import { useEffect, useState } from 'react'

export interface Store<T> {
  get(): T
  set(value: T): void
  reset(): void
  subscribe(listener: () => void): () => void
}

export function createStore<T>(initial: T): Store<T> {
  let value = initial
  const listeners = new Set<() => void>()
  const notify = () => {
    listeners.forEach((listener) => {
      listener()
    })
  }
  return {
    get: () => value,
    set: (next) => {
      value = next
      notify()
    },
    reset: () => {
      value = initial
      notify()
    },
    subscribe: (listener) => {
      listeners.add(listener)
      return () => {
        listeners.delete(listener)
      }
    },
  }
}

export function useStore<T>(store: Store<T>): T {
  const [value, setValue] = useState(store.get())
  useEffect(() => store.subscribe(() => setValue(store.get())), [store])
  return value
}