import { ObjectChangeTracker } from "@schoolbelle/common/object-change-tracker";
import { FileListService, FileInfoType } from "@schoolbelle/api/file";
import { MailMergeItem } from "@schoolbelle/api/letter";
import { pushMethod } from "@schoolbelle/api/notification-push";
import { LetterTranslationsService } from "./letter-translations.serivce";
export declare class LetterTracker extends ObjectChangeTracker {
    letter_id: number;
    type: string;
    title: string;
    content: string;
    targets: any;
    targets_simplified: any;
    fileList: FileListService;
    files: (Blob | FileInfoType)[];
    hasMailmerge: boolean;
    mailmerge: MailMergeItem[];
    readonly questionnaire_id: any;
    readonly survey_id: any;
    survey_id_g3: string;
    push_method: pushMethod;
    sms_content: string;
    sms_sender: string;
    author_name: string;
    translations: LetterTranslationsService;
    lang: string;
    _draw_at: Date;
    draw_at: Date;
    _issue_at: Date;
    issue_at: Date;
    readonly isChanged: boolean;
    constructor();
    load(data?: any): void;
    overwrite(data: any): void;
}