import _ from 'lodash' export const ADD = 'LIST_ADD' export const UPDATE = 'LIST_UPDATE' export const REMOVE = 'LIST_REMOVE' export const RECEIVE = 'LIST_RECEIVE' const defaultState = { data: [], byId: {}, indexOf: {}, } export default function reduce(state = defaultState, action) { switch (action.type) { case ADD: return { ...state, data: [...state.data, action.item], byId: { ...state.byId, [action.item.id]: action.item }, indexOf: { ...state.indexOf, [action.item.id]: state.data.length }, } case UPDATE: { const index = state.indexOf[action.item.id] if (index == null) { return state } const data = [...state.data] data[index] = action.item return { ...state, data, byId: { ...state.byId, [action.item.id]: action.item } } } case REMOVE: { const index = state.indexOf[action.id] if (index == null) { return state } const data = [...state.data] const indexOf = { ...state.indexOf, [action.id]: null } data.splice(index, 1) for (let i = data.length - 1; i >= index; i--) { indexOf[data[i].id] = i } return { ...state, data, indexOf, byId: { ...state.byId, [action.id]: null }, } } case RECEIVE: return { ...state, data: action.list, byId: _.fromPairs(action.list.map(item => [item.id, item])), indexOf: _.fromPairs(action.list.map((item, index) => [item.id, index])), } default: return state } } /** * @public */ export function add(item) { return { type: ADD, item } } /** * @public */ export function update(item) { return { type: UPDATE, item } } /** * @public */ export function remove(id) { return { type: REMOVE, id } } /** * @public */ export function receive(list) { return { type: RECEIVE, list } }