'use strict'

var bearerToken = require('express-bearer-token')
var cors = require('cors')
var couchbase = require('couchbase')

var express = require('express')
var jwt = require('jsonwebtoken')
var morgan = require('morgan')
var uuid = require( 'uuid')
var swaggerUi = require('swagger-ui-express')
const swaggerDocument = require('./swagger.json')

// Specify a key for JWT signing.
var JWT_KEY = 'IAMSOSECRETIVE!'

// Create a Couchbase Cluster connection
const CB = {
  host: process.env.CB_HOST || 'db',
  username: process.env.CB_USER || 'Administrator',
  password: process.env.CB_PASS || 'password'
}

async function main() {
  var cluster = await couchbase.connect(
    `couchbase://${CB.host}`,
    {
      username: CB.username,
      password: CB.password
    }
  )

    // Open a specific Couchbase bucket, `travel-sample` in this case.
    var bucket = cluster.bucket('travel-sample')

    // Set up our express application
    var app = express()
    app.use(morgan('dev'))
    app.use(cors())
    app.use(express.json())

    app.use('/apidocs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));

    var tenants = express.Router({mergeParams: true})

    app.get('/', (req, res) => {
      return res.send(
        `<h1>Node.js Travel Sample API</h1>
        A sample API for getting started with Couchbase Server and the Node.js SDK.
        <ul>
          <li><a href="/https/raw.githubusercontent.com/apidocs">Learn the API with Swagger, interactively</a>
          <li><a href="https://github.com/couchbaselabs/try-cb-nodejs">GitHub</a>
        </ul>`
      )
    })

  app.get('/api/airports',
    runAsync(async (req, res) => {
      const searchTerm = req.query.search
      let where
      let options

      if (searchTerm.length === 3) {
        // FAA code
        where = 'faa = $FAA'
        options = { parameters: { FAA: searchTerm.toUpperCase() } }
      } else if (
        searchTerm.length === 4 &&
        (searchTerm.toUpperCase() === searchTerm ||
          searchTerm.toLowerCase() === searchTerm)
      ) {
        // ICAO code
        where = 'icao = $ICAO'
        options = { parameters: { ICAO: searchTerm.toUpperCase() } }
      } else {
        // Airport name
        where = 'CONTAINS(LOWER(airportname), $AIRPORT)'
        options = { parameters: { AIRPORT: searchTerm.toLowerCase() } }
      }

      let qs = `SELECT airportname from \`travel-sample\`.inventory.airport WHERE ${ where };`

      const result = await cluster.query(qs, options)
      const data = result.rows
      const context = [`N1QL query - scoped to inventory: ${qs}`]
      return res.send({data, context})
    })
  )

  app.get('/api/flightPaths/:from/:to',
    runAsync(async (req, res) => {
      const fromAirport = req.params.from
      const toAirport = req.params.to
      const leaveDate = new Date(req.query.leave)

      const dayOfWeek = leaveDate.getDay()

      let qs1 = `SELECT faa AS fromFaa
                FROM \`travel-sample\`.inventory.airport
                WHERE airportname = $FROM
                UNION
                SELECT faa AS toFaa
                FROM \`travel-sample\`.inventory.airport
                WHERE airportname = $TO;`

      const options1 = {
        parameters: {
          FROM: fromAirport,
          TO: toAirport,
        }
      }

      const result = await cluster.query(qs1, options1)
      const rows = result.rows
      if (rows.length !== 2) {
        return res.status(404).send({
          error: 'One of the specified airports is invalid.',
          context: [qs1],
        })
      }
      const { fromFaa, toFaa } = { ...rows[0], ...rows[1] }

      let qs2 = `
          SELECT a.name, s.flight, s.utc, r.sourceairport, r.destinationairport, r.equipment
          FROM \`travel-sample\`.inventory.route AS r
          UNNEST r.schedule AS s
          JOIN \`travel-sample\`.inventory.airline AS a ON KEYS r.airlineid
          WHERE r.sourceairport = $FROM
          AND r.destinationairport = $TO
          AND s.day = $DAY
          ORDER BY a.name ASC;
        `
      const options2 = {
        parameters: {
          FROM: fromFaa,
          TO: toFaa,
          DAY: dayOfWeek
        }
      }

