import Decimal from 'decimal.js'
import { isFiniteNumber } from '@/lib/number'

type MaybeNumber = number | null | undefined
type DecimalInput = Decimal.Value

export const toDecimal = (value: DecimalInput) => new Decimal(value)

export const roundTo = (value: DecimalInput, decimalPlaces = 2) =>
  new Decimal(value).toDecimalPlaces(decimalPlaces, Decimal.ROUND_HALF_UP).toNumber()

const sumFiniteValues = (values: Iterable<unknown>) => {
  let total = new Decimal(0)
  for (const value of values) {
    if (!isFiniteNumber(value)) continue
    total = total.plus(value)
  }
  return total.toNumber()
}

export const addNumbers = (...values: MaybeNumber[]) => sumFiniteValues(values)

export const sumByNumber = <T>(list: T[], pick: (item: T) => MaybeNumber) => {
  let total = new Decimal(0)
  for (const item of list) {
    const value = pick(item)
    if (!isFiniteNumber(value)) continue
    total = total.plus(value)
  }
  return total.toNumber()
}

export const decimalAggSum = (params: { values?: unknown[] }) => {
  const values = params.values || []
  let hasFinite = false
  for (const value of values) {
    if (!isFiniteNumber(value)) continue
    hasFinite = true
    break
  }
  if (!hasFinite) return null
  return sumFiniteValues(values)
}