import type { FeeCost, GasCost, RouteExtended, Token } from '@lifi/sdk'
import { formatTokenPrice } from './format.js'

export interface FeesBreakdown {
  amount: bigint
  amountUSD: number
  token: Token
}

export const getAccumulatedFeeCostsBreakdown = (
  route: RouteExtended,
  included = false
) => {
  const gasCosts = getGasCostsBreakdown(route)
  const feeCosts = getFeeCostsBreakdown(route, included)
  const gasCostUSD = gasCosts.reduce(
    (sum, gasCost) => sum + gasCost.amountUSD,
    0
  )
  const feeCostUSD = feeCosts.reduce(
    (sum, feeCost) => sum + feeCost.amountUSD,
    0
  )
  const combinedFeesUSD = gasCostUSD + feeCostUSD
  return {
    gasCosts,
    feeCosts,
    gasCostUSD,
    feeCostUSD,
    combinedFeesUSD,
  }
}

const getGasCostsBreakdown = (route: RouteExtended): FeesBreakdown[] => {
  return Array.from(
    route.steps
      .reduce((groupedGasCosts, step) => {
        const gasCosts = step.execution?.gasCosts ?? step.estimate.gasCosts
        if (gasCosts?.length) {
          const {
            token,
            amount: gasCostAmount,
            amountUSD: gasCostAmountUSD,
          } = getStepFeeCostsBreakdown(gasCosts)
          const groupedGasCost = groupedGasCosts.get(token.chainId)
          const amount = groupedGasCost
            ? groupedGasCost.amount + gasCostAmount
            : gasCostAmount
          const amountUSD = groupedGasCost
            ? groupedGasCost.amountUSD + gasCostAmountUSD
            : gasCostAmountUSD
          groupedGasCosts.set(token.chainId, {
            amount,
            amountUSD,
            token,
          })
          return groupedGasCosts
        }
        return groupedGasCosts
      }, new Map<number, FeesBreakdown>())
      .values()
  )
}

const getFeeCostsBreakdown = (
  route: RouteExtended,
  included?: boolean
): FeesBreakdown[] => {
  return Array.from(
    route.steps
      .reduce((groupedFeeCosts, step) => {
        let feeCosts = step.execution?.feeCosts ?? step.estimate.feeCosts
        if (typeof included === 'boolean') {
          feeCosts = feeCosts?.filter(
            (feeCost) => feeCost.included === included
          )
        }
        if (feeCosts?.length) {
          const {
            token,
            amount: feeCostAmount,
            amountUSD: feeCostAmountUSD,
          } = getStepFeeCostsBreakdown(feeCosts)
          const groupedFeeCost = groupedFeeCosts.get(token.chainId)
          const amount = groupedFeeCost
            ? groupedFeeCost.amount + feeCostAmount
            : feeCostAmount
          const amountUSD = groupedFeeCost
            ? groupedFeeCost.amountUSD + feeCostAmountUSD
            : feeCostAmountUSD
          groupedFeeCosts.set(token.chainId, {
            amount,
            amountUSD,
            token,
          })
          return groupedFeeCosts
        }
        return groupedFeeCosts
      }, new Map<number, FeesBreakdown>())
      .values()
  )
}

const getStepFeeCostsBreakdown = (
  feeCosts: FeeCost[] | GasCost[]
): FeesBreakdown => {
  const { token } = feeCosts[0]

  const { amount, amountUSD } = feeCosts.reduce(
    (acc, feeCost) => {
      const feeAmount = BigInt(Number(feeCost.amount).toFixed(0) || 0)
      const amountUSD = formatTokenPrice(
        feeAmount,
        feeCost.token.priceUSD,
        feeCost.token.decimals
      )

      acc.amount += feeAmount
      acc.amountUSD += amountUSD
      return acc
    },
    { amount: 0n, amountUSD: 0 }
  )

  return {
    amount,
    amountUSD,
    token,
  }
}