      const result2 = await cluster.query(qs2, options2)
      const rows2 = result2.rows
      if (rows2.length === 0) {
        return res.status(404).send({
          error: 'No flights exist between these airports.',
          context: [qs1, qs2],
        })
      }

      rows2.forEach((row) => {
        row.flighttime = Math.ceil(Math.random() * 8000)
        row.price = Math.ceil((row.flighttime / 8) * 100) / 100
      })

      return res.send({
        data: rows2,
        context: ["N1QL query - scoped to inventory: ", qs2],
      })
    })
  )

  app.use('/api/tenants/:tenant/', tenants)

  const makeKey = key => key.toLowerCase()

  tenants.route('/user/login').post(
    runAsync(async (req, res) => {
      const tenant = makeKey( req.params.tenant )
      const user = req.body.user
      const userKey = makeKey( user )
      const password = req.body.password
      var scope = bucket.scope(tenant)
      var users = scope.collection("users")

      try {
        const result = await users.get(userKey)

        if (result.value.password !== password) {
          return res.status(401).send({
            error: 'Password does not match.',
          })
        }

        const token = jwt.sign({user}, JWT_KEY)

        return res.send({
          data: {token},
          context: [`KV get - scoped to ${tenant}.users: for password field in document ${user}`]
        })
      } catch (err) {
        if (err instanceof couchbase.DocumentNotFoundError) {
          return res.status(401).send({
            error: 'User does not exist.',
          })
        }
        else {
          throw(err)
        }
      }
    })
  )

  tenants.route('/user/signup').post(
    runAsync(async (req, res) => {
      const user = req.body.user
      const userDocKey = makeKey(user)
      const password = req.body.password

      const tenant = makeKey( req.params.tenant )
      var scope = bucket.scope(tenant)
      var users = scope.collection("users")

      try {
        const userDoc = {
          name: user,
          password: password,
          flights: [],
        }

        await users.insert(userDocKey, userDoc)

        const token = jwt.sign({user}, JWT_KEY)

        return res.status(201).send({
          data: {token},
          context: [`KV insert - scoped to ${tenant}.users: document ${userDocKey}`]
        })
      } catch (err) {
        if (err instanceof couchbase.DocumentExistsError) {
          return res.status(409).send({
            error: 'User already exists.',
          })
        }
        else {
          throw(err)
        }
      }
    })
  )

  tenants.route('/user/:username/flights')
  .get(authUser,
    runAsync(async (req, res) => {
      const username = req.params.username
      const userDocKey = makeKey(username)

      const tenant = makeKey( req.params.tenant )
      var scope = bucket.scope(tenant)
      var users = scope.collection("users")
      var bookings = scope.collection("bookings")

      if (username !== req.user.user) {
        return res.status(401).send({
          error: `Username does not match token username. ${username} VS ${req.user.user}`,
        })
      }

      try {
        const result = await users.get(userDocKey)
        const ids = result.content.bookings || []

        const inflated = await Promise.all(
          ids.map(
            async flightId => (await bookings.get(flightId)).content))

        return res.send({
          data: inflated,
          context:
            [ `KV get - scoped to ${tenant}.users: for ${ids.length} bookings in document ${userDocKey}`]
        })
      } catch (err) {
        if (err instanceof couchbase.DocumentNotFoundError) {
          return res.status(403).send({
            error: 'Could not find user.',
          })
        }
        else {
          throw(err)
        }
      }
    })
  )
  .put(authUser,
    runAsync(async (req, res) => {
      const username = req.params.username
      const userDocKey = makeKey(username)

      const newFlight = req.body.flights[0]
      const tenant = makeKey( req.params.tenant )

      var scope = bucket.scope(tenant)
      var users = scope.collection("users")
      var bookings = scope.collection("bookings")

