// @flow

import { List } from "immutable";
import { combineReducers } from "redux";

import { Model, MessageType } from "./types";
import { SEND_MESSAGE } from './actions';

const init = new Model();

type ActionType = SEND_MESSAGE;

function mainReducer(
  model: Model = init,
  action: { type: ActionType, payload: Object }
) {
  switch (action.type) {
    case SEND_MESSAGE:
      return sendMessage(model, action.payload);
    default:
      return model;
  }
}

function nullReducer(
  model: Model = init,
  action
) {
  switch (action.type) {
    default:
      return model;
  }
}

// private function!!
function sendMessage(model, payload) {
  if (payload) {
    const message = new MessageType({ text: payload.message })
    const new_model = model.updateIn(
      ["messages"],
      messages => messages.push(message)
    );
    return new_model;
  } else {
    return model;
  }
}

const app = combineReducers({
  mainReducer,
  nullReducer
});

export default app;