import { combineReducers, Reducer } from "redux";
import { iterate, populateHash } from "./helpers";
import { changeDefaultReducer, DEFAULT_REDUCER } from "./tiles/selectors";
import { ITile } from "./tiles/types";
import { isFunction, isString } from "./utils";

export function createNestedReducers(value: any): Reducer<any> {
  return combineReducers(
    Object.keys(value).reduce((hash: any, key: string) => {
      const elem: Function | {} = value[key];
      hash[key] = isFunction(elem) ? elem : createNestedReducers(elem);

      return hash;
    }, {})
  );
}

export function createReducers(
  modules: ITile[],
  topReducer: string = DEFAULT_REDUCER
): Reducer<any> {
  if (topReducer !== DEFAULT_REDUCER) {
    changeDefaultReducer(topReducer);
  }

  const nestedModules: any = iterate(modules).reduce(
    (hash: any, module: ITile) => {
      populateHash(hash, module.tileName, module.reducer);

      return hash;
    },
    {}
  );

  return createNestedReducers(nestedModules);
}