import {
  newComputeByArgumentsCachePool,
  newComputeByOptionsCachePool,
  Callback,
} from 'cache-compute'

type State = { acc: number }

let sum2 = (a: number, b: number): number => {
  console.log('perform some expensive computation...:', [a, b])
  return a + b
}
let sum2Cache = newComputeByArgumentsCachePool(sum2)

type SumOptions = { a: number; b: number }
let sumDict = ({ a, b }: SumOptions): number => {
  console.log('perform some expensive computation...:', { a, b })
  return a + b
}
let sumDictCache = newComputeByOptionsCachePool(sumDict)

export let selector_dict = {
  getBigger2(
    state: State,
    options: { delta: number },
    callback: Callback<number>,
  ) {
    let compute = sum2Cache(callback)
    compute(state.acc, options.delta)
  },
  getBiggerDict(
    state: State,
    options: { delta: number },
    callback: Callback<number>,
  ) {
    let compute = sumDictCache(callback)
    let a = state.acc
    let b = options.delta
    compute({ a, b })
  },
}

import { makeSyncComputeCacheByArguments } from 'cache-compute'

let users = [
  { name: 'Alice', birthday: new Date('2000-01-01').getTime() },
  { name: 'Bob', birthday: new Date('2000-02-02').getTime() },
]

const YEAR = 1000 * 60 * 60 * 24 * 365.25
function toProfile(user) {
  const now = Date.now()
  return {
    name: user.name,
    age: Math.floor((now - user.birthday) / YEAR),
  }
}

function updateUser(index, user) {
  users = [...users]
  users[index] = { ...users[index], ...user }
  runSelectors()
}

let selectors = []
function runSelectors() {
  selectors.forEach(fn => fn())
}

function watchProfile(index) {
  const watchUsers = profile =>
    // e.g. push to websocket client
    console.log({ index, profile })
  const checkUsers = makeSyncComputeCacheByArguments(toProfile, watchUsers)
  const selector = () => checkUsers(users[index])
  selector()
  selectors.push(selector)
}

console.log('== init ==')
watchProfile(0)
watchProfile(1)
// will print both user profiles

console.log('== update alice ==')
updateUser(0, { name: 'Alex' })
// only print first user profile

console.log('== update bob ==')
updateUser(1, { name: 'Bobby' })
// only print second user profile