FunctionProject/api/assets/functions/main/convertCurrency.js

const axios = require('axios')
const errorHandling = require('../../utils/errorHandling')
const { requiredFields } = require('../../config/errors')
const formatNumberResult = require('../secondary/formatNumberResult')

/* OUTPUTS */
module.exports = ({ res, next }, argsObject) => {
  let { number, baseCurrency, finalCurrency } = argsObject

  // S'il n'y a pas les champs obligatoire
  if (!(number && baseCurrency && finalCurrency)) {
    return errorHandling(next, requiredFields)
  }

  // Si ce n'est pas un nombre
  number = parseFloat(number)
  if (isNaN(number)) {
    return errorHandling(next, { message: 'Veuillez rentré un nombre valide.', statusCode: 400 })
  }

  axios.get(`https://api.exchangeratesapi.io/latest?base=${baseCurrency}`)
    .then((response) => {
      const rate = response.data.rates[finalCurrency]
      if (!rate) {
        return errorHandling(next, { message: "La devise n'existe pas.", statusCode: 404 })
      }
      const result = rate * number
      const dateObject = new Date(response.data.date)
      const year = dateObject.getFullYear()
      const day = ('0' + (dateObject.getDate())).slice(-2)
      const month = ('0' + (dateObject.getMonth() + 1)).slice(-2)
      const date = `${day}/${month}/${year}`
      const resultHTML = `<p>${formatNumberResult(number)} ${response.data.base} = ${formatNumberResult(result.toFixed(2))} ${finalCurrency}</p><p>Dernier rafraîchissement du taux d'échange : ${date}</p>`
      return res.status(200).json({ date, result, resultHTML })
    })
    .catch(() => errorHandling(next, { message: "La devise n'existe pas.", statusCode: 404 }))
}