useCloudDB for TG

useCloudDB.ts

import { useCloudStorage } from "@tma.js/sdk-react"
import { useEffect, useState } from "react"

type OP = 'addItem' | 'getAll' | 'purge'
const createKeys = (length: number, idxKey: Function): string[] => Array.from({ length: length }).map((_, idx: number) => idxKey(idx))

export const useCloudDB = (tableName: string, threshold: number) => {
  const cs = useCloudStorage()
  const [busy, setBusy] = useState(false)
  const [threshReached, setThreshReached] = useState(false)
  const [opStack, setStack] = useState<[Function, OP, string][]>([])
  const nextIdxKey = tableName + '_next_idx';
  const idxKey = (idx: number) => tableName + '_' + idx
  
  const getNextIdx = async () => Number(await cs.get(nextIdxKey) || 0)

  useEffect(() => {
    console.log('cloud storage hook')
    if (busy || opStack.length === 0)
      return

    setBusy(true)
    const [[resolve, op, item], ...rest] = opStack
    setStack(rest)

    setTimeout(async () => {
      const nextIndex = await getNextIdx()
      
      if (op === "addItem") {
        await Promise.all([
          cs.set(idxKey(nextIndex), item),
          cs.set(nextIdxKey, (nextIndex + 1).toString()),
        ])
        resolve(nextIndex)
        nextIndex === threshold && setThreshReached(true)
      } else if (op === "getAll") {
        resolve(await cs.get(createKeys(nextIndex, idxKey)))
      } else if (op === "purge") {
        Promise.all([
          cs.delete(createKeys(nextIndex, idxKey)),
          cs.set(nextIdxKey, (0).toString())
        ])

        resolve()
      }

      setBusy(false)
    })
  }, [opStack, busy])

  return {
    addItem: async (item: string): Promise<number> => new Promise((resolve: any) => 
      setStack(stack => [...stack, [resolve, "addItem", item]])),
    getAll: async () => new Promise((resolve: Function) => 
      setStack(stack => [...stack, [resolve, "getAll", "ok"]])),
    purge: async () => new Promise((resolve: Function) => 
      setStack(stack => [...stack, [resolve, "purge", "ok"]])),
    threshReached,
  }
}


/*
useCloudDB manages ops by stacking them.
Every exported function returns a Promise.
You can react when the threshReached (10) with an useEffect for example.

Use it like this in React:

```ts
const { addItem, getAll, purge, threshReached } = useCloudDB("ListIDakaTable", 10)
```