const Koa = require('koa')
const Router = require('koa-router')
const { createLogger, format: { printf }, transports } = require('winston')

const logger = createLogger({
  format: printf(info => info.message),
  transports: [
    new transports.Console()
  ]
})

const app = new Koa()
const router = new Router()

const bodyParser = require('koa-bodyparser')

app.use(bodyParser())

const mongoose = require('mongoose')

// you can create test db via mLab for this gist
const connect = 'mongodb://user.password:57383/db'

mongoose
  // if you need
  // .set('debug', true)
  .connect(connect, {
    useNewUrlParser: true,
    useCreateIndex: true,
    useFindAndModify: false,
    keepAlive: 1,
    poolSize: 5
  })

const userSchema = new mongoose.Schema({
  login: {
    type: String,
    unique: true,
    lowercase: true,
    trim: true,
    required: true,
    default: () => Date.now().toString(32).slice(2)
  }
})

const User = mongoose.model('User', userSchema)

const passport = require('koa-passport')

passport.serializeUser((user, done) => {
  logger.info('serializeUser')

  done(null, user.id)
})

passport.deserializeUser((id, done) => {
  logger.info('deserializeUser')

  User.findById(id, done)
})

const { Strategy, ExtractJwt } = require('passport-jwt')

passport.use(new Strategy({
  jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
  secretOrKey: 'customSecretKey',
  algorithms: 'HS512'
}, (payload, done) => {
  logger.info('jwtStrategy')

  User.findById(payload.id, (err, user) => {
    if (err) {
      return done(err, false)
    }

    if (!user) {
      return done(null, false)
    }

    return done(null, user)
  })
}))

app.use(passport.initialize())

const auth = async (ctx, next) => {
  logger.info('startAuth')

  logger.info('beforeKoaPassport')

  // await next(), becaurse koa-passport return next()
  await passport.authenticate('jwt', { session: false })(ctx, next)

  logger.info('afterKoaPassport')

  if (!ctx.state.user) {
    ctx.throw(401, 'Unauthorized')
  }

  logger.info('endAuth')
}

const getUsers = async (ctx) => {
  logger.info('startGetUsers')

  const users = await User.find({})

  ctx.body = {
    payload: users
  }

  logger.info('endGetUsers')
}

router.get('/users', auth, getUsers)

app.use(router.routes()).use(router.allowedMethods())

app.listen(3000)