// Copyright (c) 2018-present, Cruise LLC

// This source code is licensed under the Apache License, Version 2.0,
// found in the LICENSE file in the root directory of this source tree.
// You may not use this file except in compliance with the License.

/**
 * A function that must be called with either an error or a value, but not both
 */
export type Callback<T> = (error: Error | null, value?: T) => void;

/**
 * Represents a timestamp based on the UNIX epoch (1970 Jan 1).
 * See also: http://wiki.ros.org/roscpp/Overview/Time
 */
export interface Time {
  /**
   * Whole seconds.
   */
  sec: number;
  /**
   * Additional nanoseconds past the `sec` value.
   */
  nsec: number;
}

export interface Filelike {
  read(offset: number, length: number, callback: Callback<Buffer>): void;
  size(): number;
}

export interface RosMsgField {
  type: string;
  name: string;
  isComplex?: boolean;

  // For arrays
  isArray?: boolean;
  arrayLength?: number;

  // For constants
  isConstant?: boolean;
  value?: unknown;
}

export interface RosMsgDefinition {
  name: string;
  definitions: RosMsgField[];
}