import { reducerWithInitialState } from 'typescript-fsa-reducers'
import { combineReducers } from 'redux'
import { sortBy } from 'lodash'

import * as actions from './actions'
import * as AuthActions from '../auth/actions'

const MAX_ACTIVITIES = 200

const loading = reducerWithInitialState(false)
  .cases([
    actions.fetchActivityGroupsSuccess,
    actions.fetchActivityGroupsByEmailSuccess,
  ], () => false)
  .cases([
    actions.fetchActivityGroupsPending,
    actions.fetchActivityGroupsByEmailPending,
  ], () => true)

const loaded = reducerWithInitialState(false)
  .case(actions.fetchActivityGroupsSuccess, () => true)
  .case(AuthActions.logout, () => false)

const activityGroups = reducerWithInitialState([])
  .cases([
    actions.fetchActivityGroupsSuccess,
    actions.receiveActivityGroups,
  ], (state, activityGroups) => {
    const filtered = state.filter((activityGroup) => {
      return !activityGroups.find(a => a.id === activityGroup.id)
    })
    const combined = sortBy(filtered.concat(activityGroups), 'latestActivity')
    if (combined.length > MAX_ACTIVITIES) {
      return combined.slice(combined.length - MAX_ACTIVITIES)
    } else {
      return combined
    }
  })
  .case(AuthActions.logout, () => [])

const activityGroupsByEmail = reducerWithInitialState([])
  .case(actions.fetchActivityGroupsByEmailSuccess, (state, activityGroups) => sortBy(activityGroups, 'latestActivity'))
  .case(actions.receiveActivityGroupsByEmail, (state, activityGroups) => {
    const filtered = state.filter((activityGroup) => {
      return !activityGroups.find(a => a.id === activityGroup.id)
    })
    const combined = sortBy(filtered.concat(activityGroups), 'latestActivity')
    if (combined.length > MAX_ACTIVITIES) {
      return combined.slice(combined.length - MAX_ACTIVITIES)
    } else {
      return combined
    }
  })
  .case(AuthActions.logout, () => [])

export default combineReducers({
  loading,
  loaded,
  activityGroups,
  activityGroupsByEmail,
})