const fs = require('fs')
const path = require('path')
const beautify = require('js-beautify').js_beautify
const config = require('./package.json')

const dist = path.join(`${__dirname}/dist`)
const maxVersion = 5

const writeVersion = () => new Promise((resolve, reject) => {
 const { version } = config
 const numbers = version.split('.')
 numbers[2] = Number(numbers[2]) + 1
 config.version = numbers.join('.')

 fs.writeFile(path.join(__dirname, 'package.json'), beautify(JSON.stringify(config), { indent_size: 2 }), (err) => {
 if (err) {
 reject()
 }
 resolve()
 console.log(`version: ${config.version}`)
 })
})

const removeFolder = (folderPath) => {
 let files = []
 if (fs.existsSync(folderPath)) {
 files = fs.readdirSync(folderPath)
 files.forEach((file) => {
 const curPath = `${folderPath}/${file}`
 if (fs.statSync(curPath).isDirectory()) {
 removeFolder(curPath)
 } else {
 fs.unlinkSync(curPath)
 }
 })
 fs.rmdirSync(folderPath)
 }
}

const start = async () => {
 const files = fs.readdirSync(dist)
 const promises = files.map(file => new Promise((resolve, reject) => {
 fs.stat(`${dist}/${file}`, (err, stats) => {
 if (err) {
 reject()
 } else {
 resolve(!stats.isFile()
 ? file
 : null)
 }
 })
 }))

 const result = await Promise.all(promises)

 const folders = result.filter((item) => {
 if (item) {
 return item.split('.').length === 3
 }
 return false
 }).sort((a, b) => {
 const an = a.split('.').map(_ => Number(_))
 const bn = b.split('.').map(_ => Number(_))
 if (an[0] === bn[0]) {
 if (an[1] === bn[1]) {
 return an[2] < bn[2]
 }
 return an[1] < bn[1]
 }
 return an[0] < bn[0]
 }).filter((item, index) => {
 return index > (maxVersion - 1)
 })

 for (const item of folders) {
 await removeFolder(`${dist}/${item}`)
 }

 await writeVersion()
}

start()