bp_activity_create_parent_document_activity( $document_ids )

function bp_activity_create_parent_document_activity( $document_ids ) {
	global $bp_document_upload_count;

	if ( ! empty( $document_ids ) && ! isset( $_POST['bp_activity_update'] ) ) {

		$added_document_ids = $document_ids;
		$content            = false;

		if ( ! empty( $_POST['content'] ) ) {

			/**
			 * Filters the content provided in the activity input field.
			 *
			 * @param string $value Activity message being posted.
			 *
			 * @since BuddyPress 1.2.0
			 *
			 */
			$content = apply_filters( 'bp_activity_post_update_content', $_POST['content'] );
		}

		$group_id  = FILTER_INPUT( INPUT_POST, 'group_id', FILTER_SANITIZE_NUMBER_INT );
		$folder_id = false;

		if ( bp_is_active( 'groups' ) && ! empty( $group_id ) && $group_id > 0 ) {
			$activity_id = groups_post_update( array( 'content' => $content, 'group_id' => $group_id ) );
		} else {
			$activity_id = bp_activity_post_update( array( 'content' => $content ) );
		}

		//save document meta for activity.
		if ( ! empty( $activity_id ) ) {
			$privacy = 'public';

			foreach ( (array) $added_document_ids as $document_id ) {
				$document = new BP_Document( $document_id );

				// get one of the media's privacy for the activity privacy.
				$privacy = $document->privacy;

				// get document folder id.
				if ( ! empty( $document->folder_id ) ) {
					$folder_id = $document->folder_id;
				}

				if ( 1 === $bp_document_upload_count ) {
					//save media activity id in media
					$document->activity_id  = $activity_id;
					$document->group_id     = $group_id;
					$document->save();
				}

				//save parent activity id in attachment meta.
				update_post_meta( $document->attachment_id, 'bp_document_parent_activity_id', $activity_id );
			}

			bp_activity_update_meta( $activity_id, 'bp_document_ids', implode( ',', $added_document_ids ) );

			// if document is from folder then save folder id in activity meta.
			if ( ! empty( $folder_id ) ) {
				bp_activity_update_meta( $activity_id, 'bp_document_folder_activity', $folder_id );
			}

			if ( empty( $group_id ) ) {
				$main_activity = new BP_Activity_Activity( $activity_id );
				if ( ! empty( $main_activity ) ) {
					$main_activity->privacy = $privacy;
					$main_activity->save();
				}
			}
		}
	}

	return $document_ids;
}