import { PropertyValues } from 'lit';
import { PktElement } from '../../base-elements/element';
import { FileItem, IPktFileUpload, TQueueItemOperation, TFileTransfer, TFileUploadItemRenderer, TFilesChangedReason, TTransferProgress, TUploadStrategy } from './fileupload-types';
export declare abstract class PktFileUploadBase extends PktElement<IPktFileUpload> implements IPktFileUpload {
    /** Unique id used for internal input + wrapper wiring. Defaults to a per-instance uuid. */
    id: string;
    /** Field name used by native input (`form`) or hidden fileId inputs (`custom`). */
    name: string;
    /** Optional label shown by `pkt-input-wrapper`. */
    label: string;
    /** Optional help text shown under label. */
    helptext: string;
    /** Mark input as required in form strategy. */
    required: boolean;
    /** Allow selecting/dropping multiple files. */
    multiple: boolean;
    /** Disable all interaction in drop zone + queue actions. */
    disabled: boolean;
    /** Stretch component width to container. */
    fullwidth: boolean;
    /** Upload mode: `form` uses native file submit, `custom` emits upload request events per file. */
    uploadStrategy: TUploadStrategy;
    /** Queue visual mode (`filename` or `thumbnail`). */
    itemRenderer: TFileUploadItemRenderer;
    /** Native file input accept hint (browser picker filtering). */
    accept: string;
    /** Built-in format validation source (csv attribute or array property). */
    allowedFormats: string[];
    /** Optional custom format validation message. Supports `{formats}` placeholder. */
    formatErrorMessage: string;
    /** Max allowed file size (bytes or string like `500KB`, `5MB`). */
    maxFileSize?: string | number;
    /** Optional custom size validation message. Supports `{maxSize}` placeholder. */
    sizeErrorMessage: string;
    /** Optional JS callback for custom validation. Property-only on purpose (not HTML-attribute friendly). */
    onFileValidation?: (file: File) => string | null;
    /** Transfer state list keyed by `fileId` (used for custom upload progress/error/cancel UI). */
    transfers: TFileTransfer[];
    /** Enables built-in comment operation in queue items (disabled in thumbnail view for parity with React). */
    addCommentsEnabled: boolean;
    /** Enables built-in rename operation in queue items (disabled in thumbnail view for parity with React). */
    renameFilesEnabled: boolean;
    /** Custom queue operations (JS property only). Supports inline + expanded operation UIs. */
    extraOperations: TQueueItemOperation[];
    /** Toggle image thumbnail behavior in queue when renderer supports it. */
    enableImagePreview: boolean;
    /** External error flag — combines with internal validation errors. */
    hasError: boolean;
    /** External error message shown in the alert under the drop zone. */
    errorMessage: string;
    /** Show "Valgfritt" tag in the input wrapper. */
    optionalTag: boolean;
    /** Show "Må fylles ut" tag in the input wrapper. */
    requiredTag: boolean;
    /** Trailing characters to keep when middle-truncating long filenames. Set to `0` to disable. */
    truncateTail: number;
    /** Controlled mode source of truth. Parent owns file list and updates this prop from events. */
    value?: FileItem[];
    /** Uncontrolled initial file list. Used once during first initialization. */
    defaultValue?: FileItem[];
    protected files: FileItem[];
    protected isDragActive: boolean;
    protected validationErrorMessage: string | null;
    protected addedAnnouncement: string;
    private thumbnailUrls;
    private hasInitializedValue;
    private hasWarnedInvalidValueCombo;
    private thumbnailFileById;
    private connectedForm;
    private addedAnnouncementTimer;
    private readonly requiredSelectionMessage;
    protected get isControlled(): boolean;
    /** True if the component itself wants to show an error (internal validation or external prop). */
    protected get hasEffectiveError(): boolean;
    /** Message to show in the alert under the drop zone. Internal validation takes priority. */
    protected get effectiveErrorMessage(): string;
    protected get hasValidationError(): boolean;
    protected firstUpdated(changedProperties: PropertyValues): void;
    protected willUpdate(changedProperties: PropertyValues): void;
    protected updated(changedProperties: PropertyValues): void;
    private syncNativeInputFiles;
    private warnInvalidValueCombo;
    disconnectedCallback(): void;
    private setAddedAnnouncement;
    connectedCallback(): void;
    protected onNativeFileChange: (event: Event) => void;
    protected openFileDialog: (event: Event) => void;
    protected onDropZoneClick: (event: MouseEvent) => void;
    protected onDragOver: (event: DragEvent) => void;
    protected onDragLeave: () => void;
    protected onDrop: (event: DragEvent) => void;
    protected addFiles(selectedFiles: File[]): void;
    protected getCurrentFiles(): FileItem[];
    protected cancelTransfer(fileId: string): void;
    protected removeFileItem(fileId: string): void;
    updateFileItem(fileId: string, updates: Partial<FileItem>): void;
    protected commitFiles(nextFiles: FileItem[], reason: TFilesChangedReason, changedFileIds?: string[]): void;
    protected getThumbnailUrl(file: FileItem): string | undefined;
    protected getTransferProgress(fileId: string): TTransferProgress;
    protected getTransferForFile(fileId: string): TFileTransfer | undefined;
    protected isImageFile(file: FileItem): boolean;
    protected formatFileSize(bytes: number): string;
    protected getResolvedAcceptValue(): string;
    protected getSupportedFormatsText(): string;
    protected getSortedFilesAndTransfers(): import('../../../../../shared-utils/fileupload').IFileAndTransfer[];
    private validateFile;
    private syncThumbnailUrls;
    private revokeAllThumbnailUrls;
    /** Polite summary: prefer the transient "file added" announcement, then fall back to upload completion. */
    protected getSrUploadedMessage(): string;
    /** Assertive summary for transfer errors (parity with React `FileUpload`). */
    protected getSrErrorsMessage(): string;
    private syncFormSubmitListener;
    private teardownFormSubmitListener;
    private onHostFormSubmit;
}