import type { AggregateErrors } from '../merge/aggregate.js'
import type { ErrorProps } from '../plugins/core/props/main.js'
import type { Plugins } from '../plugins/shape/main.js'

import type { PluginsOptions } from './plugins.js'

/**
 * The `cause` option, as used when merged to the error instance
 */
export type NormalizedCause<CauseArg extends Cause> = CauseArg extends Error
  ? CauseArg
  : object

/**
 * Optional `cause` option
 */
export type Cause = unknown

/**
 * Options passed to error constructors, excluding any plugin options
 */
interface MainInstanceOptions<
  AggregateErrorsArg extends AggregateErrors,
  CauseArg extends Cause,
> {
  /**
   * The `errors` option aggregates multiple errors into one. This is like
   * [`new AggregateError(errors)`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/AggregateError/AggregateError)
   * except that it works with any error class.
   *
   * @example
   * ```js
   * const databaseError = new DatabaseError('...')
   * const authError = new AuthError('...')
   * throw new InputError('...', { errors: [databaseError, authError] })
   * // InputError: ... {
   * //   [errors]: [
   * //     DatabaseError: ...
   * //     AuthError: ...
   * //   ]
   * // }
   * ```
   */
  readonly errors?: AggregateErrorsArg

  /**
   * Any error's message, class and options can be wrapped using the
   * [standard `cause` option](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/cause).
   *
   * Instead of being set as a `cause` property, the inner error is directly
   * [merged](https://github.com/ehmicky/merge-error-cause) to the outer error,
   * including its
   * [`message`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/message),
   * [`stack`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/stack),
   * [`name`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/name),
   * [`AggregateError.errors`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/AggregateError)
   * and any [additional property](#%EF%B8%8F-error-properties).
   *
   * @example
   * ```js
   * try {
   *   // ...
   * } catch (cause) {
   *   throw new InputError('Could not read the file.', { cause })
   * }
   * ```
   */
  readonly cause?: CauseArg
}

/**
 * Options passed to error constructors, used internally only with additional
 * generics
 */
export type SpecificInstanceOptions<
  PluginsArg extends Plugins,
  ChildProps extends ErrorProps,
  AggregateErrorsArg extends AggregateErrors,
  CauseArg extends Cause,
> = MainInstanceOptions<AggregateErrorsArg, CauseArg> &
  PluginsOptions<PluginsArg, ChildProps>

/**
 * Options passed to error constructors: `new ErrorClass('message', options)`
 */
export type InstanceOptions<PluginsArg extends Plugins = Plugins> =
  SpecificInstanceOptions<PluginsArg, ErrorProps, AggregateErrors, Cause>