import { isInRange } from '../lib/dateFilter'

const getDate = (value) => {
  const d = new Date(value)

  let month = d.getUTCMonth() + 1
  const year = d.getUTCFullYear()

  if (month < 10) {
    month = `0${month}`
  }

  return `${month}/${year}`
}

const compute = (transactions, dateFrom, dateTo, order) => {
  const emptyCategory = {
    id: -1,
    label: 'Sans catégorie',
    color: '#cccccc',
  }
  let data = {}

  if (!order) {
    order = 'sum'
  }

  transactions.forEach((transaction) => {
    if (transaction.debit === 0) {
      return
    }

    if (!isInRange(transaction.date, dateFrom, dateTo)) {
      return
    }

    let category = transaction.category ?? emptyCategory

    if (!Object.hasOwn(data, category.label)) {
      data[category.label] = {
        category: category,
        average: 0,
        monthAverage: 0,
        months: {},
        count: 0,
        sum: 0,
      }
    }

    ++data[category.label].count
    data[category.label].sum += transaction.debit

    const date = getDate(transaction.date)

    if (!Object.hasOwn(data[category.label].months, date)) {
      data[category.label].months[date] = 0
    }

    data[category.label].months[date] += transaction.debit
  })

  for (let i in data) {
    data[i].average = data[i].sum / data[i].count

    const monthsValues = Object.values(data[i].months)

    data[i].monthAverage = monthsValues.reduce((a, b) => a + b, 0) / monthsValues.length
  }

  data = Object.values(data).sort((a, b) => {
    if (a[order] < b[order]) {
      return 1
    }

    if (a[order] > b[order]) {
      return -1
    }

    return 0
  })

  return data
}

export { compute }