/**
 * Storage backend interface and types
 */
export interface StorageResult {
    /** Unique key/path for the stored file */
    key: string;
    /** Public URL if backend supports it, undefined otherwise */
    publicUrl?: string;
}
export interface StorageUploadOptions {
    size?: number;
    hash?: string;
    mimeType?: string;
}
export interface StorageBackend {
    /** Backend type identifier */
    readonly type: StorageBackendType;
    /** Whether this backend provides public URLs */
    readonly hasPublicUrl: boolean;
    /**
     * Upload a file to storage
     * @param buffer File content
     * @param filename Original filename
     * @returns Storage result with key and optional public URL
     */
    upload(buffer: Buffer, filename: string): Promise<StorageResult>;
    uploadStream(stream: NodeJS.ReadableStream, filename: string, options?: StorageUploadOptions): Promise<StorageResult>;
    /**
     * Download a file from storage
     * @param key File key/path
     * @returns File content as Buffer
     */
    download(key: string): Promise<Buffer>;
    /**
     * Download a file from storage as a readable stream.
     * @param key File key/path
     * @returns Readable stream of file content
     */
    downloadStream(key: string): NodeJS.ReadableStream;
    /**
     * Delete a file from storage
     * @param key File key/path
     */
    delete(key: string): Promise<void>;
    /**
     * Check if a file exists in storage
     * @param key File key/path
     */
    exists(key: string): Promise<boolean>;
    /**
     * Initialize the storage backend
     */
    init(): Promise<void>;
}
export type StorageBackendType = 'local' | 's3' | 'webdav' | 'r2';
export interface LocalStorageConfig {
    type: 'local';
    storagePath: string;
}
export interface S3StorageConfig {
    type: 's3';
    endpoint: string;
    bucket: string;
    region: string;
    accessKeyId: string;
    secretAccessKey: string;
    pathStyle?: boolean;
}
export interface WebDAVStorageConfig {
    type: 'webdav';
    endpoint: string;
    username?: string;
    password?: string;
    basePath?: string;
}
export interface R2StorageConfig {
    type: 'r2';
    accountId: string;
    bucket: string;
    accessKeyId: string;
    secretAccessKey: string;
}
export type StorageConfig = LocalStorageConfig | S3StorageConfig | WebDAVStorageConfig | R2StorageConfig;
export declare function readStream(stream: NodeJS.ReadableStream): Promise<Buffer<ArrayBuffer>>;
type StreamingRequestInit = Omit<RequestInit, 'body'> & {
    duplex?: 'half';
};
type FetchRequestInit = RequestInit & {
    duplex?: 'half';
};
export declare function createStreamingRequestInit(stream: NodeJS.ReadableStream, init: StreamingRequestInit): FetchRequestInit;
export {};