// @ts-ignore - Only used in doc comments
import type { Omit } from "./Omit";
// @ts-ignore - Only used in doc comments
import type OmitFn from "./Omit";
import type { Args, GenericFn, GenericResolver } from "../HKT";
import type { Eq, IsPropertyKeyLiteral } from "../helpers";

/**
 * Less strict version of {@link Omit}.The **W** suffix (short for **W**idening) means that the key
 * type is widened to `PropertyKey`.
 *
 * Sig: `(k: PropertyKey, o: object) => object`
 */
// We do not use the built-in `Omit` type because it does not keep the readonly modifier.
export type OmitW<K extends keyof O, O> = {
  [P in keyof O as P extends K ? never : P]: O[P];
};

interface Resolver extends GenericResolver<[PropertyKey, object], object> {
  on1_: ([k]: Args<this>) => [[object], object];
  on_1: ([, o]: Args<this>) => [[PropertyKey], object];
  on11: ([k, o]: Args<this>) => [
    [],
    IsPropertyKeyLiteral<typeof k> extends true ?
      { [P in keyof typeof o as P extends typeof k ? never : P]: (typeof o)[P] } extends infer R ?
        Eq<R, typeof o> extends true ?
          typeof o
        : R
      : never
    : object,
  ];
}

/**
 * [Fn] Less strict version of {@link OmitFn}.The **W** suffix (short for **W**idening) means that
 * the key type is widened to `PropertyKey`.
 *
 * Sig: `(k: PropertyKey, o: object) => object`
 */
export default interface OmitWFn extends GenericFn<Resolver> {
  def: ([k, o]: Args<this>) => {
    [P in keyof typeof o as P extends typeof k ? never : P]: (typeof o)[P];
  };
}