//type OcflExtensionCreate = <T extends typeof import('./extension').OcflExtension>(this: T, config?: OcflExtensionConfig) => InstanceType<T>;

// import { Abortable } from "events";
// import { ObjectEncodingOptions, OpenMode, PathLike } from "fs";
// import { FileHandle } from "fs/promises";
type OpenMode = number | string;

interface ReadFile {
  /**
   * Provide a common interface to read a file inside an object. 
   * A concrete subclass MAY implement this method to provide read access to its underlying storage backend.
   * The default implementation uses the {@linkcode OcflStore#createReadStream} method.
   * @param path - The absolute path of the file to be read.
   * @param options - Options to be passed to the underlying method
   */
  readFile(
    filePath: string,
    options?:
      | {
        encoding?: null | undefined;
        flag?: OpenMode | undefined;
      }
      | null
  ): Promise<Buffer>;

  /**
   * Provide a common interface to read a file inside an object. 
   * A concrete subclass MAY implement this method to provide read access to its underlying storage backend.
   * The default implementation uses the {@linkcode OcflStore#createReadStream} method.
   * @param path - The absolute path of the file to be read.
   * @param options - Options to be passed to the underlying method
   */
  readFile(
    filePath: string,
    options:
      | {
        encoding: BufferEncoding;
        flag?: OpenMode | undefined;
      }
      | BufferEncoding
  ): Promise<string>;
}

export interface InventoryDigests {
  [key: string]: string[];
}

export interface InventoryVersion {
  created: string;
  message?: string;
  state: InventoryDigests;
  user?: {
    name: string;
    address?: string;
  };
}

export interface Inventory {
  /** A unique identifier for the OCFL Object. */
  id: string;
  /** The URI of the inventory section of the specification version matching the object conformance declaration. */
  type: 'https://ocfl.io/1.0/spec/#inventory' | 'https://ocfl.io/1.1/spec/#inventory';
  /** 
   * The algorithm used for calculating digests for content-addressing 
   * within the OCFL Object and for the Inventory Digest. 
   * This MUST be the algorithm used in the manifest and state blocks 
   */
  digestAlgorithm: 'sha256' | 'sha512';
  /** The version directory name of the most recent version of the object. */
  head: string;
  manifest: InventoryDigests;
  versions: {
    [key: string]: InventoryVersion;
  };
  fixity?: {
    [key: string]: {
      [key: string]: string[];
    };
    // [key in 'md5'|'sha1'|'sha256'|'sha512'|'blake2b-512'|'blake2b-160'|'blake2b-256'|'blake2b-384'|'sha512-256'|'size'|'crc32']: {};
  };
  /** 
   * The name of the designated content directory within the version directories.
   * @default content
   */
  contentDirectory?: string;
}

//type Enum<T extends readonly string[]> = {[key in T[number]]: ReturnType<typeof enumeration<T>>};
//declare function enumeration<T extends readonly string[]>(arr:  T): Enum<T>;
export type IDataType = string | ArrayBufferLike | Uint8Array | Uint16Array | Uint32Array;

export interface CommonHasher {
  init: () => CommonHasher;
  update: (data: IDataType) => CommonHasher;
  digest: {
    (outputType: "binary"): Uint8Array;
    (outputType?: "hex"): string;
  };
  digestSize: number;
}

export interface MultiHasher {
  multi: true;
  update: (data: IDataType) => MultiHasher;
  digest: {
    (outputType: "binary"): { [key: string]: Uint8Array };
    (outputType?: "hex"): { [key: string]: string };
  };
}

export type OcflVersion = '1.0' | '1.1';

export type OcflExtensionConfig = { extensionName?: string;[key: string]: any };
type OcflStorageLayout = import('./extension').OcflStorageLayout<OcflExtensionConfig>;

/** Configuration options for an OCFL Object. */
export type OcflStorageConfig = {
  /** Absolute path to the ocfl storage root. */
  root: string;
  /** Absolute path to storage workspace directory. */
  workspace?: string;
  /** A layout that identifies an arrangement of directories and OCFL objects under the storage root */
  layout?: OcflStorageLayout | OcflExtensionConfig | string;
  /** A default list of digest algorithm names to be added to the fixity block of objects under this storage. */
  fixityAlgorithms?: string[];
  /** Digest algorithm for content-addressing, must use either sha512 or sha256. Defaults to 'sha512'. */
  digestAlgorithm?: 'sha256' | 'sha512';
  /** Content directory name. Only applies to a newly created object. @defaultValue `"content"` */
  contentDirectory?: string;
  /** Ocfl version. Only applies to a newly created object. @defaultValue {@link OcflConstant.OCFL_VERSION} */
  ocflVersion?: OcflVersion;
};

/** Configuration options for an OCFL Object. */
export type OcflObjectConfig = {
  /** Absolute path to the ocfl object root. */
  root: string;
  /** Absolute path to object workspace directory. */
  workspace?: string;
  /** Identifier for the object.  Only be used in a newly created object. */
  id?: string;
  /** Reference to existing extensions defined outside of the object, such as in the storage root. */
  extensions?: import('./extension').OcflExtension<{}>[];
  /** Additional digest algorithms to be calculated for each file and added to the fixity block. */
  fixityAlgorithms?: string[];
  /** Digest algorithm for content-addressing, must use either sha512 or sha256. Defaults to 'sha512'. */
  digestAlgorithm?: 'sha256' | 'sha512';
  /** Content directory name. Only applies to a newly created object. @defaultValue `"content"` */
  contentDirectory?: string;
  /** Ocfl version. Only applies to a newly created object. @defaultValue {@link OcflConstant.OCFL_VERSION} */
  ocflVersion?: OcflVersion;
};