import { camelCase } from 'lodash'

import apiService from '../api/api.service.js'

const update = ({store, statuses, timeline, showImmediately}) => {
  const ccTimeline = camelCase(timeline)

  store.dispatch('setError', { value: false })

  store.dispatch('addNewStatuses', {
    timeline: ccTimeline,
    statuses,
    showImmediately
  })
}

const fetchAndUpdate = ({store, credentials, timeline = 'friends', older = false, showImmediately = false}) => {
  const rootState = store.rootState || store.state
  const timelineData = rootState.statuses.timelines[camelCase(timeline)]

  return fetchStatuses({timelineData, store, credentials, timeline, older})
    .then((statuses) => update({store, statuses, timeline, showImmediately}),
      () => store.dispatch('setError', { value: true }))
}

const fetchStatuses = ({timelineData, credentials, timeline = 'friends', older = false, userId = false}) => {
  const args = { timeline, credentials }

  if (older) {
    args['until'] = timelineData.minVisibleId
  } else {
    args['since'] = timelineData.maxId
  }

  if (timeline === 'user') {
    args['userId'] = userId
  }

  return apiService.fetchTimeline(args)
}

const startFetching = ({ timeline = 'friends', credentials, store }) => {
  fetchAndUpdate({timeline, credentials, store, showImmediately: true})
  const boundFetchAndUpdate = () => fetchAndUpdate({ timeline, credentials, store })
  return setInterval(boundFetchAndUpdate, 10000)
}
const timelineFetcher = {
  fetchAndUpdate,
  startFetching,
  fetchStatuses
}

export default timelineFetcher