var express = require('express')
var sampledata = require('./sampledata')
var db = require('./mysql')
var score = require('./score')

const app = express()
const port = 3000
const multiplier_temp = 5

const sampleRegions = [
  {
    id: 29837,
    name: "Timbuktu",
    country: "Mali"
  }
]
const samplePresets = [
  {
    id: 29837,
    parameter: "temperature",
    label: "warm",
    values: [22, 25]
  }
]

// db.connect((err) => {
//   if (err) throw err;
//   console.log('Database connected!')
// });

app.get('/', (req, res) => res.send('Hello Timo!'))
app.get('/v1/regions', (req, res) => res.json(sampleRegions))
app.get('/v1/presets', (req, res) => res.json(samplePresets))
app.get('/v1/search', (req, res) => {
  // check query params
  let response = {}

  response.meta = {
    params: req.params,
    query: req.query,
    headers: req.headers
  }
  
  console.log('log params')
  console.log(req.query.from)
  console.log(req.query.to)
  console.log(req.query.temperature)

  search(req.query.from, req.query.to, { temperature: req.query.temperature }).then(searchResults => {
    response.data = searchResults
    res.json(response)
  })
})

app.listen(port, () => console.log(`Travopti backend listening at http://localhost:${port}`))

async function search(from, to, queries) {
  console.log('search')
  // validate regex: YYYY-MM-DD
  let re = /([12]\d{3}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01]))/i;
  if (!from.match(re) || !to.match(re)) throw new Error("invalid parameter: " + from + " " + to)
  
  // -- Prepare search --
  // calculate average if traveldates are in more than one month
  let monthFrom = Number(from.split("-")[1])
  let monthTo = Number(to.split("-")[1])
  let values = []
  let virtDays = 0
  if (monthFrom === monthTo) {
    let element = {
      month: monthFrom,
      days: Number(to.split("-")[2]) - Number(from.split("-")[2])
    }
    virtDays = element.days
    values.push(element)
  } else {
    for (let index = monthFrom; index <= monthTo; index++) {
      let element = {}
      if (index === monthFrom) {
        element = {
          month: index,
          days: 31 - Number(from.split("-")[2])
        }
      } else if (index === monthTo) {
        element = {
          month: index,
          days: Number(to.split("-")[2])
        }
      } else {
        element = {
          month: index,
          days: 30
        }
      }
      virtDays += element.days
      values.push(element)
    }
  }
  // retrieve data from database
  const minMax = await getClimateMinMax()
  const data = await Promise.all(values.map(async (val) => {
    return await getAllClimatePerMonth(val.month)
  }))
  console.log("data from getAllClimatePerMonth")
  //console.log(data)
  // calculate score
  // TODO: calculate score for all months
  let scores_temp
  if (queries.temperature) {
    scores_temp = calculateTempScores(data[0], queries.temperature.split(',')[0], queries.temperature.split(',')[1], minMax)
  }
  // TODO: calculate ratio
  return { TODO___temperature_scores: scores_temp }
}

function calculateTempScores(regionDataRows, searchLowParam, searchMaxParam, minMax) {
  console.log('calculateTempScores')
  console.log(searchLowParam)
  console.log(searchMaxParam)
  console.log(minMax)
  //console.log(regionDataRows)
  let result = regionDataRows.map(x => {
    console.log(x.temperature_mean)
    return {
      region_id: x.region_id,
      value: x.temperature_mean,
      score: Math.round(score.calculateScoreRange(minMax.min.temperature_mean, minMax.max.temperature_mean, multiplier_temp, x.temperature_mean, searchLowParam, searchMaxParam)*100)/100
    }
  
  })
  return result
}

async function getClimateMinMax() {
  console.log('getClimateMinMax')
  const sqlMin = `SELECT 
  MIN(temperature_mean) AS temperature_mean,
  MIN(temperature_mean_min) AS temperature_mean_min, 
  MIN(temperature_mean_max) AS temperature_mean_max, 
  MIN(percipitation) AS percipitation, 
  MIN(sunshine) AS sunshine
  FROM region_climate`
  const sqlMax = `SELECT 
  MAX(temperature_mean) AS temperature_mean,
  MAX(temperature_mean_min) AS temperature_mean_min, 
  MAX(temperature_mean_max) AS temperature_mean_max, 
  MAX(percipitation) AS percipitation, 
  MAX(sunshine) AS sunshine
  FROM region_climate`
  const [qResMin, qResMax] = await Promise.all([getQueryRows(sqlMin), getQueryRows(sqlMax)])
  console.log(qResMin)
  return { min: qResMin[0], max: qResMax[0] } 
}

async function getQueryRows(sql) {
  console.log('getQueryRows')
  const [rows, fields] = await db.execute(sql)
  return rows
}

async function getRegionIdsWithMeteostatData() {
  console.log('getRegionIdsWithMeteostatData')
  //return await getQueryRows(`SELECT * FROM regions WHERE meteostat_id IS NOT NULL`)
  return await getQueryRows(`SELECT region_id FROM region_climate GROUP BY region_id`)
}

async function getClimatePerRegionAndMonth(regionId, month) {
  console.log('getClimatePerRegionAndMonth')
  const sql = `SELECT region_id, AVG(temperature_mean), AVG(temperature_mean_min), AVG(temperature_mean_max), AVG(percipitation), AVG(sunshine) FROM region_climate WHERE month = ${month} AND region_id = ${regionId}`
  return await getQueryRows(sql)
}

async function getAllClimatePerMonth(month) {
  console.log('getAllClimatePerMonth')
  const sql = `SELECT 
    region_id, 
    ROUND(AVG(temperature_mean), 1) AS temperature_mean, 
    ROUND(AVG(temperature_mean_min), 1) AS temperature_mean_min, 
    ROUND(AVG(temperature_mean_max), 1) AS temperature_mean_max, 
    ROUND(AVG(percipitation), 1) AS percipitation, 
    ROUND(AVG(sunshine), 1) AS sunshine
    FROM region_climate WHERE month = ${month} GROUP BY region_id`
  return await getQueryRows(sql)
}