import { useQuery } from "@tanstack/react-query"
import { parseUnits } from "viem"
import { ONE_SECOND_MS } from "../utils/time"
import { usePortalApiClient } from "./usePortalApiClient"
import { useCollateralPrice } from "./useCollateralPrice"

export const CONVERSION_RATE_DECIMALS = 18

// If the oracle has not been updated in at least 60 seconds, it is stale.
const MAX_PRICE_DELAY = 60 * ONE_SECOND_MS

export const QUERY_KEY = "passport.assetsConversionRates"

/**
 * Hook to fetch assets conversion rates.
 * @see https://github.com/mezo-org/musd/blob/f0b2030315f0d8b0fc11a9fc778856fe4673051f/solidity/contracts/PriceFeed.sol
 * @returns {}.data.{}.price - The latest asset price.
 * @returns {}.data.{}.digits - The latest asset price digits.
 * @returns {}.isPending - Whether the request is pending.
 * @returns {}.isError - Whether there was an error fetching the price.
 */
export function useAssetsConversionRates() {
  const portalApiClient = usePortalApiClient()
  const { data: collateralPriceData } = useCollateralPrice()

  const collateralPrice = collateralPriceData?.toString()

  return useQuery({
    queryKey: [QUERY_KEY, collateralPrice],
    queryFn: () => {
      if (!collateralPriceData) {
        throw new Error("Collateral price is not available.")
      }

      return Promise.all([
        portalApiClient.getPortalStatistics(),
        new Promise((resolve) => {
          resolve(collateralPriceData)
        }) as Promise<typeof collateralPriceData>,
      ])
    },
    enabled: !!collateralPrice,
    select: ([portalStatistics, btcPrice]) => {
      const tTokenConversionRate = portalStatistics.tTokenPrice

      const tPrice = parseUnits(
        tTokenConversionRate.toString(),
        CONVERSION_RATE_DECIMALS,
      )

      return {
        rates: {
          mT: tPrice,
          BTC: btcPrice,
        },
        decimals: CONVERSION_RATE_DECIMALS,
      }
    },
    refetchInterval: MAX_PRICE_DELAY,
  })
}