field name is. If the field
 * has a strict value set, then it will be tested for that, else a more generic
 * filtering is applied. After the more strict filter is applied, if the `$context`
 * is 'raw' then the value is immediately return.
 *
 * Hooks exist for the more generic cases. With the 'edit' context, the {@see 'edit_$field'}
 * filter will be called and passed the `$value` and `$bookmark_id` respectively.
 *
 * With the 'db' context, the {@see 'pre_$field'} filter is called and passed the value.
 * The 'display' context is the final context and has the `$field` has the filter name
 * and is passed the `$value`, `$bookmark_id`, and `$context`, respectively.
 *
 * @since 2.3.0
 *
 * @param string $field       The bookmark field.
 * @param mixed  $value       The bookmark field value.
 * @param int    $bookmark_id Bookmark ID.
 * @param string $context     How to filter the field value. Accepts 'raw', 'edit', 'db',
 *                            'display', 'attribute', or 'js'. Default 'display'.
 * @return mixed The filtered value.
 */
function sanitize_bookmark_field( $field, $value, $bookmark_id, $context ) {
	$int_fields = array( 'link_id', 'link_rating' );
	if ( in_array( $field, $int_fields, true ) ) {
		$value = (int) $value;
	}

	switch ( $field ) {
		case 'link_category': // array( ints )
			$value = array_map( 'absint', (array) $value );
			// We return here so that the categories aren't filtered.
			// The 'link_category' filter is for the name of a link category, not an array of a link's link categories.
			return $value;

		case 'link_visible': // bool stored as Y|N
			$value = preg_replace( '/[^YNyn]/', '', $value );
			break;
		case 'link_target': // "enum"
			$targets = array( '_top', '_blank' );
			if ( ! in_array( $value, $targets, true ) ) {
				$value = '';
			}
			break;
	}

	if ( 'raw' === $context ) {
		return $value;
	}

	if ( 'edit' === $context ) {
		/** This filter is documented in wp-includes/post.php */
		$value = apply_filters( "edit_{$field}", $value, $bookmark_id );

		if ( 'link_notes' === $field ) {
			$value = esc_html( $value ); // textarea_escaped
		} else {
			$value = esc_attr( $value );
		}
	} elseif ( 'db' === $context ) {
		/** This filter is documented in wp-includes/post.php */
		$value = apply_filters( "pre_{$field}", $value );
	} else {
		/** This filter is documented in wp-includes/post.php */
		$value = apply_filters( "{$field}", $value, $bookmark_id, $context );

		if ( 'attribute' === $context ) {
			$value = esc_attr( $value );
		} elseif ( 'js' === $context ) {
			$value = esc_js( $value );
		}
	}

	// Restore the type for integer fields after esc_attr().
	if ( in_array( $field, $int_fields, true ) ) {
		$value = (int) $value;
	}

	return $value;
}

/**
 * Deletes the bookmark cache.
 *
 * @since 2.7.0
 *
 * @param int $bookmark_id Bookmark ID.
 */
function clean_bookmark_cache( $bookmark_id ) {
	wp_cache_delete( $bookmark_id, 'bookmark' );
	wp_cache_delete( 'get_bookmarks', 'bookmark' );
	clean_object_term_cache( $bookmark_id, 'link' );
}