hooks.ts

import DEFAULT_TOKEN_LIST from '@uniswap/default-token-list'
import { TokenList } from '@uniswap/token-lists'
import { useMemo } from 'react'
import { useAppSelector } from 'state/hooks'
import sortByListPriority from 'utils/listSort'

import BROKEN_LIST from '../../constants/tokenLists/broken.tokenlist.json'
import UNSUPPORTED_TOKEN_LIST from '../../constants/tokenLists/unsupported.tokenlist.json'
import { AppState } from '../index'
import { UNSUPPORTED_LIST_URLS } from './../../constants/lists'
import { WrappedTokenInfo } from './wrappedTokenInfo'

export type TokenAddressMap = Readonly<{
  [chainId: number]: Readonly<{ [tokenAddress: string]: { token: WrappedTokenInfo; list: TokenList } }>
}>

type Mutable<T> = {
  -readonly [P in keyof T]: Mutable<T[P]>
}

const listCache: WeakMap<TokenList, TokenAddressMap> | null =
  typeof WeakMap !== 'undefined' ? new WeakMap<TokenList, TokenAddressMap>() : null

function listToTokenMap(list: TokenList): TokenAddressMap {
  const result = listCache?.get(list)
  if (result) return result

  const map = list.tokens.reduce<Mutable<TokenAddressMap>>((tokenMap, tokenInfo) => {
    const token = new WrappedTokenInfo(tokenInfo, list)
    if (tokenMap[token.chainId]?.[token.address] !== undefined) {
      console.error(`Duplicate token! ${token.address}`)
      return tokenMap
    }
    if (!tokenMap[token.chainId]) tokenMap[token.chainId] = {}
    tokenMap[token.chainId][token.address] = {
      token,
      list,
    }
    return tokenMap
  }, {}) as TokenAddressMap
  listCache?.set(list, map)
  return map
}

const TRANSFORMED_DEFAULT_TOKEN_LIST = listToTokenMap(DEFAULT_TOKEN_LIST)

export function useAllLists(): AppState['lists']['byUrl'] {
  return useAppSelector((state) => state.lists.byUrl)
}

/**
 * Combine the tokens in map2 with the tokens on map1, where tokens on map1 take precedence
 * @param map1 the base token map
 * @param map2 the map of additioanl tokens to add to the base map
 */
export function combineMaps(map1: TokenAddressMap, map2: TokenAddressMap): TokenAddressMap {
  const chainIds = Object.keys(
    Object.keys(map1)
      .concat(Object.keys(map2))
      .reduce<{ [chainId: string]: true }>((memo, value) => {
        memo[value] = true
        return memo
      }, {})
  ).map((id) => parseInt(id))

  return chainIds.reduce<Mutable<TokenAddressMap>>((memo, chainId) => {
    memo[chainId] = {
      ...map2[chainId],
      // map1 takes precedence
      ...map1[chainId],
    }
    return memo
  }, {}) as TokenAddressMap
}

// merge tokens contained within lists from urls
function useCombinedTokenMapFromUrls(urls: string[] | undefined): TokenAddressMap {
  const lists = useAllLists()
  return useMemo(() => {
    if (!urls) return {}
    return (
      urls
        .slice()
        // sort by priority so top priority goes last
        .sort(sortByListPriority)
        .reduce((allTokens, currentUrl) => {
          const current = lists[currentUrl]?.current
          if (!current) return allTokens
          try {
            return combineMaps(allTokens, listToTokenMap(current))
          } catch (error) {
            console.error('Could not show token list due to error', error)
            return allTokens
          }
        }, {})
    )
  }, [lists, urls])
}

// filter out unsupported lists
export function useActiveListUrls(): string[] | undefined {
  return useAppSelector((state) => state.lists.activeListUrls)?.filter((url) => !UNSUPPORTED_LIST_URLS.includes(url))
}

export function useInactiveListUrls(): string[] {
  const lists = useAllLists()
  const allActiveListUrls = useActiveListUrls()
  return Object.keys(lists).filter((url) => !allActiveListUrls?.includes(url) && !UNSUPPORTED_LIST_URLS.includes(url))
}

// get all the tokens from active lists, combine with local default tokens
export function useCombinedActiveList(): TokenAddressMap {
  const activeListUrls = useActiveListUrls()
  const activeTokens = useCombinedTokenMapFromUrls(activeListUrls)
  return combineMaps(activeTokens, TRANSFORMED_DEFAULT_TOKEN_LIST)
}

// list of tokens not supported on interface for various reasons, used to show warnings and prevent swaps and adds
export function useUnsupportedTokenList(): TokenAddressMap {
  // get hard-coded broken tokens
  const brokenListMap = useMemo(() => listToTokenMap(BROKEN_LIST), [])

  // get hard-coded list of unsupported tokens
  const localUnsupportedListMap = useMemo(() => listToTokenMap(UNSUPPORTED_TOKEN_LIST), [])

  // get dynamic list of unsupported tokens
  const loadedUnsupportedListMap = useCombinedTokenMapFromUrls(UNSUPPORTED_LIST_URLS)

  // format into one token address map
  return useMemo(
    () => combineMaps(brokenListMap, combineMaps(localUnsupportedListMap, loadedUnsupportedListMap)),
    [brokenListMap, localUnsupportedListMap, loadedUnsupportedListMap]
  )
}
export function useIsListActive(url: string): boolean {
  const activeListUrls = useActiveListUrls()
  return Boolean(activeListUrls?.includes(url))
}