import _difference from 'lodash/difference'

import { ActionType } from '../actions/types'
import { selectNormalizedActionRelationsSequence } from '../selectors'
import { RootState } from '../store'

export const atleastOneSourceAndActionRule = (state: RootState) => {
  const types = state.actions.map(({ type }) => type)
  const sources = types.filter(type => type === ActionType.SOURCE)
  const actions = types.filter(type => type === ActionType.ACTION)

  if (sources.length === 0) {
    throw new Error('At least one source is required')
  }

  if (actions.length === 0) {
    throw new Error('At least one action is required')
  }

  if (sources.length > 1) {
    throw new Error('Only one source is required')
  }

  return true
}

export const noMissedActionRelationsRule = (state: RootState) => {
  const relations = selectNormalizedActionRelationsSequence()(state)
  const missed = _difference(state.relations, relations)

  if (missed.length > 0) {
    throw new Error('No missed relations allowed')
  }

  return true
}

export const noCircularActionRelationsRule = (state: RootState) => {
  // TODO: Implement
  return !state
}