const fs = require('fs')
const path = require('path')
const express = require('express')
const bodyParser = require('body-parser')
const request = require('./util/request')
const packageJSON = require('./package.json')
const exec = require('child_process').exec
const cache = require('./util/apicache').middleware
const { cookieToJson } = require('./util/index')
const fileUpload = require('express-fileupload')
const decode = require('safe-decode-uri-component')

// version check
exec('npm info NeteaseCloudMusicApi version', (err, stdout, stderr) => {
  if (!err) {
    let version = stdout.trim()
    if (packageJSON.version < version) {
      console.log(
        `最新版本: ${version}, 当前版本: ${packageJSON.version}, 请及时更新`,
      )
    }
  }
})

const app = express()
app.set('trust proxy', true)

// CORS & Preflight request
app.use((req, res, next) => {
  if (req.path !== '/' && !req.path.includes('.')) {
    res.set({
      'Access-Control-Allow-Credentials': true,
      'Access-Control-Allow-Origin': req.headers.origin || '*',
      'Access-Control-Allow-Headers': 'X-Requested-With,Content-Type',
      'Access-Control-Allow-Methods': 'PUT,POST,GET,DELETE,OPTIONS',
      'Content-Type': 'application/json; charset=utf-8',
    })
  }
  req.method === 'OPTIONS' ? res.status(204).end() : next()
})

// cookie parser
app.use((req, res, next) => {
  req.cookies = {}
  //;(req.headers.cookie || '').split(/\s*;\s*/).forEach((pair) => { //  Polynomial regular expression //
  ;(req.headers.cookie || '').split(/;\s+|(?<!\s)\s+$/g).forEach((pair) => {
    let crack = pair.indexOf('=')
    if (crack < 1 || crack == pair.length - 1) return
    req.cookies[decode(pair.slice(0, crack)).trim()] = decode(
      pair.slice(crack + 1),
    ).trim()
  })
  next()
})

// body parser
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: false }))

app.use(fileUpload())

// static
app.use(express.static(path.join(__dirname, 'public')))

// cache
app.use(cache('2 minutes', (req, res) => res.statusCode === 200))
// router
const special = {
  'daily_signin.js': '/daily_signin',
  'fm_trash.js': '/fm_trash',
  'personal_fm.js': '/personal_fm',
}

fs.readdirSync(path.join(__dirname, 'module'))
  .reverse()
  .forEach((file) => {
    if (!file.endsWith('.js')) return
    let route =
      file in special
        ? special[file]
        : '/' + file.replace(/\.js$/i, '').replace(/_/g, '/')
    let question = require(path.join(__dirname, 'module', file))

    app.use(route, (req, res) => {
      ;[req.query, req.body].forEach((item) => {
        if (typeof item.cookie === 'string') {
          item.cookie = cookieToJson(decode(item.cookie))
        }
      })
      let query = Object.assign(
        {},
        { cookie: req.cookies },
        req.query,
        req.body,
        req.files,
      )

      question(query, request)
        .then((answer) => {
          console.log('[OK]', decode(req.originalUrl))

          const cookies = answer.cookie
          if (Array.isArray(cookies) && cookies.length > 0) {
            if (req.protocol === 'https') {
              // Try to fix CORS SameSite Problem
              res.append(
                'Set-Cookie',
                cookies.map((cookie) => {
                  return cookie + '; SameSite=None; Secure'
                }),
              )
            } else {
              res.append('Set-Cookie', cookies)
            }
          }
          res.status(answer.status).send(answer.body)
        })
        .catch((answer) => {
          console.log('[ERR]', decode(req.originalUrl), {
            status: answer.status,
            body: answer.body,
          })
          if (!answer.body) {
            res.status(404).send({
              code: 404,
              data: null,
              msg: 'Not Found',
            })
            return
          }
          if (answer.body.code == '301') answer.body.msg = '需要登录'
          res.append('Set-Cookie', answer.cookie)
          res.status(answer.status).send(answer.body)
        })
    })
  })

const port = process.env.PORT || 3000
const host = process.env.HOST || ''

app.server = app.listen(port, host, () => {
  console.log(`server running @ http://${host ? host : 'localhost'}:${port}`)
})

module.exports = app
