import { LitElement } from "lit";
export interface DownloadItem {
    id: string;
    url: string;
    filename: string;
    size: number;
    downloaded: number;
    status: "pending" | "downloading" | "paused" | "completed" | "error";
    chunks: ChunkInfo[];
    error?: string;
    startTime?: number;
    endTime?: number;
}
export interface ChunkInfo {
    start: number;
    end: number;
    downloaded: number;
    status: "pending" | "downloading" | "completed" | "error";
}
export declare class DownloadManager extends LitElement {
    static styles: import("lit").CSSResult[];
    chunkSize: number;
    maxConcurrentDownloads: number;
    maxConcurrentChunks: number;
    downloads: DownloadItem[];
    private isAddingFiles;
    private activeDownloads;
    private storageKey;
    connectedCallback(): void;
    disconnectedCallback(): void;
    private setupVisibilityChangeHandler;
    private loadState;
    saveState(): void;
    private getFileSize;
    createChunks(totalSize: number): ChunkInfo[];
    private downloadChunk;
    private downloadFile;
    pauseDownload(downloadId: string): void;
    resumeDownload(downloadId: string): void;
    removeDownload(downloadId: string): void;
    clearCompleted: () => void;
    formatBytes(bytes: number): string;
    formatDuration(ms: number): string;
    getProgressPercentage(download: DownloadItem): number;
    private getDownloadSpeed;
    private getETA;
    private addDownload;
    handleAddDownload: (event: Event) => void;
    private getStatusClass;
    private getProgressBarClass;
    render(): import("lit-html").TemplateResult<1>;
}