import { mkdtemp, rename, rm, stat } from 'node:fs/promises'
import { dirname, join } from 'node:path'

const exists = async (path) => {
  try {
    await stat(path)
    return true
  } catch (error) {
    if (error.code === 'ENOENT') return false
    throw error
  }
}

export const createOutput = (destination) => mkdtemp(join(dirname(destination), '.generated-next-'))

export const publishOutput = async (staging, destination) => {
  const previous = `${staging}-previous`
  const hadPrevious = await exists(destination)
  if (hadPrevious) await rename(destination, previous)
  try {
    await rename(staging, destination)
  } catch (error) {
    if (hadPrevious) await rename(previous, destination)
    throw error
  }
  if (hadPrevious) await rm(previous, { recursive: true })
}

export const discardOutput = (staging) => rm(staging, { recursive: true, force: true })