export enum ERR_CODES {
  // General
  UnknownErr,
  Unimplemented,
  Other,

  // System/Timeout errors 
  Canceled,
  Timeout,
  RemoteServiceErr,
  OutOfMemory,

  // Validation/Input errors
  InvalidAction,
  BadConfig,
  InvalidArgument,
  OutOfRange,

  // Access errors
  PermissionDenied,
  Unauthenticated,

  // Entity errors
  EntityExists,
  EntityNotFound,
  Outdated,

  // Not error by itself, but adds some additional
  // information to the error in error stack
  ErrClarification,
};

export const getErrCode = (name: keyof typeof ERR_CODES): ERR_CODES | undefined => {
  return ERR_CODES[name];
}

export abstract class Err extends Error {
  abstract code: ERR_CODES;
  get_name() { return this.constructor.name };
}

export const getErrStack = (err: Error): Error[] => {
  const errStack: Error[] = []
  let thisErr: Error = err 
  while (thisErr.cause) {
    errStack.push(thisErr)
    if (thisErr.cause instanceof Error)
    thisErr = thisErr.cause
  }
  return errStack
}

// ===============================
// == Some useful error classes ==
// ===============================

export class BadConfigErr extends Err { code = ERR_CODES.BadConfig }