import {IDynaduxReducerDic} from "../Dynadux/Dynadux";


export const combineMultipleReducers = <TState>(...reducerDics: Array<IDynaduxReducerDic<TState>>): IDynaduxReducerDic<TState> => {
  const output: IDynaduxReducerDic<TState> = {};

  reducerDics
    .forEach(reducerDic => {
      Object.keys(reducerDic)
        .forEach(action => {
          if (!output[action]) {
            output[action] = reducerDic[action];
            return;
          }

          const originalReducer = output[action];
          output[action] = (params) => {
            const stateA = params.state || {};
            const stateB = originalReducer({
              ...params,
              state: stateA as any,
            });
            return reducerDic[action]({
              ...params,
              state: {
                ...stateA,
                ...stateB,
              } as any,
            });
          };
        });
    });

  return output;
};