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 computeBar = (transactions, stacked, dateFrom, dateTo, selectedCategories) => {
  const indexes = {}
  const labels = []
  const bars = {}
  const emptyCategory = {
    id: -1,
    label: 'Sans catégorie',
    color: '#cccccc',
  }

  transactions.forEach((transaction) => {
    if (!isInRange(transaction.date, dateFrom, dateTo)) {
      return
    }

    let category = transaction.category ?? emptyCategory

    if (!selectedCategories[category.label]) {
      return
    }

    let date = getDate(transaction.date)

    if (!Object.hasOwn(indexes, date)) {
      indexes[date] = labels.length
      labels.push(date)
    }

    if (!Object.hasOwn(bars, category.label)) {
      bars[category.label] = {
        label: category.label,
        data: [],
        borderColor: category.color,
        backgroundColor: category.color,
        fill: true,
        cubicInterpolationMode: 'monotone',
      }
    }
  })

  for (let key in bars) {
    labels.forEach(() => {
      bars[key].data.push(0)
    })
  }

  transactions.forEach((transaction) => {
    if (!isInRange(transaction.date, dateFrom, dateTo)) {
      return
    }

    let category = transaction.category ?? emptyCategory

    if (!selectedCategories[category.label]) {
      return
    }

    let date = getDate(transaction.date)

    bars[category.label].data[indexes[date]] += transaction.debit - transaction.credit
  })

  labels.forEach((label, key) => {
    for (let bKey in bars) {
      if (bars[bKey].data[key] < 0) {
        bars[bKey].data[key] = 0
      }
    }
  })

  if (stacked) {
    labels.forEach((label, key) => {
      let sum = 0

      for (let bKey in bars) {
        sum += bars[bKey].data[key]
      }

      for (let bKey in bars) {
        bars[bKey].data[key] = (bars[bKey].data[key] * 100) / sum
      }
    })
  }

  return {
    labels: labels,
    datasets: Object.values(bars),
  }
}

const computeDoughnut = (transactions, dateFrom, dateTo, selectedCategories) => {
  const indexes = {}
  const labels = []
  const data = []
  const backgroundColor = []
  const emptyCategory = {
    id: -1,
    label: 'Sans catégorie',
    color: '#cccccc',
  }

  transactions.forEach((transaction) => {
    if (!isInRange(transaction.date, dateFrom, dateTo)) {
      return
    }

    let category = transaction.category ?? emptyCategory

    if (!selectedCategories[category.label]) {
      return
    }

    if (!Object.hasOwn(indexes, category.id)) {
      indexes[category.id] = labels.length
      labels.push(category.label)
      backgroundColor.push(category.color)
      data[indexes[category.id]] = 0
    }

    data[indexes[category.id]] += transaction.debit - transaction.credit
  })

  for (let i in data) {
    if (data[i] < 0) {
      data[i] = 0
    }
  }

  return {
    labels: labels,
    datasets: [
      {
        data: Object.values(data),
        backgroundColor: backgroundColor,
      },
    ],
  }
}

export { computeDoughnut, computeBar }