export const loadTagSelector = (index: number) => async (
  dispatch: Dispatch<Action>,
  getState: GetState
) => {
  const {buckets, tags} = getActiveQuery(getState()).builderConfig

  if (!tags[index] || !buckets[0]) {
    return
  }

  const tagsSelections = tags.slice(0, index)
  const queryURL = getState().links.query.self
  const orgID = getState().orgs.org.id

  dispatch(setBuilderTagKeysStatus(index, RemoteDataState.Loading))

  try {
    const timeRange = getActiveTimeMachine(getState()).timeRange
    const searchTerm = getActiveTimeMachine(getState()).queryBuilder.tags[index]
      .keysSearchTerm

    const keys = await queryBuilderFetcher.findKeys(index, {
      url: queryURL,
      orgID,
      bucket: buckets[0],
      tagsSelections,
      searchTerm,
      timeRange,
    })

    const {key} = tags[index]

    if (!key) {
      let defaultKey: string

      if (index === 0 && keys.includes('_measurement')) {
        defaultKey = '_measurement'
      } else {
        defaultKey = keys[0]
      }

      dispatch(setBuilderTagKeySelection(index, defaultKey))
    } else if (!keys.includes(key)) {
      // Even if the selected key didn't come back in the results, let it be
      // selected anyway
      keys.unshift(key)
    }

    dispatch(setBuilderTagKeys(index, keys))
    dispatch(loadTagSelectorValues(index))
  } catch (e) {
    if (e instanceof CancellationError) {
      return
    }

    console.error(e)
    dispatch(setBuilderTagKeysStatus(index, RemoteDataState.Error))
  }
}

export const refreshTimeMachineVariableValues = () => async (
  dispatch,
  getState: GetState
) => {
  const contextID = getState().timeMachines.activeTimeMachineID

  // Find variables currently used by queries in the TimeMachine
  const {view, draftQueries} = getActiveTimeMachine(getState())
  const draftView = {
    ...view,
    properties: {...view.properties, queries: draftQueries},
  }
  const variables = extractVariablesList(getState())
  const variablesInUse = filterUnusedVars(variables, [view, draftView])

  // Find variables whose values have already been loaded by the TimeMachine
  // (regardless of whether these variables are currently being used)
  const hydratedVariables = getHydratedVariables(getState(), contextID)

  // Refresh values for all variables with existing values and in use variables
  const variablesToRefresh = variables.filter(
    v => variablesInUse.includes(v) || hydratedVariables.includes(v)
  )

  await dispatch(refreshVariableValues(contextID, variablesToRefresh))
}

export const executeQueries = () => async (dispatch, getState: GetState) => {
  const {view, timeRange} = getActiveTimeMachine(getState())
  const queries = view.properties.queries.filter(({text}) => !!text.trim())

  if (!queries.length) {
    dispatch(setQueryResults(RemoteDataState.Done, [], null))
  }

  try {
    dispatch(setQueryResults(RemoteDataState.Loading, null, null, null))

    await dispatch(refreshTimeMachineVariableValues())

    const orgID = getState().orgs.org.id
    const activeTimeMachineID = getState().timeMachines.activeTimeMachineID
    const variableAssignments = [
      ...getVariableAssignments(getState(), activeTimeMachineID),
      ...getTimeRangeVars(timeRange),
    ]

    const startTime = Date.now()

    pendingResults.forEach(({cancel}) => cancel())

    pendingResults = queries.map(({text}) =>
      executeQueryWithVars(orgID, text, variableAssignments)
    )

    const results = await Promise.all(pendingResults.map(r => r.promise))

    const duration = Date.now() - startTime
    const files = results.map(r => r.csv)

    files.forEach(checkQueryResult)

    dispatch(setQueryResults(RemoteDataState.Done, files, duration))
  } catch (e) {
    if (e instanceof CancellationError) {
      return
    }

    if (get(e, 'status') === RATE_LIMIT_ERROR_STATUS) {
      const retryAfter = get(e, 'headers.Retry-After')
      dispatch(notify(rateLimitReached(retryAfter)))
    }

    console.error(e)
    dispatch(setQueryResults(RemoteDataState.Error, null, null, e.message))
  }
}