import * as types from '../types'
//数据
const state = {
 travelsList: [],
 searchKey: {
  page: 0,
  limit: 20
 },
 scroll: true
}
//用户行为(可以处理异步),触发 mutations 来改变 state
const actions = {
 /**
  * 获取约跑步列表
  */
 getTravelsList({ commit }) {
  if(state.scroll) {
   commit(types.GET_TRAVELS_PAGE_NUM)
   commit(types.COM_LOADING_STATUS, true),
   commit(types.GET_TRAVELS_SCORLL_STATUS, false)
   api.TravelsList()
    .then(res => {
     console.log(res)
     commit(types.COM_LOADING_STATUS, false),
     commit(types.GET_TRAVELS_SCORLL_STATUS, true)
     commit(types.GET_TRAVELS_LIST, res)
    })
  }
 },
 /**
  * 参加
  */
 joinTravel({ commit }, id) {
 ...
 }
}
//可以过滤 state 中的数据
const getters = {
 travelsList: state => state.travelsList,
 travelListIndex: state => state.travelsList.slice(0,4)
}
//唯一能改变 state 的方法(纯函数)
const mutations = {
 [types.GET_TRAVELS_LIST](state, res) {
  if(state.searchKey.page <= 1) {
   state.travelsList = res.data
  } else {
   state.travelsList = state.travelsList.concat(res.data)
  }
 },
 [types.GET_TRAVELS_SEARCH_KEY](state, params) {
  state.searchKey = params
 },
 [types.GET_TRAVELS_PAGE_NUM](state) {
  state.searchKey['page'] += 1
 },
 [types.GET_TRAVELS_SCORLL_STATUS](state, status) {
  state.scroll = status
 }
}
//导出一个 travel store 模块
export default {
 state,
 actions,
 getters,
 mutations
}