/* eslint-env node */
require('dotenv').config()
const express = require('express')
const app = express()
const path = require('path')
const mongo = require('mongodb')
const MongoClient = mongo.MongoClient
console.log('Starting with parameters:')
const parameters = ['PORT', 'MONGO_SERVER', 'MONGO_DB']
parameters.forEach((parameter) => console.log(`${parameter}=${process.env[parameter]}`))
app.listen(process.env.PORT, () => {
  console.log('Listening on ' + process.env.PORT)
})

let db
async function connectToMongo() {
  try {
    const mongoUrl = `mongodb://${process.env.MONGO_SERVER}:27017`
    const client = await MongoClient.connect(mongoUrl, { useNewUrlParser: true })
    db = client.db(process.env.MONGO_DB)
    console.log('Connected succesfully to server')
  } catch (e) {
    console.log(e)
    setTimeout(connectToMongo, 5000)
  }
}

connectToMongo()

app.use(function (req, res, next) {
  res.header('Access-Control-Allow-Origin', '*')
  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
  next()
})

app.get('/type/:type/startDate/:startDate/endDate/:endDate/sample/:sample', async (req, res) => {
  const startDate = new Date(req.params.startDate * 1000)
  const endDate = new Date(req.params.endDate * 1000)
  const sample = parseInt(req.params.sample)
  // const query = {
  //   _id: {
  //     $gt: objectIdFromDate(startDate),
  //     $lt: objectIdFromDate(endDate)
  //   },
  //   type: req.params.type,
  //   value: {
  //     $ne: NaN
  //   }
  // }
  const agg = [
    {
      $match: {
        $and: [
          { _id: { $gt: objectIdFromDate(startDate), $lt: objectIdFromDate(endDate) } },
          { type: req.params.type },
          { value: { $ne: NaN } }
        ]
      }
    },
    {
      $group: {
        _id: {
          $toDate: {
            $subtract: [
              { $toLong: { $toDate: '$_id' } },
              { $mod: [{ $toLong: { $toDate: '$_id' } }, 1000 * 60 * sample] }
            ]
          }
        },
        value: { $avg: '$value' },
        // count: { $sum: 1 },
        date: { $min: { $toDate: '$_id' } }
      }
    },
    {
      $project: {
        _id: 0,
        value: { $round: ['$value', 1] },
        date: { $toLong: '$date' }
      }
    },
    { $sort: { date: 1 } }
  ]
  try {
    const docs = await db.collection('dht22').aggregate(agg).toArray()
    res.json(docs)
  } catch (err) {
    console.log(err)
  }
})

app.get('/v0/type/:type/startDate/:startDate/endDate/:endDate/sample/:sample', async (req, res) => {
  const startDate = new Date(req.params.startDate * 1000)
  const endDate = new Date(req.params.endDate * 1000)
  const sample = parseInt(req.params.sample)
  const query = {
    _id: {
      $gt: objectIdFromDate(startDate),
      $lt: objectIdFromDate(endDate)
    },
    type: req.params.type,
    value: {
      $ne: NaN
    }
  }
  try {
    const docs = await db.collection('dht22').find(query).toArray()
    const sampledDocs = docs
      .filter((value, index) => index % sample === 0)
      .map((doc) => {
        return { ...doc, date: dateFromObjectId(doc._id) }
      })
    res.json(sampledDocs)
  } catch (err) {
    console.log(err)
  }
})

function objectIdFromDate(date) {
  return mongo.ObjectId(Math.floor(date.getTime() / 1000).toString(16) + '0000000000000000')
}

function dateFromObjectId(objectId) {
  return Math.floor(mongo.ObjectId(objectId).getTimestamp().getTime() / 1000)
}

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

app.get('/*', function (req, res) {
  res.sendFile(path.join(__dirname, '../dist/index.html'))
})

module.exports = app