      if (username !== req.user.user) {
        return res.status(401).send({
          error: 'Username does not match token username.',
        })
      }

      const flightId = uuid.v4()

      try {
        await bookings.upsert(flightId, newFlight)
      }
      catch (err) {
        return res.status(500).send({
          error: 'Failed to add flight data',
        })
      }

      try {
        await users.mutateIn(userDocKey, [
          couchbase.MutateInSpec.arrayAppend(
            'bookings',
            flightId,
            { createPath: true })])

        return res.send({
          data: {
            added: [ newFlight ],
          },
          context:
            [`KV update - scoped to ${tenant}.users: for bookings subdocument field in document ${userDocKey}`]
        })
      } catch (err) {
        if (err instanceof couchbase.DocumentNotFoundError) {
          return res.status(403).send({
            error: 'Could not find user.',
          })
        }
        else {
          throw(err)
        }
      }
    })
  )

  app.get('/api/hotels/:description/:location?',
    runAsync(async (req, res) => {
      const description = req.params.description
      const location = req.params.location
      var scope = bucket.scope("inventory")
      var hotels = scope.collection("hotel")
      const qp = couchbase.SearchQuery.conjuncts([
        couchbase.SearchQuery.term('hotel').field('type'),
      ])

      if (location && location !== '*') {
        qp.and(
          couchbase.SearchQuery.disjuncts(
            couchbase.SearchQuery.match(location).field('country'),
            couchbase.SearchQuery.match(location).field('city'),
            couchbase.SearchQuery.match(location).field('state'),
            couchbase.SearchQuery.match(location).field('address')
          )
        )
      }
      if (description && description !== '*') {
        qp.and(
          couchbase.SearchQuery.disjuncts(
            couchbase.SearchQuery.match(description).field('description'),
            couchbase.SearchQuery.match(description).field('name')
          )
        )
      }

      const result = await cluster.searchQuery('hotels-index', qp, { limit: 100 })
      const rows = result.rows
      if (rows.length === 0) {
        return res.send({
          data: [],
          context: [`FTS search - scoped to: inventory.hotel (no results)\n${JSON.stringify(qp)}`],
        })
      }

      const addressCols = [
        'address',
        'state',
        'city',
        'country'
      ]

      const cols = [
        'type',
        'name',
        'description',
        ...addressCols
      ]

      const results = await Promise.all(
        rows.map(async (row) => {
          const doc = await hotels.get(row.id, {
            project: cols
          })
          var content = doc.content
          content.address =
            addressCols
            .flatMap(field => content[field] || [])
            .join(', ')
          return content
        })
      )

      return res.send({
        data: results,
        context: [
          `FTS search - scoped to: inventory.hotel within fields ${cols.join(', ')}\n${JSON.stringify(qp)}`]
      })
    })
  )

  // Error handler. Must be defined after other routes/middleware
  app.use((err, req, res, next) => {
    const errText = err.toString()
    if (errText.match(/LCB_ERR_KVENGINE_INVALID_PACKET/)) {
      return res.status(500).send({
        error: "Received LCB_ERR_KVENGINE_INVALID_PACKET error from Couchbase. Please check the SDK release notes and ensure you are using a compatible server version."
      })
    }
    else {
      return res.status(500).send({
        error: `${err.toString()}: ${JSON.stringify(err)}`
      })
    }
    next()
  })

  app.listen(8080, () => {
    console.log(`Connecting to backend Couchbase server ${CB.host} with ${CB.username}/${CB.password}`)
    console.log('Example app listening on port 8080!')
  })
}

function authUser(req, res, next) {
  bearerToken()(req, res, () => {
    // Temporary Hack to extract the token from the request
    req.token = req.headers.authorization.split(' ')[1]
    jwt.verify(req.token, JWT_KEY, (err, decoded) => {
      if (err) {
        return res.status(400).send({
          error: 'Invalid JWT token',
          cause: err,
        })
      }

      req.user = decoded
      next()
    })
  })
}

function runAsync (callback) {
  return function (req, res, next) {
    callback(req, res, next)
      .catch(next)
  }
}

main()