           The site URL sending the mail.
	 * }
	 */
	$subject = apply_filters( 'wp_privacy_personal_data_email_subject', $subject, $site_name, $email_data );

	/* translators: Do not translate EXPIRATION, LINK, SITENAME, SITEURL: those are placeholders. */
	$email_text = __(
		'Howdy,

Your request for an export of personal data has been completed. You may
download your personal data by clicking on the link below. For privacy
and security, we will automatically delete the file on ###EXPIRATION###,
so please download it before then.

###LINK###

Regards,
All at ###SITENAME###
###SITEURL###'
	);

	/**
	 * Filters the text of the email sent with a personal data export file.
	 *
	 * The following strings have a special meaning and will get replaced dynamically:
	 * ###EXPIRATION###         The date when the URL will be automatically deleted.
	 * ###LINK###               URL of the personal data export file for the user.
	 * ###SITENAME###           The name of the site.
	 * ###SITEURL###            The URL to the site.
	 *
	 * @since 4.9.6
	 * @since 5.3.0 Introduced the `$email_data` array.
	 *
	 * @param string $email_text Text in the email.
	 * @param int    $request_id The request ID for this personal data export.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request           User request object.
	 *     @type int             $expiration        The time in seconds until the export file expires.
	 *     @type string          $expiration_date   The localized date and time when the export file expires.
	 *     @type string          $message_recipient The address that the email will be sent to. Defaults
	 *                                              to the value of `$request->email`, but can be changed
	 *                                              by the `wp_privacy_personal_data_email_to` filter.
	 *     @type string          $export_file_url   The export file URL.
	 *     @type string          $sitename          The site name sending the mail.
	 *     @type string          $siteurl           The site URL sending the mail.
	 */
	$content = apply_filters( 'wp_privacy_personal_data_email_content', $email_text, $request_id, $email_data );

	$content = str_replace( '###EXPIRATION###', $expiration_date, $content );
	$content = str_replace( '###LINK###', sanitize_url( $export_file_url ), $content );
	$content = str_replace( '###EMAIL###', $request_email, $content );
	$content = str_replace( '###SITENAME###', $site_name, $content );
	$content = str_replace( '###SITEURL###', sanitize_url( $site_url ), $content );

	$headers = '';

	/**
	 * Filters the headers of the email sent with a personal data export file.
	 *
	 * @since 5.4.0
	 *
	 * @param string|array $headers    The email headers.
	 * @param string       $subject    The email subject.
	 * @param string       $content    The email content.
	 * @param int          $request_id The request ID.
	 * @param array        $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request           User request object.
	 *     @type int             $expiration        The time in seconds until the export file expires.
	 *     @type string          $expiration_date   The localized date and time when the export file expires.
	 *     @type string          $message_recipient The address that the email will be sent to. Defaults
	 *                                              to the value of `$request->email`, but can be changed
	 *                                              by the `wp_privacy_personal_data_email_to` filter.
	 *     @type string          $export_file_url   The export file URL.
	 *     @type string          $sitename          The site name sending the mail.
	 *     @type string          $siteurl           The site URL sending the mail.
	 * }
	 */
	$headers = apply_filters( 'wp_privacy_personal_data_email_headers', $headers, $subject, $content, $request_id, $email_data );

	$mail_success = wp_mail( $request_email, $subject, $content, $headers );

	if ( $switched_locale ) {
		restore_previous_locale();
	}

	if ( ! $mail_success ) {
		return new WP_Error( 'privacy_email_error', __( 'Unable to send personal data export email.' ) );
	}

	return true;
}