import { Action, ActionCreatorsMapObject } from "redux";

export interface ActionWithPayload<T, P> extends Action<T> {
  payload: P;
}
// Overload the createAction function types
export function createAction<T extends string>(type: T): Action<T>;
export function createAction<T extends string, P>(
  type: T,
  payload?: P
): ActionWithPayload<T, P>;
export function createAction<T extends string, P>(type: T, payload?: P) {
  return payload === undefined ? { type } : { type, payload };
}

/**
 * `A` is an object with a bunch of key: createAction() in it.
 *  Type ActionsUnion is all of the return types for each of those createActions (SimpleAction, ActionWithPayload)
 */
export type ActionsUnion<A extends ActionCreatorsMapObject> = ReturnType<
  A[keyof A]
